|Skylab - |
Credit: NASA. 28,885 bytes. 380 x 282 pixels.
First and only US space station to date. Project began life as Apollo Orbital Workshop - outfitting of an S-IVB stage with docking adapter with equipment launched by several subsequent S-1B launches. Curtailment of the Apollo moon landings meant that surplus Saturn V's were available, so the pre-equipped, five times heavier, and much more capable Skylab resulted.
External solar/meteoroid shield ripped off during ascent, tearing away one solar panel wing and debris jamming the remaining panel. Without shield temperatures soared to 52 deg C (126 deg F). Launch of the crew was delayed for 10 days to develop procedures and crew training to make the workshop habitable. Repairs by subsequent crews led to virtually all mission objectives being met. Skylab re-entered on July 11, 1979. Major Events: .
Addressing an Institute of Aerospace Science meeting in New York, George von Tiesenhausen, Chief of Future Studies at NASA's Launch Operations Center, stated that by 1970 the United States would need an orbiting space station to launch and repair spacecraft. The station could also serve as a manned scientific laboratory. In describing the 91-m-long, 10-m-diameter structure, von Tiesenhausen said that the station could be launched in two sections using Saturn C-5 vehicles. The sections would be joined once in orbit.
A study to recommend, define, and substantiate a logical approach for establishing a rotating manned orbital research laboratory for a Saturn V launch vehicle was made for MSC. The study was performed by the Lockheed-California Company, Burbank, California. It was based on the proposition that a large rotating space station would be one method by which the United States could maintain its position as a leader in space technology.
MSC and MSFC program officials and engineers held their first coordination meeting on the S-IVB Orbital Workshop and related Apollo Applications Program experiment activities. Among the most significant results of this meeting was a request by Houston for inclusion of an artificial gravity experiment as part of the S-IVB command and service module concept of the Workshop. MSFC officials undertook to define the feasibility of such an experiment, examining several possible technical approaches (including cables a concept that MSC found less shall appealing). MSFC investigators also sought help from LaRC, where considerable work along this line had been done as part of that Center's MORL study program.
John H. Disher, Saturn/Apollo Applications Deputy Director, requested the Manned Space Flight Management Operations Director to officially change the designation of the Saturn IB/Centaur Office to Saturn Applications. This change, Disher said, reflected the change in status of the office and provided for necessary management of potential Saturn Applications such as the Saturn V/Voyager by the Office of Manned Space Flight. However, on the same day, Disher ordered E. F. O'Connor at MSFC to halt all Saturn IB/Centaur efforts (except those already underway that could not be recalled) and disapproved the request for an additional $1.1 million for the program. (Any funds required for definition of a Saturn V/Voyager mission, he said, would be authorized separately.)
The Space Science Board of the National Academy of Sciences issued a report outlining research objectives in lunar and planetary exploration for the 1970s and early 1980s. The report affirmed earlier recommendations by the Space Science Board to NASA that unmanned exploration of Mars should have first priority in the post- Apollo space era. Secondary importance was assigned to detailed investigation of the lunar surface and to unmanned Venus probes. Clearly, the report reflected a predominant mood within the scientific community that scientific research in space take predominance over manned programs whose chief objectives, said the report, were 'other than scientific.'
Among these would be three 'S-IVB/Spent-Stage Experiment Support Modules' (i.e., 'wet' Workshops), three Saturn V-boosted orbital laboratories, and four Apollo telescope mounts. The initial AAP launch was slated for April 1968. The schedule was predicated upon non-interference with the basic Apollo lunar landing program, minimum modifications to basic Apollo hardware, and compatibility with existing Apollo launch vehicles.
In a memorandum to Headquarters staff members, Advanced Manned Missions Program Director Edward Z. Gray summarized the three separate study efforts underway within NASA directed toward evaluating the S-IVB stage as a manned laboratory: (1) The spent-stage experiment support module (SSESM) study, a joint effort by MSC and MSFC. (2) A spent S-IVB-stage utilization study at MSFC. (3) A Saturn V single-launch space station.
|Apollo CSM Interior - Interior of the Apollo Command Service Module on display at Kennedy Space Center, Florida.|
Credit: © Mark Wade. 58,405 bytes. 506 x 392 pixels.
The 'Jet Shoes' experiment was an astronaut maneuvering system consisting of two small thrusters mounted one beneath each foot and oriented so that the thrust vectors passed close to the center of body mass with legs and feet in a comfortable position. During January, an engineering development model of the 'Jet Shoes' was tested by several astronauts on the MSC air bearing facility in cooperation with the Principal Investigator. Although the tests by the astronauts were shirt-sleeve runs, an LaRC test pilot made several runs in an inflated pressure suit. The results were unsatisfactory. In his objections to the experiment, Slayton suggested that its attempted use by an astronaut wearing a life support unit would provide extremely poor visibility.
NASA Administrator James E. Webb testified on the NASA FY 1968 authorization bill before the Senate Committee on Appropriations' Subcommittee on Independent Offices. Asked by Sen. Spessard Holland (D Fla.) to make a choice between a substantial cut in funding for the Apollo Applications Program and the Voyager program, Webb replied that both were vital to the U.S. space effort.
Nomenclature for the OWS included in the AAP presented in the FY 1969 budget was confirmed by NASA. The ground-outfitted OWS to be launched with Saturn V would be designated the 'Saturn V Workshop.' (This had sometimes been called the 'dry Workshop.') The OWS that would be launched by a Saturn IB would be referred to as the 'Saturn I Workshop.' (Colloquially it had been referred to as the 'wet workshop.') Terminology 'Uprated Saturn I' would not be used officially. This launch vehicle would be referred to as the 'Saturn IB.'
The first rocket carried a Naval Research Laboratory and University of Maryland payload to a 179-km altitude to flight test a design verification unit of the high-resolution spectroheliograph planned for use on the ATM. The second rocket carried an American Science and Engineering, Inc., payload to a 150-km altitude to obtain high-resolution x-ray pictures of active regions of the Sun during solar flare and general x-ray emission of solar corona. The rocket and instrumentation performed satisfactorily, but the payload of the first rocket failed to separate, thus preventing functioning of the parachute recovery system.
The action involved 27 H-1, eight F-1, and three J-2 rocket engines.
Their joint recommendations included a phasedown on contractor activity following the AS 205 launch; deactivation of Launch Complexes 34 and 37 to allow maximum storage of equipment and minimum maintenance on items remaining in place; and continuance of KSC analysis of manpower required to support the AAP dual launch requirement, with contractor participation at the earliest date.
|Apollo CSM - Apollo CSM with Launch Escape Tower|
Credit: © Mark Wade. 4,184 bytes. 609 x 174 pixels.
The rocket carried a Naval Research Laboratory payload to 187.9-km altitude to record photographically 18 extreme ultraviolet spectra of solar photosphere, chromosphere, and corona, using a flight design verification unit of the high-resolution spectrograph planned for ATM-A and ATM-B. Rocket and instruments performed satisfactorily.
Gilruth and Von Braun support decision to fly a complete integrated solution on a single Saturn V launch.
MSC and MSFC presented a status report on weight of flight modules, measurement lists by modules, plans for controlling the lists, and criteria for measurement selection. KSC gave a report on the status of LC 34/37 equipment and facilities and plans for getting them ready for AAP. MSFC presented the status of a joint MSC/ MSFC study of stowage on AAP-2, a status report on the caution and warning system, and the current plan for LM/ATM extravehicular activity film exchange. MSC reviewed plans for the development of mission operations documentation and presented the results of a joint MSFC/MSC study on the use of the CSM to rescue a malfunctioned LM/ATM.
Study results indicated there were several areas of the OWS that would require unique configuration characteristics. Among the areas of concern were antenna location and coverage; CSM/MDA docking interface strength; reaction control system characteristics, propellant consumption, and attitude control logic to maintain solar orientation in the face of gravity gradient torques; ATM mounting and deployment provisions; and the ATM solar array structure.
During the Mercury program a modified version of the Goodrich Navy Mark IV suit was used. In the Gemini program a modified version of a suit developed by David Clark Company for the USAF was used. Hamilton Standard had overall development responsibility for the Apollo suit and associated portable life support system. A subcontract was awarded to International Latex Corporation for development of this suit. After suit development was completed, the production contract was awarded to International Latex, and the initial suit was designated A5L. The A6L design incorporated a thermal/ meteoroid garment. Following the Apollo fire, the suit was redesigned to eliminate flammable materials and was designated A7L (designation A8L was never used). Two hard-shell, constant-volume suits were under development, an extravehicular suit was being developed by Litton Industries, and an intravehicular suit was being developed by AiResearch Corporation. Both of the latter would be used in the Apollo Applications Program.
