SKYLAB OPERATIONS SUMMARY The Skylab space station was launched May 14, 1973, from the NASA Kennedy Space Center by a huge Saturn V launch vehicle, the moon rocket of the Apollo Space Program. Sixty-three seconds after liftoff, the meteoroid shield--designed also to shade Skylab's workshop--deployed inadvertently. It was torn from the space station by atmospheric drag. This event and its effects started a ten-day period in which Skylab was beset with problems that had to be conquered before the space station would be safe and habitable for the three manned periods of its planned eight-month mission. When the meteoroid shield ripped loose, it disturbed the mounting of workshop solar array "wing" two and caused it to partially deploy. The exhaust plume of the second stage retro-rockets impacted the partially deployed solar array and literally blew it into space. Also, a strap of debris from the meteoroid shield overlapped solar array "wing" number one such that when the programmed deployment signal occurred, wing number one was held in a slightly opened position where it was able to generate virtually no power. In the meantime, the space station had achieved a near-circular orbit at the desired altitude of 435 kilometers (270 miles). All other major functions including payload shroud jettison, deployment of the Apollo Telescope Mount (Skylab's solar observatory) and its solar arrays, and pressurization of the space station occurred as planned. Scientists, engineers, astronauts, and management personnel at the NASA Marshall Space Flight Center and elsewhere worked throughout the first ten-day period of Skylab's flight to devise the means for its rescue. Simultaneously, Skylab--seriously overheating--was maneuvered through varying nose-up attitudes that would best maintain an acceptable "holding" condition. During that ten-day period and for some time thereafter, the space station operated on less than half of its designed electrical system, in the partially nose-up attitudes, was generating power at reduced efficiency. The optimum condition that maintained the most favorable balance between Skylab temperatures and its power generation capability occurred at approximately 50 degrees nose-up. Skylab's achievements are a summary of the accomplishments of many ground-based persons as well as its three separate crews who were launched in Apollo-type command modules by Saturn IB vehicles on May 25, July 28, and November 16, 1973. In Skylab, both the man-hours in space and the man-hours spent in performance of extravehicular activities (EVA) under micro-gravity conditions exceeded the combined totals of all of the world's previous space flights up to that time. By deploying the parasol-type sun shield through Skylab's solar scientific airlock and later releasing workshop solar array wing number one during EVA, the first crew made the remainder of the mission possible. The second crew, also during EVA, erected another sun shield, a twin-pole device. The effectiveness of Skylab crews exceeded expectations, especially in their ability to perform complex repair tasks. They demonstrated excellent mobility, both internal and external to the space station, showing man to be a positive asset in conducting research from space. By selecting and photographing targets of opportunity on the Sun, and by evaluating weather conditions on Earth and recommending Earth