senthil_rajasek 3 hours ago

Also,the mission to rescue the Swift telescope made news this week.

Soon I'll be seeing a sign for a "Joe's Satellite Repair Service" shop right next to the local autobody shop.

https://www.mos.org/article/space-news-deep-dive-saving-swif...

khurs 5 hours ago

Good spot by whoever noticed it!

ck2 3 hours ago

Can we swap the US Military and NASA budgets for just one year please?

Just one year

It would be AMAZING

Or even what we fund Israel's 2/3 of all their weapons are bought by US

We'd have 10% speed of light probes going outside of solar system already

Well at least Nancy Grace Roman L2 Telescope is launching, hope it goes perfectly

  • avmich 3 hours ago

    Can we really accelerate any probe to faster than 1% c? Or 2% c?

    • r2_pilot 3 hours ago

      Yes, with lasers or nuclear energy

    • patagurbon 3 hours ago

      We have the physics but not the engineering. See the Breakthrough Starshot project for instance

    • tclancy 3 hours ago

      Per new Space Force regulations, we are using F for an adjusted speed of light. We are currently able to achieve 1.48F.

    • kimixa 3 hours ago

      No, not even close. The issue is simply exhaust velocity and reaction mass, that leads us into the tyranny of the rocket equation - in that you have to carry that reaction mass with you and accelerate that mass too. Even if you had magic infinite energy - e.g. it's supplied externally by a laser or similar.

      Using the theorized maximum of 31km/s exhaust velocity of project orion (much higher than any current high impulse propulsion technologies) you'd need to have thrown out something similar to 10^42 times the probe's mass out the back at that 31km/s velocity.

      That means to accelerate a 1kg probe to 1%c you'd need to start with a spacecraft holding a reaction mass equivalent to a few trillion suns worth of mass.

      Hardly seems worth it.

      It's all about exhaust velocity - increase that and it scales down quickly. Using the theoretical max of 500km/s of VASIMIR for example means it's only 400x the mass of the probe of reaction mass - but that's still theory and max thrust limits means it'll take the order of millions of years to reach that sort of speed.

      • zer00eyz 3 hours ago

        > No, not even close.

        10% of C is theoretically possible with a space sail, and lasers.

        Will it work? Well we don't know cause we haven't tried.

        • kimixa 3 hours ago

          Space sails are super low thrust though, even lower than my VASIMIR example - so will take even longer to reach the desired speed - though they have the advantage of not having to carry the complex and heavy engine I ignored that in the rough estimates anyway.

          So by the time they're theoretically close to the desired speed they'll be on the other side of the galaxy at least, even if it took millions of years to get there at the much slower average speed.

          • tatjam 2 hours ago

            You can't use a solar sail for this, but if you use lasers, you can get a few newtons / GW of incident laser power. Sci-fi stuff but if you can make a very very light reflector that can somehow be cooled (microscopic IR dipoles come to mind), and a very very focused and powerful laser, you can go a long way. Not sure what the purpose of moving a thin metalized foil at a fraction of lightspeed would be, though :)

            • kimixa 2 hours ago

              Yeah, many of the theoretical solar sail ideas fall down on what I consider a useful "probe" is, and what it can mass. As mentioned in my other comment, if you define the "probe" to be "a single particle" we /already/ do this all the time in particle accelerators. But it's clearly not a useful "probe" I believe the original thought experiment implied. A few hundred grams of super thin solar sail material is still very much in the "Not A Probe" definition in my mind.

              Plus even the best laser dispersion quickly gets significant at the distances required to give the sail the time to accelerate at such a low thrust.

      • blauditore 2 hours ago

        And why not accelerate using swing-bys on moons and planets? Of course this gets harder the faster you're already moving, but IIUC Voyager 1 has roughly 0.01% c, and this was launched 50 years ago.

        • kimixa 2 hours ago

          It might help a bit, as you mentioned that Voyager is currently going about ~17km/s, so nearly 0.005% c, so it's already nearly 1/200th of the way there to our target of 1% c.

