Author Topic: IUS Q&A  (Read 7952 times)

Offline Jim

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Re: IUS Q&A
« Reply #20 on: 11/22/2014 06:45 PM »
Does anybody know how long an IUS (or any other solid rocket motor for that matter) can stay in space and still remain operational?

A STAR-48 was used on Magellan for Venus orbit insertion.    Reconsats had SRM's in the recovery capsules for deorbit.   The LEASAT on STS 51-G (I believe) was in orbit until the repair mission.
« Last Edit: 11/22/2014 06:47 PM by Jim »

Online Galactic Penguin SST

Re: IUS Q&A
« Reply #21 on: 12/16/2017 02:14 AM »
Assuming that the IUS stages are used in such a way that the satellite is only carried to a standard GTO (as opposed to direct orbit insertion as it was done in history), what is the maximum payload that can be carried?
Chinese spaceflight is a cosmic riddle wrapped in a galactic mystery inside an orbital enigma... - (not) Winston Churchill

Online edkyle99

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Re: IUS Q&A
« Reply #22 on: 12/16/2017 02:13 PM »
Assuming that the IUS stages are used in such a way that the satellite is only carried to a standard GTO (as opposed to direct orbit insertion as it was done in history), what is the maximum payload that can be carried?
According to a 1984 IUS users guide, the IUS structure had been tested to handle an 8,000 lb payload maximum.  Weights above 8,000 lbs would require a load reassessment, but payloads up to 16,000 lbs were thought possible.  The two-stage IUS was designed primarily for geosychronous missions.  For other missions, stage 2 propellant was offloaded to provide more payload capability.  Indeed, both IUS motors were designed to allow for propellant offloading.  The geo mission requirement was 5,000 lbs.  IUS could put about 7,700 lbs into a 12-hour circular orbit.  It could, in theory, boost 16,000 lbs into a 2,500 nmi x 20 deg circular orbit, or about 10,000 lbs to minimal escape velocity, etc.  My guess is that a GTO payload could weigh somewhere in the 8,000 to 10,000+ lb range, depending on inclination.   This all assumes Shuttle launch.

 - Ed Kyle
« Last Edit: 12/16/2017 02:25 PM by edkyle99 »

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