Payload Assist Module

The Payload Assist Module (PAM) is a modular upper stage designed and built by <a href="/facts/McDonnell_Douglas/cplglcRH">McDonnell Douglas</a> (<a href="/facts/Boeing/tF5sMe9F">Boeing</a>), using <a href="/facts/Thiokol/alHU0yG6">Thiokol</a> Star-series solid propellant rocket motors. The PAM was used with the <a href="/facts/Space_Shuttle/7BoyetEv">Space Shuttle</a>, <a href="/facts/Delta_(rocket_family)/gQH4EUYB">Delta</a>, and <a href="/facts/Titan_(rocket_family)/sTTkEDps">Titan</a> launchers and carried <a href="/facts/Satellite/PTX8c68t">satellites</a> from <a href="/facts/Low_Earth_orbit/rq1TwayJ">low Earth orbit</a> 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:

<ul><li>PAM-A (<a href="/facts/Atlas_(rocket_family)/G4rKFbb7">Atlas</a> 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)</li>
<li>PAM-D (<a href="/facts/Delta_(rocket_family)/gQH4EUYB">Delta</a> class), uses a <a href="/facts/Star_48/FrTEvI2K">Star-48B</a> rocket motor, designed for satellites up to 2,750 lb (1,250 kg)</li>
<li>PAM-DII (Delta class), uses a <a href="/facts/Star_(rocket_stage)/4gsDHQ2p">Star-63</a> rocket motor, designed for satellites up to 4,150 lb (1,880 kg)</li>
<li>PAM-S (Special), uses a Star-48B as a kick motor for the space probe <a href="/facts/Ulysses_(spacecraft)/0nEMdFvj">Ulysses</a></li></ul>
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.

Payload Assist Module open-in-new

Payload Assist Module