Sunday 13 September 2009

Tunnels on the moon

I recently read some interesting stuff on the prospects of using lava tubes on the moon to house a moon base.

Lava tube are left over from volcanic activity. They are self contained spaces in volcanic rock, found anywhere from a few meters under the surface, to a few thousand.

On Earth, these tubes are typically a few meters high. On the moon, they are likely to be ten times the size (none have been found yet, but i'm not sure any have been looked for).

If one of these tubes could be made air tight, and structurally sound, it could be an excellent basis for a lunar outpost. If a tube were found, say, ten meters beflow the surface, it would most likely be structurally strong enough to withstand a little light engineering, and could be propped up with steels imported from Earth (expensive), bricks made from the lunar regolith (difficult, and if you can build them, you're half way to not needing the lava tube) or perhaps an inflatable structure.

Some sort of spraying robot could then traverse the length of the tube, spraying the walls with plastic, or preferably a cement made from local regolith to make it air tight.

Ironically, the larger size of lunar lava tubes would make this exercise much more difficult, in terms of spraying, and keeping the tube at a reasonable temperature (note to self: check ambient temperature of lunar surface ).

The first such base, therefore, would want to be perhaps, five meters tall and ten meters long. The floor could be levelled with an inflatable pontoon, and fixtures bolted into the wall.

Larger tubes would have their advantages, though. Under artificial light, a garden would make the living space much more palatable, not to mention the benefits of a small farm, even a smelt and a factory.

Lava tubes might be used within a few years build up of resources on the moon.

Friday 31 July 2009

Space Exploration Architecture

Conjectures on the mission architecture that could be used for human exploration of the solar system over the coming decades.

Whatever options are chosen for human mission scenarios, they need to be cost effective. The world can only afford to divert a finite fraction of it’s resources towards space exploration, especially in the current economic melt down.

Space missions need to be relatively safe. I say relatively, because many people feel that present day mission planning, compared to the 1960’s, has become far to risk averse.

Finally, another desirable aspect would be that missions leave a building block for future endeavours to build upon. This might be either the design of a ship or station segment that can be reused, or the hardware itself can be reused.

However, the real benefit of this stance must always be scrutinised. It’s a nice idea that modules used to build a moon-base could also be used on Mars, but the environments are really quite different. Many believe that going back to the moon will not actually be good preparation and training for going to Mars, but just an unnecessary distraction.

So the following articles are some ideas of the projects that might comprise an overall strategy for exploring the solar system.

Tuesday 17 March 2009

Rockets, the Only Game in Town

This was an excellent article in New Scientist, comparing the advantages of rockets with air breathing engines.

I like Henry Spencer's writing, it's always clear and concise, and usually convincing.

So, if rockets have a cost/weight/simplicity advantage over air breathing engines, how does that alter our options for a launch vehicle cheap enough to open up the space frontier?

The emphasis has to be on price (and, I guess, environmental friendliness). Not safety, not reusability per se, just anything that will bring the price down of orbit access. Make it cheap enough, and the cost of satellites will come down, and risk to the payload will come down - a reverse price spiral.

A straight up and down ballistic rocket is technology we know and understand. If the stages and boosters can be recovered by parachute, all the better. Liquids are hard to work with, solids cannot be throttled, and are pretty noxious to boot. That leaves hybrids.

For manned vehicles, the capsule should be reusable. Either a parachute and dunk in the ocean (how hard would it be to refurb this capsule?) or perhaps land like a delta clipper.

So, simple is best. Should be able to start developing hybrid motors that work for simple sounding rockets for £5mil.

Anyone game?

Thursday 12 March 2009

Kepler, at last

Yes, Kepler has been launched, at last, and safely, thank goodness.

Unlike other exo-planet search tools, it will be able to watch a hundred thousand stars at once, looking for flickers in their star light that might indicate a planet passing infront of them.

This will be the first mission that will have a decent chance of detecting an Earth sized planet orbiting in a "habitable zone", a distance from a star where water could in liquid form. As such a planet would have to pass infron of the star twice before we can calculate it's orbit, we will probably have to wait a year and a half before the first confirmed sightings.

Well worth the wait, though.

Wednesday 4 February 2009

Corot-Exo-7b - smallest yet

Corot has discovered the smallest planet yet, two Earth masses.

OK, it's a tad hot, with an orbital period of 20 hours, but we're getting closer to Goldielocks all the time.

http://news.bbc.co.uk/1/hi/sci/tech/7868100.stm