Author Topic: STS-51A...  (Read 2981 times)

psowen

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STS-51A...
« on: June 28, 2009, 09:21:37 AM »
What was the point of bringing the sattelites back to Earth?   They weren't launched on a later mission were they?

Just to demonstrate that it could be done?
STS-1-8-41C-51A-26

psowen

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Re: STS-51A...
« Reply #1 on: June 28, 2009, 09:37:03 AM »
http://www.sattel.com/life_of_palapa_b2.htm

Nevermind I found this on my own research.  Palpa B2 was relaunched.   Interesting.


The commercial satellite Palapa B2 was launched for the Indonesian government on STS-41B in February 1984.  However, it failed to reach geosynchronous orbit due to an onboard rocket malfunction.  Sattel Technologies (California) purchased the satellite from an insurance group while it was circling the earth in a useless orbit, and contracted with NASA to retrieve it.  Retrieval occurred in November 1984 on Space Shuttle mission STS-51A.  Sattel also contracted Hughes Aircraft Company (the original manufacturer) and McDonnell Douglas (launch service provider) to refurbish and relaunch the satellite, then renamed Palapa B2-R.  The relaunch in April 1990 was successful, and title transferred back to Indonesia.  See the Palapa B2-R history at http://samadhi.jpl.nasa.gov/msl/Programs/palapa.html.


In this photograph Astronaut Dale A. Gardner, having just completed the major portion of his second extravehicular activity (EVA) period in three days, is holding up a "For Sale" sign.

The sign is referring to the two satellites, Palapa B-2 and Westar 6 that the astronauts retrieved from orbit after their Payload Assist Modules (PAM) failed to fire. 

Astronaut Joseph P. Allen IV, who also participated in the two EVAs, is clearly reflected in Gardner's helmet visor.  Portions of each of the two recovered satellites can be seen in the lower right corner of the photo, with Westar 6 nearer Discovery's aft.

NASA Photo

The road to relaunch was a rocky one in several respects.  The satellite was in a useless orbit at about 250 n. mi. altitude.  To lower it to an altitude that could be reached by the Shuttle, NASA and Hughes engineers worked out a tricky maneuver in which on-board thrusters were fired in a manner calculated to lower the satellite to 160 n. mi.  Sattel purchased the satellite before the in-orbit maneuver details were fully worked out and prior to orbital operations commencing, and took the risk that the maneuver would be successful.

A movie of the recovery can be seen (subscription needed) at http://spaceflightnow.com/plus/sts51a.html.  The recovery effort is discussed (pp 8 & 11) at http://www.jsc.nasa.gov/history/suddenly_tomorrow/chapters/Chpt15.pdf
A report written at the time (in 1990) appears here: http://www.planet4589.org/space/jsr/back/news.35

Hughes didn't want to do the refurbishment, thinking it could obtain a larger contract for a new replacement satellite instead.  Hughes' rationale was that it had a policy prohibiting doing business with former employees (Weischadle had left Hughes just a year earlier.)  Pressure from the Indonesian government,
a Hughes customer, solved the problem.

The relaunch wasn't supposed to happen on a McDonnell Douglas launch vehicle.  When Palapa B2 was originally launched on the Shuttle, NASA was contractually committed to relaunch it on the Shuttle if the need ever arose.  Back then no relaunch had ever occurred and this seemed a very remote possibility.  Then, just before Sattel needed the relaunch that no one though would happen, President Reagan signed an executive order banning NASA from performing further commercial launches.  As only the government can do, NASA then abrogated its commercial launch contracts and never looked back.  The original $25 million relaunch price that NASA had committed to when Sattel purchased the satellite from the insurers jumped overnight to the going rate for a commercial Delta launch of $50 million!  That triggered a rush to find $25 million more financing almost overnight, which the United States Export-Import Bank agreed to fund.

In the end, Palapa B2 made history twice.  First, it was one of TWO satellites (the other was Westar 6) launched side by side in the cargo bay of the same Shuttle mission, in which BOTH experienced the very same perigee motor stage malfunction!  BOTH satellites went into useless low earth orbits of the same altitude.  Second, Palapa B2 and Westar 6 were the first satellites in history to be retrieved and relaunched.  Only Palapa B2, however, was relaunched at the Cape where it had started its incredible journey of millions of miles, 6 years earlier.  Finally, Palapa B2 had arrived safely back on earth after 288 days in orbit, having traveled 119 million miles in space!!

During its 9 months in low earth orbit Palapa B2 was struck by thousands of meteorites that left small impact holes on its solar cells. During refurbishment the solar cells were removed and many were unavoidably destroyed in the process. The few remaining nearly-intact cells were encapsulated in Plexiglas displays of which only four are known to exist today. 

Also, the Palapa B2 Star 30 rocket motor cone has been carefully preserved since Morton-Thiokol, its manufacturer, removed it from the retrieved satellite.  To see it, no one would think it had traveled 119 million miles in space!

As Palapa B2-R lives out the remainder of its life in geosynchronous orbit over Asia, these cells and the AKM cone are likely the only remnants on earth of Palapa's amazing journey and unique history.  Those interested in rare NASA collectibles may contact Sattel by email through the link on the Contact page.

 

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STS-1-8-41C-51A-26