NASA Administrator Thomas O. Paine approved the shift from a 'wet' to a 'dry' Orbital Workshop concept for AAP following a review presentation by program officials on the potential benefits of such a change. On 22 July, AAP Director William C. Schneider ordered program managers at the three Centers to implement the change, abandoning the idea of using a spent Saturn IB second stage for a Workshop and adopting the concept of a fully equipped 'dry' configuration-with the ATM integrated into the total payload-launched aboard a Saturn V.
Credit: © Mark Wade. 7,033 bytes. 561 x 304 pixels.
Program objectives for AAP remained unchanged, however. The schedule called for first launch in 1972. The Workshop would be placed in a circular orbit first. About a day later, the three-man crew would ride aboard a Saturn IB into orbit to link up with the Workshop-ATM cluster, thus beginning the manned portion of the mission.
Representatives from NASA Hq, KSC, MSC, MSFC, Harvard College Observatory, and Naval Research Laboratory attended. Except for the mechanical reticle subsystem, a requirement recently added to the telescope system, the Perkin-Elmer design appeared sound. Only minor discrepancies were noted.
Following the decision to implement the Saturn V dry Workshop, LM-2 was the only flight LM article to remain on Earth. Therefore, NASA Hq requested MSC consideration for early disposition of it to the Smithsonian Institution as an artifact of historical interest. Since it was expected that the Smithsonian would exhibit LM-2 as a replica of LM-5, Headquarters also requested that MSC consider refurbishment to provide a more accurate representation of the LM- 5 configuration before its transfer to the Smithsonian.
MSFC definitized the existing contract with McDonnell Douglas for two Orbital Workshops for the Apollo Applications Program, converted S IVB stages to be launched by Saturn V boosters. The contract was slated to run through July 1972, with most of the work to be performed at the company's plant at Huntington Beach, California. The first Workshop was tentatively scheduled for flight in mid-1972, with the second article initially serving as a backup vehicle if needed.
The new schedule called for seven Saturn IB and two Saturn V launches, with flight of the first Workshop slated for July 1972.
They were incorporating the recommendation into the latest program operating plan proposals. If the recommendation were accepted, LC-34 would be partially deactivated and placed in a 'down- mode' condition.
The objectives, constraints, and guidelines for a second OWS were stated in general terms along the following lines: OWS would reflect the same physical features and capabilities exhibited by the initial Workshop and would use the flight hardware to be procured as backup for the first Workshop missions. Crew complement would consist of three men (at least one scientist astronaut). Operating life would be 12 to 24 months, nominally continuously manned. Orbital altitude would be in the range of 390 to 500 km at an inclination up to 55°.
Two major directions were identified for manned space flight in the next decade. These were further exploration of the Moon, with possibly the establishment of a lunar surface base, and the continued development of manned flight in Earth orbit, leading to a permanent manned space station supported by a low-cost shuttle system. To maintain direction, the following key milestones were proposed: 1972 - AAP operations using a Saturn V launched Workshop 1973 - Start of post-Apollo lunar exploration 1974 - Start of suborbital flight tests of Earth to orbit shuttle - Launch of a second Saturn V Workshop 1975 - Initial space station operations - Orbital shuttle flights 1976 - Lunar orbit station - Full shuttle operations 1977 - Nuclear stage flight test 1978 - Nuclear shuttle operations-orbit to orbit 1979 - Space station in synchronous orbit By 1990 - Earth orbit space base - Lunar surface base - Possible Mars landing
Credit: © Mark Wade. 3,260 bytes. 341 x 174 pixels.
Major facilities and equipment needed to convert LC-39 to an elevated pedestal configuration were studied, as well as estimated cost figures, program schedules, and interrelationships with other NASA programs. The study indicated that use of the elevated pedestal concept in LC-39 appeared technically and operationally feasible. However, because of the close operational coupling of the Apollo and AAP if this concept were implemented, it was decided to defer further consideration of this concept.
The rockets achieved expected performance, solar pointing systems functioned properly, payloads were successfully recovered, and preliminary results appeared excellent. The information obtained by the rocket flights on solar emission intensity, filter performance, film response, and exposure time would be available in time to provide a useful and effective feedback into the ATM instruments development program.
Olin E. Teague, Chairman of the House of Representatives Committee on Science and Astronautics Subcommittee on Manned Space Flight, suggested that space rescue and emergency coordination would offer opportunities to bring the space-faring nations of the world closer together. In an initial response to the letter, NASA Hq appointed a Space Station Safety Advisor and established a Shuttle Safety Advisory Panel.
KSC Director Kurt H. Debus announced that LC-34 would be used for Saturn IB-related AAP manned launches (scheduled to begin in mid-1972), while LC-37 would be placed in a semi- deactivated 'minimum maintenance' condition. Thomas W. Morgan, AAP Manager of the Florida Center, said that design of modifications to LC-34 to meet the needs of AAP would begin on 1 January 1970, while the modifications to the pad itself would begin around the end of the summer. The current estimate for the cost of modifying the complex and bringing it to a state of readiness was about $3.7 million.
The stage had earlier been used as a Saturn V facilities vehicle to check out manufacturing, testing, and launching facilities during the Apollo/Saturn V program.
MSC was directed to take some immediate actions including determination of the disposition of CSM-115A, pending a final decision as to its possible use in a second Workshop mission.
Among the items covered were the film vault design, film test program, subsystems status, module ground test program, quality and reliability, mission operations support to MSC, prototype refurbishment, project schedules, and funding.
NASA announced that the Apollo Applications Program had been redesignated the Skylab Program. The name Skylab, a contraction connoting a laboratory in the sky, was proposed by Donald L. Steelman, USAF, while assigned to NASA. The name was proposed following an announcement by NASA in 1968 that they were seeking a new name for AAP. Then NASA decided to postpone renaming the program because of budgetary restrictions. Skylab was later referred to the NASA Project Designation Committee and was approved 17 February 1970.
|Skylab - Artist's concept of Skylab space station cluster in Earth's orbit|
Credit: NASA. 69,090 bytes. 629 x 476 pixels.
The requirement was not mandatory for mission success. The schedule impact was unacceptable.
Issues discussed were whether there should be a Skylab II, and, if so, what its fundamental mission and configuration should be, how long it should stay in orbit, what its experiment payload should be, and how many manned launches should be planned for it. MSC recommended that artificial gravity and expanded Earth-survey experiments be included as major objectives of a second Skylab Program.
The contract called for delivery by July 1971 of a six-lens camera unit which would become part of the Earth resources experiment package in the Skylab missions.
Apollo 18 and 19 might be scrapped because some NASA planners wanted to use the boosters and spaceships already being built to speed the space base and space station programs. Assistant Administrator George M. Low was reported as saying NASA already was studying the possibility of canceling Apollo 19 and using its Saturn V booster and the Apollo spacecraft for a second Skylab. NASA said there was sentiment for using Apollo 18 equipment for an even more ambitious venture-base station-that would stay aloft for 10 years (vs. 1 year for Skylab) and could be added onto until it could accommodate 100 men.
The focus was on those actions available to ensure the rapid return of command and service modules in the event of a malfunction forcing an abort and possible actions that would permit completion of OWS onboard functions to ensure acquisition of maximum experiment data.
The feasibility of docking a second Orbital Workshop to Skylab 1 had been under consideration. However, the practical problems that would be engendered by such an operation were formidable. They included such items as docking loads, docking control, flight attitude of tandem Skylabs, consumables, and in-orbit storage of Skylab 1.
Previous plans were to conduct the Saturn IB launches from LC-34, a part of the U.S. Air Force Eastern Test Range used by NASA, a tenant at Cape Canaveral Air Force Station, Florida. However, program studies showed the feasibility of the pedestal concept of launching the Saturn IB from LC-39 and indicated a cost savings of $13.5 million. The pedestal would be of standard steel structural design; however, there were unique conditions considered. One of these was the requirement to withstand engine exhaust temperatures of 3000 K (5000°F). Another dealt with winds. The pedestal was designed to launch an S-IB at maximum vehicle allowed winds (59.4 km) and to withstand a 200-km per hr hurricane without the launch vehicle. Launch Complex 34, which became operational in 1961, was placed in a standby condition after the Apollo 7 flight in October 1968. It would have required extensive updating of equipment and repairs to ready it for the Skylab Program.
