Falcon scrub: Rocket ‘deformed’

by Braddock Gaskill

SpaceX have been forced to scrub the debut launch of their Falcon 1 rocket, one hour into the opening of today’s launch window, due to a faulty pressurization valve, which – during draining – caused a vacuum condition, deforming the tank barrel in the first stage.

This is the second time SpaceX has been forced to scrub, following a previous attempt on November 26. SpaceX CEO Elon Musk hopes a third attempt can take place late in January.

**Please note your opportunity to participate in a Q and A with SpaceX VP of Development Operations Chris Thompson. Details at the end of the article**

The launch was to take place from the Kwajalein Atoll in the Pacific, part of the Marshal Islands under lease as an Army missile test site. The customer for this mission is DARPA and the Air Force.

The payload Falcon1 is still hoping to launch successfully is the 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 first SpaceX launch aborted on November 26th, after a manual vent valve on a liquid oxygen (LOX) tank was inadvertently left open when the ground crew left the small launch island of Omelek. It took time to gain the permission from the Army range safety officer so that the crew could return to correct the problem from their location several miles away.

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 they lose helium if there is no LOX to cool the bottles.

SpaceX had moved quickly and chartered a C-17s to fly two empty LOX containers to Hawaii for refill, sourced a third tank, and sent them on a barge back to Kwajalein. In addition, in the final moments before SpaceX’s last launch attempt the engine computer rebooted unexpectedly.

However, with plenty of LOX on the island, the weather worked against SpaceX’s wish to head into the final countdown at the opening of the launch window (2pm EST, 7pm UK) for the second attempt.

High winds of up to 28 knots proved to be four knots over their launch criteria, preventing the release of the strongback arm which holds the rocket in place prior to launch. The countdown was then placed into a T-15 minutes hold.

While SpaceX waited for the winds to ease during the hold, a critical fault was discovered on the first stage tank of the rocket. The launch was officially scrubbed around 30 minutes into the hold.

It has still not been noted by SpaceX as to what caused the structural issue with the first stage. However, they have released information on the next possible attempt.

‘Launch is scrubbed until early next year, as there is a structural issue with the 1st stage fuel tank that will require repair.’ said Musk, in an official statement. ‘I will provide further comment as soon as this has been carefully analyzed.

‘Consistent with our policy, we must be 100% green for launch with no outstanding concerns whatsoever. It is not just a matter of repairing the damage, but also understanding at a fundamental level how to ensure it never happens again.

‘ We will also do another full review of all the vehicle systems, including propulsion, structures, avionics, software and ground support systems. Therefore, I expect that the earliest that launch would occur is late January.

‘Third time’s the charm.’

Providing the repair of the first stage can be completed in time, a window is expected to open in the third week of January, 2006. Confirmation will be gained by SpaceX from the military – as they own the range Falcon 1 wishes to launch over.

However, a later statement points to a more serious issue with the rocket – and the ability to be able to aim for January.

‘Due to high winds, we placed the countdown on hold and began draining the fuel tank,’ added Musk. ‘As we drained fuel from the 1st stage tank, a faulty pressurization valve caused a vacuum condition in the tank.

‘This caused a fuel tank barrel section to deform and suck slightly inward. It is important to note that the root cause is an electrical fault with a valve, not structural design.

‘At this point, it appears that no other damage was sustained to the vehicle or the satellite. The rocket will be lowered down this afternoon and placed in its hangar for further inspection.’

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A successful SpaceX launch tomorrow could possibly not come at a better time for SpaceX if it helps to block the US Federal Trade Commission approval of the Boeing and Lockheed-Martin United Launch Alliance (ULA).

‘We understand that the Department of Defence and the Air Force are meeting soon, within days, to decide what they will recommend to the Federal Trade Commission. If they recommend it, we hope we will receive (FTC) approval,’ a Boeing spokesman told The Decatur Daily newspaper yesterday.

Boeing and Lockheed-Martin have both filed motions to dismiss a civil lawsuit filed against them by SpaceX in October in the US Federal District Court of the Central District of California. A hearing date for the dismissal motions has been set for January 9th.

The lawsuit may be indirectly aimed at discouraging the US Federal Trade Commission (FTC) from approving the proposed merger of Boeing Delta IV and Lockheed Atlas V launch operations under a joint United Launch Alliance (ULA). The FTC delayed their expected ruling with a request for more information just days after SpaceX filed the suit.


NasaSpaceFlight is hosting a special opportunity for our readers to ask SpaceX VP of Development Operations Chris Thompson questions about the Falcon I and life at SpaceX.

Post your questions to our forum, and we will select ten questions to be answered by Chris Thompson.
Link: http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=1051&posts=1

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