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Falcon 1 Maiden Flight Update: Posted December 7, 2005 Liquid Oxygen
Regarding liquid oxygen (LOX) supplies, we expect to have enough on hand this time to fill the rocket four or five times over. This should account for almost any issue with a particular storage tank as well as an extended hold on the pad. We chartered a C-17 to fly two of our empty high quality LOX containers to Hawaii, sourced another high quality LOX container on Hawaii and put all three on the barge to Kwajalein. In addition, our LOX plant on Kwajalein has been repaired and is producing LOX on island again.
Many have asked how we could run out of LOX on a remote tropical island on the last launch attempt. The team tried hard to avoid it, but several issues conspired to create the problem:
Engine Computer
The engine computer reboot anomaly was definitively traced to a ground power problem. Importantly, this would have had no effect on flight, since we switch to vehicle power before the autosequence begins. The reason it cropped up at Kwajalein was that the higher load on the longer umbilical (three times longer than in prior tests) coupled with high temperatures in Kwajalein resulted in increased resistance in the ground umbilical. This was just enough to lower the voltage below minimums and cause an engine computer reset when drawing maximum power. The same max power test was repeated on internal vehicle batteries with no problem at all. This problem has been solved by slightly increasing voltage on the ground umbilical.
SpaceX Launch Overview On launch day, the Falcon 1 countdown to launch is expected to reach T-Zero. At that point, the hold-down clamps will release and the Falcon 1 rocket will begin its journey to orbit, accelerating to 17,000 mph (twenty-five times the speed of sound) in less than ten minutes. Designed from the ground up by SpaceX, Falcon 1 is a two stage rocket powered by liquid oxygen and purified, rocket grade kerosene. The Falcon 1 launch will make history for several reasons:
The maiden flight will take place from the Kwajalein Atoll of the Marshall Islands. The customer for this mission is DARPA and the Air Force and the payload will be FalconSat-2, part of the Air Force Academy’s satellite program that will measure space plasma phenomena, which can adversely affect space-based communications, including GPS and other civil and military communications. The target orbit is 400 km X 500 km (just above the International Space Station) at an inclination of 39 degrees. The reason for the delay was an auxiliary liquid oxygen (LOX) fill tank had a manual vent valve incorrectly set to vent. The time it took to correct the problem resulted in significant LOX boiloff and loss of helium, and it was the latter that caused the launch abort. LOX is used to chill the helium bottles, so we lose helium if there is no LOX to cool the bottles.
Although we were eventually able to refill the vehicle LOX tanks, the rate at which we could add helium was slower than the rate at which LOX was boiling away. There was no way to close the gap, so the launch had to be called off. In addition, we experienced an anomaly with the main engine computer that requires further investigation and was arguably reason in and of itself to postpone launch.
Viewing for Media on Launch Day The live feed of this historic launch will be available to the media at SpaceX Headquarters in El Segundo, CA – five minutes south of Los Angeles International Airport. Media check-in will begin at 12:00 p.m. PST on launch day. The launch window is 1 – 5 p.m. (PST). Food and beverages will be made available. Still photos and videos of the launch will be made available to the public on www.spacex.com within a couple of hours of the launch.
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