First test launch of Army's Pershing tactical missile from Cape Canaveral. References: 17 .
McDonnell conducted a successful drop test, using a boilerplate spacecraft fitted with impact skirt, straps and cables, and a beryllium heat shield. During the tests the stainless steel straps were successfully stretched to design limits. References: 483 .
MSC and the David Clark Company reached an agreement on a contract for Apollo Block I space suits. The first suits, expected by July 1, would go to North American for testing. References: 16 .
Mars flyby 31 July 1969; returned 75 images of Martian surface. Ten days before the scheduled launch, a faulty switch opened the main valves on the Atlas stage. This released the pressure which supported the Atlas structure, and as the booster deflated it began to crumple. Two ground crewman started pressurizing pumps, saving the structure from further collapse. The two ground crewman, who had acted at risk of the 12-story rocket collapsing on them, were awarded Exceptional Bravery Medals from NASA.
The Mariner 6 spacecraft was removed, put on another Atlas/Centaur, and launched on schedule. The main booster was jettisoned 4 min. 38 sec. after launch, followed by a 7.5 minute Centaur burn to inject the spacecraft into Mars direct trajectory. After Mariner 6 separated from the Centaur the solar panels were deployed. A midcourse correction involving a 5.35 second burn of the hydrazine rocket occurred on 1 March 1969. A few days later explosive valves were deployed to unlatch the scan platform. Some bright particles released during the explosion distracted the Canopus sensor, and attitude lock was lost temporarily. It was decided to place the spacecraft on inertial guidance for the Mars flyby to prevent a similar occurrence.
On 29 July, 50 hours before closest approach, the scan platform was pointed to Mars and the scientific instruments turned on. Imaging of Mars began 2 hours later. For the next 41 hours, 49 approach images (plus a 50th fractional image) of Mars were taken through the narrow-angle camera. At 05:03 UT on 31 July the near-encounter phase began, including collection of 26 close-up images. Due to a cooling system failure, channel 1 of the IR spectrometer did not cool sufficiently to allow measurements from 6 to 14 micrometers so no infrared data were obtained over this range. Closest approach occurred at 05:19:07 UT at a distance of 3431 km from the martian surface. Eleven minutes later Mariner 6 passed behind Mars and reappeared after 25 minutes. X-band occultation data were taken during the entrance and exit phases. Science and imaging data were played back and transmitted over the next few days. The spacecraft was then returned to cruise mode which included engineering and communications tests, star photography TV tests, and UV scans of the Milky Way and an area containing comet 1969-B. Periodic tracking of the spacecraft in its heliocentric orbit was also done.
Mariner 6 returned 49 far encounter and 26 near encounter images of Mars. Close-ups from the near encounter phases covered 20% of the surface. The spacecraft instruments measured UV and IR emissions and radio refractivity of the Martian atmosphere. Images showed the surface of Mars to be very different from that of the Moon, in some contrast to the results from Mariner 4. The south polar cap was identified as being composed predominantly of carbon dioxide. Atmospheric surface pressure was estimated at between 6 and 7 mb. Radio science refined estimates of the mass, radius and shape of Mars. References: 1 , 2 , 5 , 6 , 278 , 296 .
Conduct third inert captive flight, Edwards (2 hours, 28 minutes), Enterprise (OV-101) References: 15 .
Manned two crew. Docked with Salyut 6. Transported a team consisting of V A Lyakhov and V V Ryumin to the Salyut-6 space station to conduct scientific investigations and experiments and repair work. Recovered June 15, 1979 16:18 GMT. Returned unmanned. References: 1 , 2 , 6 , 32 , 33 .
Time 19 minutes. References: 81 .
Test from shuttle of 20 km long tether; satellite unintentionally deployed when tether broke. Re-entered March 19.