Payload Assist Module

The Payload Assist Module (PAM) is a modular upper stage operated with solid propellant, used with the Space Shuttle, Delta, and Titan launchers. The rocket was used to carry satellites from a low earth orbit to a geostationary transfer orbit or an interplanetary course. The payload was spin stabilized by being mounted on a rotating plate. Originally developed for the Space Shuttles, different versions of the PAM followed:

• PAM-A (Atlas class), development terminated
• PAM-D (Delta class), uses a Star-48B rocket motor
• PAM-D2 (Delta class), uses a Star-63 rocket motor
• PAM-S (Special) as a kick motor for the space probe Ulysses

The PAM-D module, used as the third stage of a Delta II rocket, is the only version in use today.

On January 12, 2001, a PAM-D module reentered the atmosphere after a "catastrophic orbital decay".^[1] The PAM-D stage, that had been used to launch a GPS satellite in 1993, crashed in the sparsely populated Saudi Arabian desert, where it was positively identified.

External links

• Payload Assist Module at the NASA Shuttle Reference Manual
• Payload Assist Module at GlobalSecurity.org

References

1. ^ "PAM-D Debris Falls in Saudi Arabia." The Orbital Debris Quarterly News. Vol. 6, Issue 2. NASA Johnson Space Center. Available online.