The agreement definitized a letter contract issued in March 1969.
|Skylab - Artist's concept illustrating cutaway view of Skylab 1 Orbital Workshop (OWS)|
Credit: NASA. 30,321 bytes. 242 x 453 pixels.
General Electric Company, Valley Forge, Pennsylvania, was awarded a contract for the design, development, and delivery of a microwave radiometer-scatterometer/altimeter instrument for the Skylab Program. The instrument would be part of the Earth-resources experiment package, which also included a multispectral photographic facility, an infrared scanner, and a 10-band multispectral scanner. Objectives of the microwave radiometer- scatterometer/altimeter experiment would be to determine the usefulness of active and passive microwave systems in providing information on land and sea conditions.
The AC Electronics contract would provide Apollo CSM and LM guidance and navigation systems test and mission support at KSC for the Apollo and Skylab Programs. The General Electric contract would provide personnel and equipment for maintenance and operation of acceptance checkout equipment and quick look data systems which were designed and built by General Electric.
The radiometer would measure brightness and temperature of the terrestrial surface of the Skylab ground track.
The AM was a 1.6-m-diameter tunnel attached to the top of the Workshop. It provided the major work area and support equipment required to activate and operate the Workshop and also formed a passageway for the astronauts to move from the Apollo CM and MDA into the Workshop. The airlock could also be depressurized and sealed off for exit into space outside the vehicle.
KSC awarded a contract to Reynolds, Smith, and Hills of Jacksonville, Florida, for architectural and engineering services in modification plans for adapting existing Saturn V facilities at Launch Complex 39 to launch Saturn IB space vehicles. A launcher-umbilical tower would require a major modification, and minor modification would be required in the service platforms of the Vehicle Assembly Building, where space vehicles were assembled and checked out before being moved to the launch pad. The firm, fixed-price contract had a performance period of 200 days, with work to be performed at the Center and in Jacksonville.
The review was a detailed technical examination of the total AM, including the environmental control systems, electrical and power management, data and communications, structural and mechanical, and other miscellaneous and experiment-support systems.
This was the final technical review before approval for manufacturing flight hardware.
MSFC issued a modification to an existing contract with McDonnell Douglas for Skylab Program work. The modification would pay for the conversion of the original OWS to be launched by a Saturn IB booster to a completely outfitted Workshop to be launched by a Saturn V. Originally the plan was to launch the second stage (S IVB) of a Saturn IB into Earth orbit. The S-IVB would be filled with fuel so that it could propel itself into orbit. Astronauts launched by a second Saturn IB would then rendezvous with the empty stage and convert it into living and working quarters. A decision was made 21 May 1969 to outfit an S-IVB on the ground and launch it ready for use on a Saturn V.
|Skylab - Artist's concept illustrating cutaway view of Skylab 1 Orbital Workshop (OWS)|
Credit: NASA. 32,944 bytes. 260 x 454 pixels.
Tests included operation of flight-configuration doors for film cassette compartments, retrieval and replacement of film cassettes, and evaluation of handrails and food restraints. The KC-135 was flown in parabolas, with 30 seconds of weightlessness achieved on each parabola in a technique that closely duplicated zero-g.
The change was initiated as a result of the implementation of an interim operating plan which deleted two Apollo missions and called for completion of all Apollo missions by June 1972.
An inquiry as to the feasibility of having a crew from another country visit the Skylab in orbit showed that, while there was nothing to indicate such a mission could not be accomplished, a considerable amount of joint planning and design would be required.
The study indicated that a second set of Skylab missions would provide a useful and worthwhile continuation of manned space flight in the mid 1970s, even if the hardware were unchanged. It would also offer an economically feasible program option if future funding for the Space Shuttle Program fell behind the anticipated growth rate.
An Orbital Workshop critical design review was conducted at McDonnell Douglas, Huntington Beach. Personnel from NASA Hq, MSC, KSC, MSFC, and McDonnell Douglas participated. The review was conducted by panels representing six different technological disciplines. Areas of potential major impact included the urine system, microbiological contamination, the water storage system, and the OWS window vibration test.
Singer-General Precision, Inc., Link Division, Houston, was selected for the award of a contract to design, develop, install, and support a Skylab simulator to provide astronaut and ground crew training at MSC. The simulator would serve as a ground-based trainer with controls and displays similar to those used during manned operations. It would also be operated in conjunction with the command module simulator and the Mission Control Center to provide complete mission training.
The week-long EVA review included astronaut performance under normal Earth gravity in the Saturn Workshop mockup and simulated weightlessness in the neutral buoyancy simulator. Ten astronauts from MSC took part in the review activities.
The Skylab MDA flight unit was flown from MSFC to Martin Marietta's Denver division where it was to be outfitted with controls and display panels for solar astronomy and Earth resources experiments, storage vaults for experiment film, and a thruster attitude control system.
It would undergo testing there until 30 December and then would be shipped to MSC for extensive ground tests. This Workshop was a version of one that would be used in the Skylab Program to accommodate teams of three astronauts for stays of up to 56 days in Earth orbit. NASA planned to launch the Skylab cluster with a Saturn V vehicle in 1972. Called a 'dynamic test article,' the Workshop model would be tested at MSC to verify its bending and vibration characteristics. The Workshop was scheduled to arrive at Michoud 17 December and at MSC 5 January.
|Skylab - Artist's concept illustrating cutaway view of Skylab 1 Orbital Workshop (OWS)|
Credit: NASA. 57,785 bytes. 581 x 414 pixels.
An assessment of the feasibility of providing a crew rescue capability for Skylab was conducted by KSC, MSC, and MSFC during 1970. The study culminated in a NASA Hq decision to provide a limited rescue capability should return capability fail while the CSM were docked to the OWS. The rescue vehicle for the first two manned Skylab missions would be the next CSM in flow at KSC. Should a rescue call occur, the CSM next in flow would be modified so as to permit a five- man carrying capacity. It would be launched with a two-man crew and return with the additional three astronauts.
The Orbital Workshop dynamic test article arrived at the Clear Lake Creek Basin adjacent to MSC aboard the barge Orion. It was offloaded on 7 January and moved to the MSC acoustic test facility where it was set up for vibroacoustic testing scheduled to start on 20 January. The acoustic test facility had been checked out previously, and the acoustic environments generated met simulated conditions surrounding the Skylab during Skylab I liftoff and Skylab 1 maximum gravity.
An Orbital Workshop management review was conducted at McDonnell Douglas. Representatives from McDonnell Douglas, NASA Hq, KSC, MSFC, and MSC attended. Significant agenda items included the program schedule, engineering changes, design status, component tests, and procurement status. The OWS flight module was about three months behind schedule. The component development and qualification testing was also behind schedule. McDonnell Douglas reorganized the procurement activity and was making a significant effort to improve this area since it directly impacted the schedule slip.
The 38.7-m-tall pedestal adapted to an existing launcher-umbilical tower so that manned Saturn IB space vehicles could be launched from facilities supporting the larger Saturn V rockets. Holloway contracted to construct the launcher- pedestal in 180 days after receiving notice to proceed.
During the final testing, the dynamic test article was exposed to the full intensity of the aerodynamic acoustic environment to qualify the Workshop structural design. No major problems were encountered. However, vibration levels in some areas exceeded the established criteria. The new vibration levels were given to McDonnell Douglas, and adjustments in the qualification test criteria were made as appropriate.
The modification would extend IBM's delivery schedule for IUs through 31 December 1973, to be compatible with the extended Apollo and Skylab Program launch schedules. IBM was under NASA contract to build 27 IUs for Saturn vehicles: 12 Saturn IBs and 15 Saturn Vs. Ten of the Saturn IB units and 12 Saturn V units had been completed. All work was being done at the company's facilities in Huntsville. The original IU contract had been granted to IBM in March 1965 for the fabrication, assembly, checkout, and delivery of the 27 units and related support functions.
The rescue capability was based on the assumption that the stranded crew would be able to wait in the Skylab cluster with its ample supply of food, water, and breathing gases until a modified CSM capable of carrying five crewmen could he launched. If a failure occurred which stranded the crewmen in their CSM, this rescue capability would not be possible.
During the past Near, design and essentially all phases of development testing had been completed for Skylab, and flight hardware was in fabrication. Definition of Space Shuttle was nearing completion. To develop a limited capability to rescue Skylab astronauts from space, NASA had initiated design action on a modification kit to give Skylab the capacity to carry two men up to orbit and five men back to Earth. Stranded astronauts could use the SkyIab cluster as shelter while the modification kit was installed and the Apollo-Saturn IB launch vehicle assigned to next revisit was made ready for launch.
|Skylab - Artist's concept illustrating cutaway view of Skylab multiple docking adapter|
Credit: NASA. 53,730 bytes. 582 x 412 pixels.
