One element in a European Space Agency push to develop vehicles capable of re-entry has been pushed back until at least 2013 as the agency seeks a launch alternative to the Russian submarine-launched Volna rocket which was withdrawn at short notice before a flight that had been expected in the run-up to the Farnborough air show.
Expert (European Experimental Re-entry Testbed), is a blunt-nosed ballistic capsule fitted with an array of sensors and a system of ceramic steering flaps that have been tested to 1,200˚C (2,190˚F) in an M7 flow at Italy's Scirocco plasma windtunnel, near Naples - one of the few sites in the world where such testing is possible. Expert is ready to fly but is stuck in storage at Alenia Aeronautica's clean room in Turin waiting for a ride.
A change of Russian policy means military systems such as the sea-launched Volna are no longer available for civil flights, leaving ESA scrambling for another suborbital vehicle capable of delivering Expert on a 15min flight to the edge of space for a 5km/s re-entry to test advanced aerothermodynamics.
Programme leader Jose Gavira says there may be other Russian launch options, and his team is also in contact with US company Orbital Sciences about using its air-launched Pegasus system.
Gavira is confident of finding a technically suitable launcher but while there are no plans to change the mission profile or modify the spacecraft, ESA faces two significant challenges. One is to secure a ground recovery site, possibly in the USA or, if in Russia, somewhere other than the Kamchatka peninsula military range that had been agreed.
The other issue is money. As Gavira puts it, Volna was "cheap" and any other option will raise the cost.
A 2013 flight is his target, then, but Gavira is expecting at least a bumpy ride from ESA's member-state ministers when they meet in November in Italy to talk about budget priorities for 2013 and beyond.
IXV ON TRACK
The delay to Expert is not going to affect the other half of ESA's re-entry vehicle development programme, as the IXV project heads "at very high speed" towards its planned 2013 launch on ESA's new Vega small launcher.
Project manager Giorgio Tumino stresses that although some of Expert's sensors will also fly on IXV, there is no technical dependence between the two.
IXV is a 2t lifting-body spaceplane that will test some never-flown technologies critical to re-entry, including advanced ceramic and ablative thermal protection as well as guidance navigation and control. Its suborbital flight will reach a peak of 450km - more than four times Expert's - and achieve speeds of 7.5km/s to fully represent return from low-Earth orbit.
IXV, says Tumino, is the start of a "bottom-up" approach to developing an affordable re-entry capability, and the agency is not attempting to replace the hugely-expensive Space Shuttle. However, ESA believes a re-entry capsule could be spaceworthy by 2015 and a vehicle capable of transporting four astronauts could be feasible by 2020.