mrp

Avatar.

2009-12-19T01:01:22Z

In the film, the skull of a dead flying beast has sclerotic rings. This makes me happy.

The film is fantastic. The story is satisfying, and the setting works hard to draw you in. Everything looked as though it were built for a purpose rather than just being made up to look cool, and as a result, everything looked cool. It applies to the base, the vehicles, the spaceship, and to the life on the planet too. The aliens look a bit too like humans? Who cares! All the alien animals share a body structure and look as though they have evolved to be part of their environment, and that excuses and overwhelms the strangeness of having human shaped blue people. Similarly, floating rocks? Makes no sense, but nevermind that because all the aircraft fly so nicely! The technology is all stuff that could work, so the unusual landscape can go hang. It does too. This is how you do film science.

I approve.

Two.

2009-12-18T16:57:11Z

Long after the report was presented, yet still unexpectedly early, NASA's new direction has been announced.

is teh link

The article is light on specifics, focussing on story and politics rather than hardware, but fortunately mentions one important detail - this is option 2 from the Augustine Commission report. Given that, let's fill in some of the gaps.

is teh link to image

That's the list of options presented in the commission report. As the table shows, plan 2 involves scrapping the Ares I, scrapping all development of lunar landers or mission specific hardware, cutting the size of the Ares V, and making a commitment to using only commercial options for moving light goods and crew into orbit.

From now on, NASA won't have the capability to do anything alone.

The heavy launch vehicle is the significant component and the main limiting factor in any planned mission. Cutting its launch capacity is a blow, but not a major one; the Ares V Lite variant should be similar enough to the original design that it can later be upgraded again to full spec if the need arises. The significant loss as far as NASA is concerned comes in the payload. It looks now as though most missions will be planned by international groups or by ESA, with NASA merely providing the ride into orbit. In the Augustine report table of options, the use of the word "constrained" meant "lacking the budget to do anything interesting once in space". Relying on collaboration to fill the gaps is a tricky thing to rely on if anything interesting is to happen. Whether there is any international interest in the truly ambitious, such as Moon, Mars, or asteroid manned missions remains to be seen.

I'm not sure yet whether this is a good move.

Maiden.

2009-12-07T22:36:54Z

is teh link to image

Somebody should let Virgin Galactic know that painting the underside of your suborbital aircraft black does not make it a spaceplane.

is teh link to image

This is what a modern spaceplane looks like.

It's completely unmanned, and in use it will end up being not much more than a satellite that can dodge missiles and land itself when it needs an upgrade, but when finished it will be a true spaceplane. It will be able to reach space and stay there for more than half an hour.

Leak.

2009-12-06T02:05:26Z

barberio linked to this and called it potentially video of the year. I agree.

is teh link to video

Herbivore.

2009-12-01T00:57:59Z

Vegetarianism, trial period of one month. Go!

One exception: Christmas dinner. I don't want to annoy anybody with that.

Let's see if this works.

Genesis.

2009-11-27T20:39:04Z

Ever since writing that post about black hole starships, I've been meaning to follow up on it with a post about something far more speculative. Instead, I've been playing Morrowind, and now Centauri Dreams has beaten me to it: is teh link to blog post I think that's a sign that I ought to finally get this done. Let's see if I can write something that explains it better than Mr. Gilster did.

We start out with seeing our universe and wondering where it came from. We know it started as a big bang, and that helps to explain how things stand now. What it doesn't do is tell what caused the bang in the first place. It wouldn't be logically inconsistent to say that there doesn't need to be a cause; time is a property of the universe, and so there need not be any time before the universe, neither does there need to be anything else beforehand, such as logic or causality. To say it just happened by accident would be a consistent explanation, but not a satisfying one, so it's worth taking a look at alternatives that might explain a little more. That's where black holes come in.

I want to say this again, to be completely clear. This is speculation. It is hypothesis, not theory. There is almost no evidence for this. On the other hand, there's no evidence against it either, and it is a neat idea.

