Arthur T Knackerbracket has processed the following story:
NASA is advancing plans to construct a radio telescope on the Moon's far side – a location uniquely shielded from the ever-increasing interference caused by Earth's expanding satellite networks. This ambitious endeavor, known as the Lunar Crater Radio Telescope, envisions deploying a massive wire mesh reflector within a lunar crater.
The project's innovative design relies on advanced robotics to suspend the reflector using cables, and if development proceeds as planned, the observatory could be operational sometime in the 2030s. Current projections estimate the cost at over $2 billion.
The far side of the Moon offers an unparalleled environment for radio astronomy, being naturally protected from the relentless radio noise and light pollution that plague observatories on Earth. The recent surge in satellite launches, especially from private ventures like Starlink, has led to a dramatic increase in orbiting satellites.
This proliferation raises concerns among astronomers about space debris, light pollution, and, most critically, the leakage of radio-frequency radiation.
Such interference poses a significant threat to sensitive scientific instruments designed to detect faint signals from the universe's earliest epochs. Federico Di Vruno, an astronomer affiliated with the Square Kilometre Array Observatory, told LiveScience, "it would mean that we are artificially closing 'windows' to observe our universe" if radio astronomy on Earth becomes impossible due to interference.
The LCRT is being developed by a team at NASA's Jet Propulsion Laboratory, part of the California Institute of Technology. Since its initial proposal in 2020, the concept has progressed through several phases of funding from NASA's Institute for Advanced Concepts. The team is currently building a prototype for testing at the Owens Valley Radio Observatory in California.
Gaurangi Gupta, a research scientist working on the project, explained that preparations are underway to apply for the next round of funding. If successful, she told LiveScience, the LCRT could transition into a "fully-fledged mission" within the next decade.
The proposed telescope features a mesh reflector spanning approximately 1,150 feet – making it larger than the now-defunct Arecibo telescope, though not as large as China's FAST observatory. The team has already selected a preferred crater in the Moon's Northern Hemisphere for the installation, but the precise site remains confidential.
Although the concept of a lunar radio telescope dates back to at least 1984, technological advances have brought the idea closer to reality. One of the most significant obstacles facing the project, however, is its cost. Gupta noted that the latest estimate for building the LCRT stands at around $2.6 billion – a figure that presents challenges given NASA's current budgetary constraints.
Beyond providing a refuge from terrestrial interference, the LCRT would open new frontiers in astronomy by enabling the study of ultra-long radio waves – those with wavelengths longer than 33 feet. Earth's atmosphere blocks these frequencies, which are essential for investigating the universe's "cosmic dark ages," a period before the first stars formed.
"During this phase, the universe primarily consisted of neutral hydrogen, photons and dark matter, thus it serves as an excellent laboratory for testing our understanding of cosmology," Gupta said. "Observations of the dark ages have the potential to revolutionize physics and cosmology by improving our understanding of fundamental particle physics, dark matter, dark energy and cosmic inflation."
NASA has already begun experimenting with lunar radio astronomy. In February 2024, the ROLSES-1 instrument was delivered to the Moon's near side by Intuitive Machines' Odysseus lander, briefly collecting the first lunar radio data. However, as Gupta pointed out, the instrument's Earth-facing orientation meant that "almost all the signals it collected came from our own planet, offering little astronomical value."
Later this year, another mission aims to place a small radio telescope on the Moon's far side, further testing the feasibility of such observations.
(Score: 3, Interesting) by pTamok on Friday June 06, @10:01AM (5 children)
What happens if China chooses the same location, and takes steps to build it first by placing equipment there before the USA?
I don't know what the Moon Treaty [wikipedia.org] says about that, or Realpolitik [wikipedia.org] by placing 'facts on the ground' [wikipedia.org], or 'facts on the lunar surface'.
(Score: 3, Interesting) by VLM on Friday June 06, @12:02PM
The moon's big and scopes are small, we'll be OK. I think the major problem would be coordination.
"Well we thought it would be fun to deploy an ultra-low-noise X-band scope, and you seem to think it would be fun to use X-band as your primary uplink transmitter 50 miles away, and being a Chinese product you left out ALL the EMI/RFI/spurious emission filtering components on your transmitter, so our scope mostly just receives broadband noise and interference from your uplink transmitter, so ..."
