Skylab 3
From The Space Library
July 28-September 25 The Skylab 3 Apollo spacecraft carrying a three-man crew was launched into near-earth orbit, rendezvoused with the Skylab 1 Orbital Workshop (launched May 14), and docked with the space laboratory for the second manned mission in the Skylab program. A series of problems threatened to disrupt the mission, but corrective actions and workarounds permitted it to proceed successfully, setting new manned flight records. The astronauts collected significant data in medical experiments, solar astronomy, and earth resources surveys for 59 days before undocking for a safe return to earth Sept. 25.
July 28-31: Skylab 3 (SL-3) lifted off on time at 7:11 am EDT from Kennedy Space Center Launch Complex 39, Pad B, on a two-stage Saturn IB launch vehicle, watched by some 100 000 persons on Florida beaches and at KSC, as well as by U.S. and foreign TV viewers. The 14168-kg (31 234-lb) Apollo command and service module (CSM-117) and its crew-Alan L. Bean (commander), Jack R. Lousma (pilot), and Dr. Owen K. Garriott (science pilot)-soared through ground fog into broken clouds. The CSM/S-IVB combination was placed in a phasing orbit with 224-km (139.2-mi) apogee and 150-km (93.2-mi) perigee at 10 min 2 sec after launch. Eight minutes later the CSM separated from the stage as planned. The galactic x-ray mapping experiment mounted in the instrument unit (IU) was deployed. At 5 hrs 19 min 53 sec after launch the S-IVB/IU deorbit maneuver was commanded, and the stage impacted the predicted Pacific Ocean area after planned maneuvers. During CSM maneuvers to rendezvous with the Workshop, a leak was detected in the CSM reaction control system (RCS) quad B thruster, one of four assemblies of rockets used to stabilize the spacecraft or to change its velocity and also used as a backup for bringing the CSM back from orbit. Analysis indicated the oxidizer valve was stuck open or partially open. Quad B was isolated; analysis showed that all deorbit mission rules could be satisfied. The CSM rendezvoused with the Workshop at 3:38 pm EDT on the fifth orbit. Rendezvous, fly-around, and docking were covered by 23 min of TV. The crew entered the multiple docking adapter (MDA) at 4:00 pm EDT and began Workshop activation, but activation was curtailed because the crew quickly began to feel motion sickness. Lousma was experiencing nausea and Bean and Garriott were uncomfortable. Bean said he and Garriott tended "to be fairly careful of how we move. And since we are moving rather slowly, then it's taking a little bit longer than we'd planned."
Motion sickness continued the second day, July 29, and the astronauts were taking scopolamine-dexedrine tablets. Bean communicated, "We feel okay, except in the stomach. . . . And our thinking is that we're not going to be able to work much faster than we are right now. . . . There's a desire to maybe take a break for an hour or two and get in the bunk and stay still for a while." Flight Director Neil B. Hutchinson told the press at JSC that extravehicular activity (Eva) to install a new sun shield and retrieve and install Apollo Telescope Mount (ATM) film probably would be delayed from July 31 to Aug. 1 at the earliest. Four to five hours of work were carried over from July 28 and 29. Still suffering from motion sickness, the astronauts continued Work-shop activation July 30 (Mission Day 3).
The first EVA was delayed to Aug. 2 and later rescheduled to Aug. 4 to ensure the astronauts' complete recovery. Activation was completed July 31 (MD-4) and research began as the crew improved slightly. Bean told ground control: "We're getting better; it's just taking a little longer than we thought. . . . Everybody feels pretty good between meals. Then mealtime comes, and we're caught . . . in the squeeze. We're trying to decide whether we ought to eat all we have to . . . to keep our strength up, or eat about what we want to, which isn't very much." A TV broadcast from the space station July 31 showed minnows for a biomedical experiment swimming in their plastic aquarium in tight spirals and sometimes apparently trying to swim toward the surface, but with their heads pointed straight down. Garriott said, "Apparently they can't make up their minds which way is up and down, either." He also turned a spider named Arabella loose in a plastic cage to observe her web-spinning abilities in zero-g conditions. Later in the mission Garriott reported baby minnows hatched in space performed in water "as if they'd already adapted while they were still in the egg." They "felt right accustomed to zero-g."
