SpaceX’s Starlink satellites are going to get more astronomer-friendly with satellites that are practically invisible to the naked eye.
The Starlink satellites have been receiving the ire of space scientists not long after they first launched last year. To that end, SpaceX has employed new technology dubbed as “VisorSat” to make the satellites more invisible to the naked eye.
Filtering out a noisy sky
The biggest problem with the Starlink satellites was their luminosity. From the ground, they look just like slowly moving stars in the night sky, which became a problem for astronomers.
CNBC says that SpaceX explained the phenomenon this way:
“This happens because the satellites are illuminated by the Sun but people or telescopes on the ground are in the dark.”
Since the majority of telescopes are ground-based, the addition of new objects in the sky obscured the telescopes’ view of the sky. Where one telescope could previously be able to monitor an empty patch of space, now it would have to contend with more luminous noise.
This made it more difficult to obtain data, and scientists have been vocal about it. “We would be left with all of these fake trails, fake galaxies, etc., in our data, damaging the science,” said Tony Tyson, the head scientist at the Rubin Observatory.
SpaceX tested this DarkSat design in space, which reduced brightness by about 55%.
But the company is launching a new VisorSat design in May that it expects will be even more effective, as by "June all future Starlink satellites will have sun visors."https://t.co/DCoYvjjQc0 pic.twitter.com/2iKZXKv9fb
— Michael Sheetz (@thesheetztweetz) April 29, 2020
Darkening the satellites
Space News writes that SpaceX originally attempted to darken the reflective surfaces on the satellites. The company called this feature “DarkSat”.
While DarkSat was fairly effective in reducing the luminosity of the satellites, it wasn’t enough to make it negligible.
The VisorSat, on the other hand, will effectively serve as an umbrella that will shield the satellites from rays of light, reducing their luminosity. This is because the satellites only reflect the light they receive.
Elon Musk describes the material by saying:
“We have a radio-transparent foam that will deploy nearly upon the satellite being released, and it blocks the sun from reaching the antennas…they flip out and block the sun and prevent reflections.”
Scientists wanted the satellites to be darker so that it would be easier to filter out the data from the Starlink system.
Although a computer-intensive task, this would go a long way in helping astronomers with their data. Tools can be used to correct data from the telescopes and compensate for any reflection of light from the satellites.
Musk was quoted with his advocacy for VisorSat in a briefing:
Our objectives, generally, are to make the satellites invisible to the naked eye within a week, and to minimize the impact on astronomy, especially so that we do not saturate observatory detectors and inhibit discoveries.
An armada of Starlink satellites
The Starlink system is SpaceX’s program to provide worldwide low-latency Internet, among other things. The company currently has approval from the United States government to launch up to 12,000 of its miniature satellites.
However, Elon Musk’s goal is to blanket the planet with at least 30,000 satellites, and all new Starlink system satellites launched will feature VisorSat.
Image courtesy of SpaceX-Imagery / Pixabay