(Score: 2, Disagree) by Username on Friday June 06, @02:20PM
I hope they do. 2b will be about 10b at the end. Let China pay it. We have better things to spend 10,000,000,000 dollars on.
(Score: 0) by Anonymous Coward on Friday June 06, @08:53PM
"given NASA's current budgetary constraints",
we may as well turn the whole thing over to China. We only do politics now, not science
As far as I know, the treaty says nobody can claim territory on the moon (Don't we have something similar for Antarctica?). It may also say you can't claim what you extract either, but that would be dumb, so I hope it doesn't.
(Score: 2) by deimtee on Saturday June 07, @01:50AM (1 child)
Absolutely nothing of any importance.
200 million years is actually quite a long time.
(Score: 1) by pTamok on Sunday June 08, @11:56AM
I should have checked. Hi ho.
Perhaps the Outer Space Treaty [wikipedia.org] is relevant?
Ratified by the USA and Russia (inherited from the USSR), and acceded to by China.
(Score: 3, Informative) by c0lo on Friday June 06, @10:31AM
'Nogh said.
https://www.youtube.com/@ProfSteveKeen https://soylentnews.org/~MichaelDavidCrawford
(Score: 1) by shrewdsheep on Friday June 06, @11:58AM (3 children)
Why not put it at a Lagrange point?
Pros: no supporting structure, more flexible to choose viewing angle
Cons: continuous propulsion necessary, somewhat worse isolation, after finishing, robots cannot visit the amusement park (to bend stuff)
(Score: 5, Interesting) by VLM on Friday June 06, @12:05PM (2 children)
Thought experiment: Space is big, points are small, its tempting to design some 10 mile wide net-like antenna thing for an L point, but eventually the L points are going to fill up with "junk" both controlled and uncontrolled. At least the moon is really big.
Possibly an interesting idea is a lunar orbiting scope and just take data samples on the far-side. That's interesting to think about.
(Score: 0) by Anonymous Coward on Friday June 06, @01:11PM (1 child)
Not sure of the exact mechanics, but I believe there are no long term stable orbits for the Moon. Everything is eventually either thrown out of orbit or impacts the surface.
(Score: 3, Interesting) by VLM on Friday June 06, @04:51PM
Post Y2K with better moon gravity data they came up with some stable-ish orbits but it took a lot of data and analysis.
An interesting "obvious" solution is a truly giant telescope reflector should have some thrust in the sun, and if the earth makes too much interference to take scientific data, the giant reflector could be an interesting solar sail about half the time when its on the near side of the moon and can't be used for science anyway. There will probably be some scaling issues and pointing issues. But if they got it "really really close to perfect" then in theory a nearly infinitely small solar sail force half the time would be enough to keep it perfect enough.
Perhaps a giant ball shaped satellite where the "front" side is a radio telescope and the "back" side is a solar sail. Or a really crazy tether design with multiple sails. I'm sure deployment would be a huge headache.
I'm not immediately aware of any lunar stability studies involving a really small constant thrust. Obviously at the limit, a really high thrust engine with an infinite fuel tank has an enormous nearly infinite range of long term stable orbits that don't involve eventual impact. And at the other extreme, most orbits around the moon with absolute zero thrust are unfortunately unstable long term although a handful of theoretically stable orbit channels exist. But I don't know the scaling in between. Somewhat less than 1 mm/s2 is a realistic upper bound for a solar sail using COTS-ish technology and that can do "a lot" in general in near earth orbit, but I couldn't even guess at the effect in lunar orbit. The fairly recent LightSail 2 mission was not exactly a sports car WRT performance and intentionally did not push the technological limits and was extremely successful at about 1/20th of a mm/s2. Of course a scope-hauling sail would be enormous so even pushing the technical limits maybe a tenth of a mm per second squared would be "reasonable" for a lunar telescope solar sail. There's a lot of seconds in a day... a 0.1 mm/s2 solar sail illuminated half the day would be a delta v budget around 9 m/s (back of envelope, probably wrong LOL) so what fraction of lunar orbits are stable if you're willing to burn 9 m/s per day to stabilize them? One thing I do know, is the Apollo capsule circularization burn to go from elliptical to circular orbit was "pretty huge like fifty kilometers change" and hand wavy cost was about "fifty" m/s so it would take a big ass solar sail about 6 days to make a similar 50 kilometer orbital height change, so I think even a VERY small solar sail assisted spacecraft should be dynamically stable perpetually in lunar orbit.
