Fly Me To Which Moon? 183
Hugh Pickens writes "NASA and the European Space Agency are expected later this week to settle an ongoing debate on whether to send a robotic mission to Jupiter's moon Europa or Saturn's moon Titan. Both are difficult places to get to — a mission to either would cost several billion dollars/euros to build and execute — and both have become alluring targets in the quest to learn whether Earth alone supports life. On the one hand, Europa is believed to have liquid oceans beneath its frozen crust which (on Earth at least) are a source of life-supporting chemistry. Scientists would like to scan Europa's surface for bits of material that may have seeped up from beneath the ice. 'Imagine if there were microbes entrained in material that has exuded onto the surface of Europa and they've been sitting there for maybe three million years,' says planetary scientist Dr. Brad Dalton. On the other hand, Titan has two enticing features in the search for life: liquids on the surface, and a thick atmosphere that can be used to slow down a spacecraft and help put it into orbit. Titan's surface water is locked into the crust as ice, but scientists suspect there may be a subsurface ocean where water mingles with ammonia. The mission will not get to the launch pad before 2020. 'It's unfortunate that there has to be a decision,' says NASA/JPL astrobiologist Dr. Kevin Hand. 'It's important to go to both. They are both such amazing and tantalizing worlds in terms of finding life.'"
Europa, but differently (Score:2, Interesting)
We need something that can see big things too, so we don't miss some Cthulhu looking thing just beneath the ice while we scrape around for little stuff.
Re:access to space (Score:2, Interesting)
Expecting government contractors to do anything more than provide the bare minimum to get the next contract is foolish.
The whole point of Apollo was that nothing fundamentally *new* was required. "All" that was needed was to put the existing technology together. The same cannot be said of RLVs.
Re:access to space (Score:5, Interesting)
If we had worked on cheaper access to space first, we could have both.
Agreed. we should have a space station at L1 [wikipedia.org] before we do any more exploring.
Re:Who cares how much it costs... (Score:3, Interesting)
Just call it "stimulus" and us yanks will just print some more money for it. :/
There's nothing wrong in this economic environment with printing money.
We are facing a severe spectre of deflation, unofficially I think its already happening.
While hyperinflation is bad, it's unlikely to happen with such a massive collapse of the credit markets and money supply, but deflation is a severe concern as the majority of people and businesses have taken on considerable debts.
Deflation makes debts more onerous. The last thing we need in an environment where people's wages are being crushed in a vice is to make their student loans even harder to pay, or conversely the last thing we need in an environment where consumer spending is slowing is to allow prices to drop, rendering corporate debts more onerous... making either untenable for their respective parties will only lead to more disaster.
Printing money with what in any other times would be considered dangerous and reckless abandon is actually a good way to provide a counter-force to this threat.
Re:WHAT ?? (Score:3, Interesting)
Obviously, life cant exist without oxygen...
oxygen catasrophe [wikipedia.org]
Anaerobic organisms [wikipedia.org]
Re:access to space (Score:4, Interesting)
L1, L2, and L3 are all semi-unstable points. You'd be better off in L4 or L5.
And solar wind at L1 is a bitch. At least the magnetosphere would protect some at L2.
I have to agree with that. It does not lessen my point about having a space station first, then expanding further, though.
Just dreamin' a bit... (Score:3, Interesting)
Two things: First, a question. What are the orbital mechanics? Would it be possible to build a "bus" that could drop off a navigation-capable "probe taxi" near each destination?
Second, a dream. If ever there was a time to send a large human crew on a career-length mission (maybe 30 - 40 years), this would be the one. High-acceleration supply/instrument packages could be sent before and after them. A serious commitment to zero-gravity construction could be undertaken. The cost would be huge, but the payback would potentially be on a scale rivaling the technology revolution that grew out of Apollo.
And let's face it, the odds that we're screwing up our only livable habitat in potentially-ugly ways are increasing. Developing the capacity to move at least a few people elsewhere isn't such a terrible idea.
Re:WHAT ?? (Score:2, Interesting)
"It would be a pretty big waste of space."- Carl Sagan
both, plus Venus and Pluto (Score:3, Interesting)
The mountains of Venus would be interesting. Radar reflection suggests that it might rain bismuth or lead.
Landing on Pluto would be a nice challenge. First there is the problem of slowing down enough. Then there is the problem of landing without melting a deep hole.
Which one is best for implanting life? (Score:3, Interesting)
Let's go to the best place for living there some day. (Sounds like neither)
So, we're always careful about not infecting extra-terrestrial ecosystems the way we have here on Earth. We're obsessed with finding some kind of 'life', (but have not so far). Well and good, and I've always supported those points of view.
But we might want to consider the chilling possibility that one day the Earth might become uninhabitable, (asteroid strike, nuclear war, superbug, whatever). OK, it's improbable, but then again so is finding 'life' on some barren, frozen moon.
