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astronautix.com International Space Station

ISS 1996
ISS 1996
The Space Shuttle docks with the International Space Station.

Credit: NASA via Marcus Lindroos. 38,137 bytes. 640 x 480 pixels.


Nation: USA. Agency: NASA.

In 1987-1993 the Russians successfully assembled and operated the 124-tonne Mir station. The station's modules were evolved from those of the secret military Almaz station of the 1970s. Mir and its crews whirled round and round the world, through the collapse of the Soviet Union and Russian economic meltdown. By 1993, Russia had acquired unmatched experience in long-duration human flight, but it was apparent that there was no money for the follow-on Mir-2.

At the same time, NASA had scaled down its space station in the seventh redesign in nine years. This more modest station Alpha deleted most of the original science experiments, but would still cost more than Clinton was willing to spend. In October 1993, with the gunfire of the coup attempt outside their windows, NASA negotiators in Moscow agreed to the 'International Space Station' (ISS), a merger of stations Alpha and Mir-2.


ISS 1993ISS 1993 - 1993 International Space Station

Credit: NASA via Marcus Lindroos. 67,695 bytes. 545 x 480 pixels.


President Clinton's endorsement of the new Option A Space Station did little to help the project. In June 1993, a bid in Congress to kill the Station failed by a single vote (215-216). Scientists continued to be critical of the project, saying its benefits were more marginal than ever after the latest redesign and that the Station had lost its political mission following the end of the Cold War.

In September, NASA presented Clinton with two final options: the small 4-man US-only 'Alpha' Station approved in June or the larger and much more capable 6-crew 'Russian Alpha' design. President Clinton chose the latter option, essentially merging the American SS Freedom and Russian 'Mir-2' projects into a new International Space Station (ISS). The President also managed to strike a deal with Congress which established a fixed annual budget of $2.1 billion. The agreement was remarkably successful; the last attempt to cancel the project was rejected in the House of Representatives in 1994. Technologically, ISS reversed the continuing trend (since 1986) toward a smaller and less capable Station. The new configuration reintroduced the US laboratory and node modules into the design. ISS will have more science racks than Freedom and provide more power for experiments. The total mass in orbit is 370 metric tons, so the International Space Station weighs almost twice as much as Space Station Freedom.


1993 ISS Diagram1993 ISS Diagram

Credit: NASA via Marcus Lindroos. 5,251 bytes. 385 x 320 pixels.


A big plus according to NASA was the Station now could be manned almost immediately as soon as the Russian FGB and Service Modules had been launched. In contrast, Space Station Freedom would not have been capable of supporting a permanent crew before a dozen or so modules had been launched.

Aerospace mergers plus increased emphasis on commercial space made it easier for the new NASA Administrator, Dan Goldin, to reform the Space Station and NASA in general. The Space Station Program Office in Reston, Virginia was cancelled as NASA selected Boeing (which bought the space divisions of other Station contractors such as McDonnell-Douglas and Rockwell in the 1990s) as the new Station prime contractor. Boeing's contract from 1995 contained less NASA oversight than usual while giving the company and its Space Station 'integrated production teams' some financial rewards in case the projected goals are met. The Johnson Space Center now hosted the Station's new program office. All this greatly simplified the project's cumbersome management structure, although the efforts to avoid cost overruns and delays were not entirely successful.


1993 ISS Cost1993 ISS Cost - 1993 International Space Station - ISS Plan. Despite its additional capabilities, the International Space Station's Fiscal 1994-2000 budget was actually lower than for any of the other redesigns. However, the International Space Station assembly sequence will now require another five years beyond the original completion date.

Credit: NASA via Marcus Lindroos. 17,907 bytes. 597 x 418 pixels.


European Space Agency contributions to the International Space Station program were seriously revised following the restructuring of the European manned spaceflight program in 1991-93. The November 1992 meeting in Granada decided to continue with a scaled back $3-billion Columbus module, but the French managed to force another reassessment in 1995 due to concerns about the US commitment to Space Station Freedom. The overall cost of the revised ESA programs was estimated to be $2 billion lower (at 1991 prices) than the original $10.8 billion projected for 1993-95. From 1993 to 2000, the total was projected to be about $25.7 billion, down from $29.7 billion.


Space Station AlphaSpace Station Alpha - The "compromise option" eventually chosen by Clinton was Option A.

Credit: NASA via Marcus Lindroos. 59,704 bytes. 537 x 473 pixels.


