DEVELOPING A LOW EARTH ORBIT MEGA-CONSTELLATION SATELLITE VISIBILITY/BRIGHTNESS FORECASTING ALGORITHM
Abstract
In May 2019, Starlink, a subsidiary of SpaceX, launched their first batch of 60 low Earth orbit communication satellites (LEOsats). Due to their very low orbits following launch and their clustering in ‘trains’, the Starlink LEOsats appeared extremely bright in the night sky (V<2). The initial and subsequent launches have caused major concern among both the amateur and professional astronomical communities (see IAU press release, 2019/06/03 and IAU press release, 2020/02/12) combined with dark sky advocates (see International Dark sky Association Press Release). This has led to Starlink to begin development of mitigation designs to reduce the Starlink LEOsat reflective brightness. First, a special darkening treatment (Starlink-1130, ‘Darksat’: SpaceX updates April 2020) then special visors to shade the reflective surfaces of the main chassis from the solar rays (Starlink-1436, ‘Visorsat’: SpaceX updates April 2020). As part of the community-wide effort to quantify the risks of LEOsat mega-constellations to ground based optical to NIR astronomy, two reports and workshops were commissioned (AAS/NSF, SATCON1 & IAU/UNOOSA, Dark & Quiet skies) to bring satellite engineers and astronomers together, to examine the impact of LEOsat mega-constellations to ground based astronomy and to produce recommendations and mitigation strategies, for both LEOsat operators and observatories. Both reports recommend the development of an algorithm that allows astronomers to determine the number of LEOsats passing through their Field Of View (FoV), centred on a specific set of celestial coordinates as a function of time, for a particular evening. Such an algorithm would allow astronomers to plan their observations, minimising the contamination from LEOsat trails in their data.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 20, 2023
- Source ID
- FA95502210292
Entities
People
- Jeremy Tregloan-reed
Organizations
- Air Force Office of Scientific Research
- United States Air Force