Not exactly a postmortem, but a failure of technology.
Originally shared by Ed S
Finding a lost satellite(*) by slide rule in 1964:
“”"
Speaking of a circular slide rule-- Howard Speegle, founder of Diva Automation, told me this last week (He gave me permission to copy it here):
Quote:
With your background, you might enjoy some aspects of my work on the Nimbus weather satellite. It had a 250 mW transmitter and our 85-foot dish with Maser amplifier could achieve autolock at -150 dbm at a range of 3000 miles.
However, the launch vehicle suffered an early burnout and the orbit was degraded, causing the satellite to be lost to the free world for three days. No one at NASA Goddard or the DEW line or any tracking stations around the world were able to locate any evidence that it existed. We scanned the skies continuously in every sort of random and geometric pattern for days, but no cigar.
Finally, I whipped out my trusty circular pocket slide rule and did a bit of jimjam combined with whazzamatazz and came up with a reasonable approximation of what the orbit would look like with a 10-second premature shutoff and suggested to my boss that they point the antenna in a certain direction at a certain time.
And lo!, it came to pass. He wanted to know where I had studied astrophysics and I didn’t think he would appreciate knowing about my plastic slide rule so I simply shrugged it off.
A few weeks later, the ham club at the University of Alaska, down the road, timidly asked if we might have any interest in the telemetry tapes they had made of the first pass. A bunch of kids using a hand-pointed chicken wire parabola had made beautiful recordings of the entire pass and subsequent passes. They had outperformed the combined might of NASA and the millions upon millions of dollars of state of the art equipment we had. Kudos to them. I don’t know whether we ever thanked them. Perhaps I should send this story to the university so they can add it to their list of accomplishments.
“”" - via Garth Wilson on the hpmuseum forum
Also:
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Premature Agena cutoff left the craft in an elliptical orbit rather than a more circular one, and one of the solar panels failed 26 days into the mission.
“”" - http://science1.nasa.gov/missions/nimbus/
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A short second-stage burn resulted in an unplanned eccentric orbit
“”" - http://www.astronautix.com/craft/nimbus.htm
See also the mostly-declassified Agena Flight History
http://www.nro.gov/foia/declass/WS117L_Records/276.PDF (“Premature termination of second burn” - p18 - but marked as “Success”)
and
http://en.wikipedia.org/wiki/Nimbus_program
http://www.spacelaunchreport.com/thrfail.txt
http://www.friends-partners.org/oldfriends/jgreen/nimbus.html
(*) “Unintended Elliptical Earth Orbit”
http://science1.nasa.gov/missions/nimbus