Disclaimers over, the concept is this: the big bang was a singularity, or at the very least, an object of such incredible density that it looked like one. A black hole is an object of such incredible density that we can't tell whether there's a singularity inside it. The similarity suggests a link, and the obvious link is that they are the same thing. The big bang, and our entire universe, could have originated with a black hole in another universe that came before. The equations can be made to work like this. What goes on inside a black hole is sufficiently unknown that with a few assumptions, they can lead to a sort of bounce, the collapsing matter and space never quite reaching singularity and instead expanding out again, budding off from the parent universe to become a brand new child universe.

With our current knowledge, we can't rule out the possibility that universes breed.

If you look at the concept intuitively, there is a rather large problem. We can see that the matter inside our universe adds up to a lot more than the mass of one black hole, even a quite big one. Intuition doesn't work on cosmology.

The total mass of our universe is, as far as we can measure, very close to zero. The matter within the universe has positive mass, the space under tension as the universe expands has negative mass. They balance almost exactly. In such a gigantic structure, we'd never notice if there was a very slight imbalance towards positive mass, the total equalling roughly the content of one black hole.

So far, so good. Up until now this has all been stuff that I believe is probably true. From here on, it gets weird.

One of the major points of thought on the fecund universe hypothesis is that of cosmological natural selection. The reasoning goes that if universes pass very close to being a singularity at the point of their birth, they are on a quantum scale and subject to uncertainty, which might allow for changes. A child universe may have laws of physics different to the parent. You have now a breeding population in which mutations can occur - that's natural selection territory. It has been suggested that universes may evolve towards having physical laws that allow for the efficient creation of black holes. The better a universe can spread out its matter evenly for the formation of galaxies and stars, the more offspring it has, and the faster it breeds. Star-filled universes extremely rapidly come to dominate the population of the multiverse, not because the others die out, just because the rate of reproduction is so vastly different.

There is a problem here too: our universe isn't fine tuned for producing black holes. The answer to that issue is where this hypothesis staggers away from cosmology, straight through philosophy and towards territory more usually occupied by religion.

As I have mentioned before, black holes are exceptionally useful to a starfaring civilisation as an engine and a power source. A civilisation that develops for long enough can likely be relied upon to eventually make black holes of their own. Technology is always going to be more efficient than nature if you take it to its highly developed limit. So, the hypothesis asks, is it possible that our universe is fine tuned not for star formation, but for life, because life makes civilisation, civilisation makes black holes, and black holes make a universe breed?

I'm not convinced by the second part, but it's certainly interesting to think about.

Cheese.

2009-11-14T07:40:44Z

Another questions meme. It works like this: I get asked five questions, I answer them. Anybody who wishes to have five questions of their own comments to say so, then they answer them and make the same offer. The meme gets passed on until we all get bored of it, such is life.

ferahgo asked:

1. Are you at or have you studied at university? You seem really into physics so I've wondered before if you've had any formal training in it.

Yes, I studied physics at the University of Warwick. The grade I got wasn't very impressive.

2. Have you ever met any famous people?

This depends on where you want to draw the line for "famous". I used to go school with Ben Croshaw, the guy who does Zero Punctuation. Even back then he used to spend his spare time in the school computer labs making point and click adventure games in visual basic. Apart from not using MSPaint anymore, his style hasn't changed much.

3. Favorite author?

Iain M. Banks, definitely and to an embarassing degree. Alastair Reynolds takes second place.

4. Your philosophical ideology in one sentence.

The universe is imperfect, we are agents of change, let's change things.

5. Favorite thing to nom.

The honest answer would be quite basic, boring stuff really: baked potato, pizza, pasta, sandwiches, etc. Anything that involves a lot of cheese. Filtering the list to get to the more interesting stuff gets us aniseed balls, granny smith apples, raw jelly and bacon curry.

Anachronism.

2009-11-13T23:25:49Z

is teh link to video

This mod has nazi dinosaurs. That is all you should need to know about it. Watch the video, then play it.

Direction.

2009-11-08T14:03:51Z

is teh link

One of the Culture stories is on its way to being made into a film.

I'd always worried that somebody might try a film of one of my favourite books and get it all wrong, so it's something of a relief to find out that this is going to be based on a minor short story from The State of the Art that I barely remember. If this turns into an incoherent mess, I'm not going to care. The only possible outcome of this that will have any significance is if the film is excellent.

