{"id":43553,"date":"2025-12-05T00:10:53","date_gmt":"2025-12-04T16:10:53","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/planned-satellite-constellations-may-swamp-future-orbiting-telescopes\/"},"modified":"2025-12-05T00:10:53","modified_gmt":"2025-12-04T16:10:53","slug":"planned-satellite-constellations-may-swamp-future-orbiting-telescopes","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/planned-satellite-constellations-may-swamp-future-orbiting-telescopes\/","title":{"rendered":"Planned satellite constellations may swamp future orbiting telescopes"},"content":{"rendered":"

On Wednesday, three NASA astronomers released an analysis showing that several planned orbital telescopes would see their images criss-crossed by planned satellite constellations, such as a fully expanded Starlink and its competitors. While the impact of these constellations on ground-based has been widely considered, orbital hardware was thought to be relatively immune from their interference. But the planned expansion of constellations, coupled with some of the features of upcoming missions, will mean that at least one proposed observatory will see an average of nearly 100 satellite tracks in every exposure.<\/p>\n

Making matters worse, some of the planned measures meant to minimize the impact on ground-based telescopes will make things worse for those in orbit.<\/p>\n

Constellations vs. astronomy<\/h2>\n

Satellite constellations are a relatively new threat to astronomy; prior to the drop in launch costs driven by SpaceX\u2019s reusable rockets, the largest constellations in orbit consisted of a few dozen satellites. But the rapid growth of the Starlink system caused problems for ground-based astronomy that are not easy to solve.<\/p>\n

Unfortunately, even if we had an infinite budget, we couldn\u2019t just solve this by increasing our reliance on space-based hardware. While orbital satellites may be above some of the problem-causing constellations, enough of the new hardware is orbiting at altitudes where they can interfere with observations. A check of the image archive of the Hubble Space Telescope, for example, shows that over four percent of recent images contain a satellite track, a significant increase from earlier in the century.<\/p>\n

(There are some space-based telescopes that aren\u2019t orbiting the Earth, like the James Webb Space Telescope, that will remain worry-free. But these require expensive launches and are too far from Earth for the sort of regular servicing that something like the Hubble has received.)<\/p>\n

And the problem will only get worse, according to three astronomers at NASA\u2019s Ames Research Center in California (Alejandro Borlaff, Pamela Marcum, and Steve Howell). Based on filings made with the Federal Communications Commission, they found that the current total of satellites represents only 3 percent of what will be in orbit a decade from now if everybody\u2019s planned launches take place.<\/p>\n

,<\/p>\n

To estimate the impact that this massive population of satellites might have on astronomy, the three researchers focused on several key orbiting observatories. One is the Hubble. Another is the recently launched SPHEREx, which will perform an all-sky survey in the infrared. The Chinese are developing a telescope called Xuntian that will operate in conjunction with their orbiting space station, and the ESA is preparing a mission called ARRAKIHS meant to characterize the dark matter halos of nearby galaxies.<\/p>\n

Lots of tracks<\/h2>\n

The impact of satellites on observations depends on many factors. Many satellites have constant infrared and radio emissions and thus always have the potential to interfere with imaging at those wavelengths. They can also reflect sunlight, but they\u2019re most likely to do that when they\u2019re near the horizon (meaning what someone on the satellite would see as the dawn or dusk edges of the Earth). While it\u2019s possible to prioritize observations that avoid the horizon, that becomes difficult when longer exposures are required. Surveys meant to identify asteroids that cross Earth\u2019s orbit will always need to image near the horizon.<\/p>\n

Another key factor is the altitude of the observatory. Something like Xuntian, which requires an orbit that takes it to a space station, will necessarily be at a relatively low altitude and therefore below more of the constellations. Something like SPHEREx, a smaller satellite that operates independently, can potentially be lifted to a higher orbit.<\/p>\n

So the risk the constellations pose to observatories can vary greatly based on where your observatory is, what wavelengths it\u2019s sensitive to, and what you\u2019re doing with it. That\u2019s why Borlaff, Marcum, and Howell looked at several very different pieces of hardware, although they did limit their analysis to interference from satellites that would be sunlit as they traversed across the observatory\u2019s field of view.<\/p>\n

,<\/p>\n

\n

\"Greyscale<\/p>\n

Simulated image of a what a typical ARRAKIHS exposure could look like if satellite constellations expand as planned.<\/p>\n

Credit:
\n Borlaff, et. al.<\/p>\n<\/figure>\n

If constellations are built out to their planned extents, there will be roughly 550,000 satellites in orbit. At that point, the researchers estimate that the average image captured by Hubble would have two satellite tracks, while SPHEREx would have five. Things get much worse from there: 69 for ARRAKIHS and 92 for Xuntian. Over a third of the Hubble images would see at least one track, while almost all the images from the other telescopes would have at least one.<\/p>\n

Xuntian\u2019s problems are largely the product of its low altitude. ARRAKIHS is higher, but it has a wider field of view and is expected to take long (600-second) exposures, increasing the chance that a satellite will wander by. Hubble, in contrast, has a narrow field of view, which limits how often satellites transit within its field of view.<\/p>\n

To validate their estimates, the researchers modeled the impact of the present population of satellites on Hubble and came up with a rate of satellite tracks similar to the rate that has actually been observed.<\/p>\n

No great solutions<\/h2>\n

There\u2019s no obvious way to deal with this. Right now, best practices involve orienting satellites to limit their ability to reflect light toward ground-based telescopes. But that orientation actually increases the odds that they\u2019ll reflect light toward space-based hardware. In addition, satellites will orient their solar panels toward the Sun, which means they\u2019re more likely to be face-on and maximally reflective toward any telescopes pointed away from the Sun.<\/p>\n

Lowering the orbits of constellations will get them out of the way of more of our observatories, but it will mean the satellites experience more atmospheric friction, so they\u2019ll have a shorter liftime in orbit\u2014something the companies putting them there are unlikely to accept. Nevertheless, that\u2019s the best solution the astronomers have, as the researchers write that it is \u201ccritical to designate safe and limited orbit layers for a sustainable use of space.\u201d<\/p>\n

Nature<\/em>, 2025. DOI: 10.1038\/s41586-025-09759-5  (About DOIs).<\/p>\n","protected":false},"excerpt":{"rendered":"

On Wednesday, three NASA astronomers released an analysis showing that several planned orbital telescopes would see their images criss-crossed by planned satellite constellations, such as a fully expanded Starlink and its competitors. While the impact of these constellations on ground-based has been widely considered, orbital hardware was thought to be relatively immune from their interference. […]<\/p>\n","protected":false},"author":1,"featured_media":43556,"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":[],"class_list":["post-43553","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/43553"}],"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=43553"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/43553\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media\/43556"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=43553"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=43553"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=43553"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}