May 21, 2009

Herschel and Planck: On speed, on course

The European Space Agency says the commissioning of scientific instruments and subsystems aboard its Herschel and Planck spacecraft has started.

The two space observatories were lifted into orbit aboard an Ariane 5 rocket last week from the French spaceport at Kourou, French Guiana. Scientists said Herschel and Planck were functioning nominally and are now en route to their final orbits around the second Lagrange point, a spot in space know as L2, approximately 932,000 miles from Earth.

Shortly after launch, both spacecraft separated, triggering the execution of automatic sequences on board, including acquisition of the spacecraft's orientation in space, configuration of the data handling system and switch-on of the high-frequency radio transmitters, the ESA said.

ESA scientists said the precise injection into a transfer orbit that was accomplished means only moderate trajectory correction maneuvers will be needed to change the spacecrafts' direction or speed.

Herschel is on a trajectory that will lead it into a large orbit around L2. Planck, which will operate from a smaller orbit, will still need a June 5 mid-course correction and a July 2 orbit-insertion maneuver, the space agency said.

Herschel, a far infrared telescope, will be the first space observatory to cover the full far infrared and sub-millimeter wavebands. Planck is designed to make the most precise measurements yet of light at microwave wavelengths.