Payload Assist Module

{{Short description|Single-stage solid-fueled booster stage}}

Image:PAM-D 1920x1080.ogv spacecraft. The stage is successively spun, fired, yo-yo de-spun and jettisoned.]]

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.{{cite web |url=http://www.globalsecurity.org/space/systems/pam.htm |title=Payload Assist Module (PAM) |publisher=Global Security |access-date=June 8, 2012}} 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 {{convert|4400|lb|abbr=on}}
  • PAM-D (Delta class), uses a Star-48B rocket motor, designed for satellites up to {{convert|2750|lb|abbr=on}}{{Cite web |last=Krebs |first=Gunter D. |title=PAM-D, PAM-D2, PAM-S |url=https://space.skyrocket.de/doc_stage/pam-d.htm |access-date=2024-01-05 |website=Gunter's Space Page}}
  • PAM-DII (Delta class), uses a Star-63 rocket motor, designed for satellites up to {{convert|4150|lb|abbr=on}}
  • 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.

2001 re-entry incident

On January 12, 2001, a PAM-D module re-entered the atmosphere after a "catastrophic orbital decay".{{cite journal |url=https://orbitaldebris.jsc.nasa.gov/quarterly-news/pdfs/odqnv6i2.pdf|title=PAM-D Debris Falls in Saudi Arabia |journal=The Orbital Debris Quarterly News |publisher=NASA Johnson Space Center |volume=6 |issue=2 |page=1 |date=April 2001}} 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.

Gallery

File:PAM-D rocket stage.jpg|PAM-D stage in assembly

File:SBS-3 with PAM-D stage.jpg|SBS-3 satellite with PAM-D stage being launched from {{OV|102}}

File:PAM-D module crash in Saudi Arabian desert.png|Saudi officials inspect a PAM-D module that re-entered the atmosphere in 2001

File:STS-61-B SATCOM Ku-2 deployment.jpg|SATCOM KU-2 attached to a PAM-DII is being released from the cargo bay of the Space Shuttle Orbiter Atlantis during STS-61B

File:Ulysses is mated with the PAM-S.jpg|Ulysses is mated with the PAM-S

References

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