Smallsats Finding New Applications

By Frank Morring, Jr.
Source: Aviation Week & Space Technology

While the number of ways to get secondary payloads off their launch vehicles is growing, Tyvak's MacGillivray notes a trend to dedicated launch vehicles for small satellites. One of them is a follow-on to the reusable suborbital human spaceflight business Virgin Galactic hopes to kick off next year with its eight-seat SpaceShipTwo. The company has started developing a two-stage, kerosene-fueled “LauncherOne” rocket that it will drop from the same WhiteKnightTwo carrier aircraft that will air-launch its human payloads.

“Secondary opportunities are great for technology demonstrators, they're great for educational missions, but as we've been speaking to you and throughout the community [for a little more than a year], you've told us it is hard to build a business case around secondary launch opportunities,” says William Pomerantz, Virgin Galactic's special projects director. “When you can't specify where you are launching from, where you are launching to, when you are launching . . . that is a constraint.”

Virgin hopes to begin flying 200-kg payloads to low Earth orbit in 2016, dropping the LauncherOne vehicle at an altitude of 50,000 ft. from anywhere that has a 9,000-10,000-ft. runway for WhiteKnightTwo. Pomerantz says the company is developing the rocket in-house, including engines and its “simple, low-cost composites structure.” The price of a mission, he says, will be “less than $10 million.”

That could play well with NASA's open-ended spaceflight-technology development program. With $600 million to invest this year, the space technology mission director is a significant potential customer for the smallsat community, and the associate administrator in charge of the program was invited to deliver the keynote address at this year's smallsat conference.

“We're trying to accelerate and invest where we can to push the whole area forward,” said Mike Gazarik. “. . . [T]here are power limitations, but what we're seeing, just like our flight-opportunities program, is a number of technology payloads that can be flown very inexpensively on a suborbital vehicle, which can be flown on a small spacecraft. We're looking at whatever we can find to be able to get to space.”

Most experts at the conference believe that, ultimately, cubesats and other small satellites will find their greatest utility in constellations that combine the capabilities of “swarms” of the relatively inexpensive spacecraft to do more, in some cases, than a single expensive satellite can accomplish. Weather constellations, to cite one example presented this year, can place sensors over a developing hurricane more frequently than today's polar-orbiting weathersats, and can provide higher-resolution data on rapidly changing conditions than the geostationary environmental platforms.

Jordi Puig-Suari, the Cal Poly professor who, with Bob Twigg of Morehead State, pioneered the cubesat standard, continues to push the envelope as an educator even as he works with Tyvak—founded and staffed by Cal Poly graduates like MacGillivray—on commercial projects. This year he presented an analysis of what it would take to launch a constellation of eight 3U cubesats from an Atlas V. It turns out that even a cold-gas propulsion system would be up to the task of stabilizing the constellation around the planet in a single plane after 40 days, with fairly straightforward deployment from the launch vehicle.

“Forty days is not that long,” Puig-Suari says. “It is kind of a commissioning time. So our conclusion is we are ready to deploy constellations today. We don't have to do anything different—or very little different—than what we have right now. The technology, the infrastructure, the systems are in place where we could have a cubesat constellation, at least a single plane, on the next Atlas V.”

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