In a way, its a cool feature of lunar orbit that unless a satellite is being actively controlled or is in a REALLY rare and weird orbit, it'll decay and impact. Lunar orbit is self cleaning, unlike earth's orbit. If my math is correct above, even an extremely small and modest actively controlled solar sail would keep a satellite in orbit for zero fuel cost.
My math is probably F-d because I know that earth geosync broadcast satellites budget "about fifty" m/s per year of delta v so a small sail generation more than that per month (not per year) indicates I've made a math mistake somewhere because otherwise it would be kinda stupid to use thrusters on broadcast sats instead of sails. Of course there's more than half a centuries experience with thrusters and just a handful of experimental missions with sails, maybe a century from now every satellite will have a set of sails.
(Score: 2) by VLM on Friday June 06, @11:58AM (2 children)
Some practical concerns, some good, some less so:
Ionosphere: Not much of one compared to Earth, but some. Should leverage this to focus on radio bands that don't work well on the earth's surface. Just saying one interesting research result will be much closer than expected (just a few hundred miles from the telescope, not hundreds of lightyears away)
Power: Big solar array full of AC inverters and switching power supplies... oh wait probably not a good idea.
Temperature: Optical scope have a rough time on the earth, but even metal scope will have problems going from sunlight to darkness for weeks at a time. Its going to be a rough environment. Maybe instead of large parabolic reflectors it would be better/easier to build a giant microwave horn antenna. There's not much high winds on the moon compared to earth, nor much rainfall, so a truly gigantic horn antenna is interesting to contemplate and MIGHT be easier to build. Remember on the surface of the earth horn antennas are huge and heavy but on the moon it could resemble a fishing net. Probably get all tangled up, unfortunately.
Comms: Some talk over the decades about orbiting comsats and geolocation 'gps' sats around the moon, probably not a good idea for this telescope. Also transmitting data back will be tricky. Simply lay down a very long fiber optic cable encircling the moon, then at the near side station ...
Delta-v: Earth orbit to lunar surface is about 2.5 km/s delta v budget. Lagrangian points are less than 1 km/s and its only another 1 km/s to go to mars instead of the moon. Asteroids are all over the map and have low surface gravity but tend to be in wild far away orbits so thats probably not a reasonable alternative. Low-thrust (ion engine) missions take more delta-v, etc. But, handwaving, its a hard sell to build on the moon when its "easier" to build at a L point or in some ways easier to build on Mars. The moon is an annoying in-between point.
(Score: 2) by VLM on Friday June 06, @05:03PM
Construction: Embarrassingly I forget the hard sci fi book but the idea was the earthlings will not permit industrial scale processing of the moon on the near earth side, so the far side is where people will be "permitted" to build giant dust refineries to generate O2 and maybe water and helium-3 and WTF they need to build moonbases. So unfortunately the far side of the moon will be under intense industrialization pressure whereas the assumption is its empty now so it'll always be empty of humans, but its probably going to be the reverse and far side lunar real estate is going to be popular for industrial use.
(Score: 4, Informative) by sgleysti on Saturday June 07, @12:22AM
It's possible to make switching power supplies quiet at radio frequencies. This whole endeavor is going to require a lot of specialized engineering; just add it to the pile.
(Score: 3, Interesting) by jb on Saturday June 07, @08:19AM (1 child)
If it's on the moon, then surely by definition it could not be the world's most sensitive telescope, the the moon is, well, not part of the world. It could well be the moon's (or perhaps even mankind's) most sensitive telescope though.
(Score: 0) by Anonymous Coward on Monday June 09, @01:31AM
The "world" often refers to whatever your reference is, rather than the planet you live on.
For example, Americans regularly run "World Series" sporting events containing teams from their entire (known) world.