The story in question was very short and didn't have much of a link with the other Culture books. This isn't going to be a good test of whether one of the full length novels could be adapted in a sensible way. It might stir up interest in them though. This is something to keep a close eye on.

Spectrum.

2009-11-04T16:34:49Z

A very simple picture today: is teh link to image

The average colour of light in the universe over time.

Hopeful.

2009-10-28T18:52:00Z

is teh link

It will be interesting to see whether this gets anything more than a five minute hearing and an instant dismissal in the middle of the current trend for nuclear disarmament. The legal and international politic aspects to it are likely to be far higher barriers to starting this than expense or difficulty.

Lighthugger.

2009-10-23T22:06:42Z

A few of you may have heard of this: is teh link

It made a minor impact in the media last week, with a slew of articles talking about an exciting new space propulsion concept that would be easy to test using the LHC. Most of the articles I saw had practically no explanation of how it would be used, and somewhere along the trail of rewriting each other's summaries had picked up the idea that it would use an easy to exploit source of energy.

Just to quickly go over this, the idea is that a relativistically moving mass can produce repulsive gravity in beams ahead and behind it. This is interesting physics and is the part that can be tested. For propulsion, how it would be used is to accelerate a gigantic mass, several thousand times the mass of your spaceship, up to above half the speed of light and then put your spaceship in its path. The ship then gets accelerated up to very close to lightspeed by the gravity beams.

Frankly, in this context it's not very interesting. If you can get the shunting mass up to 0.5c, you've already solved the interstellar travel problem, and you might as well just give the engines that did the job some more fuel and travel aboard that.

If there was any justice in science reporting, the paper that should have gotten all the attention instead is this: is teh link

Black hole rockets! Black hole power generators! Black hole factories!

As fun as they are, none of these are new ideas. As soon as you know about Hawking radiation, the notion of using it for direct mass to energy conversion is obvious. I had wondered about the possibility of using it as a starship engine myself a few years ago, and was quite disappointed to discover that other people had got there first. What is new is a serious consideration of the science and engineering involved as a preliminary feasability study.

The paper didn't have any pictures, so to help explain what they're proposing, I have created the world's crappiest diagram:

This is the black hole spaceship. It works the same way as any other rocket: make a bloody huge explosion behind you and ride the blast using a really tough nozzle to deflect reaction mass backwards, and you forwards. The explosion in this case is an artificial black hole.

You may have heard it said before that black holes aren't really black. They give off particles and light. They radiate. This is Hawking radiation, and it has an interesting property - the smaller the hole, the more intense the radiation. Huge natural black holes that have been born from stars and have sat about eating hydrogen for billions of years radiate so feebly that it's overwhelmed by the light from dust around them. A hole with the mass of a planet would be about the right size to be visible. Once you get down to sub-micrometre black holes, you're dealing with objects that have the same kind of power outputs as a nuclear weapon, and it doesn't stop there.

The paper talks about attometre scale black holes, which would have a mass of mere thousands of tonnes, and could continue outputting hundreds of petawatts for over a decade. They certainly match the requirement for a bloody huge explosion, and if you put a sufficiently indestructible rocket nozzle near one, it's going to pick up a lot of momentum. The trick is to make sure the black hole follows on behind you so that you can continue to accelerate.

This is where the concept starts running into problems. To make the acceleration of the black hole match that of the spaceship, you fire extra mass into it from behind. You try to match the rate at which it is radiating energy by putting extra mass into it, and use that as an excuse to give it momentum at the same time, trading a bit of push from the spaceship to keep the hole following. Unfortunately, to do this, you have to fire a particle beam of kilograms per second at extremely close to the speed of light into a moving target of barely more than an attometre diametre, without missing at any moment for fear of carving a hole through your nozzle bowl. It's a nightmarish feat of aiming with catastrophic consequences for failure, and this is only the second worst difficulty.

In theory there's no upper limit on the performance of an engine like this, as far as we know. Our current theories are a bit flawed when it comes to quantum-scale black holes, nevertheless it wouldn't be unreasonable to expect a system like this to be able to produce accelerations of over 1000g sustained for the better part of a century, assuming you can engineer all the components well enough, light enough and durable enough.

