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Falcon 1 - Demonstration Flight 1 - March 24, 2006
Flight Summary
The first Falcon 1 launch in March of 2006 ended prematurely when the first stage engine shut down 34 seconds into flight due to a fire caused by a fuel leak. A Return to Flight board, convened by DARPA and with participation by SpaceX, NASA, the US Air Force and the US Naval Research Laboratory, conducted a thorough review and traced the malfunction to the failure of an aluminum B-nut at the turbopump fuel inlet. It is believed that this failure was due to stress corrosion, likely caused by prolonged environmental exposure at Kwajalein. In response to the findings, SpaceX has made a number of improvements to our overall launch system. In addition to reducing the total number of B-nuts in the engine assembly and replacing the rest with Stainless-Steel nuts, we have implemented several updates to the vehicle, the Ground-Support Equipment, and our overall launch processes and procedures.
Falcon 1 Maiden Flight Update
Posted March 31, 2006
SpaceX Maiden Launch Video and Image Gallery
Still Photography
Credit for all images:Thom Rogers/SpaceX
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Falcon 1 Maiden Flight Update
Posted March 25, 2006
Preliminary SpaceX Internal Analysis
(Note: There will be a formal US Government led anomaly investigation in partnership with SpaceX. The report issued by that team will reflect the fully considered official opinion. The website updates reflect only the preliminary analysis of SpaceX and are provided pursuant to our policy of early and full disclosure.)
The good news is that all vehicle systems, including the main engine, thrust vector control, structures, avionics, software, guidance algorithm, etc. were picture perfect. Falcon's trajectory was within 0.2 degrees of nominal during powered flight.
However, at T+25s, a fuel leak of currently unknown origin caused a fire around the top of the main engine that cut into the first stage helium pneumatic system. On high resolution imagery, the fire is clearly visible within seconds after liftoff. Once the pneumatic pressure decayed below a critical value, the spring return safety function of the pre-valves forced them closed, shutting down the main engine at T+29s.
It does not appear as though the first stage insulation played a negative role, nor are any other vehicle anomalies apparent from either the telemetry or imaging. Falcon was executing perfectly on all fronts until fire impaired the first stage pneumatic system.
Our plan at this point is to analyze data and debris to be certain that the above preliminary analysis is correct and then isolate and address all possible causes for the fuel leak. In addition, we will do another ground up systems review of the entire vehicle to flush out any other potential issues.
I cannot predict exactly when the next flight will take place, as that depends on the findings of this investigation and ensuring that our next customer is comfortable that all reasonable steps have been taken to ensure reliability. However, I would hope that the next launch occurs in less than six months.
It is perhaps worth noting that those launch companies that succeeded also took their lumps along the way. A friend of mine wrote to remind me that only 5 of the first 9 Pegasus launches succeeded; 3 of 5 for Ariane; 9 of 20 for Atlas; 9 of 21 for Soyuz; and 9 of 18 for Proton. Having experienced firsthand how hard it is to reach orbit, I have a lot of respect for those that persevered to produce the vehicles that are mainstays of space launch today.
I am very encouraged and grateful that our launch customers took the time to call and express their support of SpaceX when their reaction could easily have been the opposite. We will stand by them as they have stood by us. SpaceX is in this for the long haul and, come hell or high water, we are going to make this work.
As SpaceX is a company that believes in maximum disclosure (within the boundaries of proprietary data and ITAR restrictions), I will try to post as much as possible about this launch attempt over the coming weeks.
Credit: Thom Rogers/SpaceX |
Falcon Taking Off
Credit: Thom Rogers/SpaceX |
Engine Closeup Showing Fire
Falcon 1 Maiden Flight Update
Posted March 24, 2006 3:00 pm
We had a successful liftoff and Falcon made it well clear of the launch pad, but unfortunately the vehicle was lost later in the first stage burn. More information will be posted once we have had time to analyze the problem.
