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10th European Space Weather Week , November 18-22, 2013, Antwerp, Belgium Space debris in the Near-Earth space: Impact on space missions Coronas-F and Coronas-Photon Sergey Kuzin, Sergey Shestov, Ulyanov Artem LPI, Moscow, Russia The work has been supported by the FP-7 eHEROES Project № 284461 of the European Commission Motivation • • • • • • • • Space debris – fragments and pieces of damaged satellites, spent rocket stages ,etc. Sizes – from millimeters to meters Estimated number: 3e5 (size>1cm), 2e4 (size > 5 cm) “Kessler syndrome” (1978) – collision cascading of space debris No effective measures yet! Fragments with size > 5 cm can be tracked from Earth by means of radars and optical sensors Smaller objects should be observed from orbit We propose to use standard star trackers for monitoring of space debris CORONAS satellites CORONAS-F CORONAS-Photon 07-31-2001 Launch date 01-30-2009 12-06-2005 End of operation 11-30-2009 549 km Apogee 562 km 501 km Perigee 539 km 82,5° Inclination 82,5° Optical star trackers Mount: Dimensions: 45 × 25 × 13 cm Weight: 5 kg Power consumption: 3 W Lens: Focal length: 70 mm Aperture: 1.8 Star tracker mount on CORONAS-Photon CCD: Dimensions: 512 × 512 pixels Pixel size: 13.5 × 13.5 µm Pixel angular size: 0.6 arcmin Exposure time: 3 sec CCD-matrix used in star trackers Attitude control Star tracker image (07-01-2009 00:01:04 UT) Detection limit d 2 S eff 1 I sun 2 Nd d 2 2 4 L d I sun d 2 S eff 16 Vrel L L V rel d2 400 [photons/p ixel] L L – the distance to the debris particle in km, d – the size of particle in cm Isun = 0.1 [W/cm2] - solar radiation flux, ad = 0.1 - the debris particle albedo, Seff = 16 [cm2] - effective area of the telescope entrance aperture, Vrel = 1 [km/s] - the debris particle relative velocity, w = 3e-4 [rad]- the CCD single pixel field of view, = 0.5 - the CCD quantum efficiency, Debris examples CORONAS-F: 85 debris tracks found (out of 2e4 images) CORONAS-Photon: 490 debris tracks found (out of 8e4 images) Stereo imaging [n h ] r [n n ] r1 = 4 m r2 = 5.5 m Vrel = 0.7 m/s A pair of CORONAS-F images taken on 11-10-2001 (08:42:40 UT) 3d-model CORONAS-F, 11-10-2001 (08:42:40 UT) 3d-model CORONAS-F, 02-05-2002 (20:47:58 UT) Self-rotating objects Frequency of rotation ≈ 680 rpm! CORONAS-F, 04-03-2002 (10:20:55 UT) Single channel dim d im ( D d ) CORONAS-Photon, 05-20-2009 (22:10:43 UT) F Dd LF L d im D = 4 cm – entrance aperture F = 7 cm – focal length d – size of a pacticle dim – size of an image L – distance to a particle L ≈ 7 m (for a small particle) Vrel ≈ 4 cm/s Orbital elements of debris particles Filename Semi-major axis, km Eccentricity Inclination 020518_211018 6810.1 0.00814 82.57 020502_204758 6845.9 0.00463 82.48 011110_084240 6870.3 0.00292 82.49 020311_055921 6825.5 0.00376 82.47 020403_102055 6891.9 0.01172 82.77 020515_223442 6811.7 0.00838 82.56 020716_181546 6787.7 0.01523 82.55 based on CORONAS-F data Possible improvements Resolution enhancement: • Increase focal length • Increase aperture • Increase stereoscopic base Coordinated observations: • Even greater stereoscopic base! • More data • Make a catalogue of debris • Theoretical modeling THANK YOU!