ESA then merged its Columbus and manned space transportation plans into a single effort in 1994, to further reduce the overall cost of the $4.6-billion COF/CTV/ATV program.. In October 1995, ESA finally decided to remain a partner in the ISS project after France, Italy and Germany managed to reach a complicated compromise on what the contributions should be and how much they would cost. The Italians received Ariane-5 and Columbus contracts from France and Germany. The $1.4-billion Columbus Orbiting Facility was also approved. The second major project was the French-led Automated Transfer Vehicle designed to carry 9,000kg of cargo to ISS. It would cost $750 million to develop. The $1.7-billion Crew Transfer Vehicle capsule was however cut from the package, although France received $60 million for CTV studies.


Space Station AlphaSpace Station Alpha - Later, additional laboratories and a habitation module could be added to create the complete Option A Space Station shown here.

Credit: NASA via Marcus Lindroos. 74,704 bytes. 640 x 480 pixels.


In addition to its other contributions, the ESA Council also approved a 'complementary' ISS Phase 2 program in July 1994 for early development of laboratory and computer support equipment used on the US and Russian ISS segments, before Columbus is launched. Important projects included a computer system and European Remote Arm for the Russian Service Module. When ESA decided not to launch the Columbus Orbiting Facility on its Ariane-5 rocket, it had to reimburse the American's for using the Space Shuttle. As part of a barter deal signed in March 1997, ESA contributed experimental racks and freezer units for the US laboratory. ESA will also contribute two Node modules worth $115 million free of charge, in return for receiving a 'free' Space Shuttle flight from the Americans to launch the Columbus Orbiting Facility (COF). The nodes are built by Alenia Spazio and based on the same basic pressurised module as the COF and Multi-Purpose Logistics Modules. One of the nodes will carry the International Space Station's environmental control and life-support system and crew quarters since the US habitation module has been postponed due to cost overruns.


1994 ISS1994 ISS - 1993 International Space Station - ISS Plan. NASA presented Clinton with two final options: the small 4-man US-only "Alpha" Station approved in June or the larger and much more capable 6-crew "Russian Alpha" design shown here. President Clinton chose the latter option, essentially merging the American SS Freedom and Russian "Mir-2" projects into a new International Space Station (ISS).

Credit: NASA via Marcus Lindroos. 67,114 bytes. 640 x 480 pixels.


Brazil joined the ISS project in 1999 and China may become a partner in the future. Despite its additional capabilities, the International Space Station's Fiscal 1994-2000 budget was actually lower than for any of the other redesigns. However, the lower cost came at a price since ISS will not be assembled as quickly as the other options. All the other redesigns planned to end the assembly phase by 2001. The International Space Station assembly sequence will now require another five years beyond that.

The ISS removed some of the space transportation burden from the Shuttle's back since the other international partners were to contribute their own rocket. However, ISS was also more challenging because its orbit had to be accessible to rockets launched from Russia's Baikonur spaceport at 45 degrees northern latitude. The greater ISS orbital inclination meant that the Shuttle's net payload was substantially reduced. NASA developed a new super lightweight aluminium-lithium propellant tank to boost the Shuttle's performance while gradually privatising Space Shuttle management to save money. The pressurised modules and about 70% of the hardware developed for the old Space Station Freedom project were adopted for the International Space Station.


1994 ISS1994 ISS - 1994 International Space Station - ISS Plan. Another view of the International Space Station. Technologically, ISS reversed the continuing trend (since 1986) toward a smaller and less capable Station. The new configuration reintroduced the US laboratory and node module into the design. ISS will have more science racks than Freedom and provide more power for experiments. The total mass in orbit is 370 metric tons, so the International Space Station weighs almost twice as much as Space Station Freedom.

Credit: NASA via Marcus Lindroos. 50,313 bytes. 574 x 480 pixels.


A major concern is whether the Americans will have the nerve to stay the course when inevitable mishaps occur. The station, like Mir, will require constant maintenance. It could not be shut down if America stopped shuttle flights for years as it did after the *Challenger* explosion. Russian engineers calculate that there is a 23% chance that the exposed Service Module will be punctured by orbital debris during the lifetime of the station. Although the alloy and type of construction there would contain any puncture within a 70x70-centimetre panel, they believe an impact on the American section would result in fractures propagating quickly across a 400x400-centimetre area, leading to explosive decompression, an uncontrollable spin and rapid break-up of the station. Fortunately the probability of such an impact is only 2%.


1993 ISS1993 ISS - 1993 International Space Station - ISS Plan. The International Space Station work distribution plan from 1999.

Credit: NASA via Marcus Lindroos. 73,682 bytes. 640 x 481 pixels.