Although use of Launch Complex 37 for Space Shuttle engine testing had been considered, other options were chosen, and the complexes were to be removed from NASA operational facilities inventory.
Chrysler was the prime contractor for the first stage of the Saturn IB, which was assembled at the Michoud Assembly Facility in New Orleans. Under the current modification, the company would maintain nine Saturn IB boosters in storage. Three of the nine vehicles were for the Skylab Program and would be launched in 1973. Those three, plus a fourth that would serve as a backup, would be maintained and modified as necessary under terms of this contract. Prelaunch checkout of the Skylab vehicles would also be accomplished under this modification. The period of performance was from 1 January 1971 to 15 August 1973. Six of the vehicles were located at the Michoud Facility; the other three were at MSFC in Huntsville.
Orbital Workshop vibration test objectives, test article status, test facility preparation status, and test schedules were reviewed by MSFC and MSC during a test readiness review prior to a Skylab OWS vibration test at MSC. The review board concluded, upon resolution of one test constraint, that the initial run could proceed on schedule on 19 March.
The study was limited to low-Earth-orbit manned missions to be down prior to the start of Space Shuttle operations in the late 1970s. Based on various considerations, the study recommended three missions: two Earth resources surveys and the Apollo-Soyuz mission. A further study would be made to determine a specific mission for the fourth available spacecraft.
Dale D. Myers, NASA Associate Administrator for Manned Space Flight, testifying before the Senate Committee on Aeronautical and Space Sciences, said that in the Skylab Program three separate three-man Skylab; flight crews would be selected during the coming year. Scientist astronauts would he included and would perform about 50 experiments in various disciplines. Twenty of these would be in the life sciences, to determine how human beings adjust and perform under conditions of prolonged space flight, up to two months' duration. The scientist astronauts would also operate the Skylab Earth resources experiment package in the second space flight phase of NASA's Earth resources program. These observations would be in conjunction with and complementary to those of the automated Earth Resources Test Satellite (ERTS) to be launched in 1972.
Nominal mission duration from launch to recovery would be limited to five days. The orbital assembly would maneuver to provide acquisition light support for the rescue CSM. The rescue CSM would be capable of rendezvous without very-high frequency ranging. Landing and recovery would be planned for the primary landing area; transfer of the crew from the MDA to the CSM would be in shirt sleeves with no extravehicular activity. The KSC rescue launch response time would vary from 10 to 45 1/2 days, depending on the transpired time into the normal checkout flow.
It was determined that the rescue kit could be installed in one shift, that suits would be worn for reentry, and that the center couch would be ballasted for launch. Studies were being conducted to determine the feasibility of jettisoning disabled CSM from the axial port.
|Skylab - Artist's concept illustrating cutaway view of Skylab Apollo Telescope Mount|
Credit: NASA. 59,440 bytes. 579 x 412 pixels.
The shield did not deploy fully and took longer than nominal for the deployment. However, it was concluded that the deployment would have been successful if performed in orbit. All components of the shield had previously passed development tests.
During the conference, a weight control limit of 86 000 kg was imposed.
The modification would extend Boeing's integration work through 31 December 1972. The basic contract began in September 1964. Included in the modification was work on requirements for Saturn V vehicles that would launch the remaining Apollo lunar exploration missions (Apollo 15, 16, and 17) and the Skylab Program's Saturn Workshop. Boeing's systems engineering and integration work at the time of this modification award included requirements and documentation for presettings for onboard computers that determined launch events, propellant loadings for all three vehicle stages, vehicle structural integrity, expected heating environments, range safety, tracking and communication data, and postflight reconstruction of launch data. Boeing was also MSFC's contractor for manufacture and testing of the first (S IC) stage of the Saturn V.
The official Skylab launch and mission designations were announced: Workshop launch: SL-1. First manned visit: SL-2. Second manned visit: SL-3. Third manned visit: SL-4.
An independent CSM mission for rendezvous and docking with the U.S.S.R. Salyut spacecraft. A combination of the above. Use of the Skylab backup CSM to conduct a cooperative docking with the Salyut vehicle and thereafter carry out a fourth visit to Skylab. This mission would occur approximately 18 months after the launch of Skylab. A second Skylab supported by two 90-day CSMs and a rescue vehicle.
A study was conducted at MSFC on the effects of various pitch attitudes at the time of the Skylab payload shroud jettison on the possibility that the shroud would collide with the Skylab at a later date. Based on the study, a 10-degree attitude error constraint on a 90-degree-pitch (nose down) shroud separation attitude was recommended to preclude such a collision.
All available stowage space in the command module would be needed for film, experiment samples and specimens, flight data files, life support equipment, and supplies.
The shroud, 18.2 m long and 6.7 m in diameter, weighed almost 12 000 kg and was the first major piece of Skylab hardware to be delivered to NASA.
Training mockups of several components of the Skylab spacecraft arrived at MSC. The Orbital Workshop and the Apollo telescope mount arrived aboard the NASA barge Orion. The shipment also included the multiple docking adapter exterior shell and a portion of the airlock module mockup. The AM one-g trainer had arrived previously at MSC on a contingent of six trucks. The trainers and hardware were scheduled for use by MSC in training prospective Skylab crewmen for missions.
The anticipated reentry mode for the rescue vehicle would be with the crewmen suited, thus providing additional return stowage volume for program-critical items. North American would define the return volume and loading available, while MSC would identify the returnable program-critical items. The rescue command and service modules would be designed for both suited and unsuited reentry and for axial and radial docking. The rescue kit would include provisions for the return of five men.
|Skylab - Artist's concept illustrating cutaway view of Skylab Airlock Module|
Credit: NASA. 53,082 bytes. 582 x 413 pixels.
The contract extension would run through 31 January 1974. The additional work was to refurbish four S-IB booster stages that would be used in the Skylab Program in 1973. The fourth vehicle (SA-209) would be assigned as a backup. All four stages had been in storage for several years. The major portion of the work would be removing the stages from storage, preparing them for delivery to KSC, and providing launch support to them throughout the Skylab launch readiness period, which would end in early 1974. Most of the work would be done at the Michoud Assembly Facility in New Orleans, but some work would be done at MSFC.
Apollo experience was utilized in the design and development of the Skylab water system which consisted of Ten 272-kg storage tanks A chiller and three water dispensers for drinking water A heater and two water dispensers for food reconstitution A heater and water dispenser for personal hygiene A portable water container and fixed and flexible plumbing with disconnect fittings
At MSFC, the ATM was placed in a clean room in the Quality and Reliability Assurance Laboratory for a system checkout. It would next undergo vibration testing in the Astronautics Laboratory and then would be refurbished to serve as a backup for the flight model. While at MSC, the ATM prototype, which was assembled at MSFC, had been subjected to space conditions in a large chamber used for testing the Apollo spacecraft.
Louis, where it would be mated to the airlock module.
MSC proposed that SL-1 should be flown at an altitude of 435 km and that the orbit should be controlled by removing any insertion dispersions and drag effects with burns of the SL 2 CSM reaction control system after that spacecraft had rendezvoused and docked with SL-1. A controlled, repeating orbit would satisfy requirements common to many Earth resources experiment proposals. In addition, multiple passes over fixed targets would increase the probability of successfully obtaining data which otherwise might be lost because of cloud cover or equipment malfunctions. It was estimated, after a study lasting several months, that implementation of a controlled orbit would enhance the probability of success of such experiments by between 25 and 50 percent. The study had also shown that the proposal was feasible with regard to hardware, operations, and the crew.
The AM had been moved from the test area on 10 January to begin the mating operation with the ATM deployment assembly and the fixed airlock shroud. The multiple docking adapter had completed shell leakage tests and was undergoing radiator leakage tests. Special illumination tests and TV camera/video recorder tests began 10 January at McDonnell Douglas. Personnel from MSC, MSFC, and NASA Hq were observing the testing.
A Skylab crew news conference, with prime and backup crewmen, was held at MSC. Astronaut Charles Conrad, Jr., said preparations were on schedule for an April 1973 launch. Contractor checkouts and tests of hardware were expected to be completed for delivery to KSC in July. Skylab would carry some 20 000 pieces of stowed equipment on board to provide life support for nine men for 140 days. 'So it all goes up at one time, and we've got a great deal of work to do, not only to learn how to operate this vehicle but also all the experiments in it. It became apparent that we could not be 100-percent cross-trained as we had been in Apollo, so we've . . . defined some areas for each guy to become expert in. That allowed us to balance out the training hours.
