Tiny Satellites Promise Low-Risk, Low-Cost Space Future
By Graeme Stemp-Morlock
National Geographic News
August 20, 2008
Photo by D. Higginbotham/MSFC/NASA
NASA’s nine–pound (four–kilogram) NanoSail–D satellite—seen here—is about the size of a loaf of bread. NanoSail–D is among a growing number of small satellite models that offer a way into space on the cheap, scientists said in August 2008. The devices—one of which was destroyed in a failed launch earlier this month—cost about $2.3 million apiece.
Space-industry belt-tightening and ever shrinking technology are combining to give tiny satellites a big future, scientists say.
Sometimes as small as softballs, the little orbiters are cheaper and quicker to build than the megabuck, monster–size satellites that have dominated for decades.
"In the last ten years small satellites have started to take off across different industries and the world," said Pat Patterson of the Space Dynamics Laboratory at Utah State University.
"Small satellites have allowed the world to access space," continued Patterson, who last week headed the 22nd Annual Conference on Small Satellites, where about a thousand aerospace scientists and industry representatives met in Logan, Utah.
"In the U.S.A. we have plenty of money for big spacecraft in space," Patterson said. "Other countries don’t have that kind of cash flow, but they do have $10 to $15 million [for a small satellite], so the market is growing."
Try and Try Again
Small satellites range from softball size to refrigerator size. The Hubble Space Telescope, by comparison, is the size of a school bus.
The new devices can measure, observe, and communicate an ever increasing amount of data.
Most critically, these devices—such as NASA’s nine–pound (four–kilogram) NanoSail–Dmodel, which is about as big as a loaf of bread—take some of the risk out of developing new space hardware.
The failed launch of a privately funded SpaceX Falcon 1 rocket ended the NanoSail–Dmission earlier this month. But the satellite’s destruction over the Pacific Ocean was a relatively minor loss, given the comparatively small investment involved.
Two NanoSail–Dsatellites had been built in just six months and cost only U.S. $2.3 million apiece—pennies in the spacecraft world, where space shuttle launches cost about $450 million each.
Although NASA has said it has no immediate plans to relaunch the satellite, scientists are hoping to try out the spare NanoSail–D.
"One of the reasons we’re experimenting with small satellites is that you don’t have to tie up a team for decades and spend a lot of money," said Edward Montgomery, who worked on the NanoSail–Dmission at NASA’s Marshall Space Flight Center in Huntsville, Alabama.
"We’re not being cavalier, but the benefit is that you can try and see what happens and try again and still save money over a conventional mission," he said.
Another project, the U.S. Naval Research Laboratory’s TacSats program, aims in the long term to provide ground forces with real–time satellite imagery and reliable communications.
But the program is also part of a growing movement to standardize the equipment, sizes, and shapes of small satellites.
Standardization would allow companies to manufacture systems in bulk, further reducing the cost and time it takes to prepare small satellites.
In fact, the Naval Research Lab hopes to develop TacSats that can be made and launched within in days or weeks of being commissioned.
Small Eyes, Deep Impact
Small satellites might also help save our planet.
An 885–foot (270–meter) asteroid named Apophis caused a scare several years ago when prediction models showed it might hit Earth in 2029.
Scientists have now ruled out that collision. But they say Apophis will still come within our moon’s orbit, and if it hits a gravitational sweet spot around the moon, it could be thrown on course to collide with Earth in 2036.
(Read about asteroids and comets targeting Earth in National Geographic magazine’s August 2008 issue.)
To help pin down Apophis’s orbit, the Planetary Society put out the call for spacecraft designs that could visit the asteroid. The winning entry was a 400–pound (180–kilogram) satellite named Foresight.
Without the support of a major space agency, though, Foresight will never make it into space, according to John Olds, head of SpaceWorks, the company that designed the winning satellite.
Meanwhile, the Canadian Space Agency hopes by 2010 to have launched its own $12 million surveillance satellite to find Apophis–size asteroids, comets, and meteoroids that orbit unnervingly close to Earth.
The Canadian satellite includes a 6–inch (15–centimeter) telescope. The whole satellite will be about the size of a large suitcase and weigh less than 150 pounds (70 kilograms).
"Various people have done estimates that suggest there are around a thousand near–Earth objects greater than a kilometer [a half mile] in size, and various research programs have found approaching 800," said Alan Hildebrand, principle investigator for the Canadian project.
"But with smaller objects, we’re talking hundreds of thousands, maybe between 200,000 and 500,000," he said.
"We’ve found just over 5,000, and remember that [the space object that likely caused] the Tunguska explosion in 1908 was probably only 30 to 50 meters [100 to 160 feet] in diameter."
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