Boeing CST-100
Boeing has proposed developing a version of its CST-100 crew spacecraft to transport cargo to and from the International Space Station. (credit: Boeing illustration)

COLORADO SPRINGS, Colo. — Boeing expects to select a single vehicle next month from an unspecified number of rockets in the running to launch unmanned flight tests and early crewed missions of the seven-person CST-100 space taxi it is developing with financial backing from NASA.

“Currently we’re doing a procurement to select a rocket that we’ll use for the test flights and probably the first set of operational flights,” John Elbon, Boeing Defense, Space & Security’s vice president and general manager of commercial crew systems, said in an April 12 interview during the National Space Symposium here.

Boeing has designed the 13-metric-ton CST-100 to be capable of launching to the international space station and other low Earth orbit destinations atop a variety of rockets, including United Launch Alliance’s Delta 4 and Atlas 5, Space Exploration Technologies’ Falcon 9, the European Ariane 5 and the proposed Liberty rocket that would be built by Minneapolis-based ATK and Les Mureaux, France-based Astrium Space Transportation.

“But we need to select one so we can do a point solution, build a launch vehicle adapter and do the test flights,” Elbon said, adding, “We have to work with the launch vehicle provider to make sure that the launch pad is capable of human access and that sort of thing.”

Elbon said the procurement has been under way since late January and that Boeing is on track to choose the rocket in May. During an April 13 news conference here he said the initial rocket selection would be used during the CST-100’s test phase to nail down performance parameters.

“There’s a next level of design that you have to do to really lay out the abort scenarios, really lay out the aero-performance, get down into the details, and so we’ll select a single vehicle to do that with,” Elbon said April 13. “Further downstream if there were economic reasons or other reasons that we wanted to be able to fly on an additional vehicle, we could do that more detailed work on that vehicle as well. So we’ll probably be in a position where with about two years or so of work we could then be totally compatible with another vehicle as we move forward.”

Elbon said Boeing is planning to conduct two wind tunnel tests of scale models of the rocket and capsule to refine ascent performance calculations and determine the precise design of the capsule’s abort profiles.

“We’ll do two of those, one’s with a smaller rocket model and one is maybe 10 or 12 feet [3 or 3.7 meters] long,” he said during the April 12 interview, adding that Boeing has not yet selected a wind tunnel facility for the tests. “That will probably be a function of the launch vehicle we select and which wind tunnels they’re typically working with.”

Boeing is developing the CST-100 in collaboration with North Las Vegas-based Bigelow Aerospace. Last year NASA awarded the team $18 million to mature the capsule design under the agency’s Commercial Crew Development (CCDev) program.

During the first round of CCDev work, Elbon said, the company completed a system design review of the CST-100, constructed a pressure-test article, test fired the capsule’s Pratt & Whitney Rocketdyne-built abort engine, developed a mockup and made progress on the capsule’s autonomous rendezvous and docking system and heat shield.

“We accomplished that with $18 million of NASA investment [and] we put in a like amount,” Elbon said April 13. “It was incredible the amount we were able to get done for that amount of money.”

Although NASA was expected to announce a second round of CCDev awards valued at around $270 million in mid-April, that did not happen and government and industry sources say the award is on hold.

“I’m hopeful that it happens relatively soon,” Elbon said April 13. “We’ve been working since the end of [CCDev 1] up to this point with internal funds to keep our team going, and I’m real anxious to get going and work with NASA.”

Elbon said Boeing would use additional funding under CCDev 2 to further CST-100 development, and plans to complete a preliminary design review of the capsule this fall while making progress toward completing a critical design review next year. In addition to the wind tunnel tests, by May 2012 — when CCDev 2 is slated to wrap up — Boeing hopes to have completed two safety reviews, abort engine firings, separation tests and a series of airbag and parachute drop tests to demonstrate the CST-100’s landing capability.

Ultimately, Elbon said, Boeing expects to conduct a pad abort test of the CST-100 crew escape system in 2013 followed by two unmanned flight tests the following year. A final flight demo, slated for late 2014, would send two Boeing test pilots to low Earth orbit, he said.



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