New Mars Forums

It would be much, much more effective to simply build a dam across the Bering Straits, and power water through one way or the other. Uses much more water, but hey, you could build a rail line on top and connect the whole world (minus Australia)...

Of course, this forgets one small thing: it's stupid and insane, just like the really long pipe. You'd be better off developing some kind of foamy goo to bomb the ocean with and increase surface albedo or lower evaporation if you wanted to harm hurricanes. And if power generation is wanted, there's plenty of other simpler ways of generating much more power.

Personally, I'd skip Uranus and head straight to Neptune. It's a more interesting planet, IMHO, and worth a look. But actually, I wouldn't send a probe there with a 'cheap throwaway' mission plan. If I were to send a Spare Parts Special to the outer solar system, I'd send it to Pluto, where even a crap probe will greatly increase out knowledge. Neptune (or Uranus for that matter) merits a well-designed big probe of the Galileo/Cassini type.

I believe this is a sort of whacko extension of environmentalism that's taken hold in some palces, which thinks that everything is so fragile that if a person sneezes, he'll wipe out a hundred species. Honestly, if life were that fragile, it would have died out a long time ago. Besides, anything living on Mars would probably take one figurative whiff of oxygen and keel over dead. It would be as deadly as chlorine is to us. And on the other hand, anything that has survived Mars's harsh weather, scorching UV, extremely thin air, salty ground, etc, is hardly going to be fragile.

Now that I think of it, I wonder how many colonists will die each year because they're drunk and don't put their suit on right before going out.

Remember, friends don't let friends EVA drunk.

Why, crappy beer, of course. Why waste the good stuff? And I imagine drunken beer-balloon races would be a popular way to kill time in Martian bars.

Actually, if I were a marketing droid in a beer company on Mars, I'd put free balloons with logos on them in every six-pack. Why pass up free advertising?

Um...
The catalyzed system uses NANOGRAMS of antimatter. For purposes of comparison, this is about as strong as a firecracker; the antimatter's usefulness is because it can be used in such vanishingly tiny amounts to initiate nuclear reactions controllably without a lot of dangerous hardware like.

Because it's not a destructive threat in such minute quantities, NASA can and apparently has shipped it around the country in portable traps. They had one such portable trap in a photo somewhere on the PSU page; it was, IIRC, being pushed by two guys on a floor dolley. They were talking about using the larger capacity trap NASA was developing to deliver antimatter for medical research around the nation, so apparently they're quite sure about the reliability of the traps (although the small amounts are not really a health problem, if they're considering making the stuff available for timely medical research they must have a low failure rate).

When talking about this technology - please, PLEASE remember the truly tiny amounts being talked about. The antimatter is used like the spark from an automobile spark plug. It's the nuclear fuel which provides the thrust; the antimatter just lets you use it with efficiency far higher than even gas-core NTR's, and the efficiency even beats out nuclear-electric and with a higher thrust to boot.

Yeah... actually, what NASA needs is a recycling ring at Fermilab (they produce lots of antiparticles for immediate use right now, and what NASA proposes is to siphon some off) and a better Penning trap capable of holding a few nanograms of material without needing a huge holding ring. The latter is the only real stumbling block. BTW, NASA estimates the cost at a few million per nanogram, there's a bit of discrepency in the prices here...

The only part that isn't currently available is the trap. And a trap of the size and weight necessary is considered feasible; there's just not been a need to move that many antiprotons around before. Current NASA/PSU research on the engine apparently revolves entirely around the trap.

I personally wouldn't be surprised if this engine ends up being the one used in the Mars missions, given the timeframe for that (2020 or threabouts)

It works sort of like a mini-Orion; small pellets of uranium wrapped around lithium deuteride are fired backwards and are detonated by antimatter. NASA refers to this as ACMF (antimatter catalyzed microfusion). The antimatter allows you to detonate very small pellets (no critical mass) this way. I believe that you can use plain uranium as well, no need for refinement.

