Lincoln Calibration Sphere 1

Lincoln Calibration Sphere 1
Names LCS-1
Mission type radar calibration
Operator MIT Lincoln Laboratory
COSPAR ID 1965-034C
SATCAT no. 01361
Mission duration 53 years, 5 months and 7 days
Spacecraft properties
Spacecraft LCS-1
Spacecraft type Aluminium sphere
Manufacturer Rohr Corp.
Dry mass 34 kg (75 lb)
Start of mission
Launch date 15:00:03, May 6, 1965 (1965-05-06T15:00:03)
Rocket Titan IIIA
Launch site Cape Canaveral LC-20
Contractor US Department of Defense
Deployed from Geocentric orbit
Deployment date 06 May 1965
End of mission
Disposal Active
Decay date In c. 30000 years
Orbital parameters
Reference system Geocentric
Regime Medium Earth
Eccentricity 0.00055
Perigee 2,786 km (1,731 mi)
Apogee 2,796 km (1,737 mi)
Inclination 32.1°
Period 145.6 minutes
RAAN 1 hour 35 minutes
Epoch May 5, 1965[1]

The Lincoln Calibration Sphere 1, or LCS-1, is a large aluminium sphere in Earth orbit since 6 May 1965. It is the oldest spacecraft still in use, having lasted for over 50 years. It was launched along with the Lincoln Experimental Satellite-2 on a Titan IIIA. It is technically the oldest operational spacecraft, but it has no power supply or fuel; it is merely a metal sphere. It has been used for radar calibration since its launch. It was built by Rohr. Corp. for the MIT Lincoln Laboratory.[2][3]

LCS-1 is a hollow sphere 1.12 m (3 ft 8 in) in diameter with a wall thickness of 3.2 mm (0.13 in).[3] The sphere was constructed from two hemispheres, made by spinning sheet metal over a mold. These hemispheres were fastened to an internal, circumferential hoop by 440 countersunk screws, then milled and polished. The initial finish had a surface roughness less than 10 micrometres and was expected to last for five years.[4] Since its launch, I-band measurements have shown periodic deviations that likely correspond to one or more new surface irregularities.[5]

Before being launched to orbit, the optical cross section of the LCS-1 was measured in L, S, C, X and K microwave bands. Four other spheres were also manufactured and measured for comparison to the one in orbit.[6]

References

  1. ↑ "NSSDCA - LCS". nssdc.gsfc.nasa.gov. NASA. Retrieved 15 September 2017.
  2. ↑ Krebs, Gunter. "LCS 1,2,3,4". Gunter's Space Page. Retrieved 23 July 2015.
  3. 1 2 "radar calibration via satellites". National Astronomy and Ionosphere Center. Acreibo Observatory. Retrieved 23 July 2015.
  4. ↑ Prosser, Reese T. (October 1965). "The Lincoln Calibration Sphere". Proceedings of the IEEE. 53 (10): 1672. doi:10.1109/PROC.1965.4319.
  5. ↑ Hall, Doyle T.; Africano, John L.; Lambert, John V.; Kervin, Paul W. (July 2007). "Time-Resolved I-Band Photometry of Calibration Spheres and NaK Droplets". Journal of Spacecraft and Rockets. 44 (4): 910–919. Bibcode:2007JSpRo..44..910H. doi:10.2514/1.27464.
  6. ↑ Burrows, M.L. "The Quality of the Lincoln Calibration Sphere" (PDF). dtic.mil. Defense Technical information Center. Retrieved 22 April 2016.


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