The unfolding space telescope

Jul 27, 2005

A novel suitcase-sized telescope could revolutionise the way we see the Earth and other planets. ESA has supported the work of a group of students in developing the Dobson Space Telescope, being tested this month aboard ESA's parabolic flight campaign aircraft.

This experimental prototype launches in a compact configuration and then unfolds to provide a cost-effective space telescope. It could lead to fleets of low-cost telescopes, bigger than the Hubble Space Telescope.
Large payloads are difficult to put into space because they are usually heavy and expensive to launch. Now a revolutionary design of unfolding telescope, inspired by telescopes used by amateur astronomers, is ready to enter a phase of detailed testing. If successful, it could dramatically reduce the cost of placing telescopes in space.

The telescope is a project of the Department of Astronautics at the Technische Universität Berlin, Germany. "We called our project the Dobson Space Telescope because we borrowed the idea from the Dobsonian telescopes used by amateur astronomers," says project manager Tom Segert, who has recently completed his degree at TU Berlin. Dobsonian telescopes are often comprised of two mirrors, held the correct distance apart by long poles. They can be dismantled and transported by car to a good observing site, where there are reassembled with nothing more complicated than a screwdriver.

In space, however, a screwdriver is useless unless you have an astronaut to turn it and so Segert plans to use a motor to unfold his telescope. Working on a shoestring budget, his first prototype used inflatable bicycle tyres to push the mirrors into position. When this proved incapable of aligning the telescope optics, Segert turned to metal truss rods and micromechanics to unfold everything into its correct place.

Using a grant from ESA's General Studies Programme, Segert and other TU Berlin students have written a full technical report and built a prototype for testing in this month aboard ESA's parabolic flight campaign aircraft. As the aircraft flies special manoeuvres, the prototype will experience periods of free-fall that mimic the conditions in space. During this time, Segert will test the telescope’s ability to unfold. Eventually, Segert hopes for a demonstration mission in space.

Earth observation made easy
Currently, space-based observations account for just one tenth of the commercial Earth observation market. The rest is supplied by aeroplane reconnaissance, which is much cheaper. Space observations cost 20 Euros per kilometre whereas aeroplane data is twenty times cheaper. Segert believes that cost-effective Earth observation microsatellites, based on his telescope design, will allow all users access to space images.

There is also nothing to stop a Dobson Space Telescope from turning its attention from Earth to the wider cosmos. In fact, Segert imagines the first missions could 'timeshare' between Earth and astronomical observation. "When the telescope flies into the shadow of the Earth and so can't take pictures of the ground, we could turn it around and observe astronomical targets," he says.

Future versions could be sent to other planets. As the telescope is so lightweight, it could be mounted on a Mars Express-sized spacecraft and used to take pictures showing details as small as 30 cm across on the Martian surface.

Although the prototype contains a respectable 50 cm-diameter mirror, Segert believes that it can scaled up in the future to achieve space telescopes bigger than the Hubble Space Telescope but still at a fraction of the cost. "If we did that," says Segert, "the astronomers would be in heaven."

Explore further: Ariane 5's first launch of 2015

Related Stories

Sentinel-2A arrives in French Guiana for 12 June launch

26 minutes ago

The latest satellite for the European Commission's environmental Copernicus programme has arrived safe and sound in French Guiana for launch on 12 June. Carrying a multispectral imager, Sentinel-2A is set ...

A novel pathway producing dimethylsulphide in bacteria

26 minutes ago

A scientific team that includes researchers from the University of Barcelona (UB) has identified a novel pathway producing dimethylsulphide, a volatile organosulfur compound which plays a major role in climate regulation.

Direct visualization of magnetoelectric domains

27 minutes ago

A novel microscopy technique called magnetoelectric force microscopy (MeFM) was developed to detect the local cross-coupling between magnetic and electric dipoles. Combined experimental observation and theoretical ...

Avoid 'crape murder' with limited pruning

31 minutes ago

Efforts to prevent people from committing "crape murder" are reducing the number of unsightly, knobby-knuckled branch ends but may leave people wondering how to correctly shape crape myrtles.

Secret life of penguins revealed

32 minutes ago

To mark World Penguin Day (25 April 2015) citizen science project Penguin Watch will release 500,000 new images of penguins and reveal secrets from a year of spying on penguins. ...

Recommended for you

Ariane 5's first launch of 2015

10 minutes ago

An Ariane 5 has lifted off from Europe's Spaceport in Kourou, French Guiana and delivered two telecom satellites into their planned orbits.

The riddle of galactic thin–thick disk solved

Apr 24, 2015

A long-standing puzzle regarding the nature of disk galaxies has finally been solved by a team of astronomers led by Ivan Minchev from the Leibniz Institute for Astrophysics Potsdam (AIP), using state-of-the-art ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.