![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2022\/12\/Starlink-V1.5-renders-Oct-2021-SpaceX-V1.0-vs-V1.5-c.jpg\")
<\/p>\nSince their initial launch in 2019, SpaceX\u2019s Starlink internet satellites have become infamous for photobombing observations from ground-based telescopes. While Starlink \u2014 along with other satellite \u201cmegaconstellations\u201d \u2014 has been a primary concern for ground-based telescope observations, a new issue has begun to pop up; the satellites are now occasionally obstructing images from one of NASA\u2019s flagship space telescopes, the Hubble Space Telescope. These \u201cphotobombings\u201d point to a concerning future for astronomy in low Earth orbit (LEO), as telescopes in LEO may begin to face the same problems ground-based telescopes face today \u2014 especially as these satellite megaconstellations grow.<\/p>\n
To learn more about this growing issue, NSF sat down with astrophysicist Dr. Jonathan McDowell from the Harvard-Smithsonian Center for Astrophysics to discuss the topic.<\/p>\n<\/p>\n
Satellites have long been an issue for astronomy, but due to the relatively low amount of satellites in orbit during the first several decades of spaceflight, the issue was not an extreme concern. The environment in LEO has been rapidly changing over the past few years, however, as more private companies (i.e. SpaceX and Amazon) and nations express interest in and launch so-called satellite \u201cmegaconstellations.\u201d The most well-known, and arguably the most controversial, megaconstellation today is Starlink \u2014 SpaceX\u2019s publicly-available internet satellites \u2014 and OneWeb, a company aiming to provide commercial internet service worldwide.<\/p>\n
Starlink and OneWeb are not the only two megaconstellations, though, as there are several megaconstellations currently in development. This includes Project Kuiper, Amazon\u2019s competitor to Starlink, which is set to begin demo launches later this year.<\/p>\n
<\/p>\n
A Starlink v1.5 satellite (left) compared to a Starlink v1.0 satellite (right). Note the comparably larger size of the solar panel, which causes significant reflections when not angled away from Earth. (Credit: SpaceX)<\/p>\n
Due to Starlink being one of the first true satellite megaconstellations \u2014 and planned to be larger than any other megaconstellation currently in development \u2014 the program has garnered much attention from the public and astronomers alike.<\/p>\n
Leading up to the maiden Starlink launch, astronomers were not immensely concerned about their effect. While astronomers knew the size of Starlink\u2019s constellation would likely threaten ground-based astronomy, they would soon find that Starlink\u2019s impact on their observations and research would be far more serious than previously thought. Dr. McDowell explained, \u201c[Astronomers] had greatly underestimated how bright these satellites were going to be. We hadn\u2019t paid it a lot of attention, and we didn\u2019t realize how enormous the satellites were going to be because they hadn\u2019t told us. [W]e didn\u2019t appreciate the impact they were going to have.\u201d<\/p>\n
Fortunately, SpaceX has been working closely with astronomers to mitigate the effects of Starlink\u2019s size and brightness on astronomical observations. The company has tested multiple designs to reduce the brightness of the satellites, such as dark paint and sunshades. However, due to thermal issues and the fact that sunshades would block the laser links on newer satellites, these mitigations were only flown on a limited number of older satellites.<\/p>\n
Technology News (adsbygoogle = window.adsbygoogle || []).push({});<\/p>\n While SpaceX is investigating newer forms of dark coatings for the satellites, the current primary brightness mitigation technique is aligning the satellites so that their large and extremely reflective solar arrays face away from Earth.<\/p>\n These mitigation techniques were all designed to limit the impacts of Starlink on ground-based astronomy. However, the techniques do little to lessen the impact of Starlink on LEO-based observation, which was previously thought to have been a safe haven from the negative effects of Starlink.<\/p>\n An image of the NGC 5353\/4 galaxy group taken with a ground-based telescope at Lowell Observatory in Arizona. The streaks are Starlink satellites transiting across the telescope\u2019s field of view. (Credit: Victoria Girgis\/Lowell Observatory)<\/p>\n Dr. McDowell explained that around 3% of Hubble\u2019s observations prior to Starlink were obstructed by satellite trails. Thankfully, this did not always mean the data was useless, as he explained, \u201cMost of that was not \u2018Throw away the science,\u2019 it was \u2018Okay, we can\u2019t use that image for this<\/em> purpose\u2019\u2026 but more and more you are getting to the point where [you say] \u2018Okay, that data is useless for the purpose we took it.’