Since 1957, with more than 50 years of exploring space, the lower thermosphere (90-320 km) is the least explored layer of the atmosphere. Satellites and space stations usually orbit at altitude over 320km (to increase orbital lifetime) Atmospheric Explorers were flown in the past in highly elliptical orbits (typically: 200 km perigee, 3000 km apogee); they carried experiments for in-situ measurements but the time spent in the region of interest below 320 km was only a few tens of minutes. Nowadays, sounding rocket flights provide the only in-situ measurements. While they do explore the whole lower thermosphere, the time spent in this region is rather short (a few minutes), there are only a few flights per year and they only provide measurements along a single column. Powerful remote-sensing instruments on board Earth observation satellites in higher orbits (600–800 km) receive the backscattered signals from atmospheric constituents at various altitudes. While this is an excellent tool for exploring the lower layers of the atmosphere up to about 100 km, it is not ideally suited for exploring the lower thermosphere because there the atmosphere is so rarefied that the return signal is weak. The same holds for remote-sensing observations from the ground with lidars and radars.
QB50 is an international network of 50 CubeSats for multi-point, in-situ measurements in the lower thermosphere and re-entry research proposed by the von Karman Institute. It has the scientific objective to study in situ the temporal and spatial variations of a number of key constituents and parameters in the lower thermosphere (90-320 km) with a network of 50 double CubeSats, separated by a few hundred kilometres and carrying identical sensors. QB50 will also study the re-entry process by measuring a number of key parameters during re-entry and by comparing predicted and actual CubeSat trajectories and orbital lifetimes.
The multi-point, in-situ measurements of QB50 will be complementary to the remote-sensing observations by the instruments on Earth observation satellites and the remote-sensing observations from the ground with lidars and radars. All atmospheric models, and ultimately thousands of users of these models, will benefit from the measurements obtained by QB50 in the lower thermosphere.
F-2 is a 2U CubeSat mission proposed by FSpace laboratory, FPT University to participate in QB50 project based on experience of FSpace team working in F-1 CubeSat project. The mission goals are to:
- Collect scientific data of the lower thermosphere (from 330km down to 90km).
- Demonstrate practical application of CubeSats, especially in a constellation of 50 CubeSats and a network of multiple ground stations around the world.
- Providing an opportunity to experiment new technology, Commercial Off The Shelf (COTS) products such as testing a smartphone in space as an onboard computer for a nano-satellite
Besides these goals, F-2 project also has strong educational objectives such as providing hands-on-project experience on a space project to engineering/science students and promoting international cooperation/capacity building among universities around the world.