The successful launch of Sputnik in 1957 marked a milestone in human history as the first time a man-made object ever orbited the Earth. But little did we know about space-based SNAFU that we are coming to terms with the advent of satellite technology. Since 64 years, our planet has rapidly accumulated in the night sky. Today, more than 3,000 satellites orbit the Earth and are joined by millions of pieces of space debris – such as pieces of a broken satellite, rocket skips and pieces of spacecraft paint. NASA estimates that there are about 6,000 tons of debris in the Low Earth Orbit alone.
This orbital refusal not only poses navigation hazards to astronauts, it also reflects sunlight below the surface, interfering with ground-based telescopic observations. A recent study accepted by Monthly notice of the Royal Astronomical Society: Letter It is revealed that there is now nowhere on Earth that is free from overflow debris and light pollution generated by satellites. More than that, researchers expected the amount of debris to increase by an order of magnitude over the next decade, as SpaceX’s StarLink programs, such as mega-constellations of Internet-beaming mini-satellites, take off.
A 2020 study at the Harvard-Smithsonian Center for Astrophysics warned, “Astronomers – and casual viewers of the night sky – should expect a future that includes relatively thousands of large satellites in low Earth orbit populations.” “The effect will be significant for certain types of observations, some observatories and certain times of the year.”
Until a few years ago, humanity had launched fewer than 10,000 objects into orbit since the beginning of the space age. However, with the advent of low-cost commercial rocket launch technology – which has seen the price per pound of cargo drop from $ 24,800 during the shuttle era to just $ 1,240 today – the rate at which we orbit satellites is accelerating. Is scheduled to increase from. .
In total, over 1825 satellites are expected to be launched in LEO by 2025 – ten times the total number of active satellites in 2018. SpaceX has permission from the US government alone to launch 12,000 Starlinks into this orbit (42,000 of them with multiple plans), while Amazon’s Cooper Project is authorized to send 3,236 satellites of its own in the coming years. Both these programs seek to create an orbital network in Low Earth Orbit capable of providing high-bandwidth, low-latency Internet connectivity from anywhere on the planet. While their intentions are noble, the unintended consequences of packing that can radically change our view of the original solar system that many spacecraft have in our skies.
NOIRlab
“If 100,000 or more LEOSATs are proposed to be deployed by multiple companies and multiple governments, no combination of mitigation is entirely related to the effects of satellite trails on the science programs of current and planned ground-based optical-NIR astronomy facilities.” May survive, ”the 2020 American Astronomical Society report noted.
For example, when the first 360 Starlinks were launched in May of 2019, their presence in the night sky was immediately noticeable. Their highly reflective design made each mini-satellite about 99 percent faster than surrounding objects, helping them reach their 550-km operational altitude over the course of five months. This effect was particularly pronounced during sunrise and sunset when the sun’s rays were reflected from the solar panels of the satellites. SpaceX’s attempt to reduce that reflection by using “darkening treatment” in early 2020 proved to be only partially successful.
“We are detecting a nearly 55 percent reduction in the reflective brightness of the DarkSat compared to other Starlink satellites,” noted a 2020 study by Jeremy Treglu-Reid from the University of Antofagasta, Chile.
The brightness of an astronomical object is measured along a scale of stellar magnitude – that is, the brighter the object, the larger and more negative its respective rating will be. For example, the Sun is rated at -26.7 magnitude, while the North Star is rated at +2. Any object above +6 is effectively invisible to the human eye, although survey binoculars and other sensitive observation systems can dim objects as +8. According to Treglon-Reid’s study, the treated Starlink satellite exhibited a magnitude of +5.33 at its operating altitude, while +6.21 for an untreated satellite.
