MITA (Minisatellite Italiano di Technologia Avanzata)
The Italian Minisatellite for Advanced Technology (MITA), developed by a team of small Italian companies (prime contractor: Carlo Gavazzi Space S.p.A. of Milan - with Contraves Italiana, FIAR Spazio, Laben, etc. as sub-contractors), is owned and funded by the Italian Space Agency (ASI). The objective of the MITA satellite project is to design and implement technology (demonstrate the capabilities of the Italian aerospace industry) of a low-cost bus for a wide range of future Earth mission applications.
The generic spacecraft bus design is modular (composed of tubular elements and closing sandwich panels), based on a cubic-shaped structure in the 100 kg (plus) mass range of a minisatellite. The spacecraft is three-axis stabilized,; the AOCS (Attitude and Orbit Control System) controls the pointing along the three axis with a precision from 0.1º (see also the MTS-AOMS payload description). The MITA bus is intended in particular for LEO missions with a lifetime of 5 years (MITA-1 has an expected lifetime of three years due to its low orbital altitude).
The bus employs dual-redundant data handling and telemetry/telecommunication subsystem chains (the other subsystems are partially redundant). The attitude control system measures attitude with the following sensors: two monoaxial horizon sensors, a triaxial magnetometer (redundant) and five coarse sun sensors. A momentum wheel and three magnetic coils are used as actuators. Electrical power is provided by two solar panels featuring GaAs solar cells. Each panel is able to produce 200 W (EOL). NiH2 batteries serve as a secondary energy source during eclipse phases of the orbit with a capacity of 150 Wh. Power conditioning and distribution is performed by a power electronics unit. The thermal control system is passive. 1) 2) 3) 4) 5) 6) 7)
Figure 1: Illustration of the MITA satellite (image credit: Carlo Gavazzi Space)
RF communications: The on-board data handling is based on transputer with DSP processor embedded. On-board storage capacity of 64 Gbit. The TM/TC protocol is CCSDS compatible. The downlink is in S-band with a frequency of 2.2 GHz, data rate: 1 Mbit/s, transmitter power: 1 W. The uplink is in S-band with a frequency of 2.1 GHz, data rate: 4 kbit/s.
Table 1: Specification of the major elements of the MITA-1 bus
Figure 2: Internal layout of the MITA spacecraft (image credit: Carlo Gavazzi Space)
Launch: MITA-1 was launched July 15, 2000 (along with CHAMP as the primary payload and Bird-RUBIN) aboard a Russian Cosmos-3M vehicle from the Plesetsk Cosmodrome, Russia.
Orbit: Circular orbit, mean altitude = 450 km (421 km x 476 km), inclination = 87.275º, period of 93.6 min.
Status of mission:
• The MITA mission operations was rather successful. However, the mission ended already on Aug. 15, 2001 (reentry of spacecraft into the atmosphere due to the rather low initial orbit, a requirement of the primary spacecraft, CHAMP). The impact occurred in the Pacific Ocean. The MITA spacecraft didn't have any propulsion means to maintain the orbit. A mission life of 13 months was achieved. The first MITA mission represented also an in-orbit validation of the platform.
• The NINA payload operated during the strongest solar flare storms within the solar cycle, acquiring unique information on particles fluxes.
• The very good in-orbit results of the MITA bus provided space qualification, opening the way for the practical implementation of the platform to scientific and application missions (use of MITA bus for AGILE, etc.).
• The commissioning phase of MITA after launch lasted for a month.
Sensor complement: (NINA-2, MTS-AOMS)
NINA-2 (New Instrument for Nuclear Analysis):
NINA-2 is of NINA heritage flown on RESURS-O1-4 (launch July 10, 1998). NINA-2 is a compact telescope, developed by INFN (Italian National Institute of Nuclear Physics) of Rome, Italy and MEPhI (Moscow Engineering and Physics Institute). The objective is to measure fluxes of charged particles, in particular to detect cosmic ray nuclei of galactic, solar, or other origin from hydrogen to iron, between 10 and 200 MeV/n (contained particles) and 1 GeV/n (outside containment).
