A US-European agreement to develop spaceplane technology may extend the remit of Sierra Nevada’s in-development Dream Chaser beyond its planned use by NASA to shuttle astronauts to and from the International Space Station. Sierra Nevada, the European Space Agency and Germany’s DLR aerospace agency have agreed to jointly evaluate technologies such as those being developed for ESA’s IXV (Intermediate eXperimental Vehicle) re-entry vehicle concept for the runway-landing Dream Chaser or other variants; launch by Ariane 5 will also be studied.
Alternatively, Dream Chaser-based European or German missions envisioned include microgravity science missions, satellite deployment and servicing, debris removal and Earth observation.
A highlight of ESA’s 2014 programme will be a suborbital test flight by the Vega rocket during the second half of the year of the 2t unmanned lifting body IXV, whose large-panel thermal protection system – which has been extensively tested in the hypersonic Scirocco wind tunnel near Naples – promises significant improvements over the small tiles that proved so problematic on NASA’s Space Shuttle.
It is IXV’s follow-on programme, PRIDE (Programme for Reusable In-orbit Demonstrator in Europe), that may result in a fully orbital, runway-landing vehicle being used for orbiting small satellites, servicing satellites or conducting scientific missions. PRIDE is being sized to fit on ESA’s Vega rocket, and carries the legacy of the Hermes spaceplane project studied by France’s CNES space agency and ESA in the 1980s, as well as the NASA-ESA-DLR X-38 crew return vehicle concept, which was abandoned in 2002.
Dream Chaser, by contrast, is being designed to carry up to seven crew and cargo. The spaceplane, derived from NASA’s HL-20 lifting body concept of the 1980s, will be restricted to low-Earth orbit as its heat shielding will not withstand re-entry from deeper space.
The project is one thread – along with capsule programmes by SpaceX and Boeing – in NASA’s so-called Commercial Crew bid to have private industry replace the astronaut transportation capability that it lost with the retirement of the Space Shuttle fleet in late 2011. Illustrating the scale of that challenge and the potential value of collaboration with ESA and DLR, Sierra Nevada has been working on Dream Chaser since the mid-2000s and has so far consumed about £300 million ($500 million) of NASA money, along with a similar amount from its own investors. An October 2013 drop-test of a full-scale but not spaceworthy version validated its aerodynamics and autonomous flight control, but much work – and cost – remains before a planned 2016 flight in space, in autonomous mode, and a 2017 flight with a human pilot on board.
Chief executive Mark Sirangelo says: “By leveraging the best that partner nations have to offer in technology and cooperating on mutually beneficial missions, Sierra Nevada will maximise the past investments made by all partners and enhance the commercial value of the Dream Chaser spacecraft.”
The prospect of developing Dream Chaser or a variant for a range of European missions also improves Sierra Nevada’s chances of turning the programme into a commercial success. The White House opened 2014 with a boon for the space industry by authorising NASA to operate the International Space Station though 2024, rather than having it de-orbited in 2020 as previously planned by partners USA, Canada, Europe, Japan and Russia. That extension is clearly of huge value to Sierra Nevada, which otherwise would have had at best a three-year window to operate Dream Chaser flights to the space station.
But as Sirangelo said of the ESA-DLR agreement: “We believe the potential demand for these international missions could grow and become significant, and in doing so will help meet the NASA and US Congressional objective for the Commercial Crew providers to succeed as standalone commercial programmes, with NASA as an anchor customer, but not sole customer.”