The ATM would be moved in May from the Quality and Reliability Assurance Laboratory to the Astronautics Laboratory for vibration tests and would be delivered to MSC I June for thermal and vacuum tests. The ATM would be launched on the first Skylab mission in 1973.
|Skylab - Artist's concept illustrating cutaway view of Apollo Telescope Mount|
Credit: NASA. 57,865 bytes. 579 x 401 pixels.
Evaluation of events and redesign resulting from the May 1971 OWS-1 meteoroid shield deployment test indicated that a successful 'mechanical separation and deployment' must be demonstrated prior to shipment of the flight article to KSC.
It would then become the backup ATM flight unit.
The Skylab rescue mission was a definite NASA commitment. The hardware, procedures, documentation, and training would need to be available immediately after the launch of Skylab 2 for a potential rescue mission. To accomplish this requirement, the rescue mission would be treated as a separate mission in the Skylab Program. The rescue mission would be established as a standing agenda item for major boards and panels, and its status would be reviewed on a regular basis with other missions.
During an Orbital Workshop meteoroid shield test at MSFC, it was discovered that in one hinge section of the foldout panel, nine of the 15 torsion springs were installed in such a manner that they were only 50-percent effective in action to assist shield deployment. Action was initiated to ensure proper spring action.
MSFC, KSC, and MSC performed studies which identified the cost and reliability tradeoffs on planned one- and two-week slips between the launches of SL-1 and SL-2. An analysis of the studies identified significant cost and reliability penalties that would be incurred if the SL-2 mission were slipped, reconfirmed the desirability of getting the CSM docked to the Orbital Workshop as soon as possible after launch of SL-1, and recommended against extending the launch interval between SL-1 and SL-2. Launch plans called for a 1-day interval between the two launches.
Astronauts would step inside a ring on the floor and raise a fireproof beta cloth curtain on a hoop and attach it to the ceiling. A flexible hose with push-button shower nozzle could spray 2.8 liters of water from the personal hygiene tank during each bath. Used water would be vacuumed from the shower enclosure into a disposable bag and deposited in the waste tank.
Ninety percent of the crew compartment fit and function hardware items were satisfactorily reviewed. Problems identified by the crew included numerous mechanical problems in the urine collection system, tools breaking, snaps debonding, and velcro debonding.
Two teams of six astronauts performed checkout activities in two, six-hour shifts daily for three days, activating the Workshop to demonstrate that it could support all activities planned for missions. The test was one of the last two major tests for the Workshop, which was 14.6 m long, 6.7 m in diameter, and scheduled for launch in early 1973. A flight demonstration would be conducted before the spacecraft was shipped to KSC during the summer.
|Skylab - View of Skylab Saturn IB Launch Configuration Complex 39B at KSC|
Credit: NASA. 29,390 bytes. 325 x 459 pixels.
An Orbital Workshop all-systems test began on 17 July 1972 and was completed on 7 August 1972 at McDonnell Douglas' Huntington Beach Vehicle Checkout Laboratory. Following the test, which lasted 309 hours, a meeting was held to verify that the OWS all-systems test had been successfully completed. At the conclusion of the meeting, it was agreed that pending closeout of the test anomalies, all test requirements had been satisfied.
The CSM arrived at KSC via the Super Guppy aircraft. Upon arrival, the CSM, which would be launched on SL-2, was installed in the Operations and Checkout Building to begin its checkout procedure.
Following preliminary checkout in the VAB transfer aisle, the S-IB 206 first stage would be erected atop the 39- m-tall pedestal on Mobile Launcher 1 on 31 August.
Twenty-four Skylab suits were delivered by the space suit manufacturer, International Latex Corporation; five were ready for delivery, nine were in the manufacturing process, and material for the remaining three had been procured.
An MSC team was conducting tests with the rescue mission configured Skylab command module at KSC. Purpose of the test was to evaluate the equipment, techniques, and procedures involved in the egress required by a five-man command module loading. Navy and Air Force helicopters were participating in the test.
A special ceremony at McDonnell Douglas, Huntington Beach, marked completion of the OWS, the main section of the Skylab space station. The OWS, with a volume equivalent to that of a five-room house, was being readied for shipment to Cape Kennedy aboard the USNS Point Barrow. The trip would take 13 days.
The ATM, which had been at MSC since mid-July, was immediately moved to the Operations and Checkout Building in KSC's industrial area and placed in the cleanroom for intensive checkout. The ATM was scheduled to be moved in January 1973 to the Vehicle Assembly Building for mating with the OWS atop the two-stage Saturn V launch vehicle. The Skylab orbital assembly- consisting of the OWS, the ATM, and the AM/MDA-was scheduled to be launched from Pad A of Launch Complex 39 in late April 1973.
The Skylab 1 Orbital Workshop was offloaded from a NASA barge and moved into the transfer aisle of the Vehicle Assembly Building (VAB) at KSC. The OWS had arrived the preceding day (22 September) aboard the Point Barrow at Port Canaveral, where it was transferred to a smaller barge for the journey through the locks, up the Banana River, and through the access canal to the barge unloading area at the VAB. Following preliminary checkout, the OWS, with its 361.4 cu m of living and working area, was scheduled to be mated to the twostage Saturn V launch vehicle on 28 September.
However, CSM 111 would continue to be the primary Apollo- Soyuz Test Project spacecraft.
Problems were encountered with improperly torqued deployment torsion bars and latch failure in the open position. One torsion bar was replaced and the others retorqued. The meteoroid shield was successfully deployed on 22 October when three out of four latches worked, and it was judged acceptable for flight. By 29 October all work had been completed, and the meteoroid shield was placed in flight configuration.
|Skylab - Double exposure to illustrate size difference between Skylab 1 and 2|
Credit: NASA. 34,373 bytes. 615 x 455 pixels.
It was decided that the S-IVB for these missions would be deorbited into the Pacific Ocean on an early revolution. The deorbit would be achieved by controlled venting of the S-IVB, dumping propellants through the main engine to provide sufficient retrovelocity for reentry. The capability to perform the deorbit would be evaluated and determined during flight; however, execution of the maneuver would be controlled from the ground. (The deorbit technique was the same used on early Earth-orbit Apollo missions.)
Examples cited were The payload shroud, where a conservative estimate of savings at the expense of 5900 kg of payload was approximately $35 million. The gas storage system where a 2700-kg heavier payload resulted in an estimated savings of $5 million. Other structural elements, in addition to the payload shroud, accommodated 2200 kg of added payload weight for an additional savings of $35 million.
Reasons for the objection were NASA would be placed in the position of retaining a backup capability for the most reliable portions of Skylab and disposing of that capability for the most immature elements such as the Workshop and solar arrays. Cost of storing these elements at the factory during the missions would be small since flight support and postflight analysis would need to be retained until the spring of 1974. Without the backup capability, the possibility existed that the program could end up with no 28-day medical data, no science data, and no EREP data, just a $2.6-billion failure.
At a NASA general management review, Dale D. Myers summarized Skylab problems which were aggravated by a requirement to replace a control and display panel in the multiple docking adapter-one of the pacing program items. He told the general management review group that confidence in the ability to maintain an April launch date was slipping. Following the review, a decision was made to delay the launch of SL-1 and SL-2 until May 1973, with tentative launch dates of 14 and 15 May. An evaluation of launch intervals between SL-2 and SL-3 and between SL-3 and SL-4 was being made to determine if an approximate recovery date of 21 December 1973 could be maintained.
No major problems were encountered in the SL-2 processing. Propellant loading and unloading, facilities, and ground support equipment tests were conducted on the Saturn IB launch vehicle at Pad B. Following tests, the vehicle was rolled back to the Vehicle Assembly Building. Prime and backup crews completed manned altitude chamber tests of the SL-2 command and service modules on 19 January, following which the spacecraft was moved to the Vehicle Assembly Building where it would be erected on the S-IB.
MSFC began implementation of a plan for preparation and storage of unassigned Saturn hardware, phaseout of the Saturn V production capability, and amendment of the facility operations contract at the Michoud Assembly Facility for minimum surveillance of stored hardware.
The evaluation indicated that the star charts aboard the Orbital Workshop were launch-date dependent. Changeout packages were being prepared for the star charts which would be carried in the command module. Changeout packages were also being prepared for the rendezvous book, the ATM systems checklist and data book, the flight plan, and the flight plan sequence for the activation and deactivation checklist.