That hints at the other major flaw of the idea. There is nothing durable enough. We know of nothing that we could build with that can reflect gamma rays. Most of the energy that the hole would put out would be gamma rays. As a result, at best a lot of power would be wasted, and at worst, the ship would demand a vast amount of shielding and heatsink. It very well may be that the first interstellar manned flight will be a billion tonnes of concrete shielding with a tiny engine on one end and a tiny armoured bunker on the other. The more shielding you need, the lower the performance of the spacecraft as a whole.

Let's hope that the future holds a few materials science breakthroughs.

Automaton.

2009-10-17T20:33:59Z

Machinarium: is teh link

I spent a happy afternoon playing this yesterday.

It's a flash-based robot themed point and click adventure game from Amanita Design. The demo gives a reasonable view of the game; the only thing it doesn't tell you is that the rest of the levels rely heavily on minigames, mostly logic puzzles, that vary in quality quite highly. Some of them are a little irritating, but I don't think they spoil the experience.

Take note of the in game walkthrough. Some of the pages are well drawn enough to be worth looking through once you've figured out the puzzle for yourself.

If the demo seems good to you, but not good enough to be worth paying for, you could make do with Samorost instead: is teh link to game

Manipulation.

2009-10-16T01:57:53Z

My current favoured snack is rocket lollies: is teh link

Their sole flaw is that the sticks are the right length such that using only lips and tongue, it is possible to push the other end of the stick up your own nose. Having discovered this, I now find myself absentmindedly doing it every time I finish eating a lolly.

Graphic.

2009-10-13T10:42:33Z

Everybody else has been linking to this, so I might as well do too.

is teh link to image

It's a visual representation of everything mankind has ever done outside of Earth orbit. Each line heading out from Earth represents a spacecraft that we've sent up there, whether a tiny probe, a giant armoured lander, a man in a tin can, or anything else. Obviously it's not to scale, orbits not shown in their real shape, a bit out of date, not much indication of which ones landed... blah, blah, pedantry.

It's quite pretty.

Haul.

2009-09-29T18:32:36Z

This morning, Universe Today linked to some photos of a Soyuz rollout: is teh link to image

They look rather pretty on the journey to the launchpad. However, it made me wonder about something. We all know about NASA's rollout system, the massively oversized crawler vehicles (is teh link to image) but what about ESA?

I'd seen photos of their launch area before and seen the rail network, but never seen a clear photo of the rollout system in operation. It turns out that there is a good reason for this: the vehicle they use for the job is incredibly embarassing.

is teh link to image

The entire launchpad is on rails, but it doesn't have independent motive power. It's being towed by that blue lorry, using a rope.

It doesn't quite have the same wow factor as the crawler, it has to be said.

Spike.

2009-09-12T11:48:31Z

From the company that previously brought us the cold war in toy unicorn form... The Avenging Narwhal playset: is teh link to image

Options.

2009-09-11T06:14:21Z

The Augustine Commission has completed its report. Their findings are as good as I could have hoped for.

If you're not interested in this, have a video of a rocket test instead: is teh link to video
Explosions that last for two minutes are a good thing and are worth watching.

For everybody else: The manned spaceflight report has several points to make, and the most crucial one is that there is no low-budget option. One of the mandated tasks of the committee was to produce two options for things that NASA could achieve on their current funding level. I was worried that one of these would be a politically acceptable getout option. They're not. One low budget plan involves not doing anything in space at all after the shuttle stops flying until after 2020, the other means abandoning human exploration beyond low earth orbit almost entirely. The message is clear - give NASA more money or nothing gets done.

Under what they choose to call a "less constrained" budget, there are a lot of interesting options being presented.

In all but one of the plans, there is a commitment to very strong support for commercial launch companies. The commission state very clearly that the Ares I is not a failed project and development should continue, but most plans do not call for it to be used in day to day supply missions to LEO. Instead, as a way to demonstrate that investments into commercial space access are safe, the report recommends that there should be guaranteed contracts to anybody who can provide suitable vehicles. I'm hesitant to call myself a fan of commercial space travel, but nonetheless, more options for what tool to use are always good.

