Giving CubeSats Electric Propulsion

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.'"

Comments

CubeSats are a revolution

[QuantumG]

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

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

[girlintraining]

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?

Re:CubeSats are a revolution

[Angst Badger]

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.

That was my first thought, too. My second thought, after reading TFA, was that this guy has slightly modified the basic design of an inkjet printer and figured out a way to avoid having his business cut into by refill vendors.

Re:CubeSats are a revolution

[wizardforce]

This is where electrodynamic tethers and laser brooms come in handy.

Re:CubeSats are a revolution

[QuantumG]

Well, despite what the article says, most CubeSats are launched into deteriorating orbits which eventually burn up.

As for radar, yes, it's nice to be able to get ground confirmation and CubeSats are more than big enough to do that, especially considering they are deployed on-orbit in clusters.

Re:CubeSats are a revolution

[girlintraining]

That was my first thought, too. My second thought, after reading TFA, was that this guy has slightly modified the basic design of an inkjet printer and figured out a way to avoid having his business cut into by refill vendors.

At $6,000+ a gallon, we should consider using rocket fuel in our inkjet printers instead. It'd be cheaper...

Re:CubeSats are a revolution

[Kral_Blbec]

FTA

The Air Force and other government agencies are interested in using CubeSats that can move between different orbits in space, and more specifically, that have the propulsion required to reenter Earth’s atmosphere and destroy themselves at the end of their mission (thereby keeping them from becoming “space junk”).

Pico

[Brian Gordon]

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.

Re:Pico

[lastchance_000]

Actually, it's a typo. It should have read pikasatellites, from Pikachu. They fit in your hand, send out bursts of highly charged particles...it makes sense, no?

Launched, yes. Orbited, not so much.

[$RANDOMLUSER]

The engines on the the DNEPR-1 launched on 26 July 2006 shut down 86 seconds into the flight. It crashed approximately 25 km downrange. So, quite a bit of "bang" for your buck.

Re:PACKING RATIO

[Areyoukiddingme]

Cubesats are never the primary payload. They're individually tiny, so they're launched in bunches as a secondary payload along with something else much bigger. Their cubical shape makes for easy fabrication of both the satellite itself and the spring-loaded launcher that they're packed in for the launch. Since they're basically freeloading on some other launch, using empty space that would otherwise be completely wasted, their own form factor doesn't really matter much. They fit in the odd bits of leftover space that a typical satellite leaves inside a rocket faring.