PARIS, March 10 (UPI) -- European Space Agency scientists say they are ready to test the smallest yet most precisely controllable engine ever built for space.

Measuring only 10 centimeters across, the ESA said its Field Emission Electric Propulsion engine produces an average thrust equivalent to the force of a falling hair, but sensitive enough to counteract the force of incoming sunshine.


Despite its low power, the ESA said FEEP's thrust range and controllability are far superior to more forceful thrusters.

"Most propulsion systems are employed to get a vehicle from A to B," said Davide Nicolini of ESA's Scientific Projects Department. "But with FEEP the aim is to maintain a spacecraft in a fixed position, compensating for even the tiniest forces perturbing it to an accuracy that no other engine design can match."

Operating together with a separate U.S.-designed propulsion system, the FEEP thrusters should yield directional control at least two orders of magnitude more accurate than any spacecraft before it, down to a millionth of a millimeter, scientists said.

This month's tests are intended to qualify the FEEP development model before construction of the final flight hardware begins.

Once proven, the ESA said its FEEP technology will take part in a broad range of missions, including precision formation flying for astronomy, Earth observation and drag-free satellites for mapping variations in Earth's gravity.