The prototype of a new constellation of extremely bright Earth-orbiting satellites is due to launch in early- to mid-September. The AST SpaceMobile company plans to orbit more than 100 of these spacecraft by the end of 2024. Astronomers at the Vera Rubin Observatory and the International Astronomical Union's Centre for the Protection of Dark and Quiet Skies from Satellite Constellation Interference (IAU CPS) are concerned because these new spacecraft will interfere with celestial observations, adding to the problems already caused by other constellations.
The first member of this new group, called BlueWalker 3, will feature a giant antenna array covering an area of 64 square meters (689 square feet). Observers on the ground will see bright sunlight reflected from this structure. After on-orbit tests of BlueWalker 3 are completed, the operational satellites, called BlueBirds, will be launched. BlueBirds may produce even more glaring light pollution since they are significantly larger. The commercial appeal of these satellites is that they will link directly to cell phones without the need of a cell tower. AST SpaceMobile has already secured a license from the Federal Communications Commission to test the prototype.
[...] Other bright satellites are waiting in the wings: 30,000 second-generation Starlink satellites are currently awaiting FCC approval. Like the BlueBirds, the new Starlinks may carry antennas for direct connection to cell phones; the antennas are slightly smaller at "only" 25 square meters, but the satellites would be far more numerous than the BlueBird constellation. That development would be very bad news for astronomy.
BlueWalker 3 is expected to be among the brightest objects in the night sky after the antenna unfolds. Amateur astronomers can help record this satellite's brightness, bringing awareness to bright satellites' effects on our night sky and on astronomy.
[...] Astrophotographers can also play an important role in the study of artificial satellites, by uploading celestial images impacted by satellite streaks to the TrailBlazer website. Meredith Rawls and Dino Bektešević (both at University of Washington) are developing this data archive as part of the IAU's response to the problems posed by spacecraft. Trailblazer stores the impacted images and records selected metadata, so users can search for satellite-streaked images by date, location, and other parameters such as sky position and telescope.
See also:
AST SpaceMobile video describing the phased array satellite.
NASA APOD showing satellite streaks over a two hour period.
Previously:
SpaceX Has Had 'Promising Conversations' With Apple About iPhone Satellite Service
AST SpaceMobile Gets US Approval to Test Satellite-based Cellular Broadband
(Score: 2) by JoeMerchant on Wednesday September 21 2022, @03:56PM
The question is: what is that optimal exposure time?
Long exposures for CMOS sensors might be 10 seconds, and if you get a thin streak you don't necessarily have to throw out the whole frame.
In practice, high investment images these days are composed of thousands of exposures, not 1/60th of a second each to be sure, but thousands none the less.
These images full of streaks are intentionally emphasizing the issue without applying any mitigation.
🌻🌻 [google.com]