Payload Assist Module
Single-stage solid-fueled booster stage
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. 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)
- PAM-DII (Delta class), uses a Star-63 rocket motor, designed for satellites up to 4,150 lb (1,880 kg)
- PAM-S (Special), uses a Star-48B as a kick motor for the space probe Ulysses
The PAM-D module was used as an optional third stage of the classic Delta rocket. The PAM-D was discontinued after the Challenger accident. A simplified 3rd stage using the STAR-48 motor was employed on Delta II.
012001 re-entry incident
On January 12, 2001, a PAM-D module re-entered the atmosphere after a "catastrophic orbital decay". 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.
Sources and credits
This article is adapted from the Wikipedia article “Payload Assist Module”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.
Images, from Wikimedia Commons:
- PAM-D 1920x1080.ogv by Digital Image Animation Laboratory of the Jet Propulsion Laboratory, Public domain
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