It’s better but not enough, Treglon-Reid reported Forbes last March. “It’s still very bright,” he said. “More needs to be done now. The idea is to get these numbers to the policy makers [and astronomical societies] Who are interacting with SpaceX [and mega constellation companies] And then try to improve it further. “
The overall impact of these satellites will depend on many factors including the time the telescope is being used, the time of day and weather being observed, and several factors including the height of the satellite constellation. Extensive field surveys in both the visible and infrared spectrums (such as those conducted by the Vera C. Rubin Observatory in Chile) are particularly vulnerable to this intervention, as they are conducted during twilight hours. And while orbiting in LEOs typically darken once in the shadow of the Earth, they fall into geosynchronous orbits 750 miles and beyond – such as the short-lived OneWeb program – “all night and nighttime during summer” Significant excerpts will appear “during winter, autumn and spring, and will have a negative impact on almost all observational events,” according to AAS.
“High-altitude satellites should be relatively less reflective than relatively low-altitude satellites. [in professional detectors]. This is due to two factors: orbital speed (low-altitude satellites move faster so spend less time on each pixel) and focus (low-altitude satellites tend to be less in-focus, so the streak is wider, But there is less peak brightness, University) Washington astronomer Dr. Meredith Rawls told Forbes.
In response to the growing problem, astronomers around the world have prepared a list of potential corrective actions and policies as part of the National Science Foundation’s SATCON-1 workshop last July. These include limiting the constellations to a maximum altitude of 550 – 600 km, requiring individual satellites to have a stellar magnitude of +7 or greater, and sharing orbital information about these constellations with the research community so that astrologers will see the sky To avoid those areas.
At the SATCON-1 workshop, SpaceX has shown that operators can reduce sunlight through satellite body orientation, sun shielding, and surface darkening. “A joint effort to obtain high-accuracy public data at approximate locations of individual satellites (or ephemerides) may enable mid-propagation shuttering during some signal avoidance and satellite.” Alternatively, operators can design their satellites to be actively devastated when they reach the end of their service life span – as Starlink’s satellites do – or they can launch a lower constellation in general. . Whether or not national or international regulators will actually adopt these recommendations.
But even though satellite operators manage to reduce the brightness of their constellations, we are confronted with an increasingly dense orbital “cemetery” of broken satellites and overhead space junk. NASA’s Orbital Space Debris Office estimates that there are half a million marble-sized pieces of junk jumping around 22,300 mph – to chip ISS’s heavily reinforced windows even at rapid impact – and about 100 million pieces a Measuring millimeters or less.
NASA became the first national space agency in 1995 to develop a comprehensive space debris mitigation plan. Those guidelines were later adapted by the 10-nation Inter-Agency Space Debris Coordination Committee (IADC) and eventually adopted by the United Nations General Assembly in 2007. The US government also established its Orbital Debris Mitigation Standards Practices (ODMSP) in 2001, in a new effort to renew new, long-burnt debris from debris control released during normal operations, from accidental eruptions The debris generated was minimized. Selection of safe flight profile and operational configuration to minimize accidental collisions, and subsequent mission disposal of space structures. “Additionally, the Department of Defense operates the Space Surveillance Network, which is charged with cataloging and tracking objects between 0.12 and 4 inches using a combination of ground-based visual telescopes and radar arrays.
Tracking this debris is only the first step. A number of space agencies are in the process of developing systems to actively capture and dispose of orbital refuse. JAXA, for example, is considering a 2,300-yard-long “electrodynamic teether” that, when deployed, will drive the debris back to the planet where it will burn during atmospheric reorientation. In 2018, a consortium led by the UK’s Surrey Space Center successfully demonstrated its RemoveDebris device – a giant space trap designed to essentially capture dead satellites and rub spacecraft up to 10 meters into space.
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By 2025, ESA hopes to launch its ClearSpace-1 mission, in which a four-dimensional capture device will attempt to snatch space debris like an oversized claw game prize, then find itself and its environment in Earth’s atmosphere. Will dispose of the offending reward.
“Space debris is a global problem because it affects all countries,” explained Airbus Mission Systems Engineer Xander Hall Cnn In 2018. “Each piece of junk in space is owned by the original operators and orbital debris is not explicitly addressed in current international law. An international effort was made to claim ownership of the wreck and help secure its removal should go. “
