Friday, May 29, 2009

Altair


NASA is bending metal to build spacecraft for the Moon. Previously in Johnson Space Center Building 220 we saw a mockup Moonbase under construction. Today we have an exclusive look at a mockup of the Altair lander being built. Here is the airlock module and small model of the completed Altair.

The ascent and airlock modules are posed with a Spacesuit for scale. The designers chose to minimize the size of the ascent module. 4 people will have to spend a week in that little thing! For scientists, the weight of lunar samples that can be returned will be limited. We hope to include modern miniaturised microscopes so that the astronauts can choose which rocks are valuable enough to return. Altair is designed to return 100 kg of samples, but designer John Gruner said at the Lunar Planetary Science Conference that it can be raised to 250 kg.

The completed Altair will be big, nearly 4 stories tall. These platforms will allow engineers to rapidly stack the modules for different configurations. They are still not sure how payloads will be lowered to the surface. Altair will be the last Constellation spacecraft to be built, so the design is subject to change. If all goes well, 10 years from now people will again walk on the Moon.

7 Comments:

Blogger Kea said...

Let's hope for the best! It is wonderful to have all these insider reports.

5:27 AM  
Blogger nige said...

Hi Louise,

Thanks for these interesting posts on new spacecraft. But can I just ask what are your views on nuclear explosion powered spacecraft such as Project Orion? There is a movie of the rocket test and the following YouTube video stars Professor Freeman Dyson and Arthur Clark defending it:

Excerpt from BBC's "To Mars by A-Bomb" (2003), with footage of the "hot rod" tests and comments by Arthur Clarke and Freeman Dyson.I've blogged about the mainstream lies on the effects of such nuclear explosions for space travel here.E.g., cosmic radiation is 100 times higher in space than on the Earth's surface. The EMP and fallout effects could be suppressed by clean weapons designs with thick casings to absorb prompt gamma radiations (see blog posts here, here, here, and here).

Thanks,
Nige

7:29 AM  
Blogger nige said...

There is also Carl Sagan talking about Project Orion on YouTube linked here: "We could go with project Orion NOW."I think the best technical summary of Project Orion is that given by Dr Theodore Taylor in John McPhee's book "The Curve of Binding Energy", circa 1974.

7:38 AM  
Blogger nige said...

Summary of Project Orion from Dr Taylor:Project Orion began in 1958 when nuclear weapons designer Dr Theodore B. Taylor moved to General Atomic to design a nuclear bomb powered spaceship, sponsored by the U.S. Advanced Research Projects Agency. It would travel directly (in a straight line!) and quickly to Mars using 2,000 nuclear bombs, carrying 150 people and attaining a top speed of 45 km/second. The travel time would be 3 months for the minimum distance to Mars of 56 million km and 6 months for the maximum Mars-Earth distance of 101 million km. In 1959 the stability of the entire system was completely proved in a scaled-down demonstration test which impressed Dr von Braun so much that he supported Project Orion after seeing the demonstration film.

Dr Taylor says in The Curve of Binding Energy (by McPhee) that the idea stemmed from the 15.2 kt REDWING-INCA nuclear test on June 26, 1956, where 30 cm diameter carbon-coated steel balls were placed 9 metres from the bomb by researcher Lew Allen, and were undamaged with only a loss of 0.1 mm of surface graphite! This gave rise to the design of the 75 ton, 41 metre diameter carbon-coated steel base pusher plate in the 76 metres high Project Orion spacecraft, where the base pusher plate is connected by hydraulic shock absorbers to the crew compartment. The steel plate acts as a radiation shield as well as ablative recoil mechanism to get propulsion: after each bomb was fired, oil would be sprayed on the plate to give it a carbon coating. The dynamics of X-ray ablation are well established in nuclear weapons design because this mechanism is what is used to cause the fusion stage in a bomb to explode: X-rays from the fission stage are channelled to the fusion stage, ablating the surface which causes a compression by recoil (Newton's 3rd law).

The nuclear test fireball experiments of Project 5.4 during Operation TEAPOT in Nevada, 1955, Project 5.9 of Operation REDWING at Bikini Atoll and Eniwetok Atoll in 1956, and then Project 8.3b of Operation PLUMBBOB in Nevada, 1957 proved that objects like steel spheres in the fireball only suffered a tiny amount of surface scarring because the thermal pulse just ablates a microscopic thickness of the surface, causing a recoil force. Actually, this kind of thin layer ablation had first been noted back on the TRINITY test of July 16, 1945:

‘The measured total radiation at [9.1-km] from the centre was 0.29 calories/cm^2 ... Examination of the specimen exposed at [975 m] shows ... the charred layer does not appear to be thicker than 1/10 millimetre.... scorching of the fir lumber used to support signal wires extended out to about [1.9 km] ... the risk of fire due to the radiation ... is likely to be much less than the risk of fire from causes existing in the buildings at the time of explosion.’

– W. G. Marley and F. Reines, July 16th Nuclear Explosion: Incendiary Effects of Radiation, Los Alamos report LA-364, October 1945, originally Secret, pp. 5-6.
Dr Taylor explained that the first nuclear bomb to start ascent would only need to be 0.1 kt, the next a second later would be 0.2 kt, and so on up to bomb number 50 which would be 20 kt, by which time a total of 200 kt would have been detonated, and the spacecraft would then be in space without having caused any significant EMP or fallout damaging effects on the Earth compared to natural background radiation.

8:21 AM  
Blogger qraal said...

In addition to Nige's enthusiasm I'd like to add a recent discussion by Brian Wang, Karl Schroeder and myself, Adam Crowl, about using a nuke to launch payloads via a cannon - essentially a giant nuclear-energised gas-gun for launching bulk materials into space. As Karl estimates almost half a terawatt of in-space solar power satellites can be launched with a single shot. As Brian points out, the potential for fall-out drops to zero due to containment in the blast chamber.

Steve Howe pointed out years ago that modern oxide fuel elements can operate at very high temperatures and release essentially zero fission products into the exhaust stream of a nuclear thermal rocket, so potentially such could launch to orbit without any fission debris spread over the launch path - unlike the pulse "Orion".

12:04 AM  
Blogger L. Riofrio said...

HI nige, and sorry it took a while to reply. Orion is an interesting idea, but unfortunately is forbidden by the nuclear test ban of 1963. However, some sort of nuclear thermal or controlled fusion propulsion is a definite possibility for the future. At JSC we constantly run into the limits of conventional rockets.

3:26 AM  
Blogger Erick said...

I've been looking for info on Altair and luckily I ran into your blog, it has great info on what I'm looking and is going to be quite useful for the paper I'm working on.
BTW is crazy how many viagra online blogs I manage to dodge in order to get the right site and the right information.
Thanks for the post and have a nice day.

12:26 PM  

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