November 26, 2005

Update to Good luck!

I had written here about the upcoming launch of the first privately Funded Orbital flight scheduled for today. It had to be scrubbed and they will try again sometime in December. From Spaceflight Now:
A frustrating scrub Saturday ended the first shot at launching the privately-developed Falcon 1 rocket, delaying until sometime in December the debut mission of this new low-cost booster fleet that could revolutionize the space marketplace.

Space Exploration Technologies was hoping to get its initial rocket into orbit from Omelek Island, a tiny dot of land among the Kwajalein Atoll located in the Central Pacific Ocean. Technical snags with ground fueling equipment at the launch pad, however, thwarted efforts to ready the 70-foot tall vehicle for its planned liftoff.

"As I warned, the likelihood of an all new rocket launching from an all new launch pad on its first attempt is low," SpaceX founder Elon Musk said follow the scrub.

Launch has been scheduled for 4 p.m. EST (2100 GMT). That time was pushed back an hour, then even more as the 25-person launch team wrestled with a glitch in the helium pressurization system.

As countdown clocks finally moved closer to liftoff, it was determined that a valve on an auxiliary liquid oxygen supply tank at the pad was incorrectly set to vent. The valve must be adjusted manually, forcing a crew to take a boat from their safe fallback position to Omelek Island for the hands-on fix.

The team was racing to get the valve closed to prevent too much super cold liquid oxygen from escaping, which would cause a lengthy resupply of the pad commodities. But the valve was closed, and reserve liquid oxygen was transferred from low-pressure tanks to the high-pressure tanks used for refueling the rocket.

The cryogenic oxidizer naturally boils away aboard the rocket, requiring replenishment through the countdown. The liquid oxygen and a highly refined kerosene propellant are consumed by the rocket's Merlin first stage and Kestrel second stage engines during the flight.

Clocks were reset for liftoff at 8 p.m. EST (0100 GMT). However, the rocket servicing by the ground systems was too affected from the earlier problem to continue with the launch attempt.

"The time it took to correct the problem resulted in significant LOX boil off 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," Musk explained.

"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."
Working with Cryogenic Materials (especially Hydrogen and Helium) is a black art -- they do not behave like fluids and Hydrogen especially causes problems with the metals used for construction (it makes them incredibly brittle). Bummer about today but they seem to be very careful and not rushing ahead for publicities sake. Posted by DaveH at November 26, 2005 7:29 PM
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