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Giving CubeSats Electric Propulsion

timothy posted more than 4 years ago | from the how-repellant dept.

Power 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.'"

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74 comments

Niggers (-1, Troll)

Anonymous Coward | more than 4 years ago | (#31016618)

Please, send the niggers and the dune coons to outer space. Esp the dune coons, the niggers are mostly just self-destructive, its the fucking islamic dune coons that are a danger to both themselves and others. yeah the peaceful serene religion of islam, thats why some of the worlds worst criminals believe in it wholeheartedly. somehow that makes sense to you PC fucks eh

CubeSats are a revolution (5, Insightful)

QuantumG (50515) | more than 4 years ago | (#31016772)

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 (4, Insightful)

girlintraining (1395911) | more than 4 years ago | (#31016866)

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 (4, Funny)

Angst Badger (8636) | more than 4 years ago | (#31016924)

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 (4, Funny)

girlintraining (1395911) | more than 4 years ago | (#31017240)

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 (1)

paganizer (566360) | more than 4 years ago | (#31019366)

My 1st thought was "Damn. I've been hearing about $10,000 to put up 1kg for almost 15 years now; when is it finally going to get here"?
My 2nd thought was that I'm not going to update my plans for a primarily Solar Powered, electrostatic ion thruster propelled, Black Sabbath "Sabotage" playing mars probe.
It would take about 15 years to get there.

PACKING RATIO (1)

sanman2 (928866) | more than 4 years ago | (#31017086)

What about having Packing Ratio Sats that are designed to stuff as many sats as possible into the payload faring of a rocket? Are cubes the best for cylindrical rockets?

Re:PACKING RATIO (4, Interesting)

Areyoukiddingme (1289470) | more than 4 years ago | (#31017424)

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.

Re:CubeSats are a revolution (4, Informative)

QuantumG (50515) | more than 4 years ago | (#31017230)

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 (1)

riboch (1551783) | more than 4 years ago | (#31020998)

I think it is actually the FCC that dictates that a satellite must decay in 25 years after the completion of the mission. This all comes about because they license LEO.

Re:CubeSats are a revolution (4, Informative)

Kral_Blbec (1201285) | more than 4 years ago | (#31017428)

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”).

Re:CubeSats are a revolution (1)

girlintraining (1395911) | more than 4 years ago | (#31017816)

The article also says they don't need it because they'd be placed in a destructive orbit anyway. So which is it? Probably both. There's nothing about the design that requires it to be in a certain orbit. Some may be placed in LEO. Others in polar orbit... others, maybe into a non-destructive orbit.

Where's the backup if the primary propulsion system fails? Oh. Right... there isn't one. One loose wire and it'll be up there for centuries, instead of years.

Re:CubeSats are a revolution (3, Insightful)

MichaelSmith (789609) | more than 4 years ago | (#31017960)

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:CubeSats are a revolution (1)

Random Destruction (866027) | more than 4 years ago | (#31019854)

Cubesats are generally chucked in LEO, and as TFS says, generally don't have propulsion. For this reason, they fall out of the sky very quickly. A few years tops. Once you introduce propulsion, you can keep them up longer, but then you can also have the ability to de-orbit at EOL.

Re:CubeSats are a revolution (1)

physburn (1095481) | more than 4 years ago | (#31019864)

At least this plan (that all it is, the demo propulsion system, hasn't been built yet). We allow the Cubesats to steer themselves away from potential collisions.

---

Space Craft [feeddistiller.com] Feed @ Feed Distiller [feeddistiller.com]

Re:CubeSats are a revolution (0)

Anonymous Coward | more than 4 years ago | (#31021748)

Is this tech going to provide enough thrust to de-orbit when they die?

Won't the Earth do that?

Re:CubeSats are a revolution (3, Informative)

khallow (566160) | more than 4 years ago | (#31018214)

ISP of 3500 s and 5.6 micronewtons of thrust. Not bad for a station keeping device on a 10 cm cube (generates roughly 3 m/s of delta v over a month, if the cube is dense as solid iron), but it's going to be vastly slow (unless, of course, you have an array of them) for other uses.

Re:CubeSats are a revolution (0)

Anonymous Coward | more than 4 years ago | (#31019768)

This idea is not original...(I've been around cubesats for many a year, I'm working on one right now) Electric propulsion drives have been around for a long time, most use some kind of pulse to zap material, anything that wont re-condense on your satellite... congrats to mit for reinventing a scaled up wheel and sticking it on a cubesat...

Re:CubeSats are a revolution (1)

Random Destruction (866027) | more than 4 years ago | (#31019868)

Yeah. i personally like the PPTs that zap teflon. I like the idea that i can fry my eggs and keep my satellite in orbit using the same material.

Pico (4, Funny)

Brian Gordon (987471) | more than 4 years ago | (#31016774)

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 (4, Funny)

lastchance_000 (847415) | more than 4 years ago | (#31016894)

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?

Re:Pico (1)

Hurricane78 (562437) | more than 4 years ago | (#31017184)

...it makes sense, no?

Yoda? Is that you? I told you to go back to bed again! It only makes sense to you, because you’re senile! ;)

Re:Pico (0)

Anonymous Coward | more than 4 years ago | (#31017298)

'Nano' is reaching the saturation that 'Micro' did a few years back, so yes it looks like it's time to move on

Pretty graph:

http://flowingdata.com/2009/11/20/buzzwords-in-academic-papers-comic/#

Re:Pico (1, Informative)

Anonymous Coward | more than 4 years ago | (#31017326)

Having recently attended a small satellite conference, I learned that when it comes to satellites, micro- refers to satellites under 100 kg, nano- refers to satellites under 10 kg, and pico- refers to satellites under 1 kg. Since the nominal mass of a 1-unit CubeSat is 1 kg, they are typically called picosatellites.

Re:Pico (0)

Anonymous Coward | more than 4 years ago | (#31018322)

coolstorybro

Re:Pico (1)

Tumbleweed (3706) | more than 4 years ago | (#31017614)

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!!!

Re:Pico (3, Insightful)

MichaelSmith (789609) | more than 4 years ago | (#31017972)

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.

Re:Pico (1)

Random Destruction (866027) | more than 4 years ago | (#31019876)

As sibling posts said, pico is under 1kg. You'll be disappointed to hear that I'm part of a team working on a femtosatellite. That is, a satellite under 100grams. Buzzword that!

Launched, yes. Orbited, not so much. (4, Informative)

$RANDOMLUSER (804576) | more than 4 years ago | (#31016876)

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:Launched, yes. Orbited, not so much. (-1, Flamebait)

Anonymous Coward | more than 4 years ago | (#31017052)

Riders on the storm.
Riders on the storm.
Cmdr loves gay porn.
His lover's asshole's torn.
Like iPad without a phone.
An Apple lover moans.
Riders on the storm.

Re:Launched, yes. Orbited, not so much. (1)

nanoakron (234907) | more than 4 years ago | (#31017872)

This should be part of the intro - none of these satellites currently exist. They were all blown up during their failed launch.

Re:Launched, yes. Orbited, not so much. (3, Informative)

Avacar (911548) | more than 4 years ago | (#31017970)

This should be part of the intro - none of these satellites currently exist. They were all blown up during their failed launch.

Actually that's incorrect. My predecessors had a cubesat on the DNEPR-1 launch; yes it blew up. That said, it was neither the first rocket to carry cubesats, nor by any means the last. TFA is correct in saying there are at least a dozen of these satellites in orbit right now, although many are now past their operation a life, and are waiting to naturally burn up. Saying that "none of these exist" is a bit of a misnomer as well, since there are cubesats waiting for launch in labs all around the world; I myself have two that will likely be going up in about three years from now.

TFA is correct, however, in saying that no cubesat currently has a propulsion system. It is wrong, however, in saying that no one else is working on this problem; in fact that is the very topic of my own research. I'd be much more impressed, however, if we could see simulations of the corrected orbits, estimated increases in lifetime, and, best yet, a working prototype. Claiming you can do this is bold; it is not an easy problem. Chemical rockets, and even 'standard' electric propulsion are become well-characterized solutions. Cubesat propulsion is on a completely different level, based on both the weakness of the thrusters, and the relatively low masses of the satellites. I feel this is a bit premature to be posted on the front of slashdot; this should have gone up in the 4-5 months TFA claims it will take to get a working prototype. That said, I applaud the novel approach. I hope it works, 'cause I know I'd buy one.

why even use propelant ? (0)

Anonymous Coward | more than 4 years ago | (#31016974)

just out of curiosity these satelites dont operate in deepspace.
Why not make use of earth's magnetic field to manouvre a bit around, maybe in combination with a small solar sail.
The point it that it wouldnt cost any propelant. (it might be less easy, but it will be able to move).

more might be done with a set of gyroscopes, they can move in areas in places where the gravitational field is curved.
Around earth it is curved, some other scientist ( not crank.dot ) have allready shown how to do that.
I'm sorry i cannt find back a link of it but it has been explored this subject and it seams valid for earth's near space.
And earth's near space is the most likely place where these devices will operate. :) you can always improve jut by using your mind....

Re:why even use propelant ? (-1)

Anonymous Coward | more than 4 years ago | (#31017000)

the easiest method is to just use an unbalanced pendulum on an internal rotating frame.

Re:why even use propelant ? (0)

Anonymous Coward | more than 4 years ago | (#31017042)

Huh?

Re:why even use propelant ? (2, Funny)

hguorbray (967940) | more than 4 years ago | (#31017208)

You silly SCA types.

Just because you have a trebuchet that doesn't mean that anything that fits in the bucket is payload. -or maybe it does...

-I'm Just Sayin'

Re:why even use propelant ? (2, Funny)

PitaBred (632671) | more than 4 years ago | (#31018598)

Not anything that fits in the bucket is payload, but anything that IS in the bucket is payload... note to self: stay away from flingy end of trebuchets with SCA people in attendance.

Re:why even use propelant ? (3, Interesting)

DarthBart (640519) | more than 4 years ago | (#31017026)

Larger satellite use magnetorquers to orient themselves in orbit. To use magnetics as a drive system, your spacecraft would have to be long so you could pulse a magnetic field down the length of it (think of it as a rail gun in reverse).

Re:why even use propelant ? (2, Interesting)

Areyoukiddingme (1289470) | more than 4 years ago | (#31017502)

And the usual answer to that is to unreel a tether after achieving orbit. In theory a picosatellite could contain a tether on a small spool. Admittedly getting such a thin tether to unwind properly might be difficult...

Re:why even use propelant ? (2, Informative)

Niffux (824706) | more than 4 years ago | (#31021256)

DTUsat-I, a CubeSat attempted this a few years ago. Unfortunately contact was never established with the satellite so it has not actually been tested, but the physical construction is fairly simple.
More info [dtusat.dtu.dk].

obama is fucking you white man (-1, Flamebait)

Anonymous Coward | more than 4 years ago | (#31017110)

he has his dick planted firmly in your ass.

Re:obama is fucking you white man (-1, Troll)

Anonymous Coward | more than 4 years ago | (#31017226)

and you like it, right? You racist fag.

A physics process? (3, Insightful)

Hurricane78 (562437) | more than 4 years ago | (#31017158)

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:A physics process? (0, Offtopic)

techno-vampire (666512) | more than 4 years ago | (#31017236)

I thought it would be a magic fairy magic process!

Personally, I was expecting that every CubeSat would have its own pony. OMG! PONIES! LOTS AND LOTS OF PINK PONIES!!!11!!!!

Ion drive (2, Interesting)

l00sr (266426) | more than 4 years ago | (#31017168)

Sounds like a variant of an ion drive [wikipedia.org], which have been around since the 50's.

Re:Ion drive (3, Insightful)

blair1q (305137) | more than 4 years ago | (#31017312)

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 (2, Insightful)

Nyeerrmm (940927) | more than 4 years ago | (#31017912)

Looking at the author's site [mit.edu], the research group has 3 peer reviewed journal articles, 6 conference papers, some ground tests and experimentation, and flight experiments by the summer -- and quite frankly as someone with a bit of experience in electric propulsion and satellite design (grad student in AERO, did some undergrad EP work), it sounds reasonable.

This doesn't sound like vaporware or pseudo-science -- I'd imagine the article is pretty accurate.

Re:Ion drive (1)

MacroRodent (1478749) | more than 4 years ago | (#31020602)

"the reaction mass is pre-ionized"

I wonder how they manage that? Isn't it equivalent to carrying a very large electric charge and somehow keeping it from getting neutralized? Same problem as in large capacitors. If they have tech to do that, wouldn't it be a wonderful electricity storage system!

MIT (0)

Anonymous Coward | more than 4 years ago | (#31017600)

While MIT is without a doubt a fantastic school, I can't help but be annoyed by the summary's phrasing here. Electrospray has been around a long time. Electrospray propulsion research as well. I myself have worked on similar devices. What he has done is make a nice compact package which offers a unique solution to a unique problem, but using more or less already existing technology. Not giving proper credit where it's due only serves to discourage everyone else slaving away in the field. Somebody tell me otherwise.

Re:MIT (1)

qubezz (520511) | more than 4 years ago | (#31018774)

Ion thrusters are used on just about every modern satellite needing trajectory correction, but this is one more small step for man. Analogy time - perpendicular recording technology on hard drives: It was not the jump from floppy disk to flash memory, but still a technological leap which made for an acceleration in increasing storage densities that had been stagnating for a while.

You fail to see this jump and potential - imagine a small array of these propulsion chips on both sides of the solar panel wings of normal sized satellites - they could be continuously spraying a few millinewtons of thrust when the attitude of the panels is near tangent to the orbit for the whole mission life to counteract orbital decay - with more efficient thrust per propellant weight than on-board ion thrusters, which could then be smaller or even eliminated if deemed redundant.

Now if we could figure out a way to install attitude control on parent poster...

Too large for a Rubik's cube (2, Informative)

Jeremy Erwin (2054) | more than 4 years ago | (#31017824)

Each edge of a Rubik's cube is 5.7 cm long. The cubesats are 5.5 times as large.

As the technology increases (1)

Ace905 (163071) | more than 4 years ago | (#31017944)

You know what's funny about this, is we're going to end up with a situation where increases in the propulsion systems end up sending newer satellites past ones launched earlier before they complete their missions. We'll end up with a cloud of ever decreasing technological junk arriving at distant civilizations....

Cool, sounds like it holds water (1)

CrazyJim1 (809850) | more than 4 years ago | (#31018252)

I remember in physics class theorizing a propulsion system for a space ship. I figured that the only way to get thrust would be to accelerate hydrogen to as fast as you can then zip it out the thrusters. You'd have low mass, but high velocity propulsion. It sounds like this guy figured out a way to do this in a compact form. If this seriously works, I'm excited because it will allow satellites all over the solar system for relatively cheap. Put a high imaging camera on your satellite and snap pictures from around the solar system! It is nice that even though NASA has a shoestring budget that space exploration can still make advances.

Re:Cool, sounds like it holds water (1)

uncle slacky (1125953) | more than 4 years ago | (#31028296)

If it's in LEO, there should be enough free atmospheric molecules (and hydrogen) to run an EHD-based "lifter" type of propulsion (aka Biefeld-Brown or Serrano effect), given an electrical supply (solar cells?):
http://en.wikipedia.org/wiki/Ionocraft [wikipedia.org]

So, no need to store fuel, either.

Re:Cool, sounds like it holds water (1)

petermgreen (876956) | more than 4 years ago | (#31030862)

One problem I see coming up is energy, roughly speaking (Newtonian physics) kinetic energy is proportional to the square of the velocity

So if you double your exhaust velocity (and keep your energy losses the same) you double your propellant efficiency but halve your energy efficiency.

In other words if you want a spaceship with high acceleration and high propellant efficancy you are going to need to find a shitload of power from somewhere....

Cubesat (0)

Anonymous Coward | more than 4 years ago | (#31018554)

I am actually working with several of these in my time at Uni. They really are tiny and only occupy a very small percentage of space (still more than 99% of LEO is unoccupied). Plus one of my personal objectives for the mission we are carrying out for the Air Force is to have them de-orbit themselves once the mission is complete. All of a spacecraft of that size would burn up upon re-entry, except if there was any titanium involved, which would survive to the surface (special regulation exists to prevent accidents with stuff like that) But getting back to the propulsion, this sounds like an interesting idea, it sadly wouldn't fit in our mission, but I'm sure it would be a nice solution for other cubesats (provided its cheap) all those parts get expensive quick.

MIT = written for retards? (1)

Gothmolly (148874) | more than 4 years ago | (#31021364)

I stopped reading after the 3rd or 4th time they explained what something as simple as an ion was. Hello MIT, you guys are eggheads, not the Discovery Channel.

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