          But then you're at a velocity so far beyond the escape velocity of most bodies you'd need to be skirting stars, then black holes to get anything more, and that's where it dives straight into "sci-fi" rather than anything even close to theoretically possible. How far away even if a body like that? Will this "probe" even survive such an encounter?

          So even with that sort of slingshot it's well within the "Estimate Rough Error" of my intial numbers. They're "order of magnitude back-of-the-envelope calculations" of spherical spaceships in an already unrealistically biased to make the numbers smaller vacuum (just reaction mass, no thought of any mass of the engine or spacecraft body itself, or containing the reaction mass itself, or anything like that).

          I probably should have stated my assumptions - in that "Can we accelerate a probe" I assumed that:

          - The "probe" is a significant size - if we define a "probe" as a "Single Ion" then we already do that at CERN and similar pretty regularly - 1kg was my assumption of "Useful Probe Mass"

          - "We" - in that "humans" as we know them today, preferably in the realisic age of civilizations as we know them, or even better within the lifetime of a currently living human.

          Also there's different levels of "theoretical". VASIMIR has only ever been shown in lab settings, so still "theoretical" as a propulsion technology. something like Project Orion is "theoretical" in that it's never been built, but likely just an engineering effort. IKAROS showed solar sails are "possible", but so many orders of magnitude away from what would be required it'll still be a significant engineering and development effort to even show the same idea at the required scale is possible. Things like lasers as remote energy sources haven't really got off the drawing board. And then at the extreme we have "theoretical" ideas like fusion rockets, which are more "Not show to be /impossible/" rather than anything we could even start at really building today.

          And each step along that "further out into theory" path means more risks, and more changes that method is shown to be less useful than really desired.

        • dh2022 39 minutes ago

          Is there a short snd simple explanation for how these planetary slingshots work? To me the gravity that increases the vehicle speed on the way to the planet will decrease the speed on the way away. Thanks!

    • ck2 2 hours ago

      I think the idea is tic-tac sized probes with nano circuitry (that doesn't exist yet)

      accelerated by lasers so they don't have to carry the power source

      Obviously stopping is the problem, they can never stop but at some point no need

      • IAmBroom 1 hour ago

        Before someone mentions IBM's (completely BS) "sub-nanometer circuitry": it isn't nearly sub-nm, except if you look at it from one particular way. The real estate is still many nanometers in dimension. The gates aren't even sub-nano; gate-to-gate interactions are, kind of.

  • cg5280 3 hours ago

    In 2024, the average American spent about $17,000 on taxes. Nearly $4000 of that went to the DoD, about $3500 went to interest on federal debt.

    I think it’s fun to think about it in this way. I personally spend hundreds of dollars a month on war.

    • germinalphrase 3 hours ago

      You have a source to share for that framing of the tax spend?

      • blobcode 3 hours ago

        Although not quite exact, here's spending data for 2024 (https://fiscaldata.treasury.gov/static-data/published-report...) - about 14% of tax dollars went to defence, 0.14*17000=2380.

        • rayiner 2 hours ago

          That’s just federal spending. $17,000 sounds too high to just be federal taxes, it looks like federal + state/local. Accounting for that, military spending is closer to 10%.

    • ck2 3 hours ago

      Defense spending in the USA is double what is publicly published

      There are all kinds of dark budgets and stuff spun off into "civilian" programs that actually aren't

      The published cost of Iran War is like $30 Billion when it is obviously over $100 Billion by experts and that doesn't including replacing all the missiles

      TWENTY-ONE TRILLION DOLLARS since 9/11 spent on defense 2001-2021

      * https://ips-dc.org/report-state-of-insecurity-cost-militariz...

      imagine how much food clothing shelter for the US and WORLD that would buy

      we'd have humans on Mars already with that budget not even knowing now how to stop space-blindness and bone-loss

      • kccqzy 3 hours ago

        > imagine how much food clothing shelter for the US and WORLD that would buy

        President LBJ proposed his Great Society agenda, which he defined as “a society where no child will go unfed, and no youngster will go unschooled.” It was a war on poverty, touching food, shelter, and education. At that same time, the country also increased its defense spending due to the heightened tension in the Cold War and escalation in the Vietnam War. The country could really do both.

