Tiny Ion Engine Runs On Water 103
symbolset writes "Discovery News is covering a project by two engineers from the University of Michigan to pair cubesats with tiny ion engines for inexpensive interplanetary exploration. The tiny plasma drive called the CubeSat Ambipolar Thruster (CAT) will ionize water and use it as propellant with power provided by solar cells. In addition to scaling down the size of ion engines they hope to bring down the whole cost of development and launch to under $200,000."
Re:No, it runs on sunlight. (Score:4, Insightful)
That answer is just as dumb.
It runs on both.
It always needs a propellant and a energy source.
Re:No, it runs on sunlight. (Score:2, Insightful)
Re:No, it runs on sunlight. (Score:4, Insightful)
The Pacific Ocean is something very inconvenient for a spacecraft in Geo-synchronous orbit. In fact, it is much, much easier to grab something from the Moon or from an asteroid or comet than it is to get that same bucket of water from the Pacific Ocean. In fact, it would be easier and "cheaper" (assuming the infrastructure was in place) to mine the ice caps of Mars than it would be to get water from the Pacific Ocean.
A really good diagram that shows some delta-v budgets for moving stuff around the solar system can be found here: http://upload.wikimedia.org/wikipedia/commons/7/74/Delta-Vs_for_inner_Solar_System.svg [wikimedia.org]
The gravity well is something that is not just from science fiction, but something that has to do with real-life physics. Or are you one of those who thinks the Apollo Moon landings happened in a Burbank studio? I suppose NASA has never sent anything above the "sky" either, not even a communications satellite? Without real people doing real things in space, you would likely be dead. I'm not exaggerating.
Re:I'm sure there is a drought in space joke somew (Score:5, Insightful)
It is a potential habitat. It is a gateway to the stars.
...and here you reveal your true colours.
Ceres is not a potential habitat.
Assume you can develop a shelter with adequate shielding from cosmic rays and solar storms, adequate insulation, pressure containment, etc. (Despite the fact that we don't know what "adequate" is, or exactly what's in "etc".) And assume you can transport inhabitants there, all the while keeeping them healthy. Fine. One teeny little failure in one annoying little subsystem, lasting a mere minute, and every inhabitant is dead. What are the odds of zero operation failures in a lifetime? Never happened in any city here on Earth. Or even any inhabited building.
Another thing. If you could build machines reliable enough to transport people safely around the solar system (and you actually wanted to have people live off Earth), why would you bother with a habitat on an asteroid? Stick with what works: the spaceship. Iain Banks had this right.
Ceres is not a gateway to the stars.
Nothing is. The stars are too far away. You'll never live long enough to learn anything from sending a physical mass to any star with Earth-like, habitable zone planets; your city won't exist long enough. Your civilization likely won't last long enough. (The Fermi paradox is no paradox at all. It's a demonstration of how far apart stars are, and how hostile and unrewarding the intervening space is...and perhaps of the rationality of other intelligent life.)
So what are we left with? Ceres is a potentially useful source of reaction mass/propellant, if anyone ever discovers a valid reason to send physical masses past geosynchronous orbit. (I'll believe mining asteroids could be profitable when I discover a pressing ubiqitous and essential materials problem for which all solutions require one particular element, and the element is both in short supply here on Earth and abundant on an asteroid near Ceres. To date, though, there are substitutes and alternatives for pretty much everything that might start to get short in the next century, so don't hold your breath.)
I can see a point to mini ion drives. They're potentially handy for sending things out to geosynchronous orbit and doing stuff there and in LEO. And I can see a point to operating telescopes with good resolving power out "in space". But I can't see why they'd need to be very far away from Earth. And even for purposes of scientific experimentation, I can't see a point to sending physical mass much past the outer part of the Oort cloud.
If you want to get a semi-knowledgeable public interested in this stuff, don't use words and phrases like 'habitat', 'gateway to the stars' or 'profit' when talking about this stuff. They scream "space cadet".