No project better illustrates the roller coaster effect of inconsistent space policies than the International Space Station, which right now is being assembled by the American, European, Russian, Japanese and Canadian national space agencies. The Space Station program was started, at NASA's urging, by President Reagan in 1984. Reagan wanted to launch a major space project shortly before the elections, since it would create jobs in important states such as California, Texas and Florida. He also wanted to invite other NATO countries to participate in the U.S-led project, since the Soviet Union had been launching international crews to their Salyut space stations since 1971. The new American station would of course be bigger and better, sending a clear signal to the world about American leadership and dominance in space. However, the space station was also going to tie the emerging European and Japanese national space programs closer to the U.S.-led project, thereby preventing those nations from becoming major, independent competitors too. Commercial space was booming and competition from other Western nations had become a major worry for the U.S. aerospace industry. There was considerable commercial interest in the Space Shuttle, and some market analysts felt a space station could be economically important as a research lab or manufacturing centre. The Reagan Administration generally extolled the virtues of free enterprise and small business, and the space station was regarded as an important market for private space investors.

NASA -- the National Aeronautics and Space Administration -- had its own institutional reasons for wanting a large space station. After the Apollo lunar landings in the late 1960s, the agency had fallen on hard times in the 1970s when the space budget was drastically reduced due to the high cost of the Vietnam War and social programs. NASA was barely able to secure funding for the Space Shuttle in 1972 as Apollo was cancelled. The space agency then had to exist on a virtual shoestring budget throughout the 1970s while struggling to complete the Shuttle development program. But the new Shuttle Transportation System (STS) turned out to be more expensive than expected when it finally became operational in 1982. STS was also unpopular with the Reagan Administration, who disliked the idea of having NASA rather than private industry run a 'national spaceline.' The senior NASA managers thus wanted another program to complement the Shuttle; something that would 'give STS something to do' while showcasing its versatility and usefulness. At the same time, the new project was going to provide much-needed employment for as many NASA centres and aerospace contractors as possible. NASA had been unable to afford hiring new employees for much of the 1970s, and it was hoped that a large space station would persuade more young engineers to join the agency.


1995 ISS Diagram1995 ISS Diagram - 1995 International Space Station - ISS Plan.

Credit: NASA via Marcus Lindroos. 12,745 bytes. 559 x 397 pixels.


Article by Marcus Lindroos
Specification

Electrical System: Solar panels.


International Space Station Chronology


01 February 1985 DOS-8 structure completed.

DOS-8 serial number 128 was originally designed as the backup to Mir and possibly the core module of Mir-2.


01 October 1986 DOS-8 major equipment installaton complete.

DOS-8 serial number 128 was originally designed as the backup to Mir and possibly the core module of Mir-2.


14 December 1987 Mir-2 draft project approved

The draft project for this greatly expanded station was approved by NPO Energia Chief Semenov on 14 December 1987 and announced to the press as 'Mir-2' in January 1988. The station would be built in a 65 degree orbit and consist mainly of enormous 90 tonne modules. But the first launch, as always, was the DOS 8. Assembly of the station was expected to begin in 1993.



Venturestar/ISSVenturestar/ISS - Venturestar docks to ISS, 1994 Concept. Lockheed-Martin's "Aeroballistic Rocket" spaceplane -- now called Venturestar -- docks with the Space Station. This 1994 illustration shows what the "Alpha" International Space Station would look like, without Russian modules.

Credit: NASA via Marcus Lindroos. 38,635 bytes. 640 x 480 pixels.


24 November 1992 Council of Chief Designers review revised Mir-2 design

With abandonment of the Buran shuttle and 37K modules, the Mir-2 design was cut back again. Mir-2 returned to its original planned 65 degree orbit, and would be assembled and flown separately from Mir. It would now consist of the DOS-8 core module, and a cross beam called the NEP (scientific-energy platform). This was equipped with equipment already proven on Mir: MSB retractable solar panels, Sfora thruster packages, small scientific packages as demonstrated on Kvant.The add-on modules now used the Progress-M service module as a tug, and were reduced in size for launch by either the Soyuz or Zenit launch vehicles.



American ISS SegmentAmerican ISS Segment - Space Transportation & American ISS Segment. Interior of the US laboratory module. The pressurized modules and about 70% of the hardware developed for the old Space Station Freedom project will be adopted for the International Space Station as well.

Credit: NASA via Marcus Lindroos. 42,227 bytes. 632 x 399 pixels.


