TRW to build Hubble successor

12 Sep 2002

NASA awards TRW a $825 million contract to build the successor to the Hubble space telescope.

TRW, US, has won the USD 824.8 million NASA contract to build and test the successor to the Hubble Space Telescope. Called the James Webb Space Telescope (JWST), it will have six times the light-gathering capability of Hubble and be able to see objects 400 times fainter than those observed by the best ground-based telescopes.

Hubble successor

The company will now set about designing and fabricating the primary mirror. This will contain 36 semi-rigid hexagonal segments or "petals". Once complete, the mirror will be at least six meters in diameter. And the TRW design has to be perfect. Unlike Hubble, astronauts will not be able to service the JWST because it will be too far away from Earth.

Before and during launch, the mirror will be folded up. Once the JWST is placed in orbit, ground controllers will send a command telling the telescope to unfold its mirror petals.

To see into space, JWST will also carry a near-infrared camera, a multi-object spectrometer and a mid-infrared camera/spectrometer.It is hoped that the infrared-detecting instruments will help astronomers to understand how galaxies first formed after the Big Bang. Light from the youngest galaxies is seen in the infrared due to the universe's expansion.

The JWST will also probe the formation of planets in disks around young stars and study supermassive black holes in other galaxies.

The entire system will be launched in 2010 aboard an expendable vehicle. It will then take three months for the spacecraft to reach its target orbit some 940 000 miles into space. Here, the spacecraft will be balanced between the gravity of the Sun and the Earth - the so-called Lagrange Point.

In this orbit, the observatory can be cooled to very low temperatures without using complex refrigeration equipment. This is thanks to the fact that a single-sided sun shield is needed on one side of the observatory only to protect it from heat from the Earth and the Sun.

Author
Jacqueline Hewett is news reporter on Optics.org and Opto & Laser Europe magazine.