Thermal blankets were fitted to motors controlling the International Space Station’s solar panels on Monday, to protect them from extreme fluctuations in solar heat.
The shielding was put in place during a spacewalk by two US astronauts. Rapid temperature variation as the ISS moves from the sunlit side of the Earth to the dark side and back is thought to be the cause of recent motor problems during solar panel manoeuvres.
During one 90-minute orbit around the Earth, temperatures outside the ISS can change from 94 °C to minus 94 °C.
“We have seen some current spikes [in the motors] and believe that this is the result of this extreme variation,” a NASA spokeswoman told New Scientist. “Our belief is that the blankets will minimise those extremes.”
Advertisement
Lift to work
The solar panel motors are used to manoeuvre the panels to face the Sun. Any failure could significantly reduce the ISS’s ability to produce electrical power. The affected solar panels are 73-metres long when fully extended – the largest aboard the ISS.
US astronauts Linda Godwin and Dan Tani performed the spacewalk from the cargo bay of space shuttle Endeavour, currently docked at the ISS. The shuttle’s robotic arm carried the astronauts to the middle of the US power tower, situated between the two solar panels and the rest of the ISS. From here, the astronauts moved 15 metres to fit the blankets to the two motors.
The space walk began at 1753 GMT and lasted four hours and 12 minutes. After fitting the thermal blankets, the astronauts attempted to repair a loose support for the starboard panel, but were unable to do so. However, NASA engineers believe that the wing is secure with just three supports secured.
“The walk was very good and accomplished its main goal,” the NASA spokeswoman added. Nevertheless, shuttle Atlantis will carry a new support when it launches for the ISS on 21 March 2002.