\u201d<\/p>\n Hubble currently orbits around 10km below the operational orbit of most Starlink satellites. This, combined with its narrow field of view, means it should be safer than other telescopes \u2014 but will still be heavily affected as more and more megaconstellations begin to grow in LEO.<\/p>\n Wide field-of-view space telescopes in LEO, such as China\u2019s upcoming Xuntian telescope, will be more severely affected. Xuntian will feature a field of view that is over 300 times larger than that of Hubble, allowing it to image a very large swath of sky at once. Wide field-of-view telescopes can be used to survey the sky, noting changes in areas over time. NASA\u2019s upcoming Nancy Grace Roman Space Telescope will serve a similar purpose.<\/p>\n The field of view of NASA\u2019s upcoming Roman telescope compared to Hubble. (Credit: NASA GSFC)<\/p>\n While Roman \u2013 alongside the joint NASA\/ESA\/CSA James Webb Space Telescope \u2014 will never need to worry about Starlink satellite streaks thanks to its position at the Earth-Sun Lagrange point 2 (L2), Xuntian \u2014 in a 390 kilometer LEO \u2014 will be faced with a tough challenge. While its wide field of view will be excellent for capturing large areas of space, it also drastically increases the chances of satellites passing through the telescope\u2019s line of sight.<\/p>\n With the negative effects of satellite megaconstellations becoming more and more clear, it raises a question: will future LEO telescopes need to take these satellite constellations into account?<\/p>\n Dr. McDowell replied simply, \u201cAbsolutely.\u201d<\/p>\n He continued, \u201cThe solution for, say, most American missions is going to be \u2018Let\u2019s put them high up.\u2019 But, if you\u2019re a developing country, like if India wanted to launch another space telescope \u2026 maybe they don\u2019t have the rockets to put it higher up. And so I think it\u2019s going to be a real challenge for future low Earth orbit observatories \u2026 particularly for ones that have a wide field of view that are searching for new things.\u201d<\/p>\n \u201cWe have the \u2018scalpels\u2019 which look at a known object with a big magnification, and then we have the surveys, which look at a bunch of sky at once, trying to find things that haven\u2019t been seen before \u2013 and those [survey telescopes] are the ones [that will be affected].\u201d<\/p>\n He then added one final thought: \u201c\u2026I think that low Earth orbit astronomy is going to be problematic every bit as much as ground-based astronomy.\u201d<\/p>\n Render of the X-Ray Imaging and Spectroscopy Mission (XRISM), an upcoming Japanese X-ray telescope. X-ray telescopes like XRISM should be less affected by satellites than ultraviolet, visible, and infrared telescopes. (Credit: JAXA)<\/p>\n But thankfully, this increase in satellite counts should not be problematic for every type of astronomy. He explained, \u201cThere may be missions where you do the calculation, and you go \u2018Yeah, that\u2019s a 1% effect, we\u2019re not going to worry about it,\u2019 and other missions where you go \u2018No, you know what, you\u2019ve got to go high because we\u2019ve just lost LEO for this purpose.’\u201d<\/p>\n X-ray telescopes in LEO, such as Japan\u2019s upcoming XRISM mission, should be minimally affected as Starlink is not bright in the X-ray spectrum.<\/p>\n As megaconstellations continue to develop and grow, astronomers will need to adjust how they study the cosmos. LEO is no longer a safe haven for astronomy \u2014 telescopes will need to be launched into higher orbits if they want to limit the effects of satellite transits. Distant locations like L2 may end up being a truly safe haven, as astronomers reach for an unobstructed view of the heavens.<\/p>\n (Lead image: The Hubble Space Telescope seen from the Space Shuttle\u2019s crew cabin during a servicing mission. Credit: NASA)<\/em><\/p>\n","protected":false},"excerpt":{"rendered":" Since their initial launch in 2019, SpaceX\u2019s Starlink internet satellites have become infamous for photobombing observations from ground-based telescopes. While Starlink \u2014 along with other satellite \u201cmegaconstellations\u201d \u2014 has been a primary concern for ground-based telescope observations, a new issue has begun to pop up; the satellites are now occasionally obstructing images from one of […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[1661,4259,276,38,1277,440,7929],"class_list":["post-24323","post","type-post","status-publish","format-standard","hentry","category-news","tag-astronomy","tag-hubble","tag-kuiper","tag-leo","tag-oneweb","tag-starlink","tag-telescopes"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/24323"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=24323"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/24323\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=24323"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=24323"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=24323"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2022\/12\/ann19035a.jpg\")
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