July 30, 2012
Credit: Credit: Raytheon
Frank Morring, Jr. Washington
Small satellites, once the realm of one-off low-budget science missions and undergraduate engineering classes, have come full circle with the growing realization among hard-pressed, high-end users that the little birds can do the big jobs, too.
The smallest of them—cubesats—are rapidly evolving into an operational commercial, scientific and military technology. Higher up the payload-weight scale, the high cost per pound of launching payloads and the growing skill of spacecraft miniaturizers are making satellites that are small enough to ride as secondary payloads attractive to a variety of customers, particularly if they can be mass-produced or produced rapidly in single units.
The launch-cost consideration may change, as the growing interest in small spacecraft attracts a new generation of small launchers designed to carry them. And the spacecraft themselves are increasingly capable, with government money flowing into the arena in search of a way to do more with less.
“From where we have been 10 years ago to where we are now is a complete 180,” says Roland Coelho, a member of the research staff at California Polytechnic State University's engineering school, one of the main U.S. centers for cubesat development. “In the past it's been primarily educational. . . . As we have kind of grown—the entire community worldwide over the past decade—we really have started to see some niche markets where cubesats can play a vital role. It's clearly the most evident in the government cubesat programs that we have today. The government, and particularly the U.S. government, has been the driving force in this technology because that's where all the funding is.”
Government interest in small satellites is not limited to cubesats, or even to spacecraft. The U.S. Defense Advanced Research Projects Agency (Darpa) is spending $46 million to find ways to launch satellites weighing up to 100 lb. on 24-hr. notice for less than $1 million (see p. 44). And the Air Force and National Reconnaissance Office consider small satellites a way to lower risk in national security spacecraft by adding redundancy in orbit.
“Even if 20% of them failed, you'd still do your mission, so there's sort of a natural resiliency in using constellations of smaller satellites,” says John Roth, whose company—Sierra Nevada Space Systems—makes small satellites for the military and others. “One of the advantages that the military recognizes also is, if we're worrying about countries taking offensive action against our satellites . . . the more satellites you have up doing the same mission, the harder it is for them to do anything to our satellites.”