August 1-September 24: Bean told ground controllers after break-fast Aug. 1 (MD-5) : "This is the first morning we've been up here . . . that after a meal everybody felt good. Everybody feels real good right now. Best since we've been here." During live TV the astronauts ate a hearty lunch to music. Bean demonstrated his proficiency in eating while hanging upside down. A medical briefing below at Johnson Space Center suggested that moving quickly from the confined CM to the large Workshop might have contributed to the motion sickness. The milder nausea experienced on the May 25-June 22 Skylab 2 mission could have been caused by a more gradual transition into the Workshop. "I think that it is merely a matter of room in which you can exercise your vestibular mechanisms, and that the workshop simply presents more of that space. . . . perhaps it was too much too soon."
On Aug. 2 a master alarm buzzer awakened the astronauts at 6:45 am EDT. Pressure and temperature were falling rapidly in the CSM reaction control system quad D because of an oxidizer leak. Because of quad B's July 28 leak, only A and C of the four quads remained fully operational. The quad D leak lasted two hours, losing an estimated 5 kg (12 lbs) of nitrogen tetroxide oxidizer. Apollo Flight Director Glynn S. Lunney said at a morning press briefing that the spacecraft was flyable with the loss of the two quads but "it would be flown in a mode which is not entirely standard." The main concern was "that we have had two problems which are related, at least they seem to be related." A flaw common to the whole RCS could necessitate the crew's immediate return to the earth or accelerated preparation of the Skylab 4 spacecraft to make it available as a rescue vehicle should the CSM become unusable. Full activation of Skylab-rescue-vehicle preparation was authorized. Launch and checkout crews began working a 24-hr-day, 7-day-week schedule, preparing two additional couches and other equipment for installation. Earliest possible date for a rescue mission was established as Sept. 5. The EVA rescheduled for Aug. 4 was again postponed, for 24 to 48 hours to free the crew for system checks, to free ground controllers to troubleshoot the problem, and to give time to work out EVA procedures for the new spacecraft configuration. While reentry procedures were being rewritten for the new configuration, the astronauts continued scientific experiments.
By the afternoon of Aug. 2 Dr. Christopher C. Kraft, Jr., JSC Director, was able to tell the astronauts that troubleshooting the RCS had indicated no apparent generic problem, but two unique quad failures, and there was now confidence that the two remaining quads would ensure attitude control should immediate reentry become necessary. "We're proceeding . . . as if we're going to have a normal mission." Astronaut Bean replied: "Fine. You just said the right words. . . . we're pretty happy with the way things are going, at the moment . . . and we agree 100 percent with what you just announced. . everybody's happy up here."
On Aug. 3 Skylab Program Director William C. Schneider said at a JSC press briefing that continuing investigation indicated the two quad failures were unrelated and reexamination of reentry capabilities showed three ways of returning to the earth: using the primary service propulsion system, using the RCS with the two operational quads, and using the hybrid RCS in the CM. "We're feeling considerably better than ... yesterday morning." A slowdown was ordered in the emergency rescue preparations. The Apollo CM would be outfitted in a Skylab 4 configuration, with three astronaut couches rather than the five needed for a rescue mission. The slowdown would delay rescue readiness until Sept. 10. Astronauts Bean, Garriott, and Lousma conducted their first full day of experiments and prepared for an earth resources experiment package pass. Garriott held the TV camera at the window to telecast a good view of the U.S. from North Dakota to North Carolina. Later the first of 26 EREP passes was made, to gather data for oil exploration, ocean temperatures, mapping, land use surveys, crop inventories, and pollution studies. A master alarm sounded in the CSM Aug. 4, later attributed to a short-circuit in Skylab's solar telescope system. The short knocked out one of the two TV systems in the ATM but did not affect Skylab's main power system. Ground crews investigated problems in the primary and secondary coolant systems Aug. 5. One had been slowly leaking since the Skylab 1 launch May 14 and was expected to become inoperative in 16 to 20 days. The secondary loop was thought to have a small leak, begun during the Skylab 2 mission and giving the loop a predicted 60-day lifetime. Possibly additional coolant would have to be carried up by the next manned mission, Skylab 4, but Program Director Schneider said there was "no immediate danger to the crew."
By Aug. 6 evaluations showed that only the primary loop was leaking; the second was sound and could operate for the rest of Skylab 3 as well as for Skylab 4. Flight surgeon Paul Buchanan's nightly bulletin said Aug. 5 that the crew "continues to report good health and optimistic outlook" and had asked about an increase in their menus "to match their growing appetites." Fluid intake and output was "optimal."
