ESA has announced the finalization of a contract with Arianespace that will see its next generation James Webb Space Telescope (JWST) lift off into Earth orbit atop an Ariane 5 launch vehicle. The ascent will take place from the agency's spaceport in Kourou, French Guiana in Oct. 2018.

Once launched, it is hoped that the James Webb Space Telescope will represent a giant leap forward in Mankind's capacity to observe a wide range of astronomical phenomenon. Among its many targets, the observatory will hunt for relics dating back to the early universe, allowing astronomers to chart the evolution of galaxies from their embryonic state to more fully-formed structures such as our own Milky Way.

The telescope will also be instrumental in the characterizing of distant exoplanets, and witnessing the birth of distant stars and planets. The JWST's science module is currently undergoing testing, while the first of its mirrors was recently installed in a clean room at NASA's Goddard Space Flight Center in Maryland

In order for the JWST to revolutionize space exploration, ESA must first ensure the insertion of the telescope into its selected orbit, which would place it 1.5 million km (0.9 million miles) from Earth in a static position on the anti-sunward side of the planet.

For this task ESA is relying on a pedigree of launch vehicles that has been in service since the 1980s. The Ariane 5 serving as the chariot for the JWST mission will use a combination of two solid fuel rocket boosters and a liquid fuel main stage to heft the JWST in to its distant orbit.

Inside the fairing of a launch vehicle like the Ariane 5, space is at a premium. In order to fit safely within the confines of the protective shell, the entire spacecraft, including the JWST's vast mirror section, which is comprised of 18 hexagonal sub-sections, will have to fold up, like an incredibly expensive piece of origami. The mirror section will later unfurl to form a single 21.3 ft (6.5 m) mirror when the telescope is safely en-route to its operational orbit.

Included in the contract is a clause that will necessitate the development of a new clean room environment in which to prepare the telescope for mounting to the launch vehicle. This is a measure designed to protect the incredibly delicate mirrors and other vital systems from being compromised by outside contaminants.

Source: ESA