In the longer term there are options for going to the moon, going to Mars, or "flexible path" options, which involve building vehicles suitable to go anywhere and then taking them to wherever seems like a good idea at the time. There are cost cutting measures demonstrated in all of the options for how to achieve these, not all of them are bad however. Shuttle-C and semi-commercial heavy lift are considered on the basis of unpleasant fallback options, the recommended plan is a quite neat compromise.

Constellation originally called for all moon exploration hardware, lander and vehicle for the journey out of LEO, to be carried on board an Ares V cargo rocket, with the crew carried seperately to dock with it before departure from earth orbit. The lander has been proving very expensive to develop because even with the carrying capacity of an Ares V, the largest rocket ever funded, it's hard to get everything to fit under the mass limit. The new plan to solve this is to make the Ares V fractionally smaller, and continue development of existing lunar hardware on the assumption that both the spaceship and the lander will be launched on a seperate AresV Lite. Suddenly the margins for mass use on each vehicle section are raised by about sixty tonnes, allowing the designers to slap on whatever components they feel are necessary without having to worry about removing something else to make room and having to redesign half of everything so far from scratch. This makes development of the launcher, the lander, and the spaceship significantly cheaper and quicker, and only has any negative impact for moon missions specifically. A lot of the flexible path destinations can be achieved without a lander stage and so would only need a single launch. Further into the future, missions can either be designed to match the Ares V Lite's carrying capacity, or the Ares V design can be brought back up to the original standard if it ever becomes necessary. Mars missions were always intended to require at least three seperate launches with assembly of components in space, some plans calling for up to six, so a marginally lower lift capacity for the cargo launcher does not make a great deal of difference to the ultimate goal.

Things are looking good. The amount of extra money being asked for is not vast, and if it's given, a lot of fun things will happen.

Ecosystem.

2009-09-05T03:21:18Z

I've been meaning to write about this for over a week, and kept being distracted.

is teh link

David Pearce is one of the more embarassing people who hangs around in the transhumanist movement. As a philosopher he may not be bad, but when he gets into speculating about future practical solutions to problems, it's easy to see that he's not much of an engineer.

This article is a good example of that. In it, he proposes that nature as a whole should be treated as something that humans have a responsibility for, not just to maintain the status quo but to actively attempt to change it for the better. The Tetrapod Zoology blog touched on this and their reaction to the idea was entirely and wildly hostile, because Pearce's proposal for eliminating suffering in the natural world is to deliberately make predators extinct. While I can understand the reaction, I think they've missed the point.

At its core, the assumption that animal suffering is equally morally wrong as human suffering is a sensible one. That's not to say that animals are morally equal to humans in all details, even as passive agents, but at a simplistic level it works. It's also clear that the natural world does generate a vast amount of suffering. The question of whether we have a right to apply human morality to animals is one for philosophers, and I think that Pearce has the right answer here: yes. A more significant question, however, is whether policing the entire animal kingdom can be done without fucking everything up and leaving the world vulnerable to accidents of the "oops, we just lost ten thousand species" sort.

Eliminating predation entirely is clearly a bad move because it puts too high a reliance on outside interference to keep the populations of herbivores stable. If we did this, and humans disappeared one day, there would be incredible overpopulation, disease, starvation, pain and death among herbivores, lasting for tens of thousands of years until a crude approximation of replacement predators can evolve. An ecosystem absolutely must be failsafe, if at any point you give up on it and walk away, it must keep running. This part at least is easy to solve, given the magical future tech that Pearce assumes. Isolate predators from their prey, and let them chase meat-robots. Give them something that is almost indistinguishable from a real animal, but incapable of being in meaningful pain.

The second part of the problem is trickier. Herbivores need predators in order to continue to be adapted for living in a world that might contain predation. Take away all the meat eaters, and evolution goes in strange directions. This is something that can only be tackled actively, with constant examining and selective breeding of managed herbivore populations. Even then you can never be sure that you've fully understood what traits need to be passed on, that there isn't some critical detail that has been missed. Ultimately the only truly reliable test of whether a form is suited for escaping from a hunter, is to let it be hunted. Whether guesswork and approximations are good enough is something for people who are doing the guessing to judge for themselves.