The first EVA was performed Aug. 6. Garriott and Lousma stepped outside the orbiting laboratory at 1:30 pm EDT to install the 3.6- by 7.3-m (12- by 24-ft), paper-thin, aluminized Mylar awning over the Workshop to reflect the sun's rays away from the spacecraft skin, damaged when the meteoroid shield was torn off during the May launch. Garriott, standing in the Skylab's open hatch, pieced together the two 16.8-m (55-ft) poles from metal sections and handed them to Lousma. Lousma attached them to a bracket to form a "V" over the Workshop. The sunshade was slowly pulled up by a system of pulleys. One rope kept twisting around the poles and the sunshade folds did not straighten immediately, but after four hours-twice the time expected-the sunshade was successfully deployed. Workshop temperatures were lowered before the EVA ended.
Astronaut Bean said Garriott and Lousma worked "at a slow and steady pace" and were not tired. Lousma retrieved and replaced film in four ATM experiments, installed two new cameras, removed a door latch from an ATM experiment, and fixed the particle-collection experiment to the rim of the ATM. Lousma also inspected the two leaking quads in the CSM RCS and looked for coolant leaks. He noted some evidence of micrometeorite pitting but no clues to causes of the malfunctions. The astronauts completed the EVA at 8:01 pm EDT, after 6 hrs 31 min, surpassing the 3-hr 30-min record set June 7 by Skylab 2 Astronauts Charles Conrad, Jr., and Dr. Joseph P. Kerwin. Garriott, first solar physicist in space, focused the ATM cameras on the sun Aug. 7 for the first time during the mission. TV audiences watched him work at the ATM panel.
By Aug. 8 Dr. Lawrence F. Dietlein, JSC Deputy Director for Life Sciences, reported the astronauts were "in excellent spirits and have no health problems." They had completely recovered from motion sickness. Their weights had stabilized after a loss of 1.8 to 2.3 kg (4 to 5 lbs) each. Data obtained on the rotating chair indicated their sensitivity to motion had lifted. Since deployment of the sunshade, temperatures in the Workshop had dropped to 296 K (74°F). The crew photographed a coronal transient with the ATM camera two hours Aug. 10. It was the first time a transient-protons and free electrons expelled violently from the sun's limb at a speed of about 312 km (194 mi) per sec, a phenomenon that occurred two or three times a year-had been observed at that range and time resolution.
Program Director Schneider announced Aug. 14 that Skylab 3 would continue its full 59-day mission. From analyses of the CSM and Work-shop, he had "concluded that there is no imminent need for rescue, and . . . we have made the decision to proceed with a normal test flow on an accelerated basis at Cape Kennedy." Skylab 4 was being pre-pared for a normal mission but would be available for a rescue mission if necessary. The earliest launch date could be Sept. 25. Schneider said, "We're reasonably confident that [CSM] 117 is a good vehicle." "Looks like they got a renewed burst of confidence down there," Bean said when told of the decision. "We feel that way up here." JSC announced Aug. 21 that the astronauts would install a new "six-pack" of gyroscopes during an Aug. 24 EVA, to replace faulty ones. The six-pack had been carried up on the Skylab 3 CM. Meanwhile the crew continued with experiments, requesting more work Aug. 14 because all had spare time and "you just can't sleep 8 hours up here." They photographed tropical storm Brenda Aug. 19 as it moved across the Yucatan Peninsula toward the Gulf of Mexico.
On Aug. 21 Astronaut Bean discovered and photographed through ATM telescopes what Skylab principal investigator Dr. Robert MacQueen called "certainly one of the biggest solar events" seen on the Skylab missions. Bean said the complex series of events on the solar limb looked "like a big bubble" sitting on the edge of the disc. He observed it with the white light coronagraph and x-ray instruments and reported it to be three fourths the size of the sun. NASA scientists alerted other facilities to make observations from ground instruments and other satellites. Dr. MacQueen said the event might have been caused by an explosion on the back side of the sun. "It was a beautiful event." The crew "did a fine job." Schneider announced Aug. 23 (MD-27) that the Skylab 3 crew had been given permission to continue the mission for another seven days. Dr. Willard R. Hawkins, JSC Deputy Director of Life Sciences for Medical Operations, told the press that he saw nothing in the medical data thus far "that would indicate that we could not press on with the mission, and . . . we feel we can go the full 59 days as planned."
