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Originally Posted by Omicron Persei 8
Hmmm...that's funny because Surveyor is still in orbit around Mars taking wonderful images and transmitting large amounts of data.
I assume you mean the Mars Climate Orbiter.
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Yes
terminal binary dyslexia The good news is, Huygen could be landing on a moon that is three times lighter rather than three times heavier. The bad news is, well, you don't want to run into me on a one way street
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Oh ok....how bout some links to back yourself up?
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Originally Posted by ftp://ftp.hq.nasa.gov/pub/pao/reports/1999/MCO_report.pdf
Throughout spring and summer of 1999, concerns existed at the working level regarding discrepancies observed between navigation solutions. Residuals between the expected and observed Doppler signature of the more frequent AMD events was noted but only informally reported. As MCO approached Mars, three orbit determination schemes were
employed. Doppler and range solutions were compared to those computed using only Doppler or range data. The Doppler-only solutions consistently indicated a flight path insertion closer to the planet. These discrepancies were not resolved.
On September 8,1999, the final planned interplanetary Trajectory Correction Maneuver-4 (TCM-4) was computed. This maneuver was expected to adjust the trajectory such that soon after the Mars orbital insertion (MOI) burn, the first periapse altitude (point of closest approach to the planet) would be at a distance of 226km. See figure 4. This
would have also resulted in the second periapse altitude becoming 210km, which was desired for the subsequent MCO aerobraking phase. TCM-4 was executed as planned on September 15, 1999.
Mars orbit insertion was planned on September 23, 1999. During the weeklong timeframe between TCM-4 and MOI, orbit determination processing by the operations navigation team indicated that the first periapse distance had decreased to the range of 150-170km
During the 24 hours preceding MOI, MCO began to feel the strong effects of Mar’s gravitational field and tracking data was collected to measure this and incorporate it into the orbit determination process. Approximately one hour prior to MOI, processing of this more accurate tracking data was completed. Based on this data, the first periapse altitude was calculated to be as low as 110km. The minimum periapse altitude considered
survivable by MCO is 80 km.
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If I am reading this correctly, the Navigating system with the Metric/Texas Unit error predicted a periapse of 220km, while the Doppler Data put it around 150-170km, a third system placed the Global Surveyor, I mean the Climate Orbiter, "as low as" 110km. That is still 120% of the lowest entry point considered survivable, so the Global Surveyor should still not have burned up. I mean the Climate Orbiter. Did NASA really address the problem?
During the
Air-Braking on the Global Surveyor mission, NASA consistently reported a slowing rate that was ~10% greater than planned. Is that because they were more efficient, was this a 10% error?
Why did the Polar Orbiter, I mean Lander, crash?