The Swedish Space Corporation (SSC) provides space subsystems, space and satellite operations, rocket and balloon systems including experiment equipment, launch services, aerospace engineering services as well as airborne maritime surveillance systems. Through its wholly owned subsidiaries ECAPS and NanoSpace, the SSC is also engaged in the development of propulsion systems and micromechanical systems for space applications.From its facility Esrange Space Center in Northern Sweden, the SSC launches sounding rockets and high-altitude balloons for research in the areas of microgravity, astrophysics, astronomy and atmospheric studies. One notable program during the late 1980s/early 1990s was a joint project with the Society of Japanese Aerospace Companies using SSC's MASER rocket to lift aloft various experiments requiring microgravity environments, at a low cost. This was during a period when U.S. Space Shuttle flights along with associated planned experiments were still being disrupted by the aftermath of the Challenger disaster.At Esrange SSC operates one of the world's busiest civilian satellite ground stations, communicating with both telecom and scientific satellites. The SSC's facility Stockholm Teleport provides satellite communication services, and the wholly owned German company LSE is specialised in satellite control and ground station services. The SSC runs a global ground station network, PrioraNet, in which its US subsidiary Universal Space Network plays a big part.[citation needed]On 1 July 2011, the SSC sold its satellite division to the German space company OHB which then formed a Swedish subsidiary named OHB-Sweden.In February 2013, a government audit was released by the Swedish National Audit Office which concluded that "Swedish space investment is distributed among multiple organizations that operate as stovepipes with no real communication between them and no common ambition."While approximately 1 billion SEK (158 million USD) is spent each year on Swedish space initiatives, the audit report calls for additional "government oversight of the European Space Agency (ESA) and a review of the Swedish Space Corporation's structure and mission."The SSC announced on 21 September 2020 that it was not renewing its contract to help operate Chinese satellites from its ground stations, and that it would cease doing business in China altogether.
A significant performance inhibitor of free-space continuous variable quantum key distribution (CVQKD) is turbulence, which gives rise to wavefront phase and amplitude aberrations. We demonstrate that in a turbulent channel, during coherent state transmissions from a continuous-wave laser, that the interferometric visibility between the local oscillator (LO) and quantum signal decreases. A solution to this is incorporating adaptive optics at the receiver to correct phase and amplitude aberrations in the wavefronts of the received quantum signal. We demonstrate the increased interferometric visibility and decrease in its fluctuations in a 60 cm and 30 m turbulent channel when using adaptive optics through channel characterisation. In an ideal CVQKD system, we show that this leads to more precise and larger positive secret key rates, improving the performance of free-space CVQKD in turbulent channels.
Early dust evolution in protoplanetary disks is dominated by sticking collisions. However, this initial phase of particle growth faces constraints - notably from destructive encounters. To find the maximum particle size achievable, we studied collisional processes during a prolonged microgravity experiment aboard a suborbital flight. Here, we specifically report an impact erosion limit. We observed individual basalt beads, each measuring 0.5 mm in diameter, colliding with and either eroding or adhering to a cluster several centimeters in size. This cluster, formed from tribocharged particles, simulates an electrostatic growth phase that surpasses the classical bouncing barrier. We find a threshold velocity of about 0.5 m/s, distinguishing between additive and erosive impacts of individual beads. Numerical simulations of grain impacts into clusters, testing both low and high charge constituents corroborate the experimental findings of surface erosion within the observed velocity range. This specific velocity threshold suggests the potential formation of pebbles several centimeters in size within protoplanetary disks. Such dimensions place these pebbles well into a regime where hydrodynamic interaction might facilitate the formation of planetesimals.
The effects of extreme acceleration, microgravity, and deceleration of a suborbital spaceflight on Bacillus subtilis ATCC 6051 spores were investigated. B. subtilis spores were exposed to a maximum acceleration of ~13 g, a microgravity phase of 6 min, deceleration of 30 g (~300 m/s2), and a maximum rotating velocity of 220 os−1 upon re-entry into Earth’s atmosphere. Post-flight analysis showed the spores exhibited no change in morphology or viability, confirming that B. subtilis spores are resilient to space flight conditions.
