Paypal Founder's Merlin Rocket Engine Fires Up 252
Baldrson writes "Wired News reports that after 2 years of development, Space Exploration Technology Corp ('SpaceEx') successfully test-fired their new LOX/Kerosene Merlin rocket engine for the 160 seconds required for orbit. SpaceEx was founded by Elon Musk from the proceeds of the 2002 sale of his prior start-up, Paypal, to Ebay. According to Musk, 5 Merlins bundled with the first stage of SpaceEx's powerful Falcon V booster will launch 5 people to orbit by 2010, thereby winning America's Space Prize which was endowed by Robert Bigelow."
Re:Big rockets? (Score:4, Informative)
Um, on launch the space shuttle is pretty much a big rocket. That's what the big fuel tank and boosters are for. Rocketing it into space.
The Shuttle's innovation was in the landing stage and the reuse of the rocket boosters and shuttle vehicle itself. This also allowed for large payloads such as science labs that could be carried in the vehicle and returned to Earth. In the case of Apollo or Soyuz style vehicles, only the small crew compartment is returned.
Re:WWW -- Space (Score:5, Informative)
And, if all of those that entered into early aviation, using the money they made in other industries (see, for example, Howard Hughes), thought the way you do, we'd be way behind and probably would have lost WWII.
Re:Big rockets? (Score:3, Informative)
I find their arguments convincing. It's an incremental step using existing technology, but it's a big one.
160 Seconds? (Score:2, Informative)
To do that in 160 seconds (2.67 minutes), you need an *average* acceleration of over 5.5g. You're also not going to get that at launch without a ridiculously overpowered engine that will crush your passengers at the end, when the ship has burned out all of its fuel and weighs a lot less. Most rocket engines aren't all that throttleable, with min thrust usually >.5 x max thrust.
For comparison, a Space Shuttle launch goes something like this:
(launch)~2g
(just before booster burnout)~3g
(just after booster burnout)less than 1g
(just before main engine burnout)~3g
The average acceleration is about 2g, meaning that the Shuttle takes around 8 minutes to go from ground to orbit.
5.5g? Average? I doubt it.
Re:Big rockets? (Score:5, Informative)
There is no way that SpaceX would be profitable selling rockets for $6 and $12 million each if he spent $1.5 billion developing them. That's part of the reason why normal space launch rockets cost $40 to $250 million (or more...).
Re:160 Seconds? (Score:3, Informative)
Second, even on a single stage rocket, an average acceleration of 5g is almost acceptable; witness certain NASA studies [nasa.gov] (about halfway down the page) which concluded that 5g for two minutes is sustainable for most all humans.
Interview with Elon Musk about SpaceX (Score:5, Informative)
Here's a quote:
HS: Private rocket development by startup companies in the post-Apollo era includes projects such as Truax's Volksrocket in the late 70s, Conestoga I and AMROC in the 80s, Beal Aerospace and several other ELV and RLV companies in the 1990s. They all came up short of space and many see their history as nothing but a tale of woe and failure. To me, though, they each appear to build on what was learned before them and to provide significant advancements in the technical and strategic knowledge needed to develop a rocket business from scratch.
It looks like SpaceX will be the startup company that finally makes it to orbit. When you studied prior efforts, what were some of the lessons [you] learned on what to do and, perhaps most importantly, what not to do?
Musk: Well, I have tried to learn as much as possible from prior attempts. If nothing else, we are committed to failing in a new way
The ones I'm familiar with failed on one or more of the following:
1. Lacked a critical mass of technical skill.
2. Insufficient capital to reach the finish line, particularly if an unexpected setback occurred.
3. Success was reliant on a series of technology breakthroughs that did not happen.
The above modes can obviously cross-feed one another.
HS: John Carmack has said something to the effect that the gap between what could be done versus what is being done is bigger in aerospace than in any other industry. Gary Hudson said that he was "amazed by how much easier the job of getting to orbit is today than even a few years go"..."Software, avionics and manufacturing technology have all improved measurably" and drastically reduced the number of people needed to design a launcher.
Now that you've gone through the rocket vehicle design phase and are well into construction, does your experience support their views or has the Falcon development perhaps been more difficult than you initially expected?
Musk: Well, hard and easy are somewhat nebulous terms. I think I have high standards and would classify getting Falcon to orbit as quite difficult. Overall though, I think we have had quite a smooth development so far, which is a credit to the hard work of the SpaceX engineering team.
The design tools, such as solid modeling and finite element analysis software are substantially more powerful than ten years ago, so that's a clear advantage. Obviously, most electronics have improved a lot too, except gyroscopes and flight termination systems.
Re:Getting up is only the first part (Score:3, Informative)
The Space Shuttle tiles aren't lighter than a good ablative heatshield would be. The shuttles have about 18.5 metric tons of tiles and thermal blankets and leading edge RCC panels, out of a total gross weight of 104 metric tons (18%).
Apollo, which was re-entering at a higher velocity coming back from the moon, has a thermal protection system weight of 850 kg out of 5,800 kg total mass (15%).
The proposed British Multi Role Capsule re-entering from low orbit had 666 kg of thermal protection system mass, out of 6,200 kg total mass (11%).
Re:Getting up is only the first part (Score:4, Informative)
That depends upon what your heatshield is made of. If it's made from the same tiles that make up the space shuttle, it would be expensive. If it's made from carbon phenolic, or a similar material, it would most likely cost less to replace it every time than to boost a more durable material into orbit. That's not to mention the fact that a tile system or similar would still have to be inspectedand partially replaced after every flight, reducing any gains in cost.
Remember that for every pound you put in orbit, you just spent thousands of dollars. Those thousands of dollars could provide for a lot of work making a heat shield on the ground.
Re:Low Environmental Impact unless it goes splat (Score:3, Informative)