If that did happen - maybe hundreds of years from now - our descendants would be pretty glad if we'd shipped out bugs that had quietly been transforming methane into oxygen (for example) over the centuries...
Re:WHAT ?? (Score:3, Interesting)
Re:access to space (Score:2, Interesting)
Unfortunately getting to L4 or L5 is a bit of a bitch. NASA is having problems getting people back to the the moon, L4 and L5 are several times further.
Shame. I would like to see NASA et al. boost the ISS out to L4 or L5 when it's finished with, instead of splashing it and losing the whole thing.
At least we would have an ad hoc laboratory to see how our existing equipment works beyond the magnetosphere, plus somewhere to go that's easier than the Moon or Mars but may be more useful than low earth orbit.
Standardize (Score:5, Interesting)
Thinking about Voyager I and II and the Mariner series, maybe it's time to create a standard probe platform (orbiter and lander halves if you insist) and build them in large quantities. Make them rugged and try to minimize expensive customization. Keep them relatively small so several can be launched at once. Then start tossing them everywhere. Use whatever orbital mechanics work (Hohmann, interplanetary transport network, whatever). But send 2, 3, or more to each destination.
Launch a dozen at Jupiter with arrivals spaced apart and you can wait to see if the first one arrives safely. If it does, send the second to another moon or to the same one for redundancy. You now have mission flexibility on a whole new level.
Send 2 to our moon. Then if you want to try a software upgrade, you can try it on those first.
And so on.
The whole point is to get the cost per craft down to the 10's of millions. If you can average 4 for $50 million and buy a rocket to launch the 4 for $50 million, you can now send 40 for the price of one. And now you have a series of missions such that if one fails, it's not a disaster. Will the data be as good as a custom probe? No way. But with so many probes you can take risks you never could before and maybe see things custom probes never could. Risks such as sending them odd places or putting some cheap funky instruments from some university.
Almost the "Faster Better Cheaper" concept, but based on mass production instead of 1 of a kind probes.
Proxima Centauri Paradox (Score:2, Interesting)
from: http://advancedmediacommittee.typepad.com/emmyadvancedmedia/2007/05/wideband_cable_.html [typepad.com]
"If we wanted to travel to Alpha Centauri (the nearest star system to the Earth) when should we start the project?"
Located a mere 24 trillion miles from downtown Manhattan, Proxima Centauri, the dimmest orb in the Alpha Centauri star system, is actually the nearest star to the Earth. It takes light, which travels at 186,200 miles per second, 4.22 years to make the trip.
Now, the Voyager spacecraft is generally considered to be the fastest man-made object traveling in space. It is heading out into interstellar space at a blistering, 38,000 miles per hour.
So, if it was pointed at Proxima Centauri (which it is not) it would take Voyager approximately 73,000 years to get there.
Let's think about project management for a moment. Most of the technology we need for this journey does not yet exist. My rocket scientist friends estimate that it will take mankind approximately 1,000 years to build the ship. Inside that 1,000 year time-frame, let's assume that technological advances allow us to travel four times faster than Voyager's top speed. If we start today, we could reasonably expect to arrive at Proxima Centauri in about 20,000 years.
However, if we wait 10,000 years to start the project, technological advances might allow us a four-fold increase in speed for each 1,000 years we wait which would reduce travel time to about 2,000 years.
Which brings us to the Alpha Centauri paradox. If we start the project today, it will take us approximately 20,000 years to get to Proxima Centauri, but if we wait 10,000 years to start the project, the whole trip will take about 12,000 years.
Yes, in the race to the nearest star, waiting 10,000 years to start will get you there 8,000 years ahead of the people who start building technology today. Would you wait?
Europa Hands Down (Score:3, Interesting)
This is not really a REAL question I hope.
Hands down, the place to go is Europa.
Titan's chemistry is not interesting, when it comes to life.
Europa will have vast energy sources, liquid water, probably at ranges of Titan to superheated on the ocean floor.
The curvature of space around Jupitor will stretch the moon as it orbits the planet, heating it to a decent temperature.
I find it AMAZING that the curvature of space time, is in itself responsible for the energy production.
It is as close to a perpetual motion engine as you will get!
Titan would be a great place to study exochemsistry, but to study life? Not as good as Europa.
Besides Arthur C Clarke has a great track record going for predictions. :-)
Go Europa!! W00t! Life or BUST!
-Hack
Re:access to space (Score:3, Interesting)
Exactly what use would a Space Station at any of the Lagrange points be for missions to Jupiter or Saturn?
Re:access to space (Score:3, Interesting)
Quite true.
The Sun-Earth Lagrange points are, however, pretty much completely worthless, and always will be. By the time we can make convenient use of them, we'd be better served by using the Sun-Jupiter Lagrange points.