The SL-2 space vehicle consisted of the following major components: an S-IB (the first stage); an S-IVB (the second stage, which comprised the propulsion stages); an IU; a CSM; and an SLA.
Consideration was being given to the feasibility of a second set of Skylab missions (designated Skylab-B) during the interval between the Apollo-Soyuz Test Project in 1975 and the start of Space Shuttle operations late in 1979. The inherent worth of a Skylab-B was recognized, but officials were reluctant to recommend it, on the premise that it would be unwise to allow it to delay or displace the development of the Space Shuttle and other programs already included in the FY 1974 budget.
The test included the SL 2 astronaut crew participation in the simulated launches of SL-1 and SL-2, mission activation and operation, deactivation, data dump, and powerdown.
The ship would provide a two- way flow of information and communication between Skylab and Mission Control Center in Houston via Goddard Space Flight Center. Upon completion of the Skylab Program, it would return to Port Canaveral. The Vanguard was originally designed to provide tracking and data acquisition for the Apollo flights. It played an important role in the Apollo Program.
Studies were conducted to determine the feasibility of conducting a controlled deorbit of the Orbital Workshop. Three methods were considered: (l) using the CSM service propulsion system; (2) using the CSM reaction control system; and (3) implementing an S-II (Saturn V second stage) deorbit. The service propulsion system deorbit was assessed as not feasible; the reaction control system deorbit was considered technically feasible but, like the service propulsion system, it had an inherent program and crew safety risk associated with it. Implementation of an S-II deorbit would have serious time and cost impacts on the program. A 1970 study, which indicated that the probability of damage from the deorbiting Skylab was so small that changes which caused major impact in cost and schedule were not worth pursuing, was confirmed.
The Skylab 1 spacecraft on its launch vehicle was moved to Launch Complex 39, Pad A, on 16 April. The SL-1 space vehicle consisted of two launch vehicle stages, an instrument unit, and the three major payload modules of the Saturn Workshop (SWS). The two launch vehicle stages and IU (S-IC, S-II, and S-IU) were identical to the first and second launch vehicle stages of the Apollo Saturn V space vehicle. The SL-1 payload consisted of the Orbital Workshop (a converted S-IVB stage), airlock module/multiple docking adapter, Apollo telescope mount, payload shroud, nose cone, and experiments.
The next major milestone in preparing the Saturn IB/Apollo for launch would occur 23 April when the kerosene to fuel the Saturn IB booster's eight engines would be pumped aboard the first stage.
Items covered in the review ranged from modules and launch vehicles readiness to missions and operations support. Following the review, NASA Skylab Program Director William C. Schneider said, 'We still have a few things to be closed out, but we have assured ourselves that the systems are all working with one or two minor open items and we're still ready to go for a 14 May launch of Skylab 1 and a 15 May launch of Skylab 2.'
KSC and MSFC were directed by NASA Hq to implement a reduction in force of contractor personnel immediately following the launches of SL-1 and SL-2, but to maintain a sufficient complement for a backup launch capability through 30 September 1973.
No significant anomalies due to the lightning static were revealed.
First and only US space station to date. Project began life as Apollo Orbital Workshop - outfitting of an S-IVB stage with docking adapter with equipment launched by several subsequent S-1B launches. Curtailment of the Apollo moon landings meant that surplus Saturn V's were available, so the pre-equipped, five times heavier, and much more capable Skylab resulted.
An unexpected telemetry indication of meteoroid shield deployment and solar array wing 2 beam fairing separation was received 1 minute and 3 seconds after liftoff. However, all other systems of the OWS appeared normal, and the OWS was inserted into a near-circular Earth orbit of approximately 435 km altitude. The payload shroud was jettisoned, and the ATM with its solar array was deployed as planned during the first orbit. Deployment of the Workshop solar array and the meteoroid shield was not successful. In fact the xternal solar/meteoroid shield had ripped off 63 seconds into ascent, tearing away one solar panel wing and debris jamming the remaining panel. Without shield temperatures soared in station. Repairs by crews led to virtually all mission objectives being met.
Following the final manned phase of the Skylab mission, ground controllers performed some engineering tests of certain Skylab systems--tests that ground personnel were reluctant to do while men were aboard. Results from these tests helped to determine causes of failures during the mission and to obtain data on long term degradation of space systems.
Upon completion of the engineering tests, Skylab was positioned into a stable attitude and systems were shut down. It was expected that Skylab would remain in orbit eight to ten years. It was to have been visited by an early shuttle mission, reboosted into a higher orbit, and used by space shuttle crews. But delays in the first flight of the shuttle made this impossible.
On July 11, 1979, Skylab disintegrated when it re-entered the earth's atmosphere after a worldwide scare over its pending crash. The debris stretched from the south-east Indian Ocean into Western Australia.
Bruce T. Lundin (Lewis Research Center) was named chairman of the Board.
The review board determined that a 'Skylab parasol,' with a strengthened ultraviolet resistant material, deployed through the scientific airlock would be the prime method for the deployment of a thermal shield on the Orbital Workshop. A 'twin pole' thermal shield and a standup extravehicular thermal sail would be flown as backup methods. Following final assessment of mission readiness with favorable recommendations, a certification of flight worthiness for the new hardware was executed.
NASA Administrator James C. Fletcher briefed members of the Senate on the anomalies that occurred during liftoff and orbit of Skylab 1.
First and failed attempt to release jammed solar panel.
Epic repair mission which brought Skylab into working order. Included such great moments as Conrad being flung through space by the whiplash after heaving on the solar wing just as the debris constraining it gave way; deployment of a lightweight solar shield, developed in Houston in one week, which brought the temperatures down to tolerable levels. With this flight US again took manned spaceflight duration record.
Skylab 2 , consisting of a modified Apollo CSM payload and a Saturn IB launch vehicle, was inserted into Earth orbit approximately 10 minutes after liftoff. The orbit achieved was 357 by 156 km and, during a six-hour period following insertion, four maneuvers placed the CSM into a 424 by 415 km orbit for rendezvous with the Orbital Workshop. Normal rendezvous sequencing led to stationkeeping during the fifth revolution followed by a flyaround inspection of the damage to the OWS. The crew provided a verbal description of the damage in conjunction with 15 minutes of television coverage. The solar array system wing (beam) 2 was completely missing. The solar array system wing (beam) 1 was slightly deployed and was restrained by a fragment of the meteoroid shield. Large sections of the meteoroid shield were missing. Following the flyaround inspection, the CSM soft-docked with the OWS at 5:56 p.m. EDT to plan the next activities. At 6:45 p.m. EDT the CSM undocked and extravehicular activity was initiated to deploy the beam 1 solar array. The attempt failed. Frustration of the crew was compounded when eight attempts were required to achieve hard docking with the OWS. The hard dock was made at 11:50 p.m. EDT, terminating a Skylab 2 first-day crew work period of 22 hours.
The second manned day of the Skylab mission was focused on entry into the OWS and deployment of the Skylab parasol.
Following the successful deployment of the parasol, the Skylab-2 crew began to transfer and store equipment and activate experiments.
The following agreements were reached: The parasol installed on the OWS would not be jettisoned until a replacement thermal shield was on board, if a twin-boom thermal shield had not been deployed during the SL-2 mission. The twin-boom sunshade and the JSC sail would be retained in the OWS at the end of the SL-2 mission.
During a Manned Space Flight Management Council telecon, four agenda items were discussed: an early launch date for SL-3; plans for an EVA solar array system repair; deorbiting of the Skylab cluster; and lengthening the SL-2 mission. The Council decided to go for a 27 July launch date, with the possibility of a further acceleration on a crash effort basis to 22 July if possible degradation of hardware because of unexpected thermal stresses required an earlier launch. Decisions on the other three agenda items were deferred pending further study.
Succeeded in release of jammed solar panel.
The Skylab 3 space vehicle was moved to KSC Launch Complex 39, Pad B, on 11 June in preparation for launch. The space vehicle consisted of a Saturn IB launch vehicle S-IB-207 first stage, S-IVB-207 second stage, and a S-IU-208 instrument unit; a CSM; and a spacecraft lunar module adapter.
