STS-57 Space Shuttle Mission Report, NSTS-08285, August 1993, pp. 27-28; memo, Randall McDaniel to EVA Section personnel (STS -57 EVA debrief notes), August 13, 1993; "STS -57: EVA Lessons Learned," presentation materials, Richard Fullerton, July 9, 1992.
July 1
STS-57/Endeavour landing
July 1
Mir/Soyuz-TM 17 PE-14 launch
July 22
Mir/Soyuz-TM 16 PE-13 landing
September 12
STS-51/Discovery launch
September 16
1993 EVA 5
World EVA 111 U.S. EVA 60
Shuttle EVA 22
Duration: 7:05
Spacecraft/mission: STS-51
Crew: Frank Culbertson, William Readdy, James Newman, Daniel Bursch, Carl Walz Spacewalkers: James Newman, Carl Walz
Purpose: Test HST repair tools and procedures
Discovery's pilot, William Readdy, was IV crewmember; he helped Walz and Newman begin preparations for their EVA 30 min early. Immediately after leaving the airlock, they made a practice translation down the payload bay door sills. At the back of the bay Walz investigated damage caused by a pyrotechnic fastener malfunction in the Advanced Communications Technology Satellite payload. Walz found that the explosion had torn a hole in Discovery's aft payload bay bulkhead, but caused no damage to the payload bay doors or other equipment. He decided not to handle the debris because it might cut his gloves. The astronauts then commenced DTO 1210 and DTO 671 tests, tools for which were stored in the Provisional Stowage Assembly (PSA) compartment in the floor of Discovery's payload bay, next to the contingency payload bay door closure tools. Walz and Newman conducted a glove-warming evaluation using the payload bay lights, then tested tethers for high- and low-torque work and a Portable Foot Restraint (PFR) designed for HST SM-01. They also compared ground training with actual work on orbit. The astronauts reported that their WETF experience was more difficult than the actual EVA. The HST-related tests assured planners that ground preparations for the flight were on a sound footing. The astronauts accomplished more than planned and remained ahead of schedule until closeout, when a PSA door refused to close, so the EVA required 45 min more than scheduled. In their debriefing the crew stressed the importance of thermal vacuum tests as part of EVA testing and training.
STS-51 Space Shuttle Mission Report, NSTS-08286, December 1993, pp. 30-33; "Eleven Day Missions with EVA," Roelof Schuiling, Spaceflight, December 1993, pp. 425-426.
September 16
1993 EVA 6 World EVA 112 Russian EVA 52 Space Station EVA 60
Duration: 4:18
Spacecraft/mission: Mir PE-14
Crew: Vasili Tsibliyev, Alexandr Serebrov Spacewalkers: Vasili Tsibliyev, Alexandr Serebrov
Purpose: Prepare for Rapana truss assembly
The Soviet Union planned to follow Mir with Mir-2, a large station building on Mir/Salyut hardware and incorporating a large truss to support solar dynamic power generation systems and antennas. Mir-2 was to have been resupplied in part by the Buran space shuttle, as well as advanced automated cargo vehicles based on Progress-M. The collapse of the Soviet Union in 1991 scuttled these plans, but paved the way for merging Mir-2 and SSF into one International Space Station (ISS). This EVA is often identified as Mir-2-related. Tsibliyev and Serebrov moved equipment from Kvant 2 to Kvant using Strela. They installed a "grate," then attached a platform behind Sofora. They then moved the container holding the Rapana truss to the attachment site and linked it to Mir's electrical system.
MirNews 187, Chris Vandenberg, September 17, 1993; MirNews 188, Chris Vandenberg, September 20, 1993; "Mir Spacewalks," Spaceflight, November 1993, p. 371; "Mir Mission Report," Neville Kidger, Spaceflight, May, 1994, p. 154.
September 20
1993 EVA 7 World EVA 113 Russian EVA 53 Space Station EVA 61
Duration: 3:13
Spacecraft/mission: Mir PE-14
Crew: Vasili Tsibliyev, Alexandr Serebrov Spacewalkers: Vasili Tsibliyev, Alexandr Serebrov
Purpose: Rapana truss assembly experiment
This was the thirtieth EVA using Orlan-DMA space suits. Tsibliyev and Serebrov returned to the Kvant module to assemble the Rapana truss, a 26-kg (57.2-lb) cylindrical framework with memory alloy joints akin to those in Sofora. They expanded when heated, causing Rapana to unfold from its container. Extension to a length of 5 m (16.4 ft) required just 3 min. The truss was scheduled for analysis after 10 mo on Mir's exterior. The cosmonauts installed space exposure samples on Rapana before closing out the EVA.
