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Deploying Satellites

The Shuttle crew basically uses two methods for deploying satellites: triggering a spring system which propels the satellite into space and away from the Shuttle, or using the RMS for unberthing the satellite and placing it as far away as possible from the Shuttle, and releasing it “quietly” into space.

Deploying satellites using the Remote Manipulator System (RMS) is covered under RMS operations Section. Mission using the RMS to deploy satellites include STS-41C, STS-27 and STS-31.

All other deployment methods are controlled from the Left Aft (L12 Panel) panel which is customized according to the mission payload.

Empty L12 Panel

After the initial deployment, Mission Control takes over the control of the satellite and moves it through the entire deployment sequence (activating various systems, guiding it into the planned orbit, opening the solar panels, etc.)


The Inertial Upper Stage (IUS) is a large rocket motor housed in the Payload bay of the shuttle. it is used to launch heavy payloads to very-high orbits (usually Geosynchronous orbit) or launching probes to interplanetary exploration.

The IUS is carried horizontally in the payload bay due to it's size and tilted up to 58 degrees for launch. When springs push the IUS away at a slow rate to a safe distance before the IUS engine ignites.

L12 Panel for IUS
L12 Panel for IUS

IUS in the payload bay (STS-26) IUS in Deployed position (STS-26)
IUS in stowed position IUS Ready for Deployment
IUS Missions: STS-26,STS-93


The Payload Assist Module (PAM-D) is a small rocked motor it is used to satellites to very-high orbits (usually Geosynchronous orbit).

The PAM is carried vertically in a housing in the payload bay and is rotated before being pushed out by a set of springs. The engine ignites when the shuttle has re-positioned to a safe distance.

L12 Panel for PAM-D Deployment
L12 Panel for PAM-D

PAM-D ready for deployment (STS-8)
PAM W/doors open
PAM Missions: STS-8,STS-51A


The ASE is used to launch the Syncom IV (LEASAT). It is carried horizontally in the payload and released out like frisbee - the “toss” induces a 0.8 RPM rotation that stabilizes the satellite before the engine fires and sends the payload to orbit.

L12 Panel for ASE
L12 Panel for ASE

LEASAT in payload bay (STS-32)
LEASAT in payload bay
ASE Missions: STS-32,STS-51A


The Micro satellites are not primary payload for the mission, they are “hitchhikers” and usually launched on the day before re-entry. The micro-sats are small and motor-less, they are carried inside canisters located in the payload bay and are ejected by springs to their final orbits.

L12 panel for Micro-satellites
STS-116 L12 Panel

Micro-Satellites Missions: STS-88, STS-96, STS-116
satellites.txt · Last modified: 2009/04/18 11:03 by pocci