Sierra Nevada Corp.’s longrunning effort to develop a reusable spacecraft called the Dream Chaser got new life Jan. 14 when the company won a billion-dollar contract to transport cargo to the International Space Station.
NASA awarded Sierra Nevada one of three Commercial Resupply Services 2 (CRS-2) contracts to carry cargo to and from the ISS starting in late 2019. The other two winners, Orbital ATK and SpaceX, already support the station with their Cygnus and Dragon spacecraft.
Sierra Nevada offered Dream Chaser, a lifting body vehicle that will launch on a United Launch Alliance Atlas 5. Dream Chaser will glide back to a runway landing, most likely at the same Kennedy Space Center runway that hosted space shuttle landings.
The contract is the biggest milestone yet in Sierra Nevada’s effort to develop Dream Chaser. “There’s certainly the excitement of a big win and being part of history,” said Mark Sirangelo, corporate vice president of Sierra Nevada Space Systems, in a Jan. 14 interview.
“We’ve certainly had a lot of ups and downs and a lot of time where we didn’t know if we were going to have the next step.”
– SNC’s Mike Sirangelo
Dream Chaser has its roots in a NASA vehicle concept, the HL-20, which in turn was based on a Soviet-era design called the BOR-4. A decade ago, a small San Diego company, SpaceDev, announced plans to use the HL-20 as the basis for a suborbital or orbital vehicle primarily aimed at the emerging space tourism market.
Sierra Nevada, who acquired SpaceDev in 2008, adapted the Dream Chaser design to support NASA’s commercial crew program. The company won several funded Space Act Agreements from NASA to support that work, but failed to win a contract for crew transportation services in 2014, losing to Boeing and SpaceX.
While Sierra Nevada pursued an ultimately unsuccessful protest of the commercial crew contract, it pitched a new version of Dream Chaser for cargo services. The cargo version of Dream Chaser includes an external cargo module and foldable wings, allowing it to fit inside a five-meter Atlas 5 payload fairing.
At a Johnson Space Center press conference to announce the CRS-2 awards, NASA officials did not give specific details about why they chose any of the winning companies, citing the need to debrief all the bidders. They suggested, though, that Dream Chaser’s ability to return to Earth relatively gently played a key role in their decision.
A runway landing, said NASA ISS chief scientist Julie Robinson, would be particularly useful when bringing biological experiments back to Earth. “If they have a really hard landing, a splashdown, and then they’re at sea for a couple of days, you’ve disrupted that research before the scientists can take that final set of measurements,” she said.
Kirk Shireman, NASA ISS program manager, said Dream Chaser offered a “dissimilar redundancy” to Cygnus and Dragon, each of which has suffered a launch failure. “We have the ability to dial up that capability if one of our other capabilities is unavailable,” he said
With the contract in place, Sierra Nevada is pressing ahead with development of Dream Chaser. Sirangelo said the company will perform a series of glide tests of a Dream Chaser test article at Edwards Air Force Base, California, later this year. Those flights will also test flight software for the orbital vehicle. The company is also working with Lockheed Martin on the structures for the first orbital vehicles.
“This year will see us doing a series of more complicated and higher flight tests with all the new software on board and then, in parallel with that, we’ll be going through the build phase for the first orbital vehicles,” Sirangelo said.
Sierra Nevada is at a disadvantage to Orbital and SpaceX, whose vehicle development was largely funded by earlier NASA commercial cargo agreements. Sirangelo, though, said the company had the resources to complete Dream Chaser. “We have been able to have the resources to start this program until the NASA program kicks in,” he said.
Sirangelo said he could not give a specific value of the CRS-2 contract because it will depend on what missions NASA orders and when. Sierra Nevada, like Orbital and SpaceX, are guaranteed a minimum of six flights under the contracts. “There is a general sense that it’s a reasonably big number, over a billion dollars for six missions,” he said.
That contract, though, finally gives Sierra Nevada some certainty about Dream Chaser’s future. “We’ve certainly had a lot of ups and downs and a lot of times where we didn’t know if we were going to have the next step,” Sirangelo said. “I think coming back from the dead a few times like a phoenix is a really fun thing.”