The silicon detector cosmic ray telescope is composed of 16 X-Y planes, giving information on the energy of the crossing particle and its incident angle. Each of the 32 sensitive elements consists of two n-type silicon detectors, 60 mm x 60 mm, divided in 16 strips and connected to a supporting ceramic frame under lateral strips (1 and 16). Each couple of detector is glued orthogonal in order to provide X and Y independent view information. The thickness of the detector is 150±15 µm for the first plane, and 380±15 µm for the remaining 15 planes. The geometric factor of the instrument ranges from 8.6 cm 2 sr for low energy particles to 1 cm 2 sr for particles crossing the detector. The instrument mass is 40 kg, power = 40 W. 8) 9) 10) 11)
Figure 3: Line drawing of the NINA-2 instrument assembly (image credit: MEPhI)
Figure 4: The NINA-2 detector (left ) and its accommodation within MITA satellite (right), image credit: INFN
Figure 5: Accommodation scheme of the MITA subsystems (NINA-2 at left)
MTS-AOMS (Micro Tech Sensor-Attitude and Orbit Measurement System):
MTS-AOMS is an ESA technology sensor package (a system that incorporates Earth, star, and magnetic field sensing into a single package for attitude and orbit control systems), developed and funded by EADS Astrium GmbH (formerly DASA), for combined attitude and orbit measurements, consisting of three elements: an APS (Active Pixel Sensor) Camera with beamsplitter-optics, the MFS (Magnetic Field Sensor), and an ARS (Angular Rate Sensor). In the optical AOCS experiment, the camera employed a CMOS/APS detector, built by IMEC/Fillfactory (Leuven, Belgium), in a so-called 'sextant-mode' configuration, thereby achieving the simultaneous imaging of the star field and the Earth horizon onto the detector via a beamsplitter. This new camera setup represents the key to autonomous attitude and orbit determination.
Off-the-shelf optics were used. The Magnetic Field Sensor, built by FhG Dresden, Germany, measured the Earth magnetic field in two axes. The moving mass Angular Rate Sensor, built, by Bosch, Stuttgart, Germany, is an all-in-silicon sensor with integrated electronics. It measured the angular rate in one axis. The MTS-AOMS instrument had a total mass of 1.2 kg, and a size of 172 mm x 78 mm x 90 mm. 12) 13)
During mission operations, valuable AOCS data was gathered and ground-processed. The overall message is: simultaneous observation of the Earth and of stars can be done in a single focal plane. Successful star identification and Earth-horizon detection was carried out using the obtained imagery, resulting in the determination of the spacecraft's position. 14)
1) P. Sabatini, R. Aceti, et al., “MITA: In-Orbit Results of the Italian Small Platform and the first Earth Observation Mission, HYPSEO,” Proceedings of the 3rd International Symposium of IAA, Berlin, Apr. 2-6, 2001, pp.71-74
2) P. Sabatini, T. Lupi, “The MITA satellite: an Italian bus for small missions,” IAA 2nd International Symposium on Small Satellites for Earth Observation, Berlin, April 12-16, 1999, pp. 35-37
3) M. Casolino, et al., “ Continuation of the mission NINA: Nina-2 experiment on MITA satellite,” Proceedings of 26th ICRC, Salt Lake City, 1999, OG 4.2.17
4) M. C. Falvella, M. Crisconio, T. Lupi, P. Sabatini, G. Valentini, F. Viola, “MITA: An Italian minisatellite for small missions,” Advances in Space Research, Vol. 31, No 2, 2003, pp. 357-361
