Night glider mode
Night Glider mode or XVV Night Glider mode ( Engl .: for Nachtgleitmodus ) is an optimizing method for aligning the solar cells of the International Space Station . This optimization serves to reduce the frictional resistance caused by the solar panels.
The solar cell surfaces usually follow the sun. However, one of the main reasons for the station's loss of altitude is the wind pressure (“air resistance”) of the surfaces in the very thin, but still existing, high atmosphere . This can be reduced in normal operation by the so-called Sun Slicer mode , in which the surfaces are aligned with the edge in the orbital direction instead of the sun. However, this reduces the yield of the solar cells. The night glider mode is a mixed mode of operation - during the day part of the orbit around the earth, the surfaces are aligned with the sun, when the ISS is in the earth's shadow, they are placed with the edge facing the orbit. This reduces the average resistance of the solar surfaces by 30 percent without having to accept losses in the energy supply.
This mode was proposed during the early development of the ISS, but was not implemented until 2003 after the Columbia disaster , when the space shuttle fleet was no longer available for supply. The fuel saving for course regulation is around 1000 kg per year.
See also
Individual evidence
- ↑ G. Landis and CY Lu, "Solar Array Orientation Options for a Space Station in Low Earth Orbit," Journal of Propulsion and Power, Vol. 7 No. 1: 123-125 (1991).
- ↑ NASAexplores.com: Station Without Shuttle ( Memento from September 1, 2007 in the Internet Archive ) (English)
- ↑ Lindy Fortenberry, Kathy Laurini, John-David F. Bartoe, and Bill Gerstenmaier, NASA Johnson Space Center, "Continuing the Journey on the International Space Station," paper IAC-03-T.1.02, 54th IAF Congress, Bremen Germany ( 2003)