Payload Assist Module

The Payload Assist Module (PAM) is a modular upper stage designed and built by McDonnell Douglas (Boeing), using Thiokol Star-series solid propellant rocket motors. The PAM was used with the Space Shuttle, Delta, and Titan launchers and carried satellites from low Earth orbit to a geostationary transfer orbit or an interplanetary course. The payload was spin stabilized by being mounted on a rotating plate.^[1] Originally developed for the Space Shuttle, different versions of the PAM were developed:

PAM-A (Atlas class), development terminated; originally to be used on both the Atlas and Space Shuttle, designed for satellites up to 4,400 lb (2,000 kg)
PAM-D (Delta class), uses a Star-48B rocket motor, designed for satellites up to 2,750 lb (1,250 kg)^[2]
PAM-DII (Delta class), uses a Star-63 rocket motor, designed for satellites up to 4,150 lb (1,880 kg)^[2]
PAM-S (Special), uses a Star-48B as a kick motor for the space probe Ulysses^[2]

PAM-D with the Phoenix spacecraft. The stage is successively spun, fired, yo-yo de-spun and jettisoned.

The PAM-D module, used as the third stage of the Delta II rocket, was the last version in use. As of 2018, no PAM is in active use on any rockets.

2001 re-entry incident

On January 12, 2001, a PAM-D module re-entered the atmosphere after a "catastrophic orbital decay".^[3] The PAM-D stage, which had been used to launch the GPS satellite 2A-11 in 1993, crashed in the sparsely populated Saudi Arabian desert, where it was positively identified.^[3]

Gallery

PAM-D stage in assembly
SBS-3 satellite with PAM-D stage being launched from Space Shuttle Columbia
Saudi officials inspect a PAM-D module that re-entered the atmosphere in 2001
SATCOM KU-2 attached to a PAM-DII is being released from the cargo bay of the Space Shuttle Orbiter Atlantis during STS-61B
Ulysses is mated with the PAM-S

References

^ "Payload Assist Module (PAM)". Global Security. Retrieved June 8, 2012.
^ ^a ^b ^c Krebs, Gunter D. "PAM-D, PAM-D2, PAM-S". Gunter's Space Page. Retrieved 2024-01-05.
^ ^a ^b "PAM-D Debris Falls in Saudi Arabia" (PDF). The Orbital Debris Quarterly News. 6 (2). NASA Johnson Space Center: 1. April 2001.

External links

Payload Assist Module Archived 2016-12-21 at the Wayback Machine at the NASA Shuttle Reference Manual
Payload Assist Module at GlobalSecurity.org

[1] "Payload Assist Module (PAM)". Global Security. Retrieved June 8, 2012.

[:0-2] Krebs, Gunter D. "PAM-D, PAM-D2, PAM-S". Gunter's Space Page. Retrieved 2024-01-05.

[orb_debris-3] "PAM-D Debris Falls in Saudi Arabia" (PDF). The Orbital Debris Quarterly News. 6 (2). NASA Johnson Space Center: 1. April 2001.

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