Overview of the PicSat satellite

PicSat is a nano-satellite of the type CubeSat. PicSat is composed of three cubic units, called a 3U, each 10x10x10cm in size (4x4x4 inch).

The lower unit contains the electronics: the antennas, communication and navigation systems, attitude control system (ADCS), including the inertia wheels and power and batteries.

The top unit houses the telescope and the star tracker. The telescope is composed of two small mirrors: a primary collecting mirror of 5 cm diameter, and a secondary mirror that sends the light collected by the primary mirror into a small hole at the centre of the unit. This is also the focal plane of the telescope. An optical fibre of only 3 micrometer in diameter is placed in the focal plane to collect the light. The fibre is attached to a small moving plate (a piezo actuator) that can move it around in very fine steps in the focal plane to keep the fiber in the correct position.

The optical fibre is connected to photodiode in the middle unit. The photodiode very accurately measures the amount of light being delivered to through the optical fibre. The middle unit also contains the payload electronics.

The whole satellite is clothed in arrays of solar panels that provide with energy for the operation of all the systems. The total weight of PicSat is about 3.5 kg and the power consumption is about 5 W, similar to an economical light bulb!

PicSat has been designed and built by our small team from the High Angular Resolution Astronomy group at the Paris Observatory / LESIA laboratory in France.