Tuesday, February 8, 2011

The Ares 1... er I mean Liberty rocket

"The bottom part of the proposed Liberty rocket would be based on the solid-fueled boosters that help get the shuttle off the ground. The top half would use the liquid-fueled core-stage technology and engine that powers the Ariane 5. The concept has been put forward by ATK from the US and Astrium from Europe. Their idea is being submitted to the US space agency (Nasa), which is seeking commercial solutions to take astronauts to and from the space station following the retirement of the shuttles later this year. There has been deep concern in the US Congress about the length of time it might take to provide commercial alternatives, leaving America reliant on Russian Soyuz vehicles until perhaps the latter part of this decade. But ATK and Astrium believe their experience means they could have the 90m-high (300ft) Liberty rocket ready to fly by 2013, and operational with astronauts on board by 2015."

Hmm looks very similar, but with a better paint job. Overall I am pleased, but only if one of these rockets actually is built. Ares 1 was fine, but this one will do also. I do think we need something like this, and soon. It will be very sad if we just give up on manned space missions for a while. Either way, there are a few key features that must be found on any rocket design in my humble (and far from expert) opinion; the crew must be in a rugged capsule that can survive all abort modes from pad to orbit, alone, and in a single configuration. The crew must ride above all rocket stages and be free of debris, and must have a launch escape system such as a LET. The first stage should use a simple solid rocket motor that is reusable. Ideally this would be unmodified SRB motors, to save time and money. However it looks like these new rockets rely on longer SRB designs. The upper stage should be a high performance liquid fueled stage that has enough potential to offer a wide range of cis-lunar orbits to support future deep space missions, which are unequivocally the future of manned space missions. I have serious doubts about the Liberty Rocket doing this; it has a 12,000 lbs lower LEO payload capability than the Ares 1. However, it looks as if it will have a similar design and will achieve all of the above suggested safety goals. The expected mass of the Orion, the capsule of choice should it be completed, is around 47,000 lbs including service module and fuel. Considering the 44,500 stats for this rocket, I am a bit worried that it is too much of a lightweight for the job. It will serve the ISS well, however.

Having said all this, I doubt that this rocket will do much to prevent a launch gap for the US space program. Frankly, given the typical slow pace of manned rocket development and the man-rating process, I would say that the gap is already upon us. Nothing done today can stop it, but only reduce the duration of the now inevitable gap. Perhaps adding a few more white-knuckle bank-account-emptying shuttle launches can prevent a gap. But at significant cost and risk. I have serious doubts about sending men on any rocket without a pad to orbit abort capability ever again. In other words, I would have considered grounding the shuttle sooner. Those billions a year would have come in handy for building proper rockets such as the Ares 1 and V. In any event, the test by 2013 and fly by 2015 dates are highly optimistic, but something is better than nothing. If no new rocket is put in the pipeline, the gap will grow to encompass most of the next decade. The Obama strategy, if it can be called that, is to basically just give up for a while and hope private industry will help us out. For manned spaceflight, it is a flop. This rocket, or any rocket really with a half-way decent design, would be a step out of this swamp.

"Liberty is a launcher concept proposed by Alliant Techsystems (ATK) and Astrium. The design is a combination of hardware from the defunct Ares I project (the Five-segment version of the Space Shuttle Solid Rocket Booster for a first stage) and from the commercial Ariane 5 launcher (the Vulcain cryogenic main engine as a second stage). It would be launched from Kennedy Space Center[1]. The launcher would be 90 m tall, it is advertised at a price of $180 million per launch and it could carry a payload of 20,140 kg (44,500 lb) to Low Earth orbit. A first test launch could take place as early as 2013, and could launch astronauts by 2015."

Other sources:
ABC news
Universe Today
Wall Street Journal

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