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

[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.