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Future of Space Telescopes in the Era of Super Heavy Lift Launch
- Log_out_ 2y agoWhat material could lenses and mirrors be made off that is not glass.. just so we do not throw rocks up the well
- gavinsyancey 2y agoWell, the JWST mirrors are made of beryllium
- rqtwteye 2y agoI guess it's not a good idea to lick them.
- dylan604 2y agoI was thinking the same thing. The beryllium is just the support structure. It's the coating of gold specifically for the spectrum JWST is built for, so why not coat the beryllium with a different material for other parts of the spectrum?
- itishappy 2y agoThat's exactly what they do! https://www.edmundoptics.com/knowledge-center/application-notes/optics/metallic-mirror-coatings/ https://www.edmundoptics.com/knowledge-center/application-no...
- ThrowawayTestr 2y agoSome telescopes are made using a big spinning dish of liquid mercury.
- AlgorithmicTime 2y ago[dead]
- johndunne 2y agoYup, these mirrors can only point directly up (zenith telescope). Any adjustment off horizontally to the earth deforms the curve of the mirror. Some liquid mirror telescopes exist today to track space debris. Cheap and useful.
- ortusdux 2y agoMembrane mirrors show promise: https://physicsworld.com/a/membrane-mirrors-take-off-for-use-in-large-space-telescopes/ https://physicsworld.com/a/membrane-mirrors-take-off-for-use...
- FredPret 2y agoFor low-frequency radiation, I wonder if you could build a big and light radio dish in orbit
- dylan604 2y agoWhy not do something similar to VLA instead. So rather than a single "big and light" dish in orbit, you make a constellation of smaller dishes that equal a single larger dish? We know SpaceX is more than capable of that kind of deployment.
- lizknope 2y agoI think the scientists don't think it is worth it. The reason we need the James Webb telescope in space is because the infrared wavelengths it studies are absorbed by the Earth's atmosphere. We can observe a lot of the radio spectrum from ground based telescopes https://en.wikipedia.org/wiki/Atmospheric_window https://en.wikipedia.org/wiki/Atmospheric_window https://en.wikipedia.org/wiki/Radio_window https://en.wikipedia.org/wiki/Radio_window https://en.wikipedia.org/wiki/Radio_telescope#Radiotelescopes_in_space https://en.wikipedia.org/wiki/Radio_telescope#Radiotelescope... > Since 1965, humans have launched three space-based radio telescopes. The first one, KRT-10, was attached to Salyut 6 orbital space station in 1979. In 1997, Japan sent the second, HALCA. The last one was sent by Russia in 2011 called Spektr-R. https://public.nrao.edu/ask/are-there-space-based-radio-telescopes/ https://public.nrao.edu/ask/are-there-space-based-radio-tele... > There have been a few radio telescopes launched into space over the years, most with the purpose of linking with ground-based radio telescopes to form an array with very long baselines (distances between antennas). One such recent project, which ceased operation just a few months ago, is RadioAstron. I don’t believe that there are any currently-operating radio telescopes in space, though.
- namibj 2y agoOne use would be to hide behind the moon to block interference from Earth, at the L2 point in the earth-moon system. Use a laser to, say, a repeater at L4 or L5, and from there further to either LEO or directly the surface.
- itishappy 2y agoMirrors can be made out of just about anything: glass, metal, ceramic, polymer, wood, you name it. The mirror itself is just a reflective coating (typically gold, silver, or aluminum), and it can be as thin as a few nanometers. The trick is shaping it and convincing it to hold that shape, which is why we currently use rigid materials like glass and metal. Something inflatable might work, but more likely we'll just stick with lightweight metals like JWST's beryllium mirrors. However, there's already a lot of rock up there. Asteroids are numerous and big. What's the concern adding more?
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- piker 2y agoGiven the reference to “the well”, it’s likely the parent was referring to mass.
- johndunne 2y agoGiven the hexagonal layout of JWST's beryllium mirrors, future telescopes could 'just' increase the size of the mirror by launching multiple payloads of these mirrors and aligning them in space to form one giant layout. It doesn't seem much of a stretch beyond the complexity and single points of failure NASA managed to hurdle with JWST. How hard can it be? ;-)
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- bell-cot 2y agoAre you concerned with glass shattering if hit by orbital junk? If so - impacts at orbital velocities tend to create plenty of debris regardless.