Resources opportunities, crewmen were instrumental in attaining extremely high quality solar and Earth oriented data. All three crews demonstrated technical skills for scientific, operational, and maintenance functions. Their manual control of the space station, their fine pointing of experiments, and their reasoning and judgment throughout the manned periods were highly effective. The capability to conduct longer manned missions was conclusively demonstrated in Skylab, first by the crew returning from the 28 day mission and, more forcefully, by the good health and physical condition of the second and third Skylab crews who stayed in weightless space for 59 and 84 days respectively. Also, resupply of space vehicles was attempted for the first time in Skylab and was proven to be effective. During their time in space, all three crews exceeded the operational and experimental requirements placed upon them by the pre-mission flight plan and schedule. In addition, the third crew performed a number of sightings of Comet Kohoutek which were not initially scheduled. 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. However, in the fall of 1977, it was determined that Skylab was no longer in a stable attitude as a result of greater than predicted solar activity. On July 11, 1979, Skylab impacted the Earth surface. The debris dispersion area stretched from the Southeastern Indian Ocean across a sparsely populated section of Western Australia. ====================================================================== SKYLAB SUMMARY SL-1 SL-2 SL-3 SL-4 LAUNCH 05-14-73 05-25-73 07-28-73 11-16-73 1:30PM EDT 9:00AM EDT 7:11AM EDT 9:01AM EST LAUNCH VEHICLES SATURN V SATURN IB SATURN IB SATURN IB ORBITAL PARAMETERS 268.1 x 269.5 Miles ORBITAL INCLINATION 50 Degrees ORBITAL PERIOD APP. 93 MINUTES DISTANCE/ ORBIT 26,575 MILES DISTANCE TRAVELED/Miles SL-2 SL-3 SL-4 TOTALS (MANNED) 11.5 Million 24.5 Million 34.5 Million 70.5 Million Miles MISSION DURATION 28 DAYS 59 DAYS 84 DAYS 171 DAYS 49 MIN 11 HRS 9 MIN 01 HR 16 MIN 13 HRS 14 MIN NUMBER OF REVOLUTIONS (MANNED) 404 858 1214 2476 ______________________________________________________________________ SKYLAB CREWS SL-2 DURATION COMMANDER Charles Conrad May 25 1973 - June 22 1973 PILOT Paul J. Weitz SCIENTIST PILOT Joseph Kerwin 28 days SL-3 COMMANDER Alan L. Bean July 28 1973 - Sep 25 1973 PILOT Jack R. Lousma SCIENTIST PILOT Owen Garriott 59 days SL-4 COMMANDER Gerald P. Carr Nov 16 1973 - Feb 08 1974 PILOT William R. Pogue SCIENTIST PILOT Edward Gibson 84 days ______________________________________________________________________ ====================================================================== SKYLAB SUMMARY continued Skylab-2 MANHOUR UTILIZATION MEDICAL ACTIVITIES 145.3 HOURS 7.5 PERCENT SOLAR OBSERVATIONS 117.2 " 6.0 " EARTH RESOURCES 71.4 " 3.7 " OTHER EXPERIMENTS 65.4 " 3.4 " SLEEP, REST & OFF DUTY 675.6 " 34.7 " PRE/POST SLEEP & EATING 477.1 " 24.5 " HOUSEKEEPING 103.6 " 5.3 " PHYSICAL TRAINING & PERSONAL HYGIENE 56.2 " 2.9 " OTHER (EVA) ETC 232.5 " 12.0 " TOTAL: 1944.3 " 100 " Skylab-3 MEDICAL ACTIVITIES 312.5 " 8.0 " SOLAR OBSERVATIONS 305.1 " 7.8 " EARTH RESOURCES 223.5 " 5.7 " OTHER EXPERIMENTS 243.6 " 6.2 " SLEEP, REST & OFF DUTY 1224.5 " 31.2 " PRE/POST SLEEP & EATING 975.7 " 24.8 " HOUSEKEEPING 158.4 " 4.0 " PHYSICAL TRAINING & PERSONAL HYGIENE 202.2 " 5.2 " OTHER (EVA) ETC 279.7 " 7.1 " TOTAL: 3925.2 " 100 " Skylab-4 MEDICAL ACTIVITIES 366.7 " 6.1 " SOLAR OBSERVATIONS 519.0 " 8.5 " EARTH RESOURCES 274.5 " 4.5 " OTHER EXPERIMENTS 403.0 " 6.7 " SLEEP, REST & OFF DUTY 1846.5 " 30.5 " PRE/POST SLEEP & EATING 1384.0 " 23.0 " HOUSEKEEPING 298.9 " 4.9 " PHYSICAL TRAINING & PERSONAL HYGIENE 384.5 " 6.4 " OTHER (EVA) ETC 571.4 " 9.4 " TOTAL: 6048.5 " 100 " Skylab TOTALS FOR SL-2, SL-3 AND SL-4 MEDICAL ACTIVITIES 824.5 " 6.9 " SOLAR RESOURCES 941.3 " 7.9 " EARTH RESOURCES 569.4 " 4.8 " OTHER EXPERIMENTS 712.0 " 6.0 " SLEEP, REST & OFF DUTY 3746.6 " 31.5 " PRE/POST SLEEP & EATING 2836.8 " 23.8 " HOUSEKEEPING 560.9 " 4.7 " PHYSICAL TRAINING & PERSONAL HYGIENE 642.9 " 5.4 " OTHER (EVA) ETC 1083.6 " 9.0 " TOTAL: 11918.0 " 100 " ====================================================================== EXPERIMENT PERFORMANCE SL-2 SL-3 SL-4 TOTALS HOURS % HOURS % HOURS % HOURS % SOLAR ASTRONOMY 117.2 29.9 305.1 28.2 519.0 33.2 941.3 31.0 EARTH OBSERVATIONS 71.4 18.2 223.5 20.6 274.5 17.6 569.4 18.8 STUDENT 3.7 0.9 10.8 1.0 14.8 0.9 29.3 0.9 ASTROPHYSICS 36.6 9.4 103.8 9.6 133.8 8.5 274.2 9.0 MAN/SYSTEMS 12.1 3.1 117.4 10.8 83.0 5.3 212.5 7.0 MATERIALS SCIENCE 5.9 1.5 8.4 0.8 15.4 1.0 29.7 1.0 LIFE SCIENCE 145.3 37.0 312.5 29.0 366.7 23.5 824.5 27.2 KOHOUTEK ----- ---- ----- ---- 156.0 10.0 156.0 5.1 TOTALS 392.2 100 1081.5 100 1563.2 100 3036.9 100 ====================================================================== EXTRAVEHICULAR ACTIVITIES SL-2 SL-3 SL-4 STAND UP EVA 05-25-73 33 MIN EVA 1 06-07-73 08-06-73 11-22-73 4 HRS 10 MIN 6 HRS 31 MIN 6 HRS 33 MIN EVA 2 06-19-73 08-24-73 12-25-73 1 HR 37 MIN 4 HRS 30 MIN 6 HRS 51 MIN EVA 3 09-22-73 12-29-73 2 HRS 42 MIN 3 HRS 30 MIN EVA 4 02-03-74 5 HRS 19 MIN TOTALS: 6 HRS 20 MIN 13 HRS 43 MIN 22 HRS 13 MIN TOTAL TIME: 41 HRS 22 MIN ====================================================================== DATE RETURNED SL-2 SL-3 SL-4 TOTALS SOLAR OBSERVATIONS 28739 FRAMES 74942 FRMS 73366 FRMS 177047 FRMS EARTH OBSERVATIONS FILM 9846 FRAMES 16800 FRMS 19400 FRMS 46146 FRMS MAGNETIC TAPE 45000 FT 93600 FT 100000 FT 238600 FT ====================================================================== SKYLAB SUMMARY (CONCLUDED) EXPERIMENT SUMMARY PLANNED ACTUAL PERCENT DEVIATION Earth Observation Passes 62 99 + 60 % Solar Viewing Time 566 hrs 724.7 hrs + 27.5 % Manned Solar Viewing Time 879.5 hrs 941.3 hrs + 7.1 % Biomedical Investigations 701 922 + 32 % Engineering/Tech Inves. 264 245 - 3.4 % Materials/Space Manuf. Inves. 10 32 +220 % Astrophysics Investigations 168 345 +105 % Student Exp. Investigations 44 52 + 18 % Science Demonstrations 26 11 - 42 % (OPTIONAL SL-4 ONLY) CONSUMABLE UTILIZATION LAUNCH END OF MISSION CONSUMABLES USED Water 6000 LBS 1710 LBS 4290 LBS Oxygen 6100 LBS 2764 LBS 3336 LBS Nitrogen 1540 LBS 607 LBS 933 LBS TACS 80000 LBS-SEC 12488 LBS 67512 LBS-SEC* * Over 12% of the TACS were used during the first 10 days of the mission MISSION ACHIEVEMENTS SL-2 FIRST MISSION INSTALLED SOLAR SHIELD "PARASOL" FROM SCIENTIFIC AIRLOCK RELEASED SOLAR ARRAY WING ON EVA DOUBLED PREVIOUS LENGTH OF TIME IN SPACE SL-3 SECOND MISSION INSTALLED TWINPOLE SOLAR SHIELD ON EVA PERFORMED MAJOR INFLIGHT MAINTENANCE DOUBLED PREVIOUS LENGTH OF TIME IN SPACE SL-4 THIRD MISSION OBSERVED AND PHOTOGRAPHED COMET KOHOUTEK INCREASED PREVIOUS LENGTH OF TIME IN SPACE BY ABOUT 50% --- SKYLAB OPERATIONS SUMMARY, PAO MSFC/NASA