5) G. Furano, V. Bidoli, M. Casolino, M. P. De Pascale, A. Iannucci, A. Morselli, P. Picozza, E. Reali, R. Sparvoli, A. Bakaldin, A. Galper, M. Koldashov, M. Korotkov, A. Leonov, V. Mikhailov, A. Murashov, S. Voronov, G. Mazzenga, M. Ricci, G. Castellini, M. Barbiellini, M. Boezio,V. Bonvicini, R. Cirami, A. Vacchi, N. Zampa, M. Ambriola, R. Bellotti, F. Cafagna, F. Ciacio, M. Circella, C. De Marzo, O. Adriani, P. Papini, S. Piccardi, P. Spillantini, “The small satellite NINA-MITA to study galactic and solar cosmic rays in low-altitude polar orbit,” Advances in Space Research, Vol. 31, No 2, 2003, pp. 351-356, URL: http://www.space.mephi.ru/download.asp?num=13
6) P. Sabatini, R. Aceti, T. Lupi, G. Annoni, F. Dalla Vedova, V. De Cosmo, F. Viola, “MITA: In orbit results of the Italian small platform and the first Earth observation mission: HYPSEO,” 4th IAA Symposium on Small Satellites for Earth Observation, Berlin, Germany, April 7¿11, 2003; also in Acta Astronautica, Vol. 52, Issues 9-12, May -June 2003, pp. 727-732
7) “The MITA Satellite: anItalian bus for small missions,” URL: http://www.cgspace.it/images/activities/satelliti/mita/mita_brochure.pdf
8) R. Sparvoli, et al., “Launch in orbit of the telescope NINA for cosmic ray observations: preliminary results,” Proceedings of The Sixth Topical Seminar on `Neutrino and Astro-Particle Physics,' Centro Studi `I Cappuccini' in San Miniato al Todesco, Italy, May 17-21, 1999
9) M. Casolino, V. Bidoli, M. DePascale, A. Bakaldin, A. Galper, M. Boezio, V. Bonvicini, M. Ambriola, R. Bellotti, O. Adriani, P. Papini, M. Ricci, G. Castellini, et al., “Launch in orbit of the NINA-2 apparatus aboard the satellite MITA,” Proceedings of ICRC 2001 (International Cosmic Ray Conference), Hamburg, Germany, Aug. 7-15, 2001, http://people.roma2.infn.it/~aldo/D109icrc01-Nina2Launch.pdf
10) M. Casolino, V. Bidoli, A. Canestro, M. De Pascale, G. Furano, A. Iannucci, A. Morselli, P. Picozza, R. Sparvoli, A. Bakaldin, A. Galper, S. Koldashov, M. Korotkov, A. Leonov, V. Mikhailov, A. Murashov, S. Voronov, G. Barbiellini, V. Bonvicini, A. Vacchi, N. Zampa, M. Ambriola, R. Bellotti, F. Cafagna, F. Ciacio, M. Circella, C. De Marzo, O. Adriani, P. Papini, S. Piccardi, P. Spillantini, S. Bartalucci, M. Ricci, M. Boezio, G. Castellini., “Continuation of the mission NINA: Nina-2 experiment on MITA satellite,” URL: http://people.roma2.infn.it/~aldo/D81icrc99ninamita_o4217.pdf
11) A. Leonov, M. Cyamukungu, J. Cabrera, P. Leleux, Gh. Gregoire, S. Benck, V. Mikhailov, A. Bakaldin, A. Galper, S. Koldashov, S. Voronov, M. Casolino, M. P. De Pascale, P. Picozza, R. Sparvoli, M. Ricci, “The measurements of light high-energy ions in NINA-2 experiment,” Annales Geophysicae, Vol. 25, 2007, pp. 2029-2036, URL: http://www.ann-geophys.net/25/2029/2007/angeo-25-2029-2007.pdf
12) M. Melf, S. Manhart, “Micro Systems Technology In-Orbit Experiment,” ESA/ESTEC Third Round Table on Micro/ Nano Technologies for Space, May 2000
13) “N° 48-2000: ESA technology flies on Italian mini-satellite launched from Russia,” URL: http://www.esa.int/export/esaCP/Pr_48_2000_p_EN.html
14) Information provided by Christopher Kuehl of EADS Astrium GmbH, Munich, Germany
The information compiled and edited in this article was provided by Herbert J. Kramer from his documentation of: ”Observation of the Earth and Its Environment: Survey of Missions and Sensors” (Springer Verlag) as well as many other sources after the publication of the 4th edition in 2002. - Comments and corrections to this article are always welcome for further updates.