MirNews 188, Chris Vandenberg, September 20, 1993; "Mir Spacewalks," Spaceflight, November 1993, p. 371; "Mir Mission Report," Neville Kidger, Spaceflight, May, 1994, p. 154.
September 22
STS-51/Discovery landing
September 28
1993 EVA 8 World EVA 114 Russian EVA 54 Space Station EVA 62
Duration: 1:52
Spacecraft/mission: Mir PE-14
Crew: Vasili Tsibliyev, Alexandr Serebrov Spacewalkers: Vasili Tsibliyev, Alexandr Serebrov
Purpose: Inspect Mir's exterior (Panorama survey)
This EVA was the first connected with new U.S.-Russian cooperation in space. Originally scheduled for September 24, it was put back four days on September 22, possibly because of a SALC fault—on the day the delay was announced, the cosmonauts were reported to be repairing a pressure valve in Kvant 2. The primary objective of the EVA was the Panorama survey, a detailed inspection of Mir's exterior designed to provide Russian, U.S., and European engineers with assurance that Mir remained in good shape to support ambitious joint space projects after 7 yr in space. Panorama was also designed to assess damage caused by the intense Perseid meteor storm of August 1993. The EVA was planned to last more than 4 hr, but had to be cut short when Tsibliyev's suit cooling system failed. He stayed near the Kvant 2 airlock while Serebrov collected TREK experiment detector plates and videotaped and photographed Mir's exterior from Kvant 2. Serebrov, the first cosmonaut to test the SPK maneuvering device (1990), said later that the SPK should have been used for Panorama. On October 8, the Russians announced that an EVA to complete Panorama and perform other tasks would occur on October 22. They also announced that PE-14 would be extended because of problems in obtaining Soyuz booster engines to launch a replacement crew.
MirNews 189, Chris Vandenberg, September 22, 1993; MirNews 190, Chris Vandeberg, September 28, 1993; "Mir Mission Report," Neville Kidger, Spaceflight, May, 1994, p. 154.
October 22
1993 EVA 9 World EVA 115 Russian EVA 55 Space Station EVA 63
Duration: 0:38
Spacecraft/mission: Mir PE-14
Crew: Vasili Tsibliyev, Alexandr Serebrov Spacewalkers: Vasili Tsibliyev, Alexandr Serebrov
Purpose: Inspect Mir's exterior (Panorama survey); miscellaneous tasks
With this EVA, scheduled to last 5 hr, Serebrov matched the old record for most career EVAs (9) held jointly by Leonid Kizim and Vladimir Solovyov since 1986. However, the EVA had to be terminated almost as it started because of a problem in the oxygen flow system of his Orlan-DMA suit, which had been worn 13 times by different cosmonauts and had exceeded its recommended operational lifetime. Before going inside the cosmonauts inspected and collected space exposure experiments, installed meteoroid detectors, and spoke with Russian Prime Minister Viktor Chernomyrdin, who was visiting the TsUP. They also snapped a few photos for the Panorama survey, but a third EVA had to be scheduled to complete the task.
MirNews 195, Chris Vandenberg, October 23, 1993; "Mir Mission Report," Neville Kidger, Spaceflight, May, 1994, p. 154; "The Experience in Operation and Improving the Orlan-type Space Suits," I. P. Abramov, Acta Astronautica, Vol. 36, No. 1, July 1995, pp. 1-12.
October 29
1993 EVA 10 World EVA 116 Russian EVA 56 Space Station EVA 64
Duration: 4:12
Spacecraft/mission: Mir PE-14
Crew: Vasili Tsibliyev, Alexandr Serebrov Spacewalkers: Vasili Tsibliyev, Alexandr Serebrov
Purpose: Inspect Mir's exterior (Panorama survey); miscellaneous tasks
After two EVAs cut short by space suit problems, Tsibliyev and Serebrov at last completed the Panorama survey of Mir's exterior. They filmed Mir's main Altair/Luch geostationary satellite system communication antenna and the solar arrays. Then they inspected Sofora's mount and attached another space exposure cassette to Mir's exterior. The cosmonauts watched a piece of metal of undetermined origin drift past. Serebrov set a new career record for most EVAs (10), but Sergei Krikalev's record for most time spent in EVA (36 hr, 29 min) remained intact. The cosmonauts tossed the Orlan-DMA suit that gave trouble on the last EVA out the Kvant 2 hatch after rigging it so it appeared to be saluting. Analysis of the Panorama photos and videotape showed Mir's exterior to be intact but contaminated by thruster emissions. The solar arrays showed minor damage from meteoroids and orbital debris collisions.
