Far sighted

A team of European academics is working on a project to develop extremely large, lightweight space reflectors. If successful, the reflectors may be deployed on a 20m-class space telescope equipped for grand astronomical discoveries, such as terrestrial (Earth-like) planets, outside our solar system.

The research team, which includes members from

, will spend the next three years working to control the shape and stability of shiny, thin-film membranes that could be used as primary mirrors for future ultra-light space telescopes. A primary mirror is the principal light-gathering surface of a reflective telescope.

The results of the programme will be of interest to space agencies, such as NASA, which are trying to reduce the weight of their telescopes while increasing the diameter of their apertures to obtain better resolutions of more faraway images.

Since the early 1960s, the astrophysics community has considered the problem of launching 20m-class space telescopes.

Weight constraint

One concern has been how to launch such huge mirrors, given the area and weight constraints in launch vehicles. For example, the active Hubble Space Telescope's primary 2.5m-diameter mirror occupied about four per cent of the volume and weight capacity of its vehicle. The yet-to-be-launched James Webb Space Telescope's 6.5m-diameter mirror is expected to occupy 15 per cent of the volume and weight capacity of its launch vehicle.