Thread

A 12-year sequence of telescope images of a star and four planets orbiting

402 points · 82 comments · mariuz

ortusdux · 1790979604 · focus · HN ↗
I'm excited for the leap in this tech that the Nancy Grace Roman telescope's new chronograph promises.
<a href="https://www.jpl.nasa.gov/missions/the-roman-coronagraph-instrument/" rel="nofollow">https://www.jpl.nasa.gov/missions/the-roman-coronagraph-inst...
The Roman Coronagraph is designed to detect planets 100 million times fainter than their stars, which is 100 to 1,000 times better than existing space-based coronagraphs. The Roman Coronagraph will be capable of directly imaging reflected starlight from a planet akin to Jupiter in size, temperature, and distance from its parent star.
1. izend · 1790980052 · focus · HN ↗
  I am as well and hopefully Starship allows even larger telescopes!
  1. lukeify · 1790981375 · focus · HN ↗
    Starship can do it.
    As long as the telescope can fit through the Starlink Pez dispenser.
    walrus01 · 1790988115 · focus · HN ↗
    If this remains a long term design limitation it'll be interesting to see if people design satellite hardware that consists of multiple individual rectangular slab sized things (generally same size/shape per piece as starlink v3 test satellites which have unfolding PV/antenna), that can latch together once dispensed, and further unfold.
    Such an architecture might not be an impossible design consideration if the goal is to have something big like the sun-shade/cold side of the Webb telescope.
    dylan604 · 1790989013 · focus · HN ↗
    I can't imagine that there will not be other versions. The Pez dispenser is just solving the problem at hand. Eventually, I wouldn't be surprised to see cargo bay doors similar to the shuttle's.
    walrus01 · 1790994879 · focus · HN ↗
    That seems likely. Best guess is the relatively small slot sized door is a cautious design while they're working out issues with re-entry heating and stresses and sacrificing ships into the ocean. Once they're very confident they have the configuration for the 'hot' side of the starship working well on re-entry (and probably after they've returned and caught a few), it could be expanded in size.
    NitpickLawyer · 1791003804 · focus · HN ↗
    Yeah, they'll have more versions for sure. There are two main designs that have been discussed / shown before (one where the entire nose hinges "backwards" and exposes the payload, and one that looks like the shuttle bay doors). And I think that for NASA decadal projects (i.e. JWST-like big telescopes) they could even go with a non-reusable Starship, with "regular" fairings that get dropped.
    topspin · 1791006218 · focus · HN ↗
    > If this remains a long term design limitation
    It is not a long term limitation. One might design any number of stages to fly in place of Starship on top of the Super Heavy booster.
    Also, large science payloads can be launched by SLS. Back in the days of the Ares program, there were proposals to launch an 8 meter reflector (ATLAST-8m)[1] using Ares V. SLS anticipates payloads of such size as well.
    So there are at least two viable platforms on which enormous space mirrors might launch, and one of them is likely to be highly cost effective. It's up to the science establishment to propose such missions and get them funded.
    [1] <a href="https://ntrs.nasa.gov/citations/20100004890" rel="nofollow">https://ntrs.nasa.gov/citations/20100004890
    alexpotato · 1791033082 · focus · HN ↗
    A. I watched a documentary on the plane about SpaceX where they showed the Pez dispenser working and it was amazing.
    B. You could have multiple panels operate as a swarm. There could be many "mirrors" that focus images on one central "collector". That would be larger than any telescope that needs to be shipped as one unit e.g. James-Webb.
    grvbck · 1791041891 · focus · HN ↗
    > B. You could have multiple panels operate as a swarm.
    Is that level of precision even remotely achievable with today's technology?
    My understanding is that orbital insertion accuracy is in the ±10-50 meters range, with the most advanced formation flying satellite swarms hitting 10 cm to 1 m precision between satellites with the help of optical navigation.
    But the precision between the panels on a telescope like JWST is in the sub-mm range, no?
    Also, I'd assume stuff like orbital decay, atmospheric drag, gravitational perturbations, and solar radiation pressure would make it difficult to maintain precision over time.
    I'm sure/hopeful there's some people here at HN working on stuff like this, please fill in and correct me!
    ortusdux · 1791056270 · focus · HN ↗
    Interferometry can be used to effectively combine multiple telescopes into one large imager. The technique becomes much more difficult at higher wavelengths, but there has been recent advances in infrared systems.
    It would be nice to see a swarm of satellites advance astronomy for once!
    <a href="https://en.wikipedia.org/wiki/Astronomical_interferometer" rel="nofollow">https://en.wikipedia.org/wiki/Astronomical_interferometer
    alexpotato · 1791134251 · focus · HN ↗
    Yes, this exactly!
    The benefit of the "pez dispenser" is that you can very efficiently send up lots of the parts and then deploy them into gigantic arrays.

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