Planck offered vastly improved performance in measuring the Cosmic Microwave Background (CMB) radiation compared to balloon-borne and ground-based experiments and exceeded the performance of any previous space-based instruments of this kind.
The spacecraft revolved about its Sun-pointing axis once per minute to stabilise its attitude. Planck used this stabilisation spin to scan the sky, observing at least 95% of it through two separate observation periods in a span of 15 months.
|The Planck spacecraft|
|Dimensions||4.20 x 4.22 m (height x width)|
|Mass||1.95 tonnes at launch|
|Spacecraft||Spin stabilised, 1 rpm|
|Telescope mirror||1.9 x 1.5 m primary reflector|
|Telescope mass||205 kg with focal plane unit|
|Lifetime||A minimum of 15 months, limited by degradation of cooling system|
|Operational orbit||Lissajous orbit at an average distance of 400 000 km from L2|
|Propulsion||Hydrazine, 12 thrusters x 20 N each, 4 thrusters x 1 Newton each|
|Solar arrays||Flat, fixed triple-junction Gallium-Arsenide cell panels on rear of spacecraft|
|Solar array area: 13m2|
|Batteries||39 Ah lithium ion batteries|
3 x low gain antennae
1 x medium gain antenna