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Archive for October, 1999


20-Oct-99 | Ice rivers in Antarctica

Canada’s RADARSAT, launched aboard a Delta II in 1995, has been used to generate the first high-resolution radar map of Antarctica. Among other items of interest, the map reveals what are known as “ice rivers,” vast rivers of — you guessed it — ice, which amazingly flow up to 100 times faster than the ice through which they channel. (18-Oct-99 NASA Press Release)

Meanwhile, though this author has not yet found any offical word, it seems that RADARSAT-II may have resolved (pardon the pun) its clarity issues, as it now appears in Florida Today‘s extended launch schedule for November, 2001. Previously it was reported here that the radar mapper’s ground resolution of 3 metres exceeds the clarity allowed by the U.S. government for non-military satellites by 2 metres, thus preventing it from being launched from a U.S. site.


20-Oct-99 | MCO hits Martian atmosphere, is lost

On Thursday, September 23, Mars Climate Orbiter fired its main engine for approximately 17 minutes to drop out of heliocentric orbit and begin Mars Orbit Insertion. Sadly, a navigational error led MCO to pass some 80 kilometers closer to the planet than was intended, and the spacecraft was destroyed during the pass through the Martian atmosphere. The mistake has been traced to confusion over units of measurement: spacecraft builder Lockheed Martin specified the force of manoeuvring thrusters in pounds; JPL controllers assumed the thrust was in newtons.

Though NASA is downplaying the loss as part of the risk involved in their “faster, cheaper, better” strategy, the mistake is a major embarrassment to the agency, and a review board has been convened for “process improvement.” One of two ships in the Mars Surveyor 1998 program, MCO was intended to perform a full Martian year of observations to better understand the seasonal changes on that planet. It was launched from Cape Canaveral on 11 December, 1998, the 264th launch of a Delta rocket.


12-Oct-99 | Next launch

The next Delta launch will be from Vandenberg AFB in California on 15 December, the longest hiatus of 1999. It will carry NASA’s Earth Observing-1 (formerly Earth Orbiter-1), an advanced land imaging mission that is part of the New Millenium Program. (This date is expected to slip somewhat.)


12-Oct-99 | Delta flight 275 – NAVSTAR IIR-3

The first NAVSTAR GPS satellite to replenish the constellation since November 1997 was launched aboard Delta 275 on Thursday, October 7, from Cape Canaveral’s SLC-17A. The flight of GPS 2R-3, which was a complete success, had been delayed by several months thanks to numerous bouts of bad weather, including a heavy rain in May that led to the original spacecraft for this flight being returned to Lockheed Martin for repairs, last month’s threat from Hurricane Floyd, and lightning indications during the time slated for second stage fuelling. Oddly, the last day’s delay was caused not only by a forecast of lousy weather, but also by the sun — a satellite used to relay telemetry from Antigua passed in front of the sun and would have resulted in a 6-minute data blackout during the flight. Following all of that, it only stands to reason that the countdown was flawless and the bird flew a mere 0.686 seconds after the opening of the launch window. The payload separated into its transfer orbit 68 minutes later. Seventeen more GPS satellites are manifested aboard Delta II; nine are set to fly before the end of 2001.


     

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