An artist's interpretation of the Dream Chaser vehicle after spacecraft separation.
Credit: SpaceDev/Sierra Nevada Corp.
A private space firm with orbital aspirations has revamped its plans for a crew-carrying spacecraft.
Poway, California-based aerospace firm SpaceDev has a new design for its Dream Chaser vehicle and hopes to offer suborbital rides within two years, with orbital flights to follow.
Instead of deriving a spacecraft from NASA's X-34 space plane concept, the firm has opted for a blunt-nosed lifting body approach to cut down on reentry heating stresses, SpaceDev chief Jim Benson said in a telephone interview. The plans stem from work SpaceDev performed with NASA's Ames Research Center to study the use of hybrid rocket propulsion for spaceflight testbeds.
"Because of the X-34's pointed nature and sharp edges, the high temperatures would meet the limits of our vehicle right at the ragged edge," Benson said, adding that the new Dream Chaser design more closely resembles the Horizontal Landing-20 (HL-20) model studied by NASA's Langley Research Center. "The HL-20 was a great little vehicle and it's already designed."
Small enough to fit inside the payload bay of a NASA shuttle with folded wings, the HL-20 Personnel Launch System was slated to carry 10 astronauts (two pilots and eight passengers) or small payloads into orbit, though funding for the program dried up in 1990.
SpaceDev's take on the small spacecraft would be lighter, seat four people for a suborbital flight and up to six for an orbital trek. The space plane is envisioned to launch atop a launch stack of hybrid rocket engines - like those developed by SpaceDev as part of the SpaceShipOne Ansari X Prize entry - and make a runway landing back on Earth, according to its designed flight profile.
"We don't use cryogenic liquids, so there's no ice or foam to worry about, and it's non-explosive," Benson said of the current design.
Benson said that with $20 million or less and about two years, SpaceDev could have a four-person suborbital Dream Chaser vehicle ready for flight. Given three more years, as well as $100 million, and the firm could develop an orbital variant, he added.
SpaceDev hopes its design will enable the firm to participate in commercial cargo and other services to support the International Space Station (ISS), and could aid future Moon expeditions as well. Last week, NASA chief Michael Griffin said private supply ships with their own launch services will be vital to deliver future cargo to the ISS.
"We're keenly interested in that," Benson said, adding that an orbital Dream Chaser could haul one ton of cargo - with limited crew - to the ISS. "Once we get into orbit, you can really make use of it. It doesn't matter if it's going to the space station, habitat modules or what...what we need is low-cost access to low Earth orbit."