The same basic principles could be applied to any point on the food web, from whales to disease causing parasites. As long as you have a sufficiently detailed model of how the creature in question interacts with its food source, you can simulate that interaction and pass on the benefits to either side without the negative consequences. A physical simulation for the predator, a software simulation for the prey.

Stunted.

2009-08-30T22:14:00Z

"What I did on my holidays"

I've spent the last week doing very little except playing Dwarf Fortress. I introduced my cousin and her boyfriend to it, now they're addicted too.

I had planned to write something more interesting than this until I got home, found that the entire house smelled odd, and lost enthusiasm for doing anything at all.

Miscellaneous.

2009-08-22T01:00:30Z

Food
Brie and mushroom sandwiches are excellent.

Space
It's starting to look more likely that my predictions of the outcome of the Augustine committee will be embarassingly wrong. My error is in assuming that there was a lot more room available for cost cutting by slowing the programme, putting costs off until later. What I hadn't spotted was that if the funding doesn't appear as needed, the ISS servicing vehicle will be completed several years after the ISS has been deorbited.

Computing
My family have infected their computer with a virus, so after several assorted silly delays, I backed up their files and tried to reinstall windows. It is not very helpful of windows install discs to tell you that your product key doesn't match only after the step involving formatting the drive.

Travel
Next week I'll probably be in the lake district with very limited internet access.

Vote.

2009-08-19T02:57:31Z

The Pirate Party has come to the UK. Most of you will probably have heard of this already. I'm not sure yet what to think of them.

If you can join the irc channel of a political party and spending an hour or so of chatting about copyright and free software, features in upcoming versions of firefox, piracy as a form of archival, etc. and then discover that one of the people you've been talking to is the party leader, that's fantastic.

However, you need more than fantastic to earn my support, and my vote.

I do think that their stance on copyright has the potential to be a good thing but that isn't anywhere near being the most important issue in an election. There are far more pressing problems in the country, and if copyright reform was their only message I'd not give them any further consideration.

Their aim to protect privacy is a very different matter. I most strongly agree that there needs to be political pressure towards protecting privacy. Over the years some truly ludicrous invasive schemes have been proposed to allow keeping of records and scrutiny over almost anything you could name. Most of them failed and were forgotten, some came dangerously close to being implemented. Anybody who wants to stand in line as one more part of the defense against badly thought out plans can only be a good thing. The question here is how effective the party can be in doing this. It's far too early to tell.

I'm happy to see a new player entering the game, more options for us when election day comes around is nice to see. Let's hope they put on a convincing show before then.

Continuation.

2009-08-15T03:09:13Z

I am aware that nobody in their right mind would copy the photo meme if they've got a large friends list, it would cause madness, argument and embarassment. Consider that rule dropped from now. Anybody want to make a silly demand with no requirement to do silly things in turn? Go ahead.

Challenge.

2009-08-13T18:52:58Z

A few months ago, a meme came around in which you invited anybody to request a photo of something in your life. I'm going to propose a more extreme version. This one is not limited to boring stuff around the house. Come up with something fun!

You may demand that I take any photo that doesn't break the following restrictions:

I'm not going to do anything dangerous, damaging or illegal.
I won't get other people involved in my own silly project.
If it will cost more than £10, I might not do it, at my own discretion.
I will only do things that are going to take more than half a day, or a few hours of travel, if they are really cool. Again, at my own discretion.

The standard meme rule also applies: if you participate, you must pass it on, copying the rules in your own journal.

Now we wait to see whether I will find myself regretting this.

Augustine.

2009-07-29T19:05:26Z

One of the meetings of the Human Space Flight plans committee is happening today. In a small part, the decisions of what NASA will be doing for the next decade are being made right this very moment.

The first thing to say is that nobody involved in this is aiming to cut the spaceflight budget entirely. Everybody wants to see human spaceflight continue in some form. I'm certain that cost cutting will be discussed, but I am equally certain that the ultimate goal of a moon landing is not in danger. It has progressed too far to give up and pretend it never happened. This is a very high profile project, and it has not had more problems than any other complex work - there is no excuse to be found to declare it a failure. What might happen instead is a change of what to do with it.

