eleveriven an hour ago

It's pretty incredible to think that we're at a point in human history where we can map 450 million galaxies and probe the origins of the universe

ChuckMcM 12 hours ago

It always surprises me how my enthusiasm for scientific discovery is affected by fears of a dystopian future. My understanding is that with red shift calibration here we'll get a much better idea of the 'when' in terms of various galactic structures emerged, that might give us an interesting idea of where we are in the life-cycle of the Milky Way. But the observation of water signatures will be the most interesting to me. Presumably there is a lot of water tied up in comets and such, but will SPHERE be able to detect those signatures near planets?

  • turtletontine 8 hours ago

    The galactic and extragalactic science cases (meaning, “stuff in the Milky Way” vs “everything inside the Milky Way”) are actually pretty unrelated here.

    We actually have quite a good idea about the history of the Milky Way and all the smaller galaxies that it’s eaten (and will eat, such as our main current satellites the Small and Large Magellanic Clouds). We’re even pretty sure that the MW merged with another large galaxy about 11bil year ago, sometimes called “Kraken” https://en.wikipedia.org/wiki/Kraken_galaxy?wprov=sfti1. SPHEREx is not interested in any of that, and it looks like it’s galactic science will mostly be mapping out where clouds of ice crystals are in the Milky Way. SPHEREx has very low spatial resolution (about 6 arcsec), so it’s certainly not observing any exoplanets, but that’s the trade off with an all-sky mission like this.

    One of the big drivers of the extragalactic science, though, is looking for signatures of cosmic inflation in the distribution of galaxies on large scales. IMO this is by far the most interesting science case, and will be genuinely exciting and novel. Its survey design doesn’t give it great resolution, but it’s amazing IR spectrophometry will let it map the rough distribution of galaxies at redshifts we haven’t been able to survey before. This is called intensity mapping

  • tiborsaas 2 hours ago

    I can't really get what you meant by "dystopian future" in this context. In my understanding that is a human caused concept.

  • eleveriven an hour ago

    As for water detection, I'd imagine SPHEREx will be better suited for large-scale mapping rather than pinpointing water on specific planets

dylan604 13 hours ago

"The SPHEREx mission <snip> will map the entire sky four times over two years, offering scientists a chance to study how galaxies form and evolve, and providing a window into how the universe came to be."

So each object will be scanned ~6 months from the previous scan. How much evolving within the universe will be noticeable within that 2 year run? My gut response is not much, but that's why we do the science to see the changes.

"designed to map the celestial sky in 102 infrared colors "

So I'm guessing the coolant used to make IR scanning possible will be the limiting factor on operational time span. This article didn't say where this satellite will be parked either, but wikipedia[0] shows it to be a geosync orbit. Would have been interesting to be able to design a replaceable coolant module to extend the observations to really make seeing the evolution possible. Obviously complexity adds to cost and design time, so of course they didn't. Just dreaming

As an example, the study of the stars orbiting around SagA* are very revealing, but have required > 10 years of observations.

[0] https://en.wikipedia.org/wiki/SPHEREx

  • niwtsol 13 hours ago

    To answer three of your questions:

    - It is passively cooled rather than using an expendable coolant- "SPHEREx relies on an entirely passive cooling system — no electricity or coolants are used, simplifying the spacecraft’s design and operational needs."

    - It is a Medium-Class Explorers (MIDEX) mission - Investigations characterized by definition, development, mission operations, and data analysis costs not to exceed $180 to $200 million total cost to NASA. I think the cost of ground support eats into the budget length. The original estimate for project was $241M, so it was a large MIDEX

    - It is in a Polar orbit around Earth at the day-night (terminator) line

    https://www.jpl.nasa.gov/press-kits/spherex/

    https://explorers.gsfc.nasa.gov/missions.html

    https://spaceflightnow.com/2019/02/14/nasa-selects-mission-t...

    • pklausler 7 hours ago

      Possibly stupid question: how does this polar orbit stay over the terminator? And how is the terminator defined for a polar orbit here, since both the north and south poles are on the terminator only at the equinoxes?

      • sbierwagen 6 hours ago

        >how does this polar orbit stay over the terminator?