Falcon 1 Maiden Flight Update
Posted March 24, 2006 1:14 pm
Revised T-zero time is 2:30 p.m. California time today.
Webcast is Now Available:
http://www.spacex.com/?content=webcast. Please note the feed will be coming over a satellite link, so users will experience periodic interruptions. When video freezes, merely restart/refresh program.
More Launch Details: http://www.spacex.com/launch_info.php
Falcon 1 Maiden Flight Update
Posted March 24, 2006 10:30 am
Launch is scheduled for today at 1 p.m. California time.
Falcon 1 Maiden Flight Update
Posted March 22, 2006
No major issues were discovered following the static fire, but, as a cautionary measure, we are going to take one more day to review data and verify system functionality. Launch is now scheduled for Friday at 1 p.m. California time.
---Elon
Falcon 1 Maiden Flight Update
Posted March 21, 2006
We had a great static fire today. Falcon was held down for almost three seconds of thrust (T+0.5s), part of which was under autonomous thrust vector control. All systems were green and no aborts were triggered.
Unless we discover something negative after a detailed data analysis, launch will happen on Thursday at 1p.m. California time.
---Elon
Falcon 1 Maiden Flight Update
Posted March 15, 2006
Falcon 1 has been removed from its hangar and erected on the launch pad. All systems are currently go for a static fire on March 17 or 18, followed by a launch between March 20 and 25.
---Elon
Credit: Chris Thompson/SpaceX |
Falcon being rolled out of the hangar
Credit: Chris Thompson/SpaceX |
On the launch pad, ready for system checks
Falcon 1 Maiden Flight Update
Posted February 24, 2006
The tentative launch window for the maiden flight of Falcon 1 is March 20 through 25. The gating items are receiving a shipment of liquid oxygen (LOX) from Hawaii and switching out the 2nd stage tank. Obviously, long term operations on Kwaj will require that we install a state-of-the-art, high reliability LOX plant on island. In the meantime, we will get through first launch with LOX shipments from Hawaii and whatever output we can generate from the sad, old clunker of a LOX plant that we currently own.
We are also replacing the 2nd stage tank, following discovery of a small leak. Fortunately, a Falcon 2nd stage tank just barely fits through the door of a standard cargo airplane (no C-17 required), so the flight is relatively inexpensive and readily available. Fixing the leak in the tank being shipped back is not a huge task, but also not something easily done far away from the factory. Countdown procedures have been modified to prevent such leaks from developing in the future.
The static fire performed during the last countdown attempt was really helpful as a preflight systems checkout, so we will be doing one again three or four days before the next countdown (most likely March 17). In addition, we are doing another systems review with DARPA, AF and NASA in early March.
---Elon
Credit: Thom Rogers/SpaceX |
Falcon 1 Maiden Flight Update
Posted February 10, 2006
We were very happy to be able to execute a flight countdown all the way to lighting the engine. Although there wasn't a launch this time, we made a lot of progress refining the rocket and launch pad -- all work that needed to be done anyway. I will post a longer update next week, after we have enough time to finish forensics of recent events and formulate next steps.
---Elon
Credit: Thom Rogers/SpaceX |
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Falcon 1 Maiden Flight Update
Posted February 9, 2006
After analyzing data from the static fire countdown, we decided to postpone the launch. The vehicle is being lowered for further investigation.
Once we have thoroughly checked out all systems, I will post an update on what was found and when the next countdown attempt will occur. Based on range availability and logistics constraints, a rough guess would be two to four weeks.
---Elon
January 2006 Update
(Note: Subscribers to the email list receive the update earlier than it is posted on the website. Email address privacy is always respected.)
New Launch Time
The new launch time is February 8 at 4:30 p.m. California time with Feb. 9 as a backup day. We will actually be ready to launch earlier, but are planning to spend extra time reviewing and double-checking all vehicle systems.
