Giving CubeSats Electric Propulsion 74
eldavojohn writes "Thirteen picosatellites were launched back in June of 2006 with the price coming down dramatically in the years since. But the Rubik's cube sized devices have no mobility, meaning once they're put in orbit, they stay in that orbit. The big problem is that traditional chemical propulsion systems are too large for ten-centimeter sided cubes weighing a kilogram. A new electric propulsion system designed by Paulo Lozano of MIT might change that. "
"The article explains how it works: 'Lozano's design relies on electrospraying, a physics process that uses electricity to extract positive and negative ions from a liquid salt that is created in a laboratory and serves as the system's propellant. The liquid contains no solvent, such as water, and can be charged electrically with no heat involved. Whereas other electric propulsion systems charge the ions in a chamber on the satellite, the ionic liquid in Lozano's design has already been charged on the ground, which is why his system doesn't need a chamber. Electricity is then converted from the main power source of the CubeSat, typically batteries or a solar panel, and applied to a tiny structure roughly the size of a postage stamp. This thin panel is made of about 1,000 porous metal structures that resemble needles and have several grams of the ionic liquid on them. By applying voltage to the needles, an electric field is created that extracts the ions from the liquid, accelerates them at very high speeds and forces them to fly away. This process creates an ionic force strong enough to produce thrust.'"
CubeSats are a revolution (Score:5, Insightful)
CubeSats are the "cheap access to space" needed for research and technology risk reduction that's been needed since the dawn of the space age.. and it didn't require some magical new propulsion method or even new economies of scale in launchers, just good standards and a very big customer, the Airforce academy.
For those of you who find the article a little light on details, here's the scientific paper:
http://sgc.engin.umich.edu/erps/IEPC_2007/PAPERS/IEPC-2007-145.pdf [umich.edu]
This preliminary work is now being flight tested.. and, if all goes well, it'll soon be commercially available. When's soon? 3 to 5 years. That's what CubeSats give you, a reduction in lab-to-market from 10 years or longer to 6.
Re:CubeSats are a revolution (Score:4, Insightful)
CubeSats are the "cheap access to space" needed for research and technology risk reduction that's been needed since the dawn of the space age.. and it didn't require some magical new propulsion method or even new economies of scale in launchers, just good standards and a very big customer, the Airforce academy.
Yeah... Just what we need -- more tiny objects in orbit around Earth. We have enough problems avoiding crashing into the big satellites we can actually see with radar, let alone worrying about a few hundred rubic's cubes up there. -_- Big satellites can be retired from choice orbits and sent to a maintenance orbit, or back plunging into the atmosphere to burn up. Is this tech going to provide enough thrust to de-orbit when they die?
A physics process? (Score:4, Insightful)
Lozano's design relies on electrospraying, a physics process...
No way! I thought it would be a magic fairy magic process! (So magic, they used the word twice!) With glitter and unicorns!
</sarcasm>
Re:Ion drive (Score:4, Insightful)
A variant, yes, but without the high energy cost of ionizing the fuel during thrusting. Also not much need for accelerating structures. if the article is accurate, the reaction mass is pre-ionized and locked into the structure. When you need thrust you pretty much just release it and it pushes you away. Neat trick, if the article is accurate.
Re:Ion drive (Score:3, Insightful)
This doesn't sound like vaporware or pseudo-science -- I'd imagine the article is pretty accurate.
Re:CubeSats are a revolution (Score:4, Insightful)
Having propulsion means you can operate it for a long time in an orbit which will decay and still expect it to reenter if it stops working.
Re:Pico (Score:4, Insightful)
What, we've exhausted the marketability of the buzzword nano and have stepped it up to pico? Somehow I doubt that regular satellites mass 10^12 kilograms.
Small to the eXtreme!!!
The mass of the moon is 7.36 × 1022 kilograms [google.com] so maybe 10^12 is normal for natural satellites.