NASA and PSU apparently also looked at two other antimatter concepts; one involved a 'solar sail' of uranium which would be hit by antiprotons to create thrust, and the other, which NASA believes is the more logical followon to ICAN, would contain a diffuse cloud of antiprotons elecromagnetically and shoot droplets of deuterium/He3 through the cloud to create what amounts to a fusion pulsejet. That engine (AIM - Antimatter Initiated Microfusion) would be capable of missions up to about ~1% the speed of light. However, it's not a near term technology, ICAN is. All ICAN needs is the ability to store the nanograms of antimatter we make long enough to make it into orbit.

Once that is accomplished, the solar system is ours - the ISP of ICAN is vastly higher than chemical propulsion, or nuclear thermal It beats out ion engines as well, at a better thrust/weight ratio.

NASA estimated the price of antimatter, with $20 million in adjustments and enhancements to the Fermi National Accelerator Laboratory, at $6.4 million per nanogram.

Actually, some searching showed that NASA's ICAN-II design requires 140 nanograms of antimatter for its proposed mission, or  $910 million dollars per mission. The trick to the engine is that NASA discovered that antimatter can cause fission in uranium without needing any particular critical mass of uranium, meaning that instead of needing to build Orion style pulse bombs, you could use antimatter striking a uranium mass as a sort of solid rocket engine with an ISP of 13,000 or so. Not bad....

Personally, I think it's worth the cost. 400 tons with a quicker transit definitely works for me, especially as NASA thinks that the next generation of the engine might put Alpha Centauri within unmanned-probe range. Of course, that's only if the storage problem is conquered...

Actually, we do have turbines small enough to power light vehicles. Jay Leno has a turbine-powered motorcycle, for instance. There's some motorsports guy who modifies very small turbine engines to fit into vehicles, because of the higher power-weight of the turbines. NASA would be looking at things differently, minimizing weight instead of maximizing power, but it's doable, and we already have some fairly small turbines, such as the one on a Tomahawk cruise missile. It's merely a matter of fitting them to a rover.

Oh, a problem does exist with turbines in ground vehicles, from Leno's experiences with the turbine motorcycle, which the world's worst case of turbo lag. With a piston car, when you stomp on the gas, the car accelerates more or less immediately. Small turbines take a while to kick in. This isn't a problem for, say, the pressurized rover on long trips, but for the base 'donkey' rover, it might be very annoying in regards to trying to move stuff.

I'm uncertain if ~Eternal~ is joking or not...

The main reason the dollar was strong was because of neomercantalist nonsense from overseas, where you'd artificially keep the dollar strong so you could export like crazy. Generally speaking, you export to the US, receiving dollars, then reinvest in the US economy to get those dollars back in the US and keep the dollar strong. Otherwise, you can't maintain lopsided trade surpluses forever. Not that you can anyways; the dollar weakening now is an excellent example of what happens when too many countries start playing that game.

The US is not in bad shape economically, especially compared to the rest of the world. It's likely to be the *least* affected, overall, by a sudden collapse of the dollar. The real victims are going to be the countries which played this game for years, because their economies are going to take a bath when the dollar weakens, and the investments they made to get rid of dollars are going to take an even bigger bath. Some countries - I'm thinking of Japan - will be in serious shit...

You know what the best analogy is? You know that "The Day After Tomorrow" movie, where global warming over decades one day suddenly reverses ocean currents in the Atlantic and storms from hell rip up the globe? This is the economic equivalent of it, caused by trying to game global trade. It's going to cause major trouble, especially in the countries responsible, but also going to trash lots of innocent bystanders.

IIRC the 'truck' was for moving heavy stuff like the nuclear reactor around. Probably not neccessary on many Mars missions... on the other hand, a half-ton truck? That's a very, very light vehicle (~1000 pounds), for comparison the Geo Metro - not exactly a Hummer - weighs about 1800 pounds. Maybe it's build out of composites... I remember reading that one of the car manufacturers, Ford if memory serves, built a composite chassis that weighed only 100 pounds.

But it does mean we can't replace the engine in a Silverado and fire it to Mars. Nuts.  :laugh: