Evaluating the Capabilities of Chip-Sized Spacecraft

kgeiger writes "The Sprite project is testing the feasibility of chip-sized spacecraft. 'Rather than hand building one-of-a-kind spacecraft, we envision constructing spacecraft on wafers in much the same way that common integrated circuits are made today. During fabrication, solar cells and other components would be incorporated with microelectromechanical systems techniques. Instead of exhaustively testing each part, as is done with current spacecraft, engineers will be able to monitor Sprite quality in a less labor-intensive fashion by using statistical process control, testing a few chips from each batch to make sure they meet specifications.' The project's goal is to deploy true 'smart dust,' comprised of 5- to 50-mg single-sensor spacecraft capable of forming deep-space sensor arrays."

Comments

too small - space gravel

[RichMan]

How do we track them all? What happens when they die on mission?

What happens when a human occupied vehicle crosses paths with one of these dead objects at 10,000km/h differentail speeds?

We really should not be cluttering up planetary and solar orbits with "gravel", time has done a nice job of cleaning out all the intra-orbit space.

Re:too small - space gravel

[Matheus]

Obligatory XKCD reference... http://xkcd.com/865/

Re:too small - space gravel

[suomynonAyletamitlU]

What happens when a human occupied vehicle crosses paths with one of these dead objects at 10,000km/h differentail speeds?

While I appreciate the sentiment (and agree), you really need to understand how amazingly, hugely, vastly much empty room there is in space. There are enormous calculations needed to hit something the size of jupiter, even if you start pointed in the right direction.

Let's say a 1km asteroid is 10,000 km away, and you yourself are in a 1km (cross-section) spacecraft. To not hit it, you have to aim to be 1km in any direction away from it--.5km from half of your body, .5km from half of its body. In other words, to hit it, you have to point anywhere within a 1km radius of dead-on. Assuming no course corrections, you have to be pointed within about .005 degrees of the object center, in every direction. Put another way, a sphere of radius 10,000km is billions of square kilometers of surface area, more than twice that of the earth, and you would have to hit around one square kilometer of it.

The moon, which is the only stellar object that could be accused of being close, is not 10,000km away; it's something more than 30x that far. At that range, the object could have a 30x greater cross-section and you'd still have that same tiny angular danger zone. Everything else is millions of km away. The only really clogged region (relatively speaking) is earth orbit, and that's because we have so much that we want to do and to leave in a relatively small space.

Is polluting the solar system still a bad idea? Sure, probably. However, to be honest, by the time our spaceflight capabilities are up to travelling to other planets in earnest, we maybe able to shield against large particulates, and we'll know approximately where they are. (There's not much in the way of interference in space like there are in wind and water; there's solar wind, gravity wells, and inertia, and not much else.) The debris is also comparable to what you might expect from asteroid collisions, comet trails, and the like, which might be substantially harder to track. More importantly, there's a lot of science to be done before we're ready for all that, and this is at least partially helping progress that. Maybe.

Re:too small - space gravel

[Zinho]

The flaw in your reasoning is that there are very few interesting places in the solar system to go, so despite the very large volume available for navigating around these obstacles it's quite a bit more likely that a later space mission will be aiming for the exact same tiny angular zone as a previous one. It's similar to the current situation with satellites in Earth orbit - I occasionally hear about congestion in the geostationary orbits despite there being lots of potential orbits around the earth, some orbits are simply more desirable than others.

Don't get me wrong, I understand that there are complexities I'm glossing over (consecutive launch opportunities to the same destination not passing through the same space as each other, for example). But when you said:

The only really clogged region (relatively speaking) is earth orbit, and that's because we have so much that we want to do and to leave in a relatively small space.

you glossed over the fact that any well-explored destination in the solar system is destined to become a "clogged region" for exactly the same reason that Earth is now. Compared to the volume of space contained in the Solar System, the interesting destinations represent a "relatively small space" not significantly larger than Earth's orbital zone.

Re:too small - space gravel

[uncanny]

So here we are on our little mud ball, and something like the Vogons suddenly show up to collect from us for destruction of something they value... or worse they assume it was a stealth attack on a craft that was just going about it's business someplace far away from us.

Didn't they see the sign posted that reads "not responsible for damage caused by debris damaging your ship" it was posted in a locked box in a dark corner in the basement of an old ladies house. If they didn't take the time to read it, then that's not our fault either.

Propulsion?

[mrxak]

Much of the weight and size in spacecraft is not the instruments, it's the fuel and engine. I get that you need a lot less of both if you've got a small mass, but still, how are you going to move the thing around?

TFA says they'll need some crazy new propulsion system, so yeah, we won't be seeing chip ships any time soon, probably.

Sure, ignore SG-1

[ThatsNotPudding]

but don't come crying to me when the replicators show up.

Re:How big of a rocket?

[NoNonAlphaCharsHere]

Oh! The humanity!