It was concluded that the units could be safely operated, and approval was given for scheduling their use. Previously, a decision to operate the units had been deferred until a more thorough briefing could be provided. Concern over their use had been based on the Aerospace Safety Advisory Panel Report on Skylab. Astronauts Edward G. Gibson and Russell L. Schweickart are shown in the MSFC Neutral Buoyancy Tank, above, simulating use of various cutting tools to be used by the Skylab 2 crew in an effort to free the Workshop's solar wing. At right, the Saturn IB launch vehicle to be u for the Skylab 3 mission is shown as it was rolled out to Launch Complex 39-B on 11 June 1973.
Replacement of film cartridges for solar camera.
A recommendation to jettison the docking ring and probe assembly on SL-2 while the crew was unsuited was reaffirmed. Major considerations in arriving at the recommendations were that a suited landing was unacceptable, the additional risk of performing the operation unsuited was extremely low, and the crew had trained premission and in flight using the proposed timeline for an unsuited jettison of the docking ring and probe assembly.
At 9:49 a.m. EDT, Skylab 2 splashed down in the Pacific Ocean 9.6 km from the recovery ship, U.S.S. Ticonderoga , and 1320 km southwest of San Diego. At 10:28 a.m., the crew and spacecraft were aboard the Ticonderoga. The objectives of the SL-1/SL-2 mission were to establish the Orbital Workshop in Earth orbit, obtain medical data on the crew for use in extending the duration of manned space flight, and perform inflight experiments. A summary assessment of the mission objectives indicated a very high degree of completion, particularly when the reduction in experiment time due to parasol deployment, solar array wing deployment, and OWS system anomalies were considered.
The launch date for Skylab 3 was officially established as 28 July 1973. The launch window would open at 7:08 a.m. EDT for 10 minutes and would provide for a rendezvous in five revolutions. Recovery of SL-3 was planned for 22 September 1973. Two members of the Skylab 3 crew, Jack R. Lousma, left, and Owen K. Garriott, center, inspect a part of the twin-pole solar sail at MSFC (above). At right, Lousma practices erecting the solar sail over a portion of the Orbital Workshop mock in the MSFC Neutral Buoyancy Tank. Nylon netting was used for this underwater training instead of the aluminized fabric the actual sail was made of.
Joint Skylab 3 flight readiness reviews and thermal shield design certification reviews were held at KSC. A comprehensive series of center reviews were completed before, and in preparation for, the flight readiness reviews.
Premature deployment of the meteoroid shield during the Skylab 1 launch interjected additional factors in the consideration of the OWS deorbit. Because of the additional uncertainties and complications deriving from these factors and the inherent crew and mission risks involved in the OWS deorbit even under expected conditions, the decision was taken to terminate all OWS deorbit efforts.
Twice-weekly experiment planning meetings were being instituted for the 59-day Skylab 3 mission. The purpose of the meetings was to formulate a balanced set of experiment requirements for each upcoming week based on a consideration of plans for the remainder of the mission.
Continued maintenance of the Skylab space station and extensive scientific and medical experiments. Installed twinpole solar shield on EVA; performed major inflight maintenance; doubled record for length of time in space. Completed 858 Earth orbits and 1,081 hours of solar and Earth experiments; three EVAs totalled 13 hours, 43 minutes.
The space vehicle, consisting of a modified Apollo command and service module payload on a Saturn IB launch vehicle, was inserted into a 231.3 by 154.7 km orbit. Rendezvous maneuvers were performed during the first five orbits as planned. During the rendezvous, the CSM reaction control system forward firing engine oxidizer valve leaked. The quad was isolated. Station-keeping with the Saturn Workshop began approximately 8 hours after liftoff, with docking being performed about 30 minutes later.
The Skylab 3 crewmen experienced motion sickness during the first three visit days. Consequently, the Orbital Workshop activation and experiment implementation activities were curtailed. By adjusting the crew's diet and maintaining a low workload, the crew was able to complete the adjustment to space flight in five days, after which flight activities returned to normal. On 25 September, the command module was reactivated and the crew performed the final OWS closeout. Following undocking and separation, the command module entered the atmosphere and landed in the Pacific Ocean approximately 300 km southwest of San Diego. Splashdown was at 6:20 p.m. EDT. The recovery ship, U.S.S. New Orleans, retrieved the command module and crew 42 minutes after landing. The total flight time was 1427 hours 9 minutes 4 seconds.
Lewis Research Center Director Bruce T. Lundin, who served as chairman of the Skylab 1 Investigation Board, presented the findings of the board and the recommended corrective actions in congressional testimony:
In a letter to the White House, NASA Administrator James C. Fletcher summarized the Skylab 2 mission: ....A situation that was bleak indeed on May 14, and for several days thereafter, improved to, a point well beyond our most optimistic forecasts at that time. 'This of course was due to a courageous crew and a dedicated team of government and industrial contractor personnel, whose dedication and ability cannot be over emphasized. Not only was the crew able to accomplish the great majority of the technical and scientific objectives established for this first Skylab mission, but they were able also to repair the Skylab space station and leave it in a condition which will allow the satisfactory completion of nearly all that we desired from the overall Skylab Program, with the unexpected additional accomplishments of demonstrating the ability to respond to adversity and demonstrating the flexibility provided by the use of man and his faculties in a hostile environment....
Skylab 2 postflight medical debriefings indicated the desirability of minimizing crew exposure to recovery ship motions for both crew reconditioning and postrecovery medical evaluations. In order to provide the Skylab 3 crew with this minimum exposure, mission duration was extended to 59 days. This allowed for a splashdown closer than 550 km of San Diego, and a crew stay time aboard the recovery ship of only 17 hours.
Installed second sunshade. Replaced solar camera film cartridges. During EVA by crew members of Skylab 3, a twin-boom sunshade, developed by MSFC, was deployed over the parasol of the OWS. A redesigned and refined thermal parasol had been launched with Skylab 3. However, its use would have required jettisoning the parasol deployed by crew members of Skylab 2, with the possibility of creating the same thermal problems that existed on the OWS prior to the parasol deployment. Following erection of the twin-pole sunshade, the cabin temperature stayed at a comfortable 293-297 K (67.7°F-74.9°F).
Anomalies that had occurred during micrometeoroid shield testing were summarized.
Representatives from NASA Hq, MSFC, GSFC, and JSC attended. Results of a feasibility study for viewing the comet were presented to the NASA Administrator on 15 August. It was agreed that observations of Kohoutek would he made at appropriate times during the SL-4 mission.
NASA decided to delete the Skylab backup Saturn V Orbital Workshop launch capability effective 15 August. All work associated with the completion, checkout, and support of Skylab backup hardware, experiments, software, facilities, and ground support equipment would be canceled immediately, except for the work that would directly support SL-3, SL-4, and rescue missions.
The space vehicle consisted of a Saturn IB launch vehicle-S-IB-208 first stage, S-IVB-208 second stage, and S-IU-207 instrument unit; a CSM-118; and a spacecraft lunar module adapter.
Replaced solar camera film cartridges; installed replacement gyroscopes.
Influenced by the stranded Skylab crew portrayed in the book and movie 'Marooned', NASA provided a crew rescue capability for the only time in its history. A kit was developed to fit out an Apollo command module with a total of five crew couches. In the event a Skylab crew developed trouble with its Apollo CSM return craft, a rescue CSM would be prepared and launched to rendezvous with the station. It would dock with the spare second side docking port of the Skylab docking module. During Skylab 3, one of the thruster quads of the Apollo service module developed leaks. When the same problem developed with a second quad, the possibility existed that the spacecraft would not be maneuverable. Preparation work began to fit out a rescue CSM, and astronauts Vance Brand and Don Lind began preparations to rescue astronauts Bean, Garriott, and Lousma aboard the station. However the problem was localized, work arounds were developed, and the first space rescue mission was not necessary. The Skylab 3 crew returned successfully in their own Apollo CSM at the end of their 59 day mission.
At a Kohoutek status meeting, JSC w as requested to determine if additional ultraviolet eye protection would be required by the Skylab 4 astronaut while performing Kohoutek operations. A study indicated that no additional eye protective devices would be required for either intra- or extravehicular viewing of the comet. The use of the existing space suit sun visors would be required during extravehicular viewing.
Discussions confirmed that there was reasonable assurance that an Apollo-Soyuz Test Project (ASTP) revisit to Skylab in mid-1975 was feasible. However, such a dual mission would create a significant planning problem for the operations team and would introduce many new considerations to the inflight planning and execution because of uncertainties in the orbital mechanics.
The Director of the Skylab Program, in offering his counterpart in the ASTP some advice in establishing an ASTP television program, stated: ' . . I ascribe at least two of my many ulcers to television. It's an emotional subject because everyone is an expert on requirements. If you can get: a. The groundrules stated, b. The requirements from the senior man who feels responsible, c. Then treat it like any other requirement, d. Put a discipline in the system more rigorous than I did, e. Take the requirements people out of the day-to-day implementation, you may only get only one TV ulcer.'