        • mrguyorama 2 hours ago

          It's like when people comment "This is why the US doesn't have healthcare" around military or war boasting.

          No, the US absolutely can afford to have a gigantic military and massive welfare. That's what being the richest country on earth means

          But for some reason we spent the past 50 years insisting that we are better off just letting a few individuals direct that wealth instead of making some choices collectively and democratically.

          People might come to their senses when the second gilded age once again leaves a third of us unemployed and parents dying in ditches.

      • laughing_man 2 hours ago

        >Defense spending in the USA is double what is publicly published

        Show your work.

        >There are all kinds of dark budgets and stuff spun off into "civilian" programs that actually aren't

        How much, though, as a percentage of the federal budget? Also, DoD does a lot of stuff that doesn't involved national defense, like breast cancer research or canal and levee maintenance.

        >The published cost of Iran War is like $30 Billion when it is obviously over $100 Billion by experts and that doesn't including replacing all the missiles

        Those missiles will be replaced in future defense budgets.

    • tshaddox 3 hours ago

      Those numbers look way off. Are you making the common mistake of ignoring mandatory spending? In 2024 defense spending and net interest were each about 13% of federal spending.

    • jocaal 2 hours ago

      Funny how people complain about federal debt, when the people complaining benefitted the most from the system. It is your children who will be paying the interest, while the older folk enjoyed a heated economy with high government spending. Economics is just as fundemental as physics. There are conservation laws that cannot be violated. However you can make other people hold the bag.

      • PaulDavisThe1st 2 hours ago

        > There are conservation laws that cannot be violated.

        Modern Monetary Theory on line 2 for you!

        There is no possible sense in which "economics is just as fundamental as physics": the latter concerns the behavior of the physical world with or without humans in it; the former describes the dynamics of a human created system featuring humans interacting with each other and the physical world.

      • wat10000 1 hour ago

        What are those conservation laws?

        • jocaal 39 minutes ago

          It's simple accounting. Net money in must be more than or equal to net money out when adjusting for any temporal changes in the face value of the assets. If you use more than you produce, either you are going to have to pay in the future, or in the case of the government, you can die and let your children pay.

          • wat10000 1 minute ago

            There's no law of conservation of money. It can be pretty trivially created and destroyed. It may not be a good idea, but it's entirely doable.

      • marcosdumay 1 hour ago

        Monetary identities can not be violated¹. What you are talking about isn't one of them.

        1 - They are also useless by themselves, any rule that actually tells you something will have exceptions.

    • rayiner 2 hours ago

      Total government spending in 2024 (at all levels) was about $9.5 trillion. So the military spending of about $950 billion was 10% of that, or $1,700. Interest on federal debt was also about 10%.

      It’s worth also looking at what other countries spend on defense. Now that the U.S. is cutting off NATO, France plans to raise military spending to 2.5% of GDP by 2030. Applying that same figure to the U.S. would bring us down to $700 billion in 2024. So you’d pay $1,250 if the U.S. military budget was similar to what France thinks is a good number.

      Germany is currently at 2.3% and plans to hit 3.5% by 2029. That’s the same percent as the U.S.

    • luckylion 2 hours ago

      > I personally spend hundreds of dollars a month on war.

      Or, put another way, you spend hundreds of dollars a month on not having to learn russian and live as putin's peasant.

      Seems like a good deal to me.

      • wat10000 1 hour ago

        The oceans exist for free.

    • BurningFrog 1 hour ago

      You spend that money on defense, not war!

