SpaceX is trying to downplay the reflective features of Starlink satellites – but despite measured success, its results won’t cut it for astronauts, according to a recent study published in The Astrophysical Journal.
ACCEPTANCE: ELON MUSK CLAIMS STARLINK SATELLITES WILL NOT INCLUDE ASTRONOMY, EXCEPT ANOTHER INVESTIGATION
Starlink’s dark satellites could still disrupt astronomy, a study says
Starlink satellites with anti-reflective coating are already half the brightness of standard models, according to the study. Although this is an improvement, the dark models do not reduce the “noise” of light pollution, according to the team of scientists from the National Astronomical Observatory in Japan – led by Takashi Horiuchi.
Named “DarkSats,” the internet satellites launched by SpaceX remain a problem at other light waves, Gizmodo reports.
The first batch of 60 Starlink satellites was launched in May 2019, but they immediately met concerns from the celestial community about the bias of constellations in Earth’s lower orbit (LEO) to prevent celestial exploration of space at night.
SpaceX could launch up to 42,000 Starlink satellites
Of course, this was correct, as Starlink satellites were taking long-range images of galaxies, comets and more. Once they’ve discovered the problem, astronomers have explained a number of ways in which SpaceX satellites can build scientific research – including the work of the upcoming Vera C. Rubin Observatory in Chile.
This may sound like a minutiae to entrepreneurs, but SpaceX’s first batch of Starlink satellites are whiter than 99% of the products in LEO. With SpaceX CEO Elon Musk planning to launch around 12,000 Starlink satellites – maybe even 42,000 – this is a threat to Earth – based astronomy as we know it.
A recent study evaluated the reflection of the DarkSat satellites
Sadly, Musk’s views on the issue in March 2020 seemed to be broken by this fact – as he said Starlink would have “no effect at all in zero, celestial discoveries.” On the bright side, he also suggested that SpaceX could “take corrective measures if it is above zero.”
SpaceX’s response was to avoid the astronomical intervention of the DarkSats, which covered the original Starlink satellites with a darker finish to reduce albedo – or the desire to reflect light. Called the Starlink-1130 version, these DarkSats were included in a batch launched on January 7, 2020 – and the latest study evaluated the effectiveness of this change at reduce the reflection.
Scientists compared Starlink satellites to reference stars
In the experiment Horiuchi and colleagues looked at the satellites with a Japanese Murikabushi Telescope, based at the Ishigakijima Astronomical Observatory. Together, the team evaluated both the DarkSats and the original version – known as Starlink-1113 – through several light waves.
The telescope allows scientists to make observations in the red, green and near-infrared bands, and also helped the team compare the brightness of each reflective object with reference stars. In total, the team of scientists made four different observations from April to June 2020.
Starlink DarkSat satellites’ black cover ‘raises surface temperature’
The Japanese-based experts described how the “albedo of DarkSat is about half that of STARLINK-1113,” according to the paper. This is a major improvement in disinfecting the visual spectrum, but not 50% of the pass rate. And worse, there are still unresolved problems in other, unseen waves.
“The dark paint on DarkSat certainly casts a shadow of sunlight compared to normal Starlink satellites, but [the constellation’s] astronomical observations are still adversely affected, “Horiuchi said The world of physics. He also confirmed how the “good in UV / optical region” mitigation enhances the spectrum, but “the black coating raises DarkSat’s surface temperature and influences intermediate infrared perceptions.”
SpaceX could raise the height of the Starlink satellite
Another upcoming version of Starlink aims for an even lower resolution. Named “VisorSats,” the new version came with a sunscreen capable of “discounting the satellites once they reach operating height,” Sky and Telescope reports. Some of these models were launched in 2020, but their albedo reduction rate compared to the original Starlink model is visible.
While it’s too early to say whether SpaceX’s latest generation of Starlink-reducing satellites will make the cut for astronauts to get a clear view of the night sky, Horiuchi also revealed The world of physics the company should consider raising the height of the internet satellites. As they write, they will go up to 340 miles (547 km) in altitude, but at the same altitude as OneWeb – rival SpaceX – at 750 miles (1,200 km), the riot will go reflective of astronomy greatly reduced.