Fish and embryo that were part of a Skylab science demonstration would be returned to JSC by Skylab 3, provided that one or more of the fish were still alive at the time of deactivation. Upon return to the recovery ship, the fish would be photographed and observed to determine any reaction to the one-g environment. They would then be returned to JSC for comparison with the backup fish and embryo which were being held in the JSC laboratory. Later histological observations and examinations of their vestibular apparatus would be performed to determine any changes between the two groups.
In all, 39 Earth-oriented passes, six solar inertial passes, two Earth-limb surveys, and two lunar calibration sequences were completed. The 15 hours of data acquisition was about 40-percent higher than the premission flight plan and included 15 780 photographs and 28 000 m of magnetic tape. Data were acquired over the United States, Central and South America, Europe, Africa, Japan, and Southeast .Asia. Special observations were made of tropical storm Christine, the Sargasso Sea, the African drought area, and the Pakistan flood area. Oblique and nadir photography was obtained for most of Paraguay as part of a joint U.S./IAGS (Inter-American Geodetic Survey) Paraguay mapping experiment.
Replaced film cartridges for solar camera.
An ad hoc committee was established to analyze the vestibular problems which occurred in previous manned space flights and to make recommendations concerning prevention and control on future flights. Particular emphasis was placed on the experiences of the Skylab 3 crew. As a result of the committee meeting, it was recommended that the crewmen of SL-4 take anti-motion-sickness medication immediately upon orbital insertion and follow this with periodic doses for the first three days of flight.
Established prelaunch procedures required each Skylab flight crew to begin a health stabilization program 21 days before liftoff.
Among the items covered were a plan for measuring both the pre- and postflight cardiac outputs of the SL-4 crew; elimination of all activities in the deactivation sequence not absolutely required; and a plan for accommodation of the circadian shift necessary for missions of various durations.
After being loaded in flight containers, they were hand carried to KSC. The eggs would be launched on Skylab 4 and then transferred to the OWS sleep compartment area where they would be monitored during the course of the SL-4 mission. The eggs were being carried at the request of the Secretary of Agriculture.
The 72 kg of additional food placed aboard the SL-4 command module included 39 kg of high-energy food bars and would supply sufficient food for an extension of the mission to 85 days, plus an additional 10 days' supply for a rescue capability. The food bars, which contained 300 calories each, would be used by the crewmen every third day of the mission in combination with the normal Skylab food. There were three kinds of energy bars-chocolate chip, crispy, and flake. Each was coated with one of three flavors- vanilla, chocolate, or strawberry- making nine different varieties. The bar, a modification of a commercially available Pillsbury food stick, was all offspring of a bar developed jointly by NASA, the U.S. Air Force, and the Pillsbury Company.
A shift in the Skylab 4 launch schedule was required in order to replace eight cracked fins on the S-IB. The hairline cracks were discovered during a postcountdown demonstration test inspection. Initial indications were that the 14 cracks were caused by load stress or salt air, or possibly a combination of both.
Other reviews included the KSC flight readiness review, 18 October; the JSC Director's flight readiness review and the JSC command and service module flight readiness review, 11 October; the MSFC review of the Skylab Workshop systems capabilities, 17 September; and the KSC SL-4 launch readiness review, 15 October 1973.
Final Skylab mission; included observation and photography of Comet Kohoutek among numerous experiments. Completed 1,214 Earth orbits and four EVAs totalling 22 hours, 13 minutes. Increased manned space flight time record by 50%. Rebellion by crew against NASA Ground Control overtasking led to none of the crew ever flying again. Biological experiments included two Mummichog fish (Fundulus heteroclitus).
The space vehicle consisted of a modified Apollo CSM and a Saturn IB launch vehicle. All launch phase events were normal, and the CSM was inserted into a 150.1- by 227.08-km orbit. The rendezvous sequence was performed according to the anticipated timeline. Stationkeeping was initiated about seven and one-half hours after liftoff, and hard docking was achieved about 30 minutes later following two unsuccessful docking attempts. Planned duration of the mission was 56 days, with the option of extending it to a maximum of 84 days.
The reactivation included the reservicing of the airlock module primary coolant loop. The commander and pilot experienced symptoms resembling motion sickness during the initial three days of the visit, and flight plan activities were adjusted accordingly. Crew health was good thereafter.
Repaired antenna. Replaced solar camera film cartridges.
Vehicle rollout to the launch complex was scheduled for 5 December. Integrated testing and the flight readiness test would be completed about 13 December. Flight readiness review dates would only be established if a rescue launch was required.
Photographed Comet Kohoutek and replaced solar camera film cartridges.
Photographed Comet Kohoutek.
Flexibility to conduct a second Skylab mission would be retained until such time as NASA planning for the FY 1976 budget was complete. To accomplish this, NASA issued the following guidelines. Launch umbilical tower 2 would be retained in its present status for possible Skylab usage until a decision was made to prepare for a Skylab launch or to begin modifications for the Shuttle Program. Action would be continued to place in storage existing hardware (including appropriate backups and spares) required for conduct of a Skylab mission. The Skylab Program would fund the activities required to place the hardware in minimum cost storage and the storage costs through June 1974.
Studies had been conducted to determine an end-of-mission configuration for the Orbital Workshop and for maintaining the option of an OWS revisit at some future date. MSFC assessed the special deactivation requirements for the AM, MDA, and the Workshop required to establish a satisfactory, economical configuration. JSC made an evaluation of ground support monitoring and control options. The OWS would be left in a configuration that would permit a revisit at some future date without reactivation.
A series of engineering tests on the Orbital Workshop was authorized following completion of the Skylab 4 mission provided that only tests which would result in significant engineering knowledge would be performed. A series of engineering tests on the Orbital Workshop was authorized following completion of the Skylab 4 mission provided that only tests which would result in significant engineering knowledge would be performed; no compromise would be made to the desired end of mission configuration by conducting the test (10 January 1974 entry); the vehicle would be left in the final configuration no later than 15 February 1974; and only a minimum of overtime and shift operation would be expended to obtain the data.
Significant repair and maintenance accomplishments of the three manned Skylab missions were reported.
Retrieved solar camera film cartridges and external materials exposure package.
Upon completion of this action, Headquarters responsibility for the SA-209 and CSM-119 would be transferred to the Program Director of the Apollo-Soyuz Test Program.
MSFC published a summary of Skylab operations.
After completion of the three programmed Skylab flights, NASA considered using the remaining backup Saturn IB and Apollo CSM to fly a fourth manned mission to Skylab. It would have been a short 20 day mission - the CSM systems would not have been powered down. Main objective would be to conduct some new scientific experiments and boost Skylab into a higher orbit for later use by the shuttle. The marginal cost of such a mission would have been incredibly low; but NASA was confident that Skylab would stay in orbit until shuttle flights began in 1978 - 1979. But the shuttle was delayed, and faster atmospheric decay than expected resulted in Skylab crashing to earth before the first shuttle mission was flown.
Preliminary feasibility studies indicated that there was insufficient time to send a suitably instrumented spacecraft to observe and study the comet at close range. However, other manned and unmanned observations were planned, with the most significant to occur during the third visit to the orbiting Skylab. Unique scientific data were obtained by the third-visit crew, helping to make Kohoutek the most comprehensively studied comet in history.
NASA realized that after the completion of the Apollo, Skylab, and ASTP programs there would still be significant Apollo surplus hardware. This amounted to two Saturn V and three Saturn IB boosters; one Skylab space station, three Apollo CSM's and two Lunar Modules. After many iterations NASA considered use of these assets for a second Skylab station in May 1973. A range of options were considered. Saturn V SA-515 would boost the backup Skylab station into orbit somewhere between January 1975 and April 1976. It would serve as a space station for Apollo and Soyuz spacecraft in the context of the Apollo ASTP mission. The Advanced or International Skylab variants proposed use of Saturn V SA-514 to launch a second workshop module and international payloads. This station would be serviced first by Apollo and Soyuz, then by the space shuttle. Using the existing hardware, these options would cost anywhere from $ 220 to $ 650 million. But funds were not forthcoming. The decision was taken to mothball surplus hardware in August 1973. In December 1976, the boosters and spacecraft were handed over to museums. The opportunity to launch an International Space Station, at a tenth of the cost and twenty years earlier, was lost.