Monday, July 06, 2009

That's one expensive 'oops'.


Many years ago, I helped design and implement the Ground Support Equipment (GSE) for one of the TIROS weather satellites*. More than a decade after working on this large software development effort, on June 24, 2002, a Titan II intercontinental ballistic missile launched the satellite into orbit from Vandenberg Air Force Base.

Today, the satellite looks something like this. The canned NASA description reads:

"The Space Environment Monitor/2... for the NOAA Space Environment Center, detects charged particles and provides measurements to determine the intensity of the Earth’s radiation belts and the flux of charged particles into the atmosphere at the satellite’s altitude. It provides knowledge of solar terrestrial phenomena and also warns of solar storms that may impair long-range communication and high-altitude operations, damage satellite circuits and solar panels, or cause changes in drag and magnetic torque on satellites. The instrument consists of two separate sensor units and a common Data Processing Unit. The sensor units are the Total Energy Detector and the Medium Energy Proton and Electron Detector..."

Pretty cool. I'd nearly forgotten about this development effort and was only reminded of it because of the massive solar storms that have erupted of late.

Some searches led me to this report of a major debacle involving another TIROS satellite in the same series. On September 6, 2003, at a Lockheed Martin facility in Sunnyvale, the NOAA-N Prime spacecraft was in the process of being repositioned from vertical to horizontal.

"[As it was being repositioned] on the 'turn over cart' at approximately 7:15 PDT today, it slipped off the fixture, causing severe damage... The 18' long spacecraft was about 3' off the ground when it fell."

"The mishap was caused because 24 bolts were missing from a fixture in the 'turn over cart'. Two errors occurred. First, technicians from another satellite program that uses the same type of 'turn over cart' removed the 24 bolts from the NOAA cart on September 4 without proper documentation. Second, the NOAA team working today failed to follow the procedure to verify the configuration of the NOAA 'turn over cart' since they had used it a few days earlier."

"The shock and vibration of the fall undoubtedly caused tremendous damage..."

It's not a bad ending, however, despite the damage to the half-billion dollar observatory. The repaired satellite was successfully launched earlier this year and is scheduled to begin operation in 2012.


* C, with a tiny bit of assembler, running under QNX on an x86 platform.

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