Dream Chaser is a space vehicle capable of carrying seven astronauts into low-earth orbit. Its development was started by Space Dev, where Sirangelo was CEO, prior to its acquisition by Sierra Nevada in October 2008.
Space Dev announced the initiation of…
Dream Chaser is a space vehicle capable of carrying seven astronauts into low-earth orbit. Its development was started by Space Dev, where Sirangelo was CEO, prior to its acquisition by Sierra Nevada in October 2008.
Space Dev announced the initiation of the Dream Chaser project in late 2005. “The core concept is based around the time when we first decided there might be an opportunity for a Shuttle replacement,” said Sirangelo.
“We thought there might be room for a commercial entry and within that sphere there might be use for more than one type of vehicle. Most of the industry settled around a capsule design placed on a rocket, but we believed that a variety of different vehicles might be needed for different types of mission.”
The Constellation program was to use the Orion capsule to be launched on board the Ares-1 rocket, while SpaceX’s Dragon spacecraft is also a capsule design.
“The Shuttle leaves a void – there are a number of things it can do that would be difficult with a capsule,” said Sirangelo.
In recognition of this void, Space Dev looked at other designs that had previously put forward. The one that took the company’s interest was the HC-20 vehicle which NASA had worked on for 10 years. It was designed to potentially function as a lifeboat for the Space Station
Interestingly, the original HC-20 design was derived from the Russian space vehicle BOR-4, which was developed and used four times in the 1970s and 80s.
Sirangelo said: “When we looked at this we saw that thirty years of design and hundreds of millions dollars had gone into it, so we looked at NASA’s model and updated it. We added our own motors so it could manoeuvre in space and manoeuvre on landing.”
The motors are a particular area of expertise for Space Dev/Sierra Nevada. It was Space Dev motors that powered the SpaceShipOne vehicle that won the Ansari X-Prize in 2004, and that will also be used in Virgin Galactic’s sub-orbital spaceplane. Dream Chaser will operate off a variant of these motors.
“These motors allow the vehicle to land anywhere there is 3000 metres of runway,” said Sirangelo. Also, in tandem with the onboard software, they allow the Dream Chaser crew to abort launch and jettison the vehicle off the launch stack if necessary. This is a process that can pose real problems and require great expenditure for a capsule design.
Space Dev did not have the resources to design its own lifting rocket, so it began working with what eventually became the United Launch Alliance to use the Atlas V rocket as the carrier for Dream Chaser.
Sirangelo is keen to stress that Dream Chaser will not make capsules obsolete, and nor is it intended to. “We don’t think it’ll replace capsule programs,” he said. “The commercial sector will have three or four companies flying LEO missions and we could be one of them.”
“Now that it’s virtually complete, we hope the Space Station will spend the next ten years doing real science. That then beggars the problem as to how things that are created in space can be returned to Earth without damaging the work done. For example, in a Soyuz there is only room for three passengers as opposed to a vehicle with cargo capacity like Dream Chaser.
A modified smaller Dream Chaser design could also be used as a utility vehicle capable of carrying out repair work that even the shuttle cannot currently do.
Sierra Nevada expects to start flight-testing Dream Chaser in 2012 with a view to entering commercial service in 2014.
NASA’s award of the US$20m seed funding actually followed two years where Sierra Nevada worked on Dream Chaser with the agency but without federal funding. “This created a sense of discipline,” said Sirangelo. “We put a project in place, we passed four milestones and in return they got to work with us and see our systems.”
“The money is helpful, and it’s certainly symbolic. We had 30 other companies competing and we got the highest award, which gives us an indication we’re not going down the wrong track.”
As a private company Sierra Nevada does not tend to release financial details, but Sirangelo confirmed that Space Dev/Sierra Nevada has invested “many millions” into Dream Chaser. Sierra Nevada’s status as a high-end provider of avionics, electronics and communications systems means that funding is never likely to be an issue for the project.