In the present work we address the problem of deploying a team of robots in ascenario where some locations of interest must be reached. Thus, a planning fora deployment is required, before sending the robots. The obstacles, the limitedcommunication range, and the need of communicating to a base station, constrainthe connectivity of the team and the deployment planning. We propose a methodconsisting of three algorithms: a distributed path planner to obtaincommunication-aware trajectories; a deployment planner providing dual-use ofthe robots, visiting primary goals and performing connectivity tasks; and aclustering algorithm to allocate the tasks to robots, and obtain the best goalvisit order for the mission.
Silicon photomultipliers (SiPMs) are prone to radiation damage which causesan increase of dark count rate. This leads to an increase in low-energythreshold in a gamma-ray detector combining SiPM and a scintillator. Despitethis drawback, they are becoming preferred for scintillator-based gamma-raydetectors on CubeSats due to their low operation voltage, small size, linearresponse to low light intensity and fast response. This increasing popularityof SiPMs among new spaceborne missions makes it important to characterize theirlong-term performance in the space environment. In this work, we report thechange of the dark count rate and low-energy threshold of S13360-3050 PEmulti-pixel photon counters (MPPCs) by Hamamatsu, using measurements acquiredby the GRBAlpha and VZLUSAT-2 CubeSats at low Earth orbit (LEO) spanning overthree years. Such a long measurement of the performance of MPPCs in space hasnot been published before. GRBAlpha is a 1U CubeSat launched on March 22, 2021,to a 550 km altitude sun-synchronous polar orbit (SSO) carrying on board agamma-ray detector based on CsI(Tl) scintillator readout by eight MPPCs andregularly detecting gamma-ray transients such as gamma-ray bursts and solarflares in the energy range of ~30-900 keV. VZLUSAT-2 is a 3U CubeSat launchedon January 13, 2022 also to a 535 km altitude SSO carrying on board, amongother payloads, two gamma-ray detectors similar to the one on GRBAlpha. We haveflight-proven the Hamamatsu MPPCs S13360-3050 PE and demonstrated that MPPCs,shielded by 2.5 mm of PbSb alloy, can be used in LEO environment on ascientific mission lasting beyond three years. This manifests the potential ofMPPCs being employed in future satellites.