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Grzegorz Brona 10.11.2017 • Exploration of space now (lecture 101) • How to construct a Polish scientific satellite - example of BRITE constellation (lecture 102) • How to build a satellite for future polish scientific missions (lecture 103) • Possible scientific missions and their outreach (lecture 104) 2 Exploration of space now why ? 3 Space 1.0 Space 2.0 The epoch before space From the Sputnik to flights. The era of great the fall of Soviets. astronomers and naked Constant flow of money eye or telescope but the priotities rather observations. not scientific. Space 3.0 Space 4.0 Era of dinosaurs based Industry in space, on technic from S 2.0. private capital involved, Space shuttles, Hubble, economic optimisation, ISS but also raise of global services, raise of telecomunication national ambitions in satellites. smaller countries. 4 Paradigms of Space 4.0 era: • Space should be affordable not only for big countries and big scientific institutes • A close cooperation between different entities targeting doing research in space, providing new technologies, products and services. • Better, cheaper launchers: 3000-25 000 USD per kg (existing rockets) drops to 2000 USD per kg for reusable Falcon-9 drops to 1500 USD per kg for Falcon Heavy Depending on a mass of a satellite 5 Paradigms of Space 4.0 era: • Use of cheaper electronic component (commercial of the shelf COTS) • Miniaturization of electronics, mechanics, removing some redundance • Outcome: reduction of costs by a factor of hundreds but increase in risk of mission failure • Risk mitigated by redundant units (still cost much lower) • Raise of small satellites operating in space • Problem of space debris 6 Nanosatellite • Open standard • 1-10 kg • 30-50% for instrument • Good for education, Total mass of all objects send some science, testing to space each year Microsatellite • 10-150 kg • 30-50% for instrument • Good for science, constelations (earth observation, telco) and some military Standard satellite • >150 kg • LEO or GEO • Military, big science, telecomunication, EO with great precission 7 Annual SmallSat conference in USA: • 1987 -> 60 participants • 2017 -> 2550 participants • >350 students • >140 lectures • >50 universities represented • Many scientific missions presented Titles of some proceedings: - EQUULEUS: Mission to Earth - Moon Lagrange Point by a 6U Deep Space CubeSat - INCA (Ionospheric Neutron Content Analyzer) - Overview of the TRYAD Project: A Fleet of Two 6U CubeSats for Research on Terrestrial Gamma Ray Flashes - Calibrating the Swarm: Networked Small Satellite Magnetometers for Auroral Plasma Science - Tracking the Untraceable, Keeping the Earth Cool - Fugitive Methane Detection from Microsat Constellations - Sun Radio Interferometer Space Experiment (SunRISE) Proposal: Status Update - The Asteroid Probe Experiment (APEX) Mission The topic of small satellites attracts a lot of attention worldwide. 8 How to construct a Polish scientific satellite – example of BRITE constellation (input from T. Zawistowski, M. Stolarski, A. Pigulski) 9 BRIght Target Explorer (BRITE) • Constellation of 6 nanosatellites • Size 20x20x20 cm • Mass 7 kg • Equiped with a telescope of 3 cm diameter • With uncooled CCD • In space from 2013-2014 BRITE - PL LEM HEWELIUSZ 10 To study bright variable stars • Photometry from the orbit – no atmospheric distortions • Bright stars – easy comparison with existing spectroscopic results • In case of combination of spectroscopic and photometric results for binary systems -> masses and radii available • For bright stars light extinction not important • 3 satellites use red filter, 3 satellites use blue filter 11 A constellation of 5 nanosatellites: BRITE-Austria (BAb) 25.02.2013 UniBRITE (UBr) 25.02.2013 Lem (BLb) 21.11.2013 Heweliusz (BHr) 19.08.2014 BRITE-Montréal (BMb) 19.06.2014 Failed BRITE-Toronto (BTr) 19.06.2014 10 000 M USD 5 M USD Resonable price for a nanosatellite: 1 M USD Non-stop coverage of FOV Bright stars are too bright for big space telescopes eg. Hubble 12 Assembly, integration and Test (AIT) at Space Research Center Subsystems: • On-board computer (OBC) • Magnetometer, sun sensors star tracker - Attitude and orbital control system (AOCS) sensors • Reaction wheels – AOCS actuators • S-Band antenna – tranceiver module (TRxM) system • Solar cells, power distribution system – power dystribution unit (PSU) • Mechanical structure • Harness (cables) • Instruments - payload 13 Star-Tracker: an optical device that measures the positions of stars using a camera. FOV 15° x 20.2°, Aptina MT9P031, Monochrome 5M CMOS 59 x 56 x 31.5 mm, Mass ~90g, Up to 5.75 mag, 3746 stars in catalog, 2.1 milion triangles On-board computer (OBC): a brain of a satellite with main tasks: • Receive and respond to commands from the ground station as well as handle the general housekeeping of the satellite. • Collect the telemetry data, format and encode the data for transmitting to the ground station. • Attitude determination and control using data from sensors. • Monitors temperature of all subsystems and maintains the satellite in specified temperature. • Store payload and telemetry data during non-visible period for transmission during visibility. Based on CPU ARM 7 Texas Instruments. 