Remember back in the days of elementary school, making a solar-powered oven out of a box and aluminum foil, setting it down over black asphalt in the midday Sun and trying to cook a hot dog? Remember launching model rockets from the P.E. field? Well, imagine your teacher had scrapped those projects from the curriculum entirely, and instead had given you your very own satellite—equipped with solar cells, antennae, a tiny computer and a radio transceiver—to monitor from its orbit in space. Your satellite might have a camera to take pictures, a sensor to predict weather, detect earthquakes, research biology or transmit signals to amateur radio stations. You could choose to monitor it online, or from a ground station using hardware.
Surely the idea of this in the 1990s would have sounded preposterous to anyone aware of how expensive satellite technology has been, since the launch of Russia’s Sputnik 1 in 1957. Even now, 54 years after the dawn of the Space Age, a large, traditional satellite might run you $150,000,000—just to build. The cheapest dedicated launch you might find for it could be $10 million, according to Scott MacGillivray, president of Tyvak Nano-Satellite Systems. But aerospace engineers at universities have found ways to make building and launching a satellite cheaper than ever.
The trick is making smaller satellites—Nanosatellites—using relatively inexpensive, off-the-shelf hardware found in personal electronics. NanoSats can be the size of a grapefruit, a Rubix cube or a postage stamp. Regardless, all have to hitch a ride, or piggyback, on a large spacecraft, such as a NASA rocket. Since what weighs less will always require less fuel to be launched, you’d think the lightest weight NanoSats would be the cheapest every time. But besides just their weight, the shape they take has an effect on their price.
Think back to grade school again. This time, you and your classmates are building onto a LEGO spaceship with the toy blocks. You can collaborate easily, with pieces designed to fit together. But there’s always that one kid who has to complicate everything. Instead of stacking up LEGOs to make little satellites on the shuttle, he presents you with a wooden ABC-block. Sure you can make it fit, with some Duct tape or glue, but it’s an added expense and effort you know you could have avoided . . . if someone could have just agreed to use standardized LEGOs.
Well, what the LEGO did for blocks is similar to what the CubeSat has done for small satellites. It’s shaped like a 10-centimeter cube that will fit in your hand, and up to three can be combined for slightly larger projects. Engineers at Stanford University and California Polytechnic State University introduced the CubeSat in 1999, along with a matching deployment system called PPOD (Poly-PicoSatellite Orbital Deployer). One PPOD houses several CubeSats inside of it, and this simplifies a launch provider’s job by allowing the workers loading up shuttles to attach one black box instead of many. Together, these two parts comprise the “CubeSat standard,” an envelope specification that has fostered creativity and collaboration across the globe.
Robert Twiggs is one of the Stanford professors credited with developing CubeSats. “What we’ve learned from the satellites we have launched, [is] the more room you give students to put things in . . . the more things they want to put in. If you can fly anything that’s going to do something that is a little different, it’s exciting to the students,” Twiggs told Space.com in 2005.
The CubeSat allows students more options when it comes to using low-cost components, and it also requires a relatively short time to develop. It can be built in one or two years, which falls in the timeline of a student’s career. This has led to dozens being launched by universities, and over 100 teams worldwide are currently developing them, according to MacGillivray.
Some of the most interesting proposed CubeSat missions include sending them to orbit the moon and giving them telescopes for tracking bright stars. But much sooner, scheduled for 2013, a CubeSat will carry a payload of thousands of microchip-sized satellites, to be released into low Earth orbit.
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Zac Manchester, a Ph.D student in aerospace engineering at Cornell University, has spent the past three years striving to develop the smallest satellite possible. So far, his efforts, combined with those of two other students and their research adviser, Professor Mason Peck, have resulted in a chip satellite they call Sprite. One Sprite is about the size of two postage stamps (2cm x 2cm x 2 mm) and intended to be launched in swarms of hundreds or thousands. Individually, Sprites are limited to transmitting a four-letter, programmed name and a few bits of data. But in mass, they could work in unison as a whole cloud, with each transmitting signals to ground stations. Collectively, these signals are expected to provide enhanced imaging, such as 3D pictures of space weather.
The most spectacular thing about Sprites, however, isn’t the images they can produce at low cost; it’s in the way they can travel and the ensuing possibilities. Like small particles of cosmic dust, they’re barely affected by gravity and can be carried on the solar wind. Manchester and Peck hope future versions might coast to the atmospheres of Saturn and Mars, where they could look for organic compounds like nucleic acids. “ . . . [I]f the probes could be made thin and lightweight enough, alternative forms of propulsion could eventually send them to distant worlds, without the need for rocket fuel,” Peck explained in his article, Exploring Space with Chip-like Satellites.
Other universities around the world have worked on satellites like Sprite, but Cornell is the first to have launched prototypes. On May 16, 2011, three Sprites were launched with the space shuttle Endeavour and mounted to the International Space Station. The prototypes will remain there for the next few years as part of a test to see how they weather the harsh conditions of space. In the meantime, Manchester has created a fundraising project on Kickstarter.com encouraging people to sponsor as many Sprites as possible for a mass-launch planned for 2013. It costs $300 to sponsor a Sprite, which allows you to name it and track its mission on Kicksat.org. However, for $1,000 you can receive “a Sprite development kit, including a fully functioning Sprite with all schematics, source code, and programming tools so that you can write your own flight code.”
“If at least 1000 space pioneers join us by sponsoring Sprites,” Manchester wrote on Kickstarter, “we’ll be able to dramatically improve and shrink our design by getting custom microchips made. If we can do that, then costs could be driven down so that every school or even every school child could one day have their own spacecraft to explore the solar system.”
