It Happens To Every Rocket Company
Posted by Pete Hague on 19 May 2012
This morning, the first attempt by SpaceX by launch a capsule to the International Space Station was aborted a fraction of a second before lift off due to a abnormal pressure in one of the Falcon 9's engines. All engines were shut down, and the rocket remained exactly where it was. SpaceX will attempt another launch on Tuesday.
This type of abort is not trivial. Most rockets are not held down like Falcon 9; once the engines fire, there is no option but to launch the rocket. Falcon 9 can turn its engines to full power, verify they are functioning properly, and only then proceed to leave the pad.
A clear demonstration of the utility of being able to hold down a rocket before launch is provided by the fate of one flight of the N1 Soviet moon rocket. On July 3, 1969, the Soviets made their last attempt to launch the rocket before they were beaten to the Moon by Apollo 11. When the rocket took off, a cascade of failures in the engines and control systems caused 29 out of 30 of them to shut off, and the gigantic rocket fell back onto the launchpad, consuming in a gigantic fireball.
I don't know enough about the specific accident to say if it could've been prevented by a hold down; however it demonstrates the worst case scenario for an engine failure. Being able to run the engines, with the rocket held down, makes this less likely to happen. The fact that this abort mode has now been successfully demonstrated, could actually make the Falcon 9 rocket look more reliable, not less.
Now it may seem this is a story about the supremacy of American engineering over Russian engineering, but it isn't. The NK-15 engines on the N-1 were, as individual units, very well made. The combination of 30 of them in the first stage of that rocket suffered serious reliability issues and never completed a single launch. However, after the fall of the USSR, engines left over from the program were bought (along with the rights to manufacture more of them) by a US company, and are considered competitive with modern designs.
Some of these engines are going to fly as part of the Antares rocket, a competitor to SpaceX's rocket, which will fly a cargo mission to the ISS later this year. Hopefully Orbital Sciences will have more success than the original users.
Commercial Space Station
Both Falcon 9 and Antares are being used to meet a commercial contract for supplying the International Space Station. Certain people are citing this new model of space exploration as the beginning of a conquest of space by private enterprise. These tend to be the same neoliberal/libertarian people who claim that the private sector is better than the public sector at everything, and always. The successes of government space programs have always been an obstacle for their ideological triumphalism.
In reality, less has changed than they would like to imagine. US space capsules have been designed, built, and even operated by private companies since the beginning of the space race. The way the duties for this are being handed out is different now (multiple providers, no more 'cost plus' contracts) and this might make it more competitive - but the situation is still a government space program buying services. The founder of SpaceX, Elon Musk, acknowledges that his company could not be doing what it does without NASA. Most of the strong ideological statements actually comes from fans of his company.
As I discussed in my blog post about asteroid mining - although the private sector can provide services to a space program, ultimately the government must fund large, long range space exploration projects. If any individuals become so insanely rich that they can afford to personally finance a viable Mars expedition, then society will have become a great deal more unequal that it is now.
(I suppose it is a personal preference whether or not you think that is OK, but judging by the drama going on in the Eurozone, you can't maintain a democratic state in such a condition long term. and a stable society is probably needed for big technological projects such as Mars missions. For those that think they can simply ignore the inequality problem through even more growth, I've already posted a refutation of that notion, as if one were actually needed.)
Original Research
Private space companies also benefit from government doing the fundamental research. Part of the reason why the first commercial space companies are in the US, is that the US has NASA - the worlds largest government space agency. NASA offers technical assistance to these companies, sells research projects off to private companies, and provides launch facilities.
We can see what the state of private spacecraft is without this kind of help; the sub-orbital spacecraft 'SpaceShipOne' is privately developed, and has fairly low capability. It runs off a very simple type of engine, which simply does not have the power required to reach orbit - and even if it did, its structure could not survive re-entry at orbital velocity. SpaceShipOne is essentially a rocket powered aircraft, that qualifies as a spacecraft only on a technicality of altitude.
