Re-entry Qarman


In the course of this project, the Qarman team is facing some major technical challenges which, if tackled successfully would mean a major breakthrough in the CubeSat society. Some of these challenges are briefly recapitulated hereunder:

The Thermal problem: Most electronics are intended to be used in a temperature range between 0-70°C. Space, however, is at the same time a very cold (when eclipsed from the sun) and hot (when facing the sun) environment. This means that electronics often need to be heated up to avoid freezing. However, since Qarman acts both as a satellite and as a re-entry vehicle, the same electronics must be shielded against the harsh thermal environment during the re-entry. During this stage of the mission, the environmental conditions are such that the satellite is surrounded by a plasma hotter than the sun. Temperature gradients are expected to be as high as 1000°C over a few mm only. Understandably, it took the team several months to simulate the problem and find solutions for it.

The communication problem: It is well known that during re-entry radio communication is impossible. This is due to the fact that the satellite is surrounded by free electrons which shield, reflect and/or attenuate electro-magnetic radiation. In practice this means that scientific data obtained during the re-entry phase cannot be sent to ground in real-time, but must be stored until the radio black-out period is over. All data must be retrieved in the short time window between the end of the black-out and the crash of the satellite. Put differently, 20 minutes worth of data must be sent in less than 5 minutes. To tackle this problem, data must be compressed and broadcasted in a certain order of priority, such that we are able to receive the most important data first.

The stability problem: The satellite caries no active de-orbiting device (such as an engine), so the only way to slow it down (and to make it plunge back into the atmosphere) is to increase the atmospheric drag using the AeroSDS panels. However, these panels should be at the same time light, thin, strong and thermally robust enough to withstand the high aerodynamic loads at high temperatures during the re-entry. If for some reason one of the panels would deform or break off during the re-entry, then the satellite would start to tumble fast, exposing parts to the stagnation heat that are not designed for this, with predictable results. The design and simulation of these panels is therefore of utmost importance for the success of the mission.