        Because it's launched at a angle greater than a straight north-south 90 degree orbit, so orbital precession will correctly follow the terminator. Depending on the orbital altitude this can be more than 140 degrees: https://en.wikipedia.org/wiki/Sun-synchronous_orbit

    • dylan604 13 hours ago

      ah, I misread the Orbital Parameters on the wiki. that day-night orbit is also a LEO which makes it even more possible to do a manned mission for upgrades. Oh, wait, we no longer have a shuttle for those types of missions.

      • mturmon 6 hours ago

        Remember, it is passively cooled (a major design plus and, I assume, part of why it was able to achieve the cost it did). So there would be no need for a manned mission. And in fact, at that cost, it wouldn’t make sense anyway.

      • nine_k 10 hours ago

        Even a Dragon could bring enough hardware and a crew for a small upgrade or repair (to say nothing of the upcoming Starship).

        • ericcumbee 9 hours ago

          Dragon lacks a Remote Manipulator System (Robot Arm) and a airlock. things that make servicing objects in space a lot easier. Im sure somewhere at NASA or SpaceX there is rough set of specs on what a shuttle like starship would look like complete with payload bay, robot arm, and eva airlock.

          • IncreasePosts 8 hours ago

            The complete specs of the arm may now belong to a hostile nation.

            • dylan604 7 hours ago

              If you're alluding to Russia, they've had them. They even failed in making their version of a shuttle. With what money would they do anything with now?

              If you're alluding to China, they probably had the data from the Russians anyways.

              Otherwise, I'm out of guesses to your vagueness.

              • sillywalk 6 hours ago

                > They even failed in making their version of a shuttle.

                Nitpick: It was sort of successful. They built a shuttle, and it successfully flew a single (un-crewed) mission of a couple orbits. The collapse of the USSR / lack of funding killed it.

            • Frederation 7 hours ago

              A nation pushing back against the morons in Washington.

              Hardly hostile. Unless you poke the bear.

            • vkou 7 hours ago

              It's amazing how all it takes is a few threats of annexation, and for GOP thought-leaders like Ben Shapiro to start talking about enslaving you[1] to work on the Panama Canal to make another country rethink its relationship with you.

              Absolute animals. As is anyone else carrying water for these politics. There's no excuse for it.

              If you had anything at all to do with putting these clowns in power - reign them back in. They are supposed to work for you. Remind them of this.

              [1] https://x.com/benshapiro/status/1876800394900152483?lang=en

              • nine_k 4 hours ago

                Sorry, "rein them in". Reign is about royal power; rein is about controlling a horse. And we definitely don't want any monarchs here.

  • mturmon 5 hours ago

    A nearby (excellent) comment (https://news.ycombinator.com/item?id=43338459) gives further context, but: the 6-month revisit period is just an artifact of the Earth-orbit-based sky scanning strategy. In 6 months the satellite, precessing at 1 degree/day, and facing away from the sun during data collection, will scan the sky completely. (See Fig 1 of the paper [0]).

    So in particular, the 6-month period is not to revisit these distant galaxies more than once to observe spectral changes. The strategy, indeed, is to “stack” the multiple exposures to beat down noise. (Fig.6 of [0], top left).

    It is possible that they have designed the system so that it could produce “just good enough” results in 6 months, with one complete scan. This is called a “threshold mission” and it would only be described in the full proposal.

    I looked through the rest of the science cases (which are secondary to the driving case of this mission), and none of them seem to be reliant on revisits. (But open to correction on this.)

    [0] https://arxiv.org/pdf/1412.4872

  • pixl97 12 hours ago

    >How much evolving within the universe will be noticeable within that 2 year run?

    Anton Petrov had a recent episode about rapid transformations in large supergiant stars, so there are some parts of space that can rapidly evolve.

    https://www.youtube.com/watch?v=gHvV9ewPY7s

  • perihelions 13 hours ago

    They're talking about galaxy evolution in the early universe, over timescales of millions of years. Statistics measured across the (large) sample group, not within one galaxy. Scroll down to "It will classify galaxies according to redshift accuracy..."

