SPACECRAFT ACCIDENTS: EXAMINING THE PAST, IMPROVING

THE FUTURE

Intelsat VI Recovery with STS-49 (Endeavour)

Bryan Palaszewski working with the

Digital Learning NetworkNASA Glenn Research Center

Intelsat VI Recovery (1/3)

• Launch: March 14, 1990.• Mission: High-power commercial

communications satellite.• Problem: Satellite was stranded in low

Earth orbit after failure of a rocket booster.• Launch: INTELSAT-VI (F-3) was

launched by a commercial Titan III rocket.

Intelsat VI Recovery (2/3) • A launch vehicle malfunction left the

Titan's second stage attached to the satellite, thus prohibiting the firing of a solid rocket motor that was to raise it to geostationary orbit.

• Satellite controllers later jettisoned the solid rocket motor with the Titan second stage attached and raised the satellite to its current orbit.

Intelsat VI Recovery (3/3) • Launched on May 7, 1992, STS-49 carried

the equipment to capture, repair, and redeploy (release) the Intelsat IV satellite.

• Astronauts used many tools, as well as their gloved hands, to stop the satellite.

• They attached a new rocket booster to the satellite and released it on May 15, 1992.

• Satellite was then boosted to it’s final geostationary orbit.

STS-49 Endeavour Crew • Commander Dan Brandenstein • Pilot Kevin Chilton• Mission Specialists

–Pierre Thuot –Rick Hieb –Kathy Thornton –Tom Akers–Bruce Melnick

Space Shuttle Equipment for Intelsat VI Recovery

• Perigee Kick Motor (PKM), which weighed 23,000 pounds.

• Capture Bar Assembly, which was designed by NASA Johnson and weighed 162 pounds.

• A cradle, designed to hold the perigee kick motor in Endeavour's cargo bay during launch, weighed 3,749 pounds.

• The docking adapter, which allowed attachment of the perigee kick motor to the INTELSAT- VI, weighed 152.8 pounds.

Intelsat VI Operations (1/3)

• Capture required three EVAs. • First space walk was conducted on

flight day four by Thuot, who was unable to attach capture bar to INTELSAT using a remote manipulator system arm.

• Second unscheduled but identical attempt by Thuot failed the following day.

Intelsat VI Operations (2/3)

• After rest on flight day six, unprecedented three-person EVA performed on flight day seven.

• During longest EVA in U.S. space history to date (8 hours, 29 minutes), Hieb, Thuot, and Akers grasped rotating INTELSAT by hand while Brandenstein maneuvered the orbiter.

Intelsat VI Operations (3/3)

• After capture bar attached to satellite, orbiter remote manipulator system arm grappled bar and placed satellite atop perigee kick motor (PKM) in cargo bay.

• Satellite deployed early on flight day eight, and INTELSAT controllers signaled PKM to fire, sending INTELSAT VI into operating orbit of 45,000 nautical miles (83,340 kilometers).