STS-87 Day 4 Highlights

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On Saturday, November 22, 1997, 6:00 a.m. CST, STS-87 MCC Status Report # 06 reports:

Today mission managers and experts in various flight control areas are meeting to formulate a plan for retrieval of the Spartan science satellite following the apparent failure of its attitude control system to activate.

The satellite is at a safe distance in front of Columbia of about 23 nautical miles (about 42 kilometers) and plans call for the crew to maintain the orbiter's distance to protect plans to rendezvous with the spacecraft on Monday to retrieve it either by mechanical arm or manually as part of a spacewalk by mission specialists Winston Scott and Takao Doi. As part of their routine pre-mission spacewalk training, the two astronauts trained for just such a contingency should it be required.

Though mission specialist Kalpana Chawla released Spartan from the robot arm on time at 3:04 p.m. yesterday, it did not execute a pre-programmed pirouette maneuver designed to verify its attitude control system was functional. Spartan officials last night said it appeared the small control jets failed to activate, leaving the satellite without the ability to orient itself for science collection.

Chawla attempted to recapture Spartan moments later, but did not receive an indication of grapple and backed the arm away, apparently initiating a rotational spin of about two degrees per second on the satellite. After attempting to match the rotation for another capture attempt, commander Kevin Kregel performed an orbiter separation maneuver to move Columbia away from the Spartan.

Special teams will meet today to formulate a formal course of action that will be finalized Sunday.

Meanwhile, the crew will spend the day checking out the Extravehicular Mobility Units, or spacesuits, and tools that will be used for Monday's spacewalk. The options for the spacewalk include retrieving the satellite and accomplishing as many of the activities that had been scheduled during the time available to test hardware and techniques that will be used on the International Space Station.

The scientific data being collected by other experiments that make up the United States Microgravity Payload are unaffected by the Spartan satellite problems and retrieval efforts underway.

The crew wakeup call from Mission Control at about 9:45 this morning signals the start of flight day 4 for Columbia's STS-87 mission.

On Saturday, November 22, 1997, 7:00 p.m. CST, STS-87 MCC Status Report # 07 reports:

Astronauts Winston Scott and Takao Doi checked out their spacesuits aboard Columbia today in preparation for a planned Monday spacewalk while Mission Control developed plans that may allow Scott and Doi to recapture the Spartan satellite by hand during that EVA.

Columbia is now about 38 statute miles behind Spartan, which was released from the shuttle on Friday. After its release, the satellite's attitude control system failed. When a recapture of the satellite was attempted, it began a slow spin that prevented any further attempts to capture it using the robotic arm. Flight controllers are now evaluating two options for recapturing the satellite by hand during the Monday evening spacewalk. A final decision on any plan to recapture Spartan is not expected until after Shuttle managers meet at 8 a.m. CST Sunday to review all options.

The first option would have Scott and Doi perform a procedure very similar to one they rehearsed prior to the flight in the event a manual recapture of the satellite would be required. Under this plan, Scott and Doi would stand in foot restraints mounted on the Multi-Purpose Experiment Support Structure to which Spartan is latched in the payload bay during the Shuttle's launch and landing. Columbia Commander Kevin Kregel would then fly to within reach of the satellite, and Scott and Doi would grasp Spartan and lower it into its normal payload bay latches.

The second option would have Scott stand in a foot restraint mounted to the end of the robotic arm while Doi remains in the payload bay. Kregel would then fly to within reach of the satellite, and Scott would be moved into position to grasp the satellite. Assisted by Doi, he would then lower Spartan into its payload bay latches.

Simulations of both options are being evaluated using a variety of facilities at the Johnson Space Center, including a virtual reality laboratory, two shuttle simulators, and the large swimming pool used for spacewalk training. All of the data gathered during the day will be presented to managers at the Sunday meeting. A press conference is currently planned at 10 a.m. CST Sunday on NASA Television.

For a rendezvous with Spartan Monday evening, Doi and Scott would exit Columbia's airlock at 6:16 p.m. CST Monday. Columbia would arrive in close proximity to Spartan at about 7 p.m. Monday. The spacewalk would conclude at about 12:16 a.m. CST Tuesday. Under either option, the Spartan retrieval would require only about two hours of the six-hour spacewalk. During the remaining four hours, a majority of the originally planned International Space Station assembly spacewalk tests would still be performed. Flight controllers do not believe it will be possible to test the Aercam Sprint experiment, a prototype free-flying television camera designed for future space station use.

Experiment work aboard Columbia continued today while the plans for the possible Spartan retrieval were evaluated. Kregel and Mission Specialist Kalpana Chawla completed three more experiment runs studying the mixing of certain metal alloys in weightlessness using a glovebox facility in the shuttle's middeck. Ukrainian Payload Specialist Leonid Kadenyuk continued studies of plant growth in weightlessness in the Collaborative Ukrainian Experiment. During the evening, each crew member will have an hour off-duty to help adjust their sleep cycles to match future mission events. The crew also will be interviewed by NBC Nightside and NBC Asian News at 9:31 p.m. CST today. The crew will go to sleep at 3:46 a.m. CST Sunday, two hours later than yesterday, and awaken at 11:46 a.m. CST Sunday.

Columbia is in excellent condition with no systems problems in an orbit with a high point of 175 miles and a low point of 171 miles. The next STS-87 status report will be issued around 6 a.m. Sunday.

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