01 November 1993 International Space Station

Cost escalation of the US Space Station Freedom, and financial difficulties in Russia, led to a summer 1993 briefing of NASA by NPO Energia on Mir-2. In November 1993 Freedom, Mir-2, and the European and Japanese modules were incorporated into a single International Space Station.


01 January 1995 X-38 development authorised.

When doubts about the availability of Soyuz developed in 1995, NASA proceeded with development of the X-38, a NASA Johnson concept - a smaller version of the X-24 lifting body with a parafoil.


01 June 1996 Soyuz TMA, X-38 selected as ISS lifeboat over Alpha Lifeboat


ISS ZaryaISS Zarya

Credit: NASA via Marcus Lindroos. 42,328 bytes. 567 x 300 pixels.


The Alpha lifeboat was based on the Zarya reentry vehicle with a solid retrofire motor and cold gas thruster package. The design was rejected in favor of use of modified Soyuz TM in short term, US X-38 in long term.
01 January 1998 Zarya FGB delivered to Baikonur

The U.S.-funded and Russian-built Zarya was a U.S. component of the International Space Station.


29 October 1998 Unity Program: ISS. Launch Site: Cape Canaveral . Launch Vehicle: Shuttle.
20 November 1998 Zarya Program: ISS. Launch Site: Baikonur . Launch Vehicle: Proton 8K82K. Perigee: 397 km. Apogee: 402 km. Inclination: 51.6 deg.


European ISS ContribEuropean ISS Contrib - Other European ISS Contributions. ESA will also contribute two Node modules worth $115 million free of charge, in return for receiving a "free" Space Shuttle flight from the Americans to launch the Columbus Orbiting Facility (COF).

Credit: ESA via Marcus Lindroos. 27,852 bytes. 640 x 384 pixels.


This was the first launch in the assembly of the International Space Station. The Zarya FGB was funded by NASA and built by Khrunichev in Moscow under subcontract from Boeing for NASA. Its design from the TKS military station resupply spacecraft of the 1970ís and the later 77KS Mir modules. Zarya included a multiple docking adapter, a pressurised cabin section, and a propulsion/instrument section with a rear docking port. Initial orbit was 176 lm x 343 km x 51.6 degrees. By November 25 it had manoeuvred to a 383 km x 396 km x 51.7 degree orbit, awaiting the launch of Shuttle mission STS-88 which docked the Unity node to it.
07 December 1998 EVA STS-88-1 Program: ISS. Flight Crew: Ross, Newman.


NASA Manned BudgetNASA Manned Budget - NASA Manned Spaceflight Budget 1975-2004

Credit: Marcus Lindroos. 8,912 bytes. 724 x 556 pixels.


Began assembly of International Space Station. Connected cables between Zarya and Unity modules.
09 December 1998 EVA STS-88-2 Program: ISS. Flight Crew: Ross, Newman.

Continued assembly of International Space Station. Connected cables between Zarya and Unity modules and deployed antennae.


12 December 1998 EVA STS-88-3 Program: ISS. Flight Crew: Ross, Newman.

Completed initial assembly of International Space Station. A canvas tool bag was attached to the exterior of Unity to provide tools for future assembly workers. Also disconnected some docking cables, so that Unity and Zarya could no longer undock.



ISSISS

Credit: NASA via Marcus Lindroos. 11,653 bytes. 512 x 359 pixels.


30 May 1999 EVA STS-96-1 Program: ISS. Flight Crew: Jernigan, Barry.

On May 30 at 02:56 GMT Tammy Jernigan and Dan Barry entered the payload bay of space shuttle Discovery from the tunnel adapter hatch. During the space walk they transferred equipment to the exterior of the station.


22 May 2000 EVA STS-101-1 Program: ISS. Flight Crew: Williams Jeffrey, Voss.

The crew reattached the US crane, attached the Russian Strela transfer boom, and replaced a faulty antenna on the Unity node. EVA handrails were fixed to the station exterior for use on later spacewalks.



ISSISS

Credit: NASA via Marcus Lindroos. 26,634 bytes. 640 x 273 pixels.


12 July 2000 Zvezda Launch Site: Baikonur . Launch Vehicle: Proton 8K82K. Perigee: 179 km. Apogee: 332 km. Inclination: 51.6 deg.

Years behind schedule, the Zvezda living module of the International Space Station, built and financed by Russia, finally reached orbit. Zvezda's initial orbit was 179 x 332 km x 51.6 deg. On July 14 the orbit was raised to 288 x 357 km. ISS was then in a 365 x 372 km orbit. After matching orbits with the ISS, Zvezda then became the passive docking target for the Russian-built, US-financed Zarya module already attached to the station. The Zarya/Unity stack docked with the Zvezda module at 00:45 GMT on July 26, forming the basic core of the International Space Station. A flood of NASA missions would follow to bring the station into operation.



