The full webcast of the entire voyage of Falcon 1 is now available. It's an amazing video and I suggest everyone take the time to check it out. I don't think there's anything out there like this. The idea of being this open to the public in any company is amazing. To do it in the space business, with such a high rate of failures, is especially noteworthy.
If you can't access it on my site (the link is a bit spotty), try this page on SpaceX's site.
Official report from SpaceX on the Falcon 1 Vehicle 3 launch:
On August 2 nd, Falcon 1 executed a picture perfect first stage flight, ultimately reaching an altitude of 217 km, but encountered a problem just after stage separation that prevented the second stage from reaching orbit. At this point, we are certain as to the origin of the problem. Four methods of analysis – vehicle inertial measurement, chamber pressure, onboard video and a simple physics free body calculation – all give the same answer.
The problem arose due to the longer thrust decay transient of our new Merlin 1C regeneratively cooled engine, as compared to the prior flight that used our old Merlin 1A ablatively cooled engine. Unlike the ablative engine, the regen engine had unburned fuel in the cooling channels and manifold that combined with a small amount of residual oxygen to produce a small thrust that was just enough to overcome the stage separation pusher impulse.
We were aware of and had allowed for a thrust transient, but did not expect it to last that long. As it turned out, a very small increase in the time between commanding main engine shutdown and stage separation would have been enough to save the mission.
The question then is why didn't we catch this issue? Unfortunately, the engine chamber pressure is so low for this transient thrust -- only about 10 psi -- that it barely registered on our ground test stand in Texas where ambient pressure is 14.5 psi. However, in vacuum that 10 psi chamber pressure produced enough thrust to cause the first stage to recontact the second stage.
It looks like we may have flight four on the launch pad as soon as next month. The long gap between flight two and three was mainly due to the Merlin 1C regen engine development, but there are no technology upgrades between flight three and four.
Good Things About This Flight
Merlin 1C and overall first stage performance was excellent
The stage separation system worked properly, in that all bolts fired and the pneumatic pushers delivered the correct impulse
Second stage ignited and achieved nominal chamber pressure
Fairing separated correctly
We discovered this transient problem on Falcon 1 rather than Falcon 9
Rocket stages were integrated, rolled out and launched in seven days
Neither the near miss potential failures of flight two nor any new ones were present
The only untested portion of flight is whether or not we have solved the main problem of flight two, where the control system coupled with the slosh modes of the liquid oxygen tank. Given the addition of slosh baffles and significant improvements to the control logic, I feel confident that this will not be an issue for the upcoming flight four."
Thanks for joining me over the week-end as we watched one of the most exciting Space events of the year. It's sad that it did not make it to orbit, but that's the reality of a Space Exploration. SpaceX is going to change the way mankind reaches space. Turns out, that's not as easy as it sounds. ;)
I'll keep posting as there is new news. In the meantime, click here to use Me.dium to stay up to date on Falcon 1 and SpaceX.
"It was obviously a big disappointment not to reach orbit on this flight [Falcon 1, Flight 3]. On the plus side, the flight of our first stage, with the new Merlin 1C engine that will be used in Falcon 9, was picture perfect. Unfortunately, a problem occurred with stage separation, causing the stages to be held together. This is under investigation and I will send out a note as soon as we understand exactly what happened.
The most important message I’d like to send right now is that SpaceX will not skip a beat in execution going forward. We have flight four of Falcon 1 almost ready for flight and flight five right behind that. I have also given the go ahead to begin fabrication of flight six. Falcon 9 development will also continue unabated, taking into account the lessons learned with Falcon 1. We have made great progress this past week with the successful nine engine firing.
As a precautionary measure to guard against the possibility of flight 3 not reaching orbit, SpaceX recently accepted a significant investment. Combined with our existing cash reserves, that ensures we will have more than sufficient funding on hand to continue launching Falcon 1 and develop Falcon 9 and Dragon. There should be absolutely zero question that SpaceX will prevail in reaching orbit and demonstrating reliable space transport. For my part, I will never give up and I mean never.
Thanks for your hard work and now on to flight four.
