2. Aalto-1 AN EXPERIMENTAL NANOSATELLITE FOR HYPERSPECTRAL REMOTE SENSING Jaan Praks, Antti Kestilä, Martti Hallikainen, Heikki Saari, Jarkko Antila, Pekka Janhunen, Rami Vainio

4. ESA (spectrometerpayload)

5. EU (e-sailpayload)

7. VTT Technical Research Centre of Finland (Spectrometer payload)

8. University of Helsinki (RADMON payload)

9. University of Turku (RADMON payload)

10. Finnish Meteorological institute (Plasma Brake payload)Supported by wide international network and Cubesat community

11. To design, build and operate first Finnish Earth Observation (EO) nanosatellite. Technology demonstration of of very small spectral imager for spaceborne EO. Development and demonstration of deorbiting device for nanosatellites based on e-sail concept and measurement of its performance. Technology demonstration of very small radiation detector for future satellites. Promotion of engineering education in Finland with the aid of satellite project. Aalto-1 mission goals

13. Community

14. Organization

15. Education

17. The satellite has to be affordable

18. The satellite needs flexible, affordable launch

19. The satellite has to be usable in education

20. There should be common standards for cooperation and continuity

21. Some subsystems should be availableCubeSat compatible nanosatellite

23. Aalto-1 Project Timeline 29.7.2011

24. Aalto-1 systemoverview

25. Aalto-1 satellite CubeSat3U compatible Dimensions: 34×10×10 cm Mass: 4 kg Orbit: Sun-synchronous mid-day LEO Attitude control: 3 axis stabilized Communication: VHF-UHF telecommand S-band data transfer Lifetime: 2 years Solar powered: max power 8 W Payloads: Imaging Spectrometer (VTT) Radiation detector (Univ. of Helsinki, Univ. of Turku, FMI) Electrostatic Plasma Brake (FMI)

27. Mass: 4 kg Dimensions: 34x10x10 cm

28. Aalto-1 The FinnishStudentSatellite

29. Aalto-1 The FinnishStudentSatellite Subsystems

30. Modular design compatiblewithCubeSatKitparts

31. Payload IIMAGING SPECTROMETER

32. VTT Technical Research Centre of Finland has developed a tiny hyperspectral camera suitable for many applications based on MEMS Fabry-Perot interferometer. Aalto-1 provides a test platform to demonstrate space readiness of this technology. World smallesthypespectralcamera for remotesensingapplicationsby VTT The Fabry-Perot Interferometer based hyperspectral hand held imager by VTT

33. Fabry-Perotinterferometerworkingprinciple Fabry - Perot Mirrors Object of the Image of the hyperspectral hyperspectral imager imager Front optics Focusingoptics for collimation for imaging Order sorting filter Air gap

34. Fabry-Perotinterferometerworkingprinciple Fabry - Perot Mirrors Object of the Image of the hyperspectral hyperspectral imager imager Front optics Focusingoptics for collimation for imaging Order sorting filter Air gap

35. Currentmodel for UAVI Major specifications of the spectral camera Spectral range: 500 – 900 nm Spectral Resolution: 9..45 nm @ FWHM Focal length: 9.3 mm F-number: 6.8 Image size: 5.7 mm x 4.3 mm, 5 Mpix Minimum total exposure time: 30 ms Field of View: 32 (across the flight direction) Ground pixel size: 3.5 cm @ 150 m height Weight: 350 g (without battery) Size: 62 mm x 61 mm/76mm x 120 mm Power consumption: 3 W

36. VTT miniaturespectrometersUAV testflights

37. Aalto-1 The FinnishStudentSatellite Spectralimager

38. Spectrometerunit for Aalto-1 satellite Mass: 400 g Dimensions: 5x10x10 cm

39. Spectralfilter: MEMS Fabry-Perotfilter (orpiezo-actuatedFabry-Perotfilter) Sensor: 5 MpxCMOS Dimensions: 5x10x10 cm Mass: 400 g Axiallenght of optics: 6 cm Spectralrange: visible Spectralresolution: 7-10 nm Spectral and spatialbinning Field of view: 10 deg Groundresolution: 40-100 m Up to 3 channelsimultaneousmeasurement Capable to measurespectralcube Producedby VTT TechnicalResearch of Finland Aalto-1 ImagingSpectrometer

41. Payload IIPLASMA BRAKE

43. About 9 uN/m2 thrust density for perfect mirror

44. At 1 AU, 1 N sail would be 330x330 m, membrane mass 1200 kg if made of 7.6 um polyimide sheet, characteristic acceleration 0.8 mm/s2

45. Thrust vectoring is possible, but thrust magnitude and direction change in unison for flat sail

46. Solar sail is old idea (roughly 100 years), implemented in space first time in 2010 (IKAROS, Japan)

47. Technical challenges of solar sail:

48. Membrane should be very thin

49. Membrane's support structures should be very lightweight as well

50. Everything must be tightly packaged and folded during launchSolar photon sail

52. Plasma stream emitted from Sun in all directions

53. Speed 350-800 km/s (lowest in ecliptic plane, higher elsewhere)‏

54. Mean density 7 cm-3 at Earth

55. Variable, but always present

56. Dynamic pressure ~2 nPa at Earth (1/5000 of photon pressure)‏

57. Electric sail (E-sail)‏

58. Slowly rotating system of long, thin, conducting and centrifugally stretched tethers which are kept positively charged (~ +20 kV) by spacecraft electron gun

59. Only modest amount of electric power needed, obtained from solar panels

60. ~500 nN/m thrust per length

61. For example, 100x20 km tethers, 1 N thrust, 100 kg mass, specific acceleration 10 mm/s2Electric solar wind sail

62. E-sail, traveling in interplanetaryspacewithoutfuel

63. 20 000 piecestrackablespacejunkorbits the Earth Image © ESA

64. Electrostaticallycharged long tether

65. Aalto-1 The FinnishStudentSatellite Plasma brake

66. Dimensions: 10x10x2,5 cm Mass: 150 g Reel for 100 m tether Controlledunwinding Tether: 10-100 m Tethermaterial: Aluminium Tetherdimeter: 50 μm Negative and positivetetherchargecontrol Coldcathodeelectronguns for positivemode Voltagesource for negativemode Plasma Break

67. Payload IIIRADiationMONitor

68. Radiationenvironment in Earthorbit Radiation in LEO is the most significant threat to electronics Need for simple and small radiation detector Trapped proton environment on LEO needs to be taken into account in the design of any spacecraft Trapped proton environment anisotropies in LEO

69. Aalto-1 The FinnishStudentSatellite RADMON

70. Dimensions: 10x10x4 cm Mass: 500 g Sidetector and CsI(Tl) scintillator Measurementrange Electrons > 60 keV (5 energychannels) Protons > 1 MeV (7 energychannels) Countingrateup to 1 MHz Readout electronics consist of a pulse shaping and peak-hold circuitry with a pre-amplifier signal being digitised with high sampling rate FPGA based logic to count particle events hitting the sensor RADMON University of Helsinki

71. EducationThe projecthasbroughttogetherspecialistsndteachersalloverFinlandmorethan 20 specialassignments6 bachelor thesis1 Masterthesis on the way1 PhDstudent1 PostDoc

73. Aalto-1 team in spring 2011

74. Thankyou! http://aalto-1.tkk.fi