European astronauts

ESA maintains its own astronaut corps, based at the European Astronaut Centre in Cologne, Germany. Attempts to develop a small manned spacecraft called Hermès stalled in the early 1990s (see panel, below), but ESA astronauts have flown as guest cosmonauts on Soyuz launches (see panel, opposite, and p.240) and as payload specialists on a number of Space Shuttle missions. The agency has supplied several components for the ISS (see p.286), and its laboratory module, the Columbus Orbital Facility, is due to launch in 2007.

European astronauts will help crew the station's expeditions, and ESA is developing the station's Automated Transfer Vehicle. Launched by Ariane 5, this unmanned spacecraft will carry supplies to the station, then remain docked for up to six months to provide additional working and living space.

Looking to the future, in 2003 ESA signed a deal with the Russian Space Agency (RSA) to launch Soyuz rockets from its Kourou spaceport. Kourou's equatorial location will boost the payload capacity of the Soyuz for Russian launches, and ESA will get access to another reliable launch vehicle. In another collaboration, ESA and the RSA are developing plans for a Soyuz-derived spacecraft, and Europe may help to make the Kliper spaceplane (see p.299) a reality.

TECHNOLOGY

HERMES

In the early 1980s, the French space agency CNES developed plans for a small spaceplane that could be launched on top of the forthcoming Ariane 5 rocket. Hermès was a mini Shuttle that, in some plans, might have been capable of carrying a crew of four and a medium-sized payload into orbit, gliding back to Earth after completing its mission. CNES persuaded ESA to adopt the project in 1987, with a planned first flight in 1998. But spiralling costs and safety modifications after the Challenger disaster eventually led to ^^^^ the project's cancellation in 1992.

EVOLUTIONARY LAUNCHER

The Ariane 4 (right) was the final stage in the development of the original Ariane launcher. Based on Viking engines mode by the French company Société Européenne de Propulsion, Ariane was upgraded throughout the 1980s, with the addition of longer stages, liquid- and solid-fuelled boosters, and more powerful rocket engines.

height 58.4m (191ft 7in)

core oiameter

3.8m (12ft Sin)

total mass

240,000kg (520,000lb)

engines

4 +1 x Viking 28 (N204/U0MH)

1 x Viking 4B

1 x Viking 28 (upper stages)

thrust at thrust

276,586kgf (608,490lbf)

manufacturer Aerospatiale manufacturer Aerospatiale

ARIANE 4 SECOND STAGE

The 11.5m (37ft 8in) second stage remained externally the same throughout Ariones 1 to 4. The single rocket engine, however, was upgraded to a Viking 48.

ARIANE 4 SECOND STAGE

The 11.5m (37ft 8in) second stage remained externally the same throughout Ariones 1 to 4. The single rocket engine, however, was upgraded to a Viking 48.

LAUNCH PREPARATIONS

The first stage of on Arione 5 rocket is hauled upright within ESA's Launcher Integration Building at Kourou, French Guiana. Two solid rocket boosters will then be attached to the sides, and the upper stages and paylood mounted on top.

payload independent upper stage upper-stage engine payload fairing third-stage propel la nt tank payload - may include two separate satellites payload support adopter third-stage engine

SYLDA 5 fairing

SYLDA 5 and fairing (may be replaced with SPELTRA upper stage for heavier payloads)

SYLDA S deployment system (enclosed in payload fairing)

second-stage propellant tank

VULCAIN ENGINE

The new version of Arione needs a different engine design to bum its cryogenic fuels, portly because they need an ignition trigger in order to burn. The new engine is called Vulcain.

hypergolic propellant rocket engine interstage solid propellant engine liquid oxygen storage tank

Xyz Union Support

Viking 2B first-stage engine

ARIANE 4 FIRST STAGE

The lower stage of Ariane 4 used four Viking 2B engines. These highly reliable engines, first introduced on the Ariane 2 and 3 variants, allowed the vehicle to make 113 successful launches throughout its career. The propellants, dinitrogen tetroxide (N204) and unsymmetrical dimethylhydrozine (UDMH), are hypergolic - they combust on contact and do not require low-temperature storage.

Viking 2B first-stage engine

TECHNOLOGY

ESA'S LAUNCH-VEHICLE SERIES ij

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