Following the problem on Dec. 19, we flew a whole new first stage to Hawaii via C-5 just in time to catch the barge from there to Kwaj a few days before New Year's Eve. The new stage should arrive at Kwaj in about a week, whereupon we will switch it out with the damaged unit, which will be sent back to California for repair. The repair is not particularly difficult or expensive, but can only be done properly in a factory setting.
What Was the Problem?
As previously reported, we traced the problem to the failure of an electronic component in one of the first stage fuel tank pressurization valves. Although we have triple redundant pressure sensors and dual redundant pressurization valves, when this component shorted, it caused the valve controller board to reboot, effectively eliminating the redundancy. This is the first time in 3.5 years of hard testing that we have ever seen this happen. Moreover, the component in question has a cycle life and power rating far in excess of the theoretical load that it should see. To address this specific problem, we are replacing the component with one that has a quasi-infinite lifespan and taking a few other steps that will isolate any issue with this component if it goes wrong in the future.
However, as I mentioned in an earlier update, we are not simply going to address this particular point problem and then merrily jump back into a countdown sequence. Throughout January, the SpaceX team will be doing another full review of vehicle systems, including propulsion, structures, avionics, software and ground support systems. We will be conducting additional engine tests, stage separation tests and avionics tests to once again attempt to flush out any issues. Even if we find nothing, the exercise is worthwhile.
Wind Delays Suck (Literally)
It is worth noting that we would have caught the problem without any damage to the vehicle if we had entered the final countdown sequence as planned. The sucked in tank damage only occurred because we partly drained the fuel tank due to the hold for high winds.
High winds are not a limitation of the rocket, which is designed to be essentially "all weather" and handle ground winds in excess of 50 mph (watch out for flying coconuts!). The ground winds limitation is actually due to the need to avoid a collision with the launch stand hold down arms, which grab the rocket at the base of the fuel tank, as the rocket lifts off.
To alleviate this problem, we have redesigned the launch stand so that the hold down arms retract out of the way on liftoff, activated by a breakwire. This gives us something very close to 100% winds availability from Kwaj. The retraction force is low, so even if there were an early activation of the actuator, it would not damage the rocket.
Another bothersome problem is the high rate of liquid oxygen (LOX) boiloff. This is not surprising when LOX is at -300F and there is a stiff wind impinging on the vehicle at 85F. To minimize boiloff, we will wrap the LOX tank in low cost cryo insulation attached with velcro straps that tear away on liftoff.
Lessons Learned on F1 Apply to F9
The challenges to date I think vindicate the strategy of building a small launch vehicle before a large one. If we had started out with an F9 class vehicle, the cost of every mistake would be multiplied by as much as an order of magnitude. As it is, we are able to overcome problems comparatively quickly and cheaply.
With the benefit of lessons learned on F1, it is taking far less time, effort and money to create F9. Despite the distraction of the F1 launch countdowns, I still anticipate a flight F9 first stage firing later this year and a maiden launch in late 2007.
Great Expectations
Those familiar with the launch business will know that countdown scrubs are a way of life. It's often said that the safest time to schedule your vacation is around launch day and that's true more often than not. Even rockets that have launched hundreds of times from launch pads that are in heavy use have multiple scrubs. Not too long ago, there was a Titan launch that had eleven scrubs and Delta launch that had six. Reasons range from hard to avoid technical glitches, like the Shuttle fuel sensor malfunction on its last launch attempt, to silly false alarms. A Titan countdown was once aborted when someone spotted a "bag of suspicious liquid" on the mobile service tower. It turned out that the latrine had simply been a bridge too far for one of the technicians.
Given that Falcon 1 is an all new rocket and is launching from an all new launch pad on a remote tropical island, countdown scrubs in the first few attempts were very likely. As it is, we have had one abort due to a launch pad issue and one due to the rocket. If this next attempt succeeds in getting to t-zero, SpaceX will be reasonably fortunate in the scheme of things.
Credit: Thom Rogers/SpaceX
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Falcon 1 on Omelek Launch Pad |
---Elon---
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