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SpaceX Successfully Tests Nine-Engine Cluster
the_other_chewey writes "At their test facility in Texas, SpaceX, the privately funded space-flight company, have successfully tested their nine-engine cluster which is planned to provide the heavy lifting capability for their Falcon 9 and Falcon 9 Heavy rockets.
The firing lasted three minutes (a full 'mission duty cycle,' i.e. a simulated launch) under full power, delivering 3.8MN (or 855,000 lbs.) of thrust. SpaceX have made a video of the test available. The Waco Tribune has a short report about it, with comments by locals."
Awesome, simply awesome. Glad to see they passed the test, or at least didn't blow up. Hope they got some good test data. Ideally they were giving it some control feedback to make sure the gimbals etc that aim the rocket were all responding correctly, performing their orbital roll etc. Getting the most bang for the buck (without the bang!) since I'm sure this test cost a not-so-small fortune considering the fuel used.
As for the "why didn't it take off" question, it was pretty firmly fitted to the ground. Despite it's size and total impulse capacity, that's over a 3 minute span. It's not designed to lift more than itself and its payload, at a marginal acceleration. The thrust output is variable also, and can't be allowed to crush the payload with G-forces. Despite its massive size, it wasn't going to be going anywhere.
I'd be interested to know the power curve on the rocket. Most of the fuel is actually spent lifting the FUEL. From one viewpoint, the engine could be constant-thrust, and would accelerate slowly at first, and increase its acceleration as it consumed fuel and became lighter with the same thrust. Or it could back off the thrust as it got lighter, to prevent the g-forces from acceleration from becoming too great for the vehicle or its payload. I'm sure the power-to-weight-ratio could get really high as it nears the end of its firing if it were left at maximum thrust. Anyone happen to know the power curve or acceleration curve on ascent? I thought I read somewhere they try to keep the g-forces under 8g, and not for too long of a period of time, at least for crew.
I work for the Department of Redundancy Department.
Unless NASA releases money for COTS-D very soon, we will still have a manned launch gap. The Falcon 9 and Dragon are man rated, but to launch people into using the Falcon 9 and Dragon, you need much more. You need a Launch Escape System and a Emergency Egress System. Neither of these is currently in development at SpaceX and both have a long lead time to develop.
Without the additional COTS-D money to start development on these systems, SpaceX will not carry people until they find the money from other sources to fund these development efforts.
engineers are all basically high-functioning autistics who have no idea how normal people do stuff
I work for the TX facility. The concrete tripod is 120' tall and the legs are 10' in diameter. The stage is 85' tall and 12' in diameter. You can see it 25 miles away when you are driving to work. It is pretty awesome (-;
850,000lbf (lbf = pounds force) is a relatively small load. It is easy to forget exactly how strong steel is in tension: using standard 50ksi steel (typical structural steel), only about 18 sq-in would be required to hold the rocket down (albeit with no factor of safety).
For comparison, the main cables in the George Washington suspension bridge in New York each carry ~260,000,000lbf, and are designed to resist almost 3 times that load. While the amount of thrust developed by the Falcon 9 is seriously impressive for a lift vehicle, it is trivial from a ground-based engineering standpoint.
There is a reason structural engineers work in kips not pounds (1 kip = 1000lb), and yes IAASE.
under construction
Dear Greater Waco Area Residents, We appreciate your feedback regarding our recent test as it allows us to improve our notification process to the surrounding community. Since we began operations in 2003, SpaceX has conducted over 2000 tests, and nearly ten have been multiple engine tests at similar times of day. During these previous tests, we did not receive complaints from citizens in your area. The weather on November 22, with low clouds and cool temperatures, drastically affected the distance the sound and light travelled. We began test procedures for this particular test at 7:00am on Friday, Nov. 21 and executed it as quickly as possible, working through hundreds of pages of procedures designed to keep the community, staff, and hardware safe. While no further tests are planned for this stage in McGregor, in the future we will increase our notification to include local news media and law enforcement in McLennan, Coryell, Bell, and Falls counties. As a resident of Central Texas for over 25 years, with family in the area, it is extremely important to me, as well as all of SpaceX, who choose to raise their families in the area, that our testing is safe for local residents. The propellants used are non-toxic and environmentally friendly, In factâ"the Falcon 9 burns a higher grade of kerosene (more environmentally friendly) than a 747 and burns only about half of what a single 747 flight does. The smoke you may have seen was composed mostly of steam and dust. SpaceX strives to be a good corporate neighbor, bring high technology jobs to the area, and stimulate the local economy. We are proud to have operations in McGregor and make use of facilities which have historically played such an important role in American history. Engines which propelled American astronauts to the moon and back were developed and tested here, as well as the Sidewinder and Phoenix missiles. The launch vehicle engines tested last night will soon take cargo, and eventually crew, to the International Space Station. Falcon 9 represents the only medium to heavy lift rocket that is 100 percent Made in America and with this vehicleâ"SpaceX will bring leadership in launch back to the US. The leadership role is currently held by former Soviet Republics, France, and China. http://www.wacotrib.com/blogs/content/shared-gen/blogs/communities/breakingnews/entries/2008/11/23/spacex_issues_statement_on_con.html
This space available.