Lots of people (and some squid) are eagerly awaiting space shuttle Endeavour’s final launch on Monday, but Cornell University’s Mason Peck has a personal stake in the mission. Endeavour will deliver three of his prototype microchip mini-satellites to the International Space Station to see how well they function in that harsh environment.
Peck’s tiny satellites — nicknamed “Sprite” and measuring just one square inch — are mounted on the Materials International Space Station Experiment (MISSE-8) pallet, which will be attached to the space station in turn. The chip satellites contain sensors, a microchip, and an antenna to transmit collected data about the chemistry of the solar wind and associated radiation and particle impacts. In a few years, the MISSE-8 panel will be removed and returned to earth, so Peck can see how well his little ChipSats fared.
The solar wind is basically a plasma (ionized gas) of charged particles emanating from the sun, traveling outward in all directions at very high speeds (almost 1 million miles per hour).
There’s a very good reason space scientists are interested in learning more about the solar wind: it can have a pronounced effect on the flight paths of spacecraft, as well as giving rise to violent eruptions called solar flares. These flares cause geomagnetic storms on Earth, capable of knocking out communication satellites and interfering with radio broadcasts, among other impacts.
Why is NASA interested in microchip satellites? Economics, pure and simple. Space flight is a pricey endeavor, and it costs many thousands of dollars per pound to launch satellites and other payloads into orbit. So the smaller the satellite, the cheaper it would be to deploy it — or to deploy a swarm of satellites, each weighing about one-tenth of a gram, for the cost of launching one full-sized satellite.
Slightly larger satellites the size of grapefruit, called “CubeSats,” have been successfully launched, but Peck’s “ChipSats” are roughly the size of a fingernail (and thus us would have very different flight dynamics).
Peck relied on students (two undergraduate and one graduate student) to build the ChipCats using mostly commercial parts, which, he says, have become so high-performance in recent years that “they have far outstripped what the aerospace industry has at its disposal.” His group has also partnered with Draper Labs to work on future prototypes.
While each ChipSat is identical in design and transmits at the same frequency, Peck says there are crucial differences between them that he and his colleagues will be able to distinguish between the three micro-satellites while monitoring the transmitted data back on earth. This experiment is a proof-of-principle project, and if it works, Peck hopes to one day see swarms of thousands of these tiny devices launched with future missions. If that happens, scientists will need to be able to tell them apart.
“Their small size allows them to travel like space dust,” Peck said of the advantages to using ChipSats in Cornell’s press release. “Blown by solar winds, they can ‘sail’ to distant locations without fuel. We’re actually trying to create a new capability and build it from the ground up. We want to learn what’s the bare minimum we can design for communication from space.”
Image credit: Cornell University