Space Station CostSpace Station Cost - Annual Cost to first Assembly Flight of the Various US Station Programs. Perhaps the most controversial aspect of the Space Station project has been its costand the project's opponents and proponents frequently cite various figures to backup their claims. Here is a quick summary of what the project has cost so far.

Credit: NASA via Marcus Lindroos. 8,518 bytes. 640 x 438 pixels.


10 September 2000 EVA STS-106-1 Program: ISS. Flight Crew: Lu, Malenchenko.

Astronauts Lu and Malenchenko made a spacewalk on September 11 beginning at 04:47 GMT. They rode the RMS arm up to Zvezda and began installing cables, reaching a distance of 30 meters from the airlock when installing Zvezda's magnetometer.


15 October 2000 EVA STS-92-1 Program: ISS. Flight Crew: McArthur, Chiao.

The astronauts connected cables between Z1 and Unity, relocated the SASA S-band antenna on Z1, and deployed Z1's SGANT Ku-band antenna. They then took the port ETSD (EVA stowage) box from the Spacelab pallet and installed it on Z1.



Space Station CostSpace Station Cost - Space Station - What Does It Cost?. Today, it appears the huge cost of the Space Shuttle (STS) and Space Station (ISS) programswill prevent NASA from doing any other manned space projects such as lunar or Mars missions.The U.S. space budget has been fairly constant since the mid-1970s and is not expected tochange in the foreseeable future.

Credit: Marcus Lindroos. 10,941 bytes. 640 x 437 pixels.


16 October 2000 EVA STS-92-2 Program: ISS. Flight Crew: Wisoff, Lopez-Alegria.

Wakata aboard the shuttle used the RMS arm to unberth the PMA-3 docking unit from the SLP pallet at 16:14 GMT, and docked it to Unity at 17:40 GMT. Wisoff and Lopez-Alegria first unbolted PMA-3 from the SLP and then guided Wakata through the delicate alignment process as PMA-3 was removed from the bay and attached to the Station.


17 October 2000 EVA STS-92-3 Program: ISS. Flight Crew: McArthur, Chiao.


AlphaAlpha

Credit: NASA via Marcus Lindroos. 78,816 bytes. 631 x 477 pixels.


The astronauts installed two 58 kg DDCU DC-to-DC converter units atop the International Space Station's Z1 Truss. The DDCUs, will convert electricity generated by the solar arrays to be attached during the next shuttle mission. The spacewalkers also completed power cable connections on both the Z1 truss and newly installed docking port, PMA-3. They connected and reconfigured cables to route power from Pressurised Mating Adapter-2 to PMA-3 for the arrival of Endeavour and the STS-97 crew next month. They also attached a second tool storage box on the Z1 truss, providing a place to hold the tools and spacewalking aids for future assembly flights. McArthur stocked the boxes with tools and hardware that had been attached to the Unity module. STS-96 Astronauts Tammy Jernigan and Dan Barry had left the tools on the outside of Unity during a May 1999 spacewalk.

AlphaAlpha

Credit: NASA via Marcus Lindroos. 6,474 bytes. 432 x 359 pixels.


18 October 2000 EVA STS-92-4 Program: ISS. Flight Crew: Wisoff, Lopez-Alegria.

Jeff Wisoff and Mike Lopez-Alegria each jetted slowly through space above Discovery's cargo bay, demonstrating the small rescue nitrogen powered SAFER backpack (Simplified Aid for EVA Rescue). This would be used in the future to help a drifting astronaut regain the safety of the spacecraft. Each astronaut performed one 15 meter flight with the SAFER while attached to the shuttle with a long tether. Lopez-Alegria and Wisoff, with Koichi Wakata operating the arm, also completed a series of wrap-up tasks during the EVA. They removed a grapple fixture from the Z1 truss, opened and closed a latch assembly that will hold the solar array truss when it arrives, deployed a tray that will be used to provide power to the U.S. Laboratory Destiny, and tested the manual berthing mechanism latches that will support Destiny. Wisoff opened and closed the latches on the capture assembly for the P6 solar arrays using a pistol grip tool. With it he made more than 125 turns to open the latches, then closed and reopened them. He left the capture latch, called 'the claw,' ready to receive the solar arrays, to be installed by the STS-97 crew. An exercise to test techniques for returning an incapacitated astronaut to the air lock was cancelled because of time constraints.



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Last update 12 March 2001.
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