Subsystems and Payloads
The first payload element is called the ‘Gamma-ray Module’, or ‘GMOD’. It is a
miniaturised sensor for use in the detection of gamma-rays from both cosmic and atmospheric phenomena. The sensor is called a silicon photomultiplier (SiPM) and has been developed by SensL in Co. Cork. The Silicon Photomultiplier has the potential to revolutionise in-situ and remote sensing of gamma-rays in space by removing the need for conventional photomultiplier tubes that are typically very bulky, fragile and require high voltages to operate.
EMOD stands for Enbio MODule. This is an experiment to see how protective coatings made by ENBIO Ltd. in Ireland, perform in space. EMOD consists of two black panels and two white panels which will have their temperature monitored.
Heat in space is a bit of an issue. In orbit around the earth if you’re in the shade it can be extremely cold (-100℃), but in direct sunlight it can get very hot (150℃). Travelling to other planets also creates large changes. Mercury, the closest planet to the sun has a surface temperature of 350℃ (hotter than your oven) while out at Neptune it's around -216℃ These changes in temperature can cause problems for spacecraft.
This is where ENBIO comes in they provide coatings for spacecraft which controls the temperature of the spacecraft. The SolarBlack is highly absorbing and highly emitting, SolarWhite is low absorbing and also highly emitting.
ENBIO coatings were already scheduled to go to space before EIRSAT-1 came along. SolarOrbiter is a European Space Agency (ESA) spacecraft expected to launch in 2018. It will get very close to the sun (within the orbit of Mercury), to study it like never before. As it will be so close, temperature control is very important in order to maintain its delicate instruments. SolarBlack will be the baseline for the heatshield of the spacecraft, facing the sun.
The coatings have been tested extensively by ENBIO and ESA. EIRSAT-1 however, will provide the first flight data of these coatings, which is extremely valuable to all involved.
The third payload, recently added, is a novel attitude control system developed by the Dynamics and Control Group in the UCD School of Mechanical and Materials Engineering. A spacecraft's "attitude" is its orientation in space. In this case it will use the Earth's magnetic field to turn itself in any desired direction. The UCD control technique is called "Wave-Based Control" (WBC). EIRSAT-1 will use a standard control system initially. At some time into the mission, in response to an instruction from Earth, the on-board computer will start using WBC to control the satellite's attitude, thereby evaluating its performance and, it is hoped, qualifying WBC for space flight.