sci17009 — Announcement

James Webb mission preparations, a perspective by Pierre Ferruit

21 December 2017

As you all know, James Webb is a joint mission between NASA, ESA and CSA. It will be a versatile observatory allowing astronomers to study targets ranging from our own Solar System to the most distant galaxies: James Webb has been built to observe galaxies as they form. We will be able look back at the first few 100 million years of the Universe — which involves seeing much further than Hubble can — and investigate galaxy formation at that time. The telescope will also be able to see and analyse the clouds of gas and dust where stars form. Another fascinating field in which James Webb will contribute is the study of exoplanets. It will be able to provide detailed analysis of the atmospheres of planets orbiting other stars — that’s really exciting! In all these domains, James Webb is expected to achieve significant breakthroughs but the most spectacular ones will probably surprise us, and will not be those we imagine today.

Europe's contribution is, in many aspects, crucial to the success of the mission. First, there are the two instruments we provide and support: NIRSpec is an ESA provided instrument and will be Webb’s workhorse spectrograph. The primary science goal for NIRSpec is enabling large spectroscopic surveys of astronomical objects with a particular focus on the study of distant galaxies. This drives the design of this multi-object spectrograph which is capable of measuring the spectra of up to several hundred objects simultaneously in a 3.4 arcminute × 3.6 arcminute field of view. The second instrument with a European contribution is MIRI, the only mid-infrared instrument on board. It is built by a consortium of nationally funded European institutes (the MIRI European Consortium), as well as the Jet Propulsion Laboratory, ESA, and NASA’s Goddard Space Flight Center.

One European contribution that will be highly visible to the public will be the launch vehicle. An Ariane 5, one of the world's most reliable launch vehicles, will be used to lift James Webb into space. Last but not least, ESA is also providing some personnel for the mission. These staff members and contractors will work alongside our american colleagues to operate James Webb. In return for these contributions, ESA gains full partnership in the James Webb mission and secures full access to the observatory for astronomers from ESA Member States, with a minimum share of 15 percent of the total observing time.

Despite the launch of the telescope being only about one and a half years away, we still have quite some work ahead us. The major milestones in 2018 will involve integrating the instruments and the telescope to the rest of the observatory — in particular to the spacecraft and the sunshield. This will be followed by a final test of the fully assembled observatory. Both the assembly and the testing will take place at Northrop Grumman Aerospace Systems. 2019 will finally see the preparation of the launch site in French Guiana by ESA, followed by the actual launch at the end of spring and the journey of the telescope to an L2 orbit. Exciting months lie ahead of us!

Contacts

Pierre Ferruit
ESA JWST Project Scientist
Email: Pierre.Ferruit@esa.int