20MIPS. 32MB RAM (EDAC), 256MB Flash. 14 Payload - telescope CCD chip: KODAK KAI-11002-M 11 Mega pixels with organisation 4008x2672 Telescope electronics CCD chip Set of lenses Blende and filters Support mechanics Reaction wheels: for attitude control without using fuel for rockets or other reaction devices. They are particularly useful when the spacecraft must be rotated by very small amounts, such as keeping a telescope pointed at a star. 3 orthogonal reaction wheels from Sinclaire Interplanetary: 5x5x4cm, masa 185g, nominal power 100mW Other device magnetorquer - built from electromagnetic15 coils 1 step: virtual model of the satellite, including information on cabling 2 step: flat-sat or a satellite on a board, testing all subsystems interactions 3 step: integration of the satellite according to long and boring procedures, no failure acceptable 16 1 test: shaking tests, checking if the satellite will survive start of the rocket, shaking can unscrew screws. Each rocket has its own set of critical frequencies and accelerations: 2 test: vacuum thermal tests (termal vacuum chamber – the only one in Poland in SRC!). What will happen if there is some air in the material structure of the satellite – outgasing! Where the heat goes in the vacuum environment? 3 test: what is the best idea to test star-tracker? 17 Dragon: orbital deployer for BRITE-PL HEWELIUSZ Designed and build at SRC in Poland Securs the rocket from problems with the satellite Safely delivers satellite to orbit LEM was launched on DNIEPR rocket (21.11.13), former balistic missile which retired after START II treaty (DubaiSat-2, STSAT-3, SkySat1, WNISAT-1, ApizeSat-7, AprizeSat-8, UniSat-5, Delfi-n3xt, Dove 3, Dove 4, Triton 1, KHISat-1, KHUSat-2, CubeBug2, GOMX-1, NEE-02, FUNCube-1, HINCube, ZACube, Icube-1, HumSat-D, PUCPSat-1, Pocket-PUCP, UWE-3, BeakerSat1, QubeScout1, WREN, 50Sat, First-Move, Velox-P2, OPTOS, BPA-3) HEWELIUSZ was lunched on Long March rocket (19.08.14) 18 For HEWELIUSZ: Low Earth Sun-synchronous orbit (a nearly polar orbit around Earth in which the satellite passes over any given point of the planet's surface at the same local solar time) 630 km with orbit period 101 minutes Ground control station: In Canada near Toronto, In Austria near Graz On the roof of Nicolaus Copernicus Astronomical Center in Warsaw 19 BRITE field: • „Naked eye” astronomy: brightness < 6.5 mag • The faintest star observed: 6.98 mag • Brightest star: -0.73 mag (Canopus) • FOV approximately 25° • Fields observed: 24 • Average number of stars per field: 27 • Total number of stars observed: 500 • Typical observation time: 5.5 months • Change treshold: 0.1-0.2 mmag 6 • All data points: > 34 x 10 20 β Cephei type stars: variable stars that exhibit small rapid variations in their brightness due to pulsations of the stars' surfaces, thought due to the unusual properties of iron at temperatures of 200,000 K in their interiors. 123 stars of this type observed. New modes detected for almost all observed stars: eg. for β Centauri 19 new modes are found with BRITE Data. New β Cephei-type stars have been found: eg. α Cru, δ Pic, π Sco Data on intenal rotation of the stars and internal structure Astro-seismography Pigulski et al. (2016) Pigulski 21 • More than 202 of the stars analysed are spectroscopic binaries stars (spectral lines in the light emitted from each star shifts first towards the blue, then towards the red, as each moves first towards us, and then away from us). • More than 256 are members of visual binary systems (for some visual orbits available). • More than 32 are eclipsing binaries systems (for these data from BRITE provide excelent photometry). New eclipsing binaries found: τ Lib Some of the binary stars have also pulsating component Pigulski et al. Pigulski eclipsing: δ Pic, V Pup, π Sco, λ Sco, spectroscopic: V389 Cyg, α Cru, β Cru, β Cen visual: β Cen, ζ Ori 22 How to build a satellite for future polish scientific missions 23 • BRITE constellation proved that small satellites can deliver useful data • Construction of nanosatellites and microsatellites are in the reach of polish entities • What shall be the next step? HyperSat platform, a multifunction and multimission satellite platform for future space missions. • The basic module dimension 30x30x10 cm • The basic module mass 10 kg • All subsystems