ACAL Technology waits for news of Rosetta Spacecraft

Rosetta made its closest approach to Earth on 13th November at an altitude of 1,540miles - inside the orbits of geostationary telecoms satellites. Rosetta has already flown 2,800million miles of its 4,400million mile journey, passing Earth three times and Mars once. The spacecraft has been using the gravitational pull of the planets to build up the speed needed to chase down and land on the comet Churyumov-Gerasimenko, near Jupiter.

Work began on the design of the custom heater mat in 1999, five years before the launch of the Rosetta spacecraft and fifteen years before it is due to land on the Churyumov-Gerasimenko comet, in November 2014. Located in the Modulus Ptolemy gas analyser, on-board the Rosetta lander, the mat is designed to trigger the actuator which releases high-purity helium, forcing cometary matter to pass through the gas analyser.

Conventionally, the helium would be released from titanium tanks via a valve. However, during the extreme period of dormancy, between the launch and the landing, a mechanical valve could have allowed sufficient leakage of helium to compromise the collection of material. Instead, the titanium tanks were sealed with a frangible pillar. This fragile, hollow seal will be broken using an actuator manufactured in a Shape Memory Alloy (SMA), which snaps open to its original shape when heated to its activation point.