    • nashashmi 12 hours ago

      Right, at that scale, For a galaxy to move a fraction of a centimeter will take a thousand years. So not much will be missed in a gap of 6 months.

      • queuebert 7 hours ago

        This is nonsensical. Do you mean a tiny movement in the field of view, which should be measured in angular distance?

        Or do you mean actual motion through the universe, in which case the galaxies are moving at hundreds of kms per second, which means they would move billions of kms in 6 mos.

  • Sanzig 13 hours ago

    Why would coolant be a consumable? These things are usually cooled with Stirling cryocoolers which are closed systems.

    • perihelions 13 hours ago

      I did a quick search and it seems there is neither?

      - "SPHEREx relies on an entirely passive cooling system — no electricity or coolants are used during normal operations"

      https://www.jpl.nasa.gov/news/6-things-to-know-about-spherex...

      edit to add:

      - "The telescope is passively cooled to below 80 K in low-Earth orbit by three nested V-groove radiators. An additional radiator cools the long wavelength focal plane temperature below 60 K to reduce detector dark current."

      https://arxiv.org/abs/2404.11017v1

      • dylan604 13 hours ago

        The Spitzer used passive cooling, but only as a method to reduce the amount of coolant required. It still needed a coolant.

        "One of the most important advances of this redesign was an Earth-trailing orbit.[1] Cryogenic satellites that require liquid helium (LHe, T ≈ 4 K) temperatures in near-Earth orbit are typically exposed to a large heat load from Earth, and consequently require large amounts of LHe coolant, which then tends to dominate the total payload mass and limits mission life. Placing the satellite in solar orbit far from Earth allowed innovative passive cooling. The sun shield protected the rest of the spacecraft from the Sun's heat, the far side of the spacecraft was painted black to enhance passive radiation of heat, and the spacecraft bus was thermally isolated from the telescope. All of these design choices combined to drastically reduce the total mass of helium needed, resulting in an overall smaller and lighter payload, resulting in major cost savings, but with a mirror the same diameter as originally designed. This orbit also simplified telescope pointing, but did require the NASA Deep Space Network for communications"[0]

        [0]https://en.wikipedia.org/wiki/Spitzer_Space_Telescope

    • jessriedel 13 hours ago

      As another comment mentions, SPHEREx is passively cooled. But fwiw, plenty of infrared space telescopes use consumable coolant:

      > Notable infrared missions that carried consumable cryogen include IRAS (1983), ISO (1995–1998), Spitzer (2003–2009 in cryo mode), Herschel (2009–2013), WISE (2009–2011 in cryo mode), and Planck (2009–2013). Each relied on a finite liquid helium (or solid hydrogen) supply to keep detectors cold and reverted to a warmer operating mode or ended once their coolant was depleted.

      • perihelions 13 hours ago

        Notably those were all far-infrared telescopes, which need even lower temperatures (liquid helium) to escape thermal noise.

    • dylan604 13 hours ago

      Every system I'm familiar with that used liquid nitrogen to cool the IR instruments has had a operational lifespan based on the coolant. JWST is one such. "The coolant will slowly vaporize, limiting the lifetime of the instrument from as short as a few months to a few years at most."[0]

      [0]https://en.wikipedia.org/wiki/James_Webb_Space_Telescope

      • perihelions 13 hours ago

        You've misread your source article—what you've quoted is not a description of Webb.

        • dylan604 12 hours ago

          Does that really change anything?

          • kadoban 10 hours ago

            Well, it doesn't apply to either JWST or the subject of the article, so kind of feels like it's worth mentioning.

            It doesn't change your specific, exact point (about previous cooling systems you were aware of), but it makes the conversation a lot less likely to confuse people IMO.

  • computerex 8 hours ago

    Thank you for awesome information!

dj_gitmo 11 hours ago

Do these missions ever build back-up hardware? What if the probe is lost because of a lunch mishap, or there is a malfunction during the deploy (see Viasat VS3 antenna deploy failure).

It is an added cost, but it cannot be that much compared to the overall R&D/tooling/launch/ect cost.