- topspin 2y agoNASA was developing plans for an 8 meter monolithic optical/UV space telescope concept[1]. NASA's concept videos from 17 years ago are still rattling around on YouTube[2]. All that died when the Ares program was cancelled and the intended launch platform, Ares V, went away. Starship and SLS are supposed to have a large enough fairings. So, maybe one day... [1] https://ntrs.nasa.gov/api/citations/20090014194/downloads/20090014194.pdf https://ntrs.nasa.gov/api/citations/20090014194/downloads/20... [2] https://www.youtube.com/watch?v=2YsNvpVSzbI https://www.youtube.com/watch?v=2YsNvpVSzbI
- dylan604 2y agoAfter JWST, why build an monolithic mirror? If you only want visible spectrum, you wouldn't need the complexity of the heat shield of JWST. If an 8 meter primary is so much better, why not make it multiple times 8 meters similar to JWST? I understand this was something from 17 years ago, but let's just keep pushing capabilities instead of incrementing them.
- topspin 2y ago"why build an monolithic mirror?" "why not make it multiple times 8 meters" Cheap, simple design that doesn't take 20 years and a NASA to develop. 8m is a massive gain in angular resolution over Hubble's 2.3m and an improvement on JWST's 6.5m. From the our linked article: “Diameter is a huge lever arm,” “The larger the diameter, the better the resolution and sensitivity.” Based on the fairing specs it looks like Starship could achieve 9m. That would be nearly double the collector area of JWST. JWST is one, very expensive, exclusive design that perhaps only NASA is capable of delivering. What if someone other than the US wants a cutting edge "Great Observatories" class space telescope? A big, simple monolithic mirror design made feasible by super heavy lifters.
- EcommerceFlow 2y agoOr maybe a 16m "single fold". Would the complexity of adding 1 fold be worth the benefit of a 2x size?
- dylan604 2y ago"Preliminary design discussions have commenced, and in May, NASA awarded BAE Systems, Lockheed Martin, and Northrop Grumman contracts worth a combined $17.5M to advance key stabilizing tech." Noticeably absent from that list: Boeing. The next time Boeing is awarded a contract, I will immediately wonder how much money it cost them into convincing someone. I just can't see how they would ever be considered again. As in, what does Boeing need to do to prove they have fixed the glitch?
- lostlogin 2y agoWhat is the glitch you are referring to? I’ve done a brief search but can’t find anything.
- dylan604 2y agoThe glitch is Boeing's focus on stock price instead of quality products. They can't seem to build an airplane correctly. They can't seem to build an orbiter correctly. I would hope all of that has been taken into consideration by the decadal survey members, and that's why they were not mentioned
- indoordin0saur 2y agoTheir Starliner human spacecraft has failed and astronauts are currently trapped on the ISS until they can figure out the problem. This is after billions of dollars and several years of delays.
- psunavy03 2y agoThey are not trapped on the ISS. NASA has stated that the capsule can safely bring them home if needed. The problem is that the service module with the flawed parts will burn up on entry, so before that they are trying to get as much test data out of it as they can. Worst case, NASA would just send a SpaceX Dragon up to bring them home, but this would be a huge amount of egg on Boeing's face. Yes, Boeing hosed up, but we don't need to exaggerate how much they hosed up.
- EcommerceFlow 2y agoI've had a crazy thought of SpaceX taking control of this industry, similarly to StarLink. An enormous percentage (like 90%+) of requests to Hubble, JWTC, etc get denied, so the market is seemingly there. Plus, maybe the data ends up being useful for training Grok 5 or whatever.
- stcredzero 2y agoAn enormous percentage (like 90%+) of requests to Hubble, JWTC, etc get denied, so the market is seemingly there. What is the TAM? Would it be worth it? However, considering that the Hubble was developed from spy satellite tech, could this also happen in reverse? What uses would a 9m mirror telescope have in terms of ground observation? Would the US government allow such a thing to go up and be available for hire?
- johndunne 2y agoJWST is a taxpayer funded science mission, and the science run on the observatory isn't a pay-per-use model. I don't think a second JWST available for hire would see anywhere near the demand JWST currently fields.