Picosatellites Personal space
usinfo | 2013-07-17 13:25
 
MANY a youngster, Babbage included, has dreamed of going into space. But becoming an astronaut is a hard slog. Sandy Antunes suggests a less daunting proxy. An astrophysicist and programmer with decades of NASA experience, Dr Antunes is a proponent of picosatellites, and has just published the second of four books on "do-it-yourself" satellites. These tiny birds weigh around a kilogram and are shot up in lieu of ballast or in empty nooks and crannies on full-blown satellite launch missions. They are becoming so popular that 2013 may see the first dedicated launches.
 
This popularity owes much to two unrelated trends: the "maker" movement in electronics and the rise of smartphones. The maker movement brings open-source fervour to hardware, and in particular to devices other than computers, such as instruments and robots, often using the Arduino platform. This reduces the expertise needed to create circuit boards and program a functional system, whether it is terrestrial or winds up in orbit.
 
On the other end of the complexity spectrum, smartphone makers' insistence on the tiniest and cheapest cameras, miniaturised sensors (like accelerometers and barometers) and specialised chips has made instruments suitable for picosatellite use as well, where size, power drain and weight are critically important. (In America, a firm needs a licence to put a camera in orbit, but that is the only significant regulatory hurdle.)
 
Since this newspaper described the potential of picosatellites in 2000, rocket firms have also become keener on ferrying them into space. That is mainly because standard formats have emerged, making them a less risky proposition for commercial launches. The most popular, CubeSat, was devised by California Polytechnic State University and Stanford University. It is a cube 10cm on a side, with standard electrical, physical and launch parameters.
 
A CubeSat may be tiny, but it packs a punch: biological experiments, earthquake sensors and propulsion tests have all been fielded using one. After being ejected, a CubeSat might unfurl antennas or a solar sail. Some designers hope to launch multiple units that then connect physically or wirelessly in space. In all, about 80 have been shoved towards low-earth orbit (LEO), and 50 or so have succeeded in orbiting and communicating with Earth. (A single launch failure in 2006 accounts for half of those lost.) Objects sent into LEO have self-decaying orbits that send them after weeks or months hurtling through the atmosphere to burn up before impact.
 
Dr Antunes says these satellites can be relatively affordable to build. He has ploughed about $7,000 in parts and testing kit into his Project Calliope, which will measure the ionosphere's light, magnetic and electric fields, and beam the data back to Earth in the form of digital sound instrument (MIDI) codes. However, he and other early adopters have learned enough (and shared this wisdom) to drop the cost for future builders. Dr Antunes's students at Capitol College, an engineering and technology school in Maryland, are designing their own CubeSat missions for as little as a few thousand dollars plus launch costs. And those launch costs remain the sticking point.
 
Over the last decade, the price has hovered in the $40,000-80,000 range to boost a ready-to-go CubeSat into LEO, although $40,000 has become more typical. NASA, which has been a strong backer of picosatellites, awards discounted $20,000 slots for serious-minded programmes to hitch onto its regular satellite launches. It has launched nine (and lost three) of the small orbiters with about 40 more scheduled through 2014.
 
Costs may drop further in 2013 if Interorbital, a start-up rocket-development and launch firm founded in 1996, begins regular trips to LEO. At present, it is still testing its rockets for reliability before moving into commercial operation as early as next year, at which point it will offer both dedicated picosatellite launches as well as more conventional satellite lifting with room for picosats. Interorbital offers CubeSat berths for $10,000 a pop. 
 
But it has an even cheaper option. It charges just $8,000 for its own TubeSat kit (13cm long by 9cm in diameter), which includes the case, indispensible components like power and communications, as well as the launch, making it well within reach of many hobbyists and academic clubs (who supply circuit boards and instrumentation of their own). Dr Antunes chose this form factor, although he has a backup plan to adapt to a CubeSat if necessary. If all goes well, the first batch of TubeSats along with CubeSats will hit LEO in 2013.
 
Anyone interested in a personal satellite can pick up a copy of Dr Antunes' DIY satellite books. Volume one focused on building a bird; volume two covers the challenges a picosatellite faces in LEO, and how to prepare for contingencies using inexpensive off-the-shelf kit (such as a $20 automotive brake-bleeder hand pump to simulate a vacuum). Another two tomes, about instrumentation and communications, are in the works. 
 
Dr Antunes has spent years on his own bird, and longs for it to fly. He has covered some of the roughly $15,000 spent so far with a grant from a science blog for $4,000 and used Kickstarter to raise about $2,500 for the ground-station instrumentation. All this adds up to the cost of a fancy motorbike—and, the 45-year-old Dr Antunes jokes, a better way for one to deal with a midlife crisis.
 
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