  • mandevil 10 hours ago

    Into the 1970's, NASA did that. That was why there was Viking 1 and 2, Voyager 1 and 2, Pioneer 10 and 11, etc. Since then, however, NASA has stopped doing that. It became a balancing act- yes, 0 to 1 is much more expensive than 1 to 2, (1 to n is not quite as cheap as it is with software but it's still much cheaper than 0->1), but NASA Science is in the business of answering questions. The question is, will building, launching, and operating (the expensive part) two Parker Solar Probe's and two Juno's answer more questions than building one Parker Solar Probe, one Juno, and one OSIRIS-Rex? Almost certainly the three different probes answers more questions than two copies of two different probes. So once launch vehicle reliability got to be good enough that the fear of total mission failure went down low enough (1), duplicate missions basically went away.

    1: Edited to add: this is actually tied into the Space Shuttle in interesting ways. See T.A. Heppenheimer, _The Space Shuttle Decision_ for why the STS became the sole space launch system for all of the US Government. Of course if it's manned it's reliability has to be so high that you don't have to worry about loss of payload, so building two copies of it was no longer necessary.

    • dj_gitmo 10 hours ago

      Great answer.

      > Of course if it's manned it's reliability has to be so high that you don't have to worry about loss of payload, so building two copies of it was no longer necessary.

      I wasn't expecting a space shuttle tie in, but of course there would be. They sure had to promise a lot to get that thing off the ground.

  • kelnos 11 hours ago

    > What if the probe is lost because of a lunch mishap

    Well, hopefully the people who are building the probe aren't eating their lunches on top of it.

    (Yes, I know. Fun typo nonetheless.)

metalman 8 hours ago

450M is somewhere between .1% and 0 % of the total number of galaxies in the observable universe, so I am laying claim to 50, galaxies, which is hopefully a full set of galaxie types, but with a little haggling and trading, buying and selling galaxies I can figure that out later. My Mom says as a child she sent away and got title to one sqare inch of the moon, but it was a much smaller universe then, especialy before inflation.

  • eleveriven an hour ago

    Imagine the value after cosmic inflation kicks in

shmageggy 14 hours ago

This is so cool, but I did not see a key piece of info in the article: does the ongoing operation of this mission fall under NASA's science budget and therefore at risk of cuts and defunding under Trump [1]?

[1] https://arstechnica.com/space/2025/03/white-house-may-seek-t...

  • eleveriven an hour ago

    That's a good question. Given how frequently NASA's science budget gets caught in political crosswinds, it's definitely a concern

  • connicpu 12 hours ago

    This one is planned to launch on Falcon so I wouldn't be too surprised if it's one project the administration spares.

    • kelnos 11 hours ago

      Sure, the launch will go through, but SpaceX doesn't see any recurring revenue from later operations, and I wouldn't put it past the current administration to cut NASA's budget such that continuing operations are affected.

    • indoordin0saur 11 hours ago

      Everything launches on a Falcon these days. No one else can catch up in terms of safety cost or speed.

      • gibolt 10 hours ago

        SpaceX is going to pass whatever company is launching Falcon in short order, leaving them in the dust

        • niwtsol 9 hours ago

          The Falcon 9 is a SpaceX rocket

  • ddon 13 hours ago

    Yep, it looks like it will be cut and closed, which is truly unfortunate. It’s disappointing to see that science nor innovation are not a priority for this administration. And this doge cutting of funding or even shutting down important projects will have long-term consequences, impacting research, education, and technological advancements that benefit everyone.

    • bpodgursky 12 hours ago

      This is a proposal (not final) budget to be sent to congress. What congress eventually allocates is what matters.

      • jeffgreco 11 hours ago

        Not according to the current presidential administration. Impoundment is their stated goal.

  • ImJamal 12 hours ago

    Trump created the Space Force so he will presumably want some amount of funding for rockets and what not. If Space Force fails it would make him look bad after all.

    • andsoitis 11 hours ago

      Notwithstanding what you said, it is worth noting that the US Space Force has been a long time in the making: https://en.wikipedia.org/wiki/United_States_Space_Force

      • ImJamal 10 hours ago

        Trump is the one who actually decided to go through with the creation of a distinct branch rather than having it as a command. I think it is fair to say he created it.