It has been a tough day. Falcon 1 Vehicle 3 did not reach orbit today.
A problem occurred with stage separation, causing the stages to hold together. On the plus side, the new Merlin 1C engine in the first stage performed flawlessly. This engine will be used on Falcon 9, the SpaceX rocket that will take cargo to the International Space Station.
Falcon 1 Vehicle 4 is almost ready for flight and Vehicle 5 is right behind it. I'll post expected launch dates as I have them.
When I was in Kwaj, I couldn't help but notice the strange pictures from around town.
Strange picture from around town
As it turned out, Kwaj was (and still is) a giant target for testing missiles launched from the continental US. Those images are the re-entry trails of the ICBM's launched from California. I found this out on a bike ride around the island. There is a beautiful view on the north side of the island looking into the center of the atoll.
The beautiful view of the center of the atoll from this chair
What it looks like when ICBMs re-enter (from the chair).
Well, I went through the Kwajrockets archive and found some goodies. I know you guys are probably scouring every corner of this blog for all the great stuff I've written, but just in case, I thought I'd give you a highlight reel.
Omelek - SpaceX's island
Did you know that Kwaj is very far away?
Some Kwaj facts:
Guam is closest at 1,400 miles away, Hawaii is 2,100 miles away
For those that aren't aware, SpaceX does almost all its work just south of Los Angeles. It's headquarters is a 500,000sf Hanger on Hawthorne airport. Check it out:
Lox load is complete. Holding to determine Collision Avoidance with ISS and avoid radiating UFKAS during powered flight. New projected T zero is 12:55pm local-time on Kwaj.
The good thing about having a little bit of free time, is that it just happens that there's a lot to talk about. Here's a diddy on the rockin' Merlin 1C, the main engine of Falcon 1 Vehicle 3.
The pintle style injector at the heart of Merlin was first used in the Apollo Moon program for the Lunar Excursion Module (LEM) landing engine, one of the most critical phases of the mission.
Specs:
Sea Level Thrust: 78,000 lb - those three F-16s I mentioned earlier Vacuum Thrust: 138,400 lb - everything is just better in space. Sea Level Isp: 255 s - Isp is Specific Impulse Vacuum Isp: 304 s
Now I know you're asking: What exactly is Isp, Kimbal? Well, funny you ask. I just happen to have an explanation...
For the Rocket Scientists out there...
The specific impulse Isp is given by:
Isp = Veq / g0
where g0 is the gravitational acceleration constant (32.2 ft/sec^2 in English units, 9.8 m/sec^2 in metric units). Now, if we substitute for the equivalent velocity in terms of the thrust:
Isp = F / (mdot * g0)
Mathematically, the Isp is a ratio of the thrust produced to the weight flow of the propellants. A quick check of the units for Isp shows that:
Isp = m/sec / m/sec^2 = sec
Now I know that a lot of folks aren't into physics, or if they are, and you still can't figure it out, our friends at NASA have a nice and easy explanation of Isp:
"Why are we interested in specific impulse? First, it gives us a quick way to determine the thrust of a rocket, if we know the weight flow rate through the nozzle. Second, it is an indication of engine efficiency. Two different rocket engines have different values of specific impulse. The engine with the higher value of specific impulse is more efficient because it produces more thrust for the same amount of propellant. Third, it simplifies our mathematical analysis of rocket thermodynamics. The units of specific impulse are the same whether we use English units or metric units. Fourth, it gives us an easy way to "size" an engine during preliminary analysis. The result of our thermodynamic analysis is a certain value of specific impulse. The rocket weight will define the required value of thrust. Dividing the thrust required by the specific impulse will tell us how much weight flow of propellants our engine must produce. This information determines the physical size of the engine. "
And from SpaceX: "With a vacuum specific impulse of 304s, Merlin is the highest performance gas generator cycle kerosene engine ever built, exceeding the Boeing Delta II main engine, the Lockheed Atlas II main engine and on par with the Saturn V F-1.
While we're waiting, I thought I'd share some fun factoids about the rocket we're checking out today:
Falcon 1 is a two stage, liquid oxygen and rocket grade kerosene (RP-1) powered launch vehicle. It is designed from the ground up by SpaceX for cost efficient and reliable transport of satellites to low Earth orbit.