EVA-2 began at 12:24 pm EDT Aug. 24 with AM depressurization by Lousma and Garriott. Lousma completed installation of the six redesigned gyros mounted inside the spacecraft by connecting cables to a computer system outside, and the new gyro system was put into operation. The astronauts installed a sail sample on a hand rail to test durability, replaced ATM film, retrieved and stored cassettes from one experiment, and removed the aperture door ramp latch from two ATM experiments, concluding EVA-2 at 4:31 pm EDT, after 4 hrs 30 min. At 8:01 am EDT Aug. 25 (MD-29) the Skylab 3 astronauts surpassed the single-mission endurance mark of 28 days 50 min set in June by Skylab 2. They had completed 404 earth orbits and had traveled 18.5 million km (11.5 million mi). And at 6:11 am EDT Sept. 5 (MD-40) Astronaut Bean surpassed the space flight record for one man of 49 days 3 hrs 38 min 36 sec, set in June by Charles Conrad, Jr., on Skylab 2. EVA-3 began at 7:18 am EDT Sept. 22. Bean and Garriott moved through space to retrieve and replace ATM film and retrieve experiments and parasol samples. EVA operations ended at 9:59 am EDT, after 2 hrs 41 min.
During the mission, spiders Arabella and Anita first spun webs in corners of their cage, without the normal circular pattern. Each day, however, each improved web formation, adding more radials, adjusting to weightlessness. Garriott said of Arabella Aug. 9 that "she learned very rapidly in zero-g without the benefit of any previous experience." She "figured out .a very nice solution to the problems of zero gravity." Later ground controllers told Garriott to share his filet mignon with the spiders to keep them alive for the entire mission. Anita, however, was found dead Sept. 16, possibly from inadequate diet.
September 24-25: The Workshop was deactivated and, on Sept. 25, the CSM powered up. The CSM undocked from the Workshop at 3:34 pm EDT, separating at 3:50. The service propulsion system engine made the deorbit maneuver at 5:38 pm EDT and the CM splashed down upside down at 6:20 pm EDT 400 km (250 mi) southwest of San Diego, Calif. The astronauts righted the CM and remained inside until the recovery ship U.S.S. New Orleans maneuvered alongside and a crane lifted the CM aboard. Immediate medical examinations found the crew in excellent spirits and surprisingly good condition. Blood pressures and heart rates were within normal range. The astronauts would remain aboard ship in San Diego for physical checks and would fly to Houston Sept. 26. They would be quarantined for one week.
The Skylab 3 mission achieved its primary objectives of performing unmanned Saturn Workshop operations, reactivating the Skylab orbital assembly in earth orbit, obtaining medical data for use in extending manned space flights, and performing inflight experiments. Despite mission problems, 150% of scheduled ATM observing time was accomplished and EREP sensors were operated on 39 Z-axis local vertical data runs and 5 solar inertial data runs, completing 218 of the 386 earth resources task sites. All medical experiments were successfully carried out. All but one of the corollary experiments achieved or exceeded objectives. Of 13 student experiments, 9 were completed. Added unscheduled tests and experiments had significantly increased the data yield above premission planning and Skylab was left in an excellent position to complete the final SL-4 mission. Skylab 3 was officially adjudged a success Oct. 11.
Major records set by the mission included the longest-duration manned space flight to date, 59 days 11 hrs 9 min; the longest cumulative time in space for one man, 69 days for Bean (who had spent 10 days on the Nov. 14-24, 1969, Apollo 12 mission) ; the longest distance in orbit for a manned mission, 41 000 000 km (25 500 000 mi) ; the longest EVA, 6 hrs 31 min on Aug. 6; and the longest cumulative orbital EVA time, for one astronaut, 13 hrs 40 min for Garriott. In the first mission to man the Orbital Workshop May 15-June 22, Skylab 2 astronauts had conducted medical, solar, and earth resources experiments for 28 days, as well as repairing the Workshop to salvage the mission. The Workshop would be operated unmanned until the November Skylab 4 launch for a third and final mission. (NASA prog off; JSC PAO press briefing transcripts, 7/28/73-9/25/73; NYT, 7/28/73-9/26/73; W Post, 7/28/73-9/26/73; W Star-News, 7/28/73-9/27/73 ; B Sun, 8/16/73, A5; 8/20/73, A3)
