Washington, Sept.28 : A small space capsule has been lost in Earth orbit after a space tether experiment went awry on Tuesday.

The capsule will re-enter the Earth's atmosphere and parachute down at an unknown location.

Despite the mishap, the team behind the mission say it shows that space tethers can provide a cheap and safe way to return a payload from an orbiting satellite back to Earth without using costly rocket boosters.

The Young Engineers Satellite 2 (YES2) mission, coordinated by ESA and the Russian Space Agency, was to have unfurled the longest human-made structure in space – a 30-kilometre-long, 0.05 millimetre-thick tether, made of a super-strong polythene fibre called Dyneema. This would have connected a Russian-operated satellite to the beach-ball-sized capsule called Fotino.

Using space tethers to return payloads to Earth was a concept first put forward by Wubbo Ockels at Delft University of Technology in the Netherlands in 1994.

The idea is for an orbiting satellite to lower its return capsule towards Earth on the end of a long tether. As the tether is extended, the Coriolis effect causes it to swing ahead of the satellite.

Once fully deployed, gravity becomes the dominant force and the capsule begins to swing back towards the vertical. Finally, when sufficient momentum is built up and when the tether is at the right point, the capsule is released, sending it back through the Earth’s atmosphere. (With inputs from ANI)