She shore is purty, ain't she?
Length: 21.3 m (70 feet) - Your standard 7 story building. Width: 1.7 m (5.5 feet) - actually, make that a 7 story pencil. Mass: 27,670 kg (61,000 lbs) - about the weight of 4 semis (sans trailer). Thrust on liftoff: 347 kN (78,000 lbf) - about the same thrust of three F-16's at full throttle.
First Stage The primary structure is made of an aluminum alloy (patent pending), graduated monocoque, common bulkhead, flight pressure stabilized architecture developed by SpaceX. The design is a blend between a fully pressure stabilized design, such as Atlas II, and a heavier isogrid design, such as Delta II. As a result, Falcon 1 first stage is able to capture the mass efficiency of pressure stabilization, but avoid the ground handling difficulties of a structure unable to support its own weight.
A single SpaceX Merlin 1C regenerative engine powers the Falcon 1 first stage, and is flying in this configuration for the first time on Flight 3. After first stage engine start, the Falcon is held down and not released for flight until all propulsion and vehicle systems are confirmed to be operating nominally.
Stage separation occurs via redundantly initiated separation bolts and a pneumatic pusher system. All components are space qualified and have flown previously on other launch vehicles.
Second Stage The tanks are precision machined from plate with integral flanges and ports, minimizing the number of welds necessary. A single SpaceX Kestrel engine powers the Falcon 1 upper stage.
The Falcon 1 Flight 3 will carry a payload stack of three separating satellites that will orbit at an inclination of 9 degrees:
1. The Trailblazer satellite, developed by SpaceDev of Poway, Calif. 2. PRESat, a micro laboratory from NASA's Ames Research Center 3. NanoSail-D, which will unfurl an ultra-thin solar sail, developed by NASA's Marshall Space Flight Center, in collaboration with NASA Ames Research Center.
Here's the timeline of what we should expect during the launch. Time to delivery of all three payloads is 18 minutes and 17 seconds.
Last night Spacex achieved a major milestone. I know, you're thinking I'm talking about the Falcon 1 launch window, but as is to be expected for a company like SpaceX, they tend to have more than one major awesome thing going on at a time.
On Thursday night was the first nine engine firing of the Falcon 9 Launch Vehicle at the Texas Test Facility out of McGregor. Last night a second successful firing completed a major milestone for NASA on the path towards a new transportation vehicle to the International Space Station. I.e. replacing the Space Shuttle. Oh yeah baby.
And of course, some awesome stats 1. 3,200lbs/sec - Fuel consumed full power 2. 832,000lbf - pounds of force generated at full power (four times the maximum thrust of a 747) 3. With some tweaks and a new fuel pump upgrade, Falcon 9 will be the most powerful singe core vehicle in the US.
From Elon - “This was the most difficult milestone in development of the Falcon 9 launch vehicle and it also constitutes a significant achievement in US space vehicle development. Not since the final flight of the Saturn 1B rocket in 1975, has a rocket had the ability to lose any engine or motor and still successfully complete its mission,” said Elon Musk, CEO and CTO of SpaceX. “Much like a commercial airliner, our multi-engine design has the potential to provide significantly higher reliability than single engine competitors.”
And for the voyeur's in all of us, here the running commentary on the test firing from the team on the ground-
Time: Friday, 01 August, 2008 6:22 PM Status: Helium trailer hooked up. We are getting ready to bring the stage up on the new helium and perform valve timing checks.
Time: Fri Aug 01 18:57:26 2008 Status: Main valve timing is good. We are setting up to test
Time: Friday, 01 August, 2008 8:43 PM Status: F9 propellant load complete. 535,000lbm propellant loaded. Next step is to set up to run 15 second trim test.
Time: Friday, 01 August, 2008 8:51 PM Status: Starting autosequence... For 15 second nine engine test
Time: Fri Aug 01 20:54:06 2008 Subject: Test complete - full 15 seconds!!!! No Aborts
And of course, no test firing post is complete without the video from last night.