Space cone to acquire expert data

By Jonathan Amos
Science reporter, BBC News

The vehicle will reach speeds of 5km/s

Europe continues to develop the technologies needed to bring spacecraft safely back to the Earth's surface.

The European Space Agency has signed the contract with industry that will lead to the production of a cone-shaped demonstration vehicle known as EXPERT.

It will be launched to 105km by a submarine missile before falling back to the ground and landing by parachute.

Its sensors' data will help improve the models used to characterise the atmospheric re-entry of spacecraft.

One of the first beneficiaries of that new insight is likely to be the ARV, Europe's proposed future cargo and astronaut transport vessel. Engineers have begun the process of detailing the specifications for this spaceship, with the intention of getting ministerial approval in 2011 to start development.

EXPERT (EPERimental Re-entry Test-bed) is basically a blunt cone with a flat surface apart from four fixed flaps. It will be just over 1.5m long and weigh slightly under 450kg.

It will carry about 15 instruments. These will record a range of aerodynamic and aerothermodynamic phenomena, including the shocks, temperature and pressure changes experienced by the vehicle as air molecules rush around it.

Because it is not going as high as orbital vehicles, EXPERT will not achieve the highest re-entry velocities. Nonetheless, the 5km/sec it does attain should be sufficient to produce the data required by scientists.

"It is entirely designed not to resemble a final operational system but to generate the aerodynamic and physical phenomena we want to investigate," said Marco Caporicci, who leads the transportation and re-entry division in Esa's human spaceflight directorate.

"This is a step towards the validation of the design tools, both computational flight dynamics and wind tunnels; and then [we can] use those tools for the actual conditions of re-entry of the operational missions, first of all the ARV."

The ARV, or Advanced Re-Entry Vehicle, is an upgraded version of the cargo re-supply vessel that Esa already flies to the International Space Station.

Currently, this freighter is discarded in a controlled burn-up in the atmosphere at the end of its mission. The ARV improvements would equip the freighter's pressurised module with the technologies necessary to make a safe passage to the Earth's surface.

In the first instance, this would allow Esa to download cargo from space; but the agency believes a further, relatively straightforward refinement would permit the module to also carry a crew of astronauts.

Thales Alenia Space (Italy) signed a contract with Esa this week to build the flight model of EXPERT. The total cost of the mission is on the order of 30m euros, about 15m of which covers the payload experiments supplied by research institutes and companies across Europe.

Launch from the Pacific Ocean on a Russian Volna rocket (a decommissioned Intercontinental Ballistic Missile - ICBM) is expected in the second half of 2010. The landing, by parachute, will be on the Kamchatka peninsula, in Russia's far east.

Thales is also working on another re-entry experimental vehicle known as IXV (Intermediate eXperimental Vehicle). Due for launch in 2012, this will achieve much faster velocities on re-entry and will be able to test specific materials technologies, as well as gathering more hypersonic flow data.