MirNews 196, Chris Vandenberg, October 30, 1993; "Mir Mission Report," Neville Kidger, Spaceflight, May, 1994, p. 154; Mir Hardware Heritage, NASA RP 1357, David S. F. Portree, March 1995, p. 142.
Endeavour's pre-dawn launch in pursuit of HST was visible for hundreds of kilometers up the east coast of the U.S. According to Story Musgrave, HST SM-01 was fraught with challenges; in addition to the night launch and "night shift" for the crew, STS-61 was planned as a grueling 11-day flight with five EVAs, the most for a Shuttle flight to date. Because of these challenges, the crew for the first Hubble servicing mission was made up of veterans. All four EVA astronauts had EVA experience; Richard Covey was a veteran Shuttle commander; Ken Bowersox was a veteran pilot; and European Space Agency (ESA) astronaut Claude Nicollier had operated the RMS in space before. According to Jeff Hoffman, this experience was particularly important when it came to preflight training—the crew all knew how training on the ground differed from actual space operations. The repair effort was subject to the attention of up to a dozen external review boards, one of which called for a backup EVA crewman. Before Gregory Harbaugh's assignment as backup, the EVA astronauts planned to fill in for each other if one became unavailable to fly. In the event, Harbaugh's services were not required, but his training experience made him ideally suited to act as HST SM-01 EVA CapCom. The HST servicing EVAs were developed over the course of 10 yr, but the astronauts made modifications based on their experience. For example, according to Hoffman, the original plan was to keep all tools outside, but the crew realized that "the critical consumable was EVA time." The astronauts decided that the hour spent preparing tools at the start of the EVA could be better spent starting the repair, so they kept some tools inside Endeavour's crew compartment so they could load up before they started using their EMU consumables. On December 3 Nicollier checked out the RMS while the EVA astronauts inspected their space suits, and cabin pressure was reduced from 101.4 kpascal (14.7 psi) to 70.3 kpascal (10.2 psi) to reduce prebreathe time. On this date, Covey guided Endeavour close to HST. Nicollier captured the telescope with the RMS and berthed it on the Flight Support System in Endeavour's aft payload bay. The primary EVA tasks included:
- replace solar arrays
- replace Rate Sensing Unit (RSU) 2
- replace Wide Field/Planetary Camera (WFPC) with improved WFPC-2
- replace Goddard High Speed Photometer (GHSP) with Corrective Optics Space Telescope Axial Replacement (COSTAR)
- replace Magnetic Sensing System (MSS) magnetometer 1
- replace RSU 3 and Electronics Control Unit (ECU) 3
- replace Solar Array Drive Electronics (SADE) 1 assembly
STS-61, 1993 - Jeffrey Hoffman and Story Musgrave (on RMS) service HST in Endeavour's payload bay. (STS061-98-050)
Image
Secondary tasks included:
- install Goddard High-Resolution Spectrometer (GHRS) power supply redundancy kit
- install 386 co-processor in DF-224 primary computer
- replace MSS 2
- replace RSU fuse plugs
- replace ECU 1
Musgrave and Hoffman left Endeavour's airlock 1 hr early. They first installed a cover on a low-gain antenna to avoid damaging it, then changed RSU 2, RSU 3, ECU 1, ECU 3, and four fuse plugs. Replacements were stored in the Small Orbital Replacement Unit Protective Enclosure in the payload bay. Other replacement parts and tools for the EVAs were stowed in the ORU Carrier in the center of the payload bay. Endeavour carried 6545 kg (14,400 lb) of servicing gear, including more than 200 individual tools and crew aids. About 40 were for nominal repair operations, while the others were for contingencies. Musgrave, the shorter of the two astronauts, was able to slip under the HST sunshade to reach the RSUs. Because the astronauts did not have to remove the sunshade, this saved about 1 hr of EVA time. Musgrave unbolted the old RSU, then Hoffman, in a foot restraint on the RMS, slid it out while Musgrave steered it free. Up to this point, Hoffman and Musgrave were ahead of timeline, but then they had difficulty closing the RSU compartment door, which was deformed due to exposure to temperature extremes during HST's first 3 yr in space. Musgrave pushed on the bottom of the door while Hoffman, on the RMS, pushed on the top. This was the only major problem experienced on any of the HST SM-01 EVAs, a fact that surprised Hoffman, given the history of EVA. According to Hoffman, if the crew had not saved time by loading tools on the middeck and slipping under the sunshades, the EVA would have ended without the door closed and been deemed a failure. The astronauts closed out by setting up the payload bay for the next EVA.