The committee is making decisions on two broad questions: where to go and how to get there.

The question of what NASA are ultimately aiming to land on is, oddly enough, a fairly minor point. No matter where we want to go outside of low earth orbit the technology to get there is ultimately the same - a heavy lift rocket of some form, likely the Ares V. All of the difficult questions such as whether a mission to Mars is worth the effort, or if a moonbase would end up being just an even more expensive version of the ISS, can be left until much later. This is all very definitely a case of Somebody Else's Problem, I expect the committee's decision to reflect this. The only circumstance in which this would change is if the moon mission is to be replaced by an accelerated Mars mission as most of the moon veterans have been advocating. If that were to happen, it would demand both immediate investment in far heavier robot probes to Mars to test large scale landing methods, and resuming work on NTR. I'm not just saying that because I'm a nuclear rocket fanatic, this is actually mentioned in NASA's presentation to the committee. Increased spending on the programme seems a very remote possibility at the moment so by far the most likely recommendation will be a there and back moon attempt followed by further goals to be decided after that.

The second point is where the real arguments will be focused. NASA have helpfully reduced their argument to flowchart form with pictures: is teh link to image. This is, in very general terms, the same decision making process that the committee will have to go through, but there are a few missing vehicles on the tree.

The main players are, in the heavy lift category:

Ares V
The vehicle currently being developed. If completed it will have the largest capacity to orbit of any rocket ever built, more than twice as large as any of the others mentioned here.
Shuttle C and STS side mount options
A standard space shuttle external tank and boosters but with the orbiter replaced with a giant expendable aeroshell. The aeroshell carries standard orbiter engines.
Direct
Similar to shuttle C but with the cargo shell on top of the external tank. Limited carrying capacity demanding a redesign of interplanetary missions and loss of flexibility, but still an improvement on the shuttles.

I've written about Direct before. This group are a major player in this game and a big part of the motivation for holding the review in the first place. They are an internal group from NASA's engineering staff who believe that Ares I and V are the wrong approach and that a system even more closely based on shuttle hardware should be used. They want a single mid-scale vehicle used for both ISS servicing and heavy launch. The arguments in favour of it and similar systems are not based on performance. the Ares V outstrips everything else in capability, but the alternatives are all cheaper to develop, would be operational more quickly, and would keep on more of NASA's existing workforce.

I don't think it is likely that any of the alternative systems for heavy launch will be adopted, but the existence of other options may force NASA to make concessions in the way they are operating. There is a very strong argument for not losing any more skilled workers.

The competitors for crew launch and ISS servicing:

Ares I
Currently being developed, but in trouble. Ares is NASA's vehicle closest to completion.
SpaceX Falcon 9
Designed from scratch with the specific aim of performing all of the same duties as Ares I at a much lower cost per launch.
Orbital Taurus II/Cygnus
A satellite delivery rocket and accompanying cargo module being designed for small cargo missions to the ISS. Not under consideration for human use.
Delta V Heavy/EELV
An already existing system that has been used for satellite launches and is under consideration for being rated for human flight. It could meet the requirements for safety while carrying crew, barely.
Extended Shuttle launches
An option that would make a lot of people happy, until something goes wrong. Explosion and loss of life is unlikely. Damage and exceptionally expensive repair and delay are a near certainty.

The competition is very strong here. Both the Falcon 9 and the Taurus 2 are sure to be used if they gain a good track record. A lot of people would like to see shuttle flights continued. Ares I is unpopular with everybody who thinks they have a better way. Despite that, I think that Ares I has a good chance of continuing development because it represents continued support of the ISS. Cutting it and relying on the Falcon 9 would look bad. Whether rightly or wrongly, it will give people an excuse to complain about lack of commitment to a major international project.

Starting with the most probable and in order of likelihood, these are what I think will be recommended:

Organisational changes only, a continuation of the status quo.
Cancelling Ares I and starting much closer cooperation with SpaceX, a highly visible show of support and resource sharing to ensure the Falcon 9 is a working alternative. A PR move.
Slowing of Constellation and extended shuttle flights.
Cancelling Ares I in favour of Direct, possibly continuing work on Ares V.