 UPSat moments after deployment from the ISS | |
| Names | QB50 GR02 |
|---|---|
| Mission type | Thermosphere research, part of theQB50 mission |
| Operator | Libre Space Foundation |
| COSPAR ID | 1998-067LX |
| SATCATno. | 42716 |
| Website | http://upsat.gr |
| Mission duration | 18 months |
| Spacecraft properties | |
| Manufacturer | University of Patras,Libre Space Foundation |
| Launch mass | 2 kg |
| Start of mission | |
| Launch date | 18 April 2017, 15:11:26 (2017-04-18UTC15:11:26) UTC |
| Rocket | Atlas V 401 (AV-070) |
| Launch site | Cape CanaveralSLC-41 |
| Contractor | United Launch Alliance |
| End of mission | |
| Last contact | 25 August 2018 (2018-08-26) |
| Decay date | 13 November 2018 (2018-11-14) |
| Orbital parameters | |
| Reference system | Geocentric |
| Regime | Low Earth |
| Eccentricity | 0.0002187 |
| Inclination | 51.6101° |
| Epoch | Mon, 12 Nov 2018 22:54:40 GMT |
UPSat was the first satellite manufactured inGreece to be successfully launched into orbit,[1] by theUniversity of Patras andLibre Space Foundation (an earlier Greek-made communications satellite, HELMARS-SAT, although entirely constructed by 1999, was not launched due to budget limitations).[2] It was part of theQB50 mission with ID GR-02. The UPSat mission was the first satellite launched into orbit made entirely ofopen-source software andopen-source hardware.[3]
The UPSat mission developed anopen-source hardware and software 2Ucubesat, minimizing the use of commercial off the shelf components, and providing hardware and software designs under the provisions of the CERN-OHLv2[4] and GNU-GPLv3[5] licenses respectfully. The vast majority of its components were designed from scratch in an open-source software and hardware way.
UPSat, as part of theQB50 cubesat constellation, was launched to theInternational Space Station at April 18, 2017 11:11 EDT atCape Canaveral in Florida, on board anAtlas V rocket transferring theCygnus cargo spacecraft to dock with the International Space Station with supplies and other scientific experiments. UPSat was released in orbit by theNanoRacks deployer from the International Space Station at 08:24 UTC 2017-05-18. After 30 minutes, UPSat subsystems commenced normal operations in orbit. TheSatNOGS ground-station network began receiving telemetry signals from UPSat in several ground-stations deployed globally shortly after its deployment.[6] All data and telemetry is publicly available. UPSat decayed at November 13, 2018.
EPS (Electrical Power System)An EPS designed from scratch around an STM32L1 MCU, utilizing softwareMPPT, harnessing power from 7 solar panels and having a 3-cell battery system.
OBC (On board Computer)An OBC designed from scratch around an STM32F4 MCU, with software built around theFreeRTOS Operating System
ADCS (Attitude Determination and Control System)An ADCS designed from scratch around STM32F4 MCU, determining attitude and position through sensor fusion (GPS,magnetometer, gyro,Sun sensor). The sensor fusion algorithm used is based on an alternative implementation ofWahba's problem, in order to accommodate gyro measurements, as introduced in.[7] This implementation uses a virtual vector base, propagated by the gyro reading, fused with the vectors provided by the sun sensor and the magnetometer, as perWahba's problem. This forms essentially a complementary filter inSO(3) between the gyro and the vector measurements. The reference vectors in ECI frame are calculated by[8] andIGRF model, respectively, given the satellites position is known by the GPS andSGP4 model.The control system is based on a spin torquer, which is used as areaction wheel for pitch control and also to stiffen roll and yaw to the satellite's orbit plane (Gyroscopic torque and momentum bias). Magneto-torquers are also used to dampen the roll and yaw motion while also control pitch angle.
SU (Science Unit)(see primary payload)
COMM (Communications system)A COMM designed from scratch around an STM32F4 MCU, using the TI CC1120 transceivers, with contingency around TX operations combined with a custom Antenna deployment system with an integrated GPS antenna.
IAC (Image Acquisition Component)(see secondary payload)
StructureThe structural sub-system is based on a "hybrid" approach of both aluminum (frame) andCFRP components (4 faces), built in-house.[9]
On-board UPSat, the primary payload, a science unit was integrated. The science unit (designed by theUniversity of Oslo and supplied through theVon Karman Institute as part of the QB50 program) was used for plasma measurements during the mission. The science unit was a multi-NeedleLangmuir Probe (mNLP) instrument that worked by measuring the current collected individually from four needle probes, placed in front of the satellite's shock front. The collected current was converted to voltage, filtered, digitalized and then sent to the central telemetry system.[10]
As a secondary payload UPSat sports an embedded Linux board (DART-4460) running a modified version of theOpenWRT operating system controlling a b/w camera (MU9PM-MH) with 1 / 2.5’’ sensor size.[11]