1. The work has been supported by the FP-7 eHEROES Project № 284461 of the European Commission 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

2. 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

3. CORONAS satellites CORONAS-FCORONAS-Photon 07-31-2001Launch date01-30-2009 12-06-2005End of operation11-30-2009 549 kmApogee562 km 501 kmPerigee539 km 82,5°Inclination82,5°

4. Optical star trackers CCD: Dimensions: 512 × 512 pixels Pixel size: 13.5 × 13.5 µm Pixel angular size: 0.6 arcmin Exposure time: 3 sec 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-matrix used in star trackers

5. Attitude control Star tracker image (07-01-2009 00:01:04 UT)

6. Detection limit L – the distance to the debris particle in km, d – the size of particle in cm I sun = 0.1 [W/cm 2 ] - solar radiation flux, a d = 0.1 - the debris particle albedo, S eff = 16 [cm 2 ] - effective area of the telescope entrance aperture, V rel = 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,

7. Debris examples CORONAS-F: 85 debris tracks found (out of 2e4 images) CORONAS-Photon: 490 debris tracks found (out of 8e4 images)

8. Stereo imaging A pair of CORONAS-F images taken on 11-10-2001 (08:42:40 UT) r 1 = 4 m r 2 = 5.5 m V rel = 0.7 m/s

9. 3d-model CORONAS-F, 11-10-2001 (08:42:40 UT)

10. CORONAS-F, 02-05-2002 (20:47:58 UT) 3d-model

11. CORONAS-F, 04-03-2002 (10:20:55 UT) Frequency of rotation ≈ 680 rpm! Self-rotating objects

12. CORONAS-Photon, 05-20-2009 (22:10:43 UT) D = 4 cm – entrance aperture F = 7 cm – focal length d – size of a pacticle d im – size of an image L – distance to a particle L ≈ 7 m (for a small particle) V rel ≈ 4 cm/s d im Single channel

13. FilenameSemi-major axis, kmEccentricityInclination 020518_2110186810.10.0081482.57 020502_2047586845.90.0046382.48 011110_0842406870.30.0029282.49 020311_0559216825.50.0037682.47 020403_1020556891.90.0117282.77 020515_2234426811.70.0083882.56 020716_1815466787.70.0152382.55 Orbital elements of debris particles based on CORONAS-F data

14. 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

15. THANK YOU!