        There are all sorts of politicians and military members who advocate for a distinct Cyber branch of the military instead of Cyber Command. If a politician ends up doing that, then he should get credit for creating it even though it has been a long time coming.

        • mmooss 8 hours ago

          > distinct Cyber branch of the military instead of Cyber Command

          It's not 'instead', it's adding a cyber branch to a different org chart. There are two major org charts in the US military:

          The services, such as Army, Navy, Space Force, etc., which are generally defined by domain (land, sea, orbit) and whose role is to recruit, organize, train, and equip forces - to prepare them, but not to deploy or command them in operations.

          The combatant commands, which are defined by geography - such as Africa Command, Indo-Pacific Command - and sometimes by geography-independent domains, such as as Space Command or Cyber Command. The combatant commands deploy the resources provided by the services in various combinations. Modern conflicts generally require resources from multiple services/domains working jointly.

          It makes some sense - you want domain experts to train and equip them for their domain, then you must necessarily deploy them jointly. Who should organize, train, and equip sea-born forces? Probably you want the Navy to do that, not the Army. Who should organize, train, and equip electronic domain forces (I hate the term 'cyber')? Do you want your IT organization organized, trained, and equipped (think of the importance of each step) by the US Marine Corps, or maybe by some actual researchers, engineers, and experienced managers?

    • kelnos 11 hours ago

      That really has nothing to do with whether or not operations for this project will be funded over the next several years.

FirmwareBurner 14 hours ago

> four suitcase-sized satellites

Americans will use anything else but the metric system :)

  • malfist 13 hours ago

    Wait, is this carry on sized or checked size?

    Is it delta's size limits, or are we following united or American Airlines? Or heaven forbid, alligent?

  • schainks 13 hours ago

    Hey! I know exactly how many Stanley cups fit in four suitcases, you don't have to tell me twice.

    </s>

xyst 12 hours ago

[flagged]

  • fernandopj 11 hours ago

    Unfounded, IMHO:

    Musk is obviously a factor in space exploration.

    Trump founded the https://en.wikipedia.org/wiki/United_States_Space_Force

    Also, as soon as China starts to put people on the Moon before Artemis can, I doubt POTUS would let that slide...

    • dakr 10 hours ago

      Trump 1 mostly targeted climate and Earth science (when it came to NASA funding). Trump 2/Musk is going after everything. They've just shut down the Office of the Chief Scientist at NASA and are planning to cut fully half of the remaining science budget.

    • Me1000 11 hours ago

      This administration under through Elon is pushing to cut 50% of NASA's science funding. Mapping galaxies we'll never visit is a purely scientific endeavor. Trump seems to care more about military expansion or for lack of a better term more "masculine" expansion of space. The science stuff is not interesting to him, and I'm honestly not sure I think Musk cares about it that much anymore either.

    • kelnos 11 hours ago

      I don't think it's unfounded. This mission is purely about science, in the pursuit of understanding our universe, and is unlikely to lead to any military applications (and even if it might, I doubt Trump et al. would have the foresight to see it).

      From the Musk perspective, he wants to go to Mars. Anything that doesn't contribute to that goal could easily go on the chopping block.

      Regarding China and the moon, this particular science experiment has nothing to do with that.

spwa4 14 hours ago

[flagged]

  • dylan604 14 hours ago

    Rule #1 of government spending is why build one when you can build two at twice the price

    • divan 13 hours ago

      Great movie

alfiedotwtf 10 hours ago

To be honest, I was expecting Elon and DOGE to have completely gutted NASA by now, while at the same time allocating more contracts to SpaceX.

  • dakr 10 hours ago

    They're working on it. NASA HQ has already cut their "Office of the Chief Scientist" (among others) and the current proposal is to cut 50% of the science budget (which would effectively kill it, it's already been squeezed).

  • dylan604 10 hours ago

    I'd imagine he's currently more focused on FAA to get them off his back about Starship issues.

    Awarding new contracts doesn't require gutting NASA first, so he can get to it later once the FAA has bent the knee

  • d--b 9 hours ago

    This is a SpaceX contract

    • apawloski 5 hours ago

      The launch vehicle is SpaceX, but the science and mission operations are NASA/JPL.