Something that is more of a true space launch vehicle, developed privately, is Reaction Engines' Skylon. This British-designed spaceplane is a fully reusable Single Stage To Orbit (SSTO) spacecraft that uses air, liquified and fed into the rocket engines, as an oxidiser during the first part of its flight. It takes off and lands like a plane, and can be turned around in 2 weeks. Its also very, very pretty:
Currently, the only part of the spacecraft that has been constructed is the pre cooler, used to liquify the incoming air. Further funding and development is contingent on this being successfully tested. As the ability to use atmospheric air in this manner is the major unknown in the design, this successful completion of the test ought to accelerate development of Skylon. Alan Bond, the managing director of Reaction Engines, states here that he will be able to go to the Farnborough International Air Show this July with an announcement that both the jet engine and conventional rockets have been superseded by this technology.
Skylon has been in development for over 20 years, and based on the projections of its creators will not fly until at least 2020. The sharp contrast between this and the rapid progress of companies like SpaceX shows the discrepancy between a first-of-a-kind space launcher like Skylon and an (admittedly well executed) nth-of-a-kind space launcher like Falcon 9. Over the same timescale over which Skylon has got from the basic concept, to the first test of flight hardware - the US government got from the first acquisition of Nazi rocket technology to landing men on the Moon. Of course, the US government had a great deal more money, and despite the scale of the operation - much of the technology involved in the Moon landing was quite simple.
These comparisons are limited, because there are so many confounding factors. However, that does not stop people using them to trying and push their ideological preference, usually for the idea of the completely superior efficiency of the private sector. Not only is this partisan and over-simplistic, it could potentially undermine the very space programs the people making these arguments claim to be in favour of.
I'd much rather people leave aside the ideological points-scoring, and support the human exploration of space.
7 Comments
Posted by Matt Cro on 21 May 2012
As you said the fact the rocket was able to be shut down less than 0.5 seconds before launch really proves the safety design of the rocket. Apparently Elon Musk tweeted that the rocket could have launched regardless as the fault was not critical, but better to stop than risk it.
As for Skylon, who do you think would end up building it (I may have asked you this over Twitter...), assuming it does get built? I don't think Britain could afford the project, but perhaps as 'prime' contractor, with other nations developing it perhaps, similar to A380, but instead we don't just build the wings.
As long as the yanks/Russkies/Chinese don't get it....
Posted by Pete on 23 May 2012
Matt, Reaction Engines themselves have stated they can't work with US companies because of ITAR, and so it would have to be a European consortium.
Basically, it has to be EADS building it, simply because I think they would use political power to kill any European competitor to Ariane 5.
Posted by Tom Conlon on 23 May 2012
I would love to see SKYLON be built and be used successfully, but it is worth bearing in mind that people have been coming up with concepts for similar airplane-like spacecraft for decades (the German "Sanger", American "X-30" and British "HOTOL" projects spring to mind) and as of yet not a great deal has come of them.
Posted by Pete on 23 May 2012
Tom,
While it is good to be skeptical, Reaction Engines a) are now demonstrating critical hardware and b) have had their work thoroughly looked over by ESA.
They are more likely to run into political/money problems than engineering problems at this point. They've had too many eyes on their work to have made an absolutely show-stopping mistake.
The other space planes you mentioned failed (or would've failed) for specifica engineering reasons. Sanger would've fried on re-entry, for instance. HOTOL is the direct ancestor of Skylon, and flaws in that design drove many of the features of Skylon.
Posted by Tom Conlon on 23 May 2012
Must admit that I wasn't aware that the SKYLON project was that far advanced (I've not really kept track of it). It is good to see that the idea of a space plane is still alive, as I think it is a fantastic idea overall.
I also agree that it would be EADS building it. I agree that it is unlikely it will be built by a single nation, especially if it remains in European hands and the main Airbus equivalent (spread over many countries) and, I think, the company with the best chances of making the project work would have to be EADS.
Do we know anything about its projected payload capability etc.?
Posted by Pete on 23 May 2012
Reaction Engines provide quite a bit of detail, including a user manual:
http://www.reactionengines.co.uk/skylon.html
also, there is a thread on nasaspaceflight.com that includes responses from one of the Reaction Engines staff:
http://forum.nasaspaceflight.com/index.php?topic=24621.660
Posted by Matt Cro on 23 May 2012
Payload to LEO is ~15 tons. It will probably be a European thing, but for a pride point of view, I hope Britain plays a leading role in it.
Even if it fails, but the engine does get developed, the spin off is their supersonic A2 jet liner, using 4 of the Sabre engines, so hopefully it won't all disappear forever god forbid it gets cancelled.