    • victorbjorklund 1 hour ago

      Doesn’t sound like those numbers are correct? I doubt out of the total taxes (all taxes, on all levels) 44% went to only pay federal debt (excluding state, city etc debt) and DoD.

  • WarmWash 3 hours ago

    The military budget is a jobs program that also keeps a (near bare minimum) level of industrial capacity afloat.

    Its why no politician left or right is really interested in cutting it. If you browse open contracts, you'll see they that they overwhelmingly buy rather banal things and spend comparatively little on the "killing people" parts.

    • malfist 3 hours ago

      What do you think NASA is? NASA is so expensive because it's a jobs program. There's no other reason for Boeing to have factories in so many states for building satellites.

      • pc86 3 hours ago

        OK so maybe they're both jobs programs, but .mil is bigger and employs more people (almost certainly at a lower per capita cost).

        • Retric 2 hours ago

          > OK so maybe they're both jobs programs, but .mil is bigger and employs more people

          Which is a direct function of its budget not a function of what it does.

          > (almost certainly at a lower per capita cost).

          DoD is extremely expensive per job due to the longe term benefits, layers of bureaucracy, and sub contractors.

      • WarmWash 3 hours ago

        You're not wrong, and no one is turning down NASA contracts, but the scale isn't comparable.

        NASA buys mostly highly specialized parts that can be pretty narrow in scope and utility.

        OTOH the DoD will buy 150,000 aluminum water canteens, which is probably the only thing keeping the one decent job in Wagatah, Maine from closing. Which happens to be of only a handful of shops in the country with the tooling for this. Wagatah, of course, is not known for it's aerospace engineering. But thankfully water is pretty important for soldiers, and the new design is x% more efficient, so Wagatah gets another 5 years of work, the DoD gets to keep a domestic source of water canteens, and if NASA needs 5 space grade aluminum storage boxes, a company in Wagatah can make them.

    • tclancy 3 hours ago

      Great. Can we change it to just be the non killing part for a few years until the bad project ideas fully die off?

      • alberto467 3 hours ago

        No it would obviously lose its purpose then.

        • adrianN 2 hours ago

          You could have a jobs program that builds infrastructure instead.

      • Schiendelman 1 hour ago

        If anything, we've been letting the killing parts languish dangerously for decades - to the point where we may not be able to defend our allies in a serious conflict.

        • dh2022 58 minutes ago

          As proven so well during this whole debacle in the Hormuz strait.

          • brookst 42 minutes ago

            Hard to see that as an indictment of military capability when it is so overwhelmingly a reflection of political incompetence.

        • exe34 41 minutes ago

          Good thing you don't have that many allies left, so it should make the job easier.

    • manoDev 2 hours ago

      The military budget is how the US enforces Bretton Woods. The jobs part is just a nice side-effect of any govt. spending.

      • laughing_man 2 hours ago

        Bretton Woods was formally terminated in 1973.

    • rcarr 35 minutes ago

      Here's a Ken Livingstone quote from the foreword of "Drama Games: For Those Who Like To Say No":

      > In the early 1980s, when the GLC (Greater London Council) was trying to save and create jobs to mitigate the impact of Thatcher's recession, we discovered that the most labour-intensive form of public spending was the arts, and so during the five years from 1981 to 1986 we increased spending on arts and recreation from £l6 million to £160 million. Virtually every actor, painter, poet, sculptor and, in particular, community artist was in work, and it made London a much more exciting city to live in. As well as taking orchestras from the Royal Festival Hall to play in the canteen at Ford's Assembly Plant in Dagenham, we particularly tried to reach disaffected youth. It's against that background that I was able to understand Chris Johnston's book. (Oh, and by the way, if you want to know which is the least labour-intensive form of public spending, it is the military.)

      Maybe if we stopped pushing insane amounts of money into fossil fuels and the military industrial complex, and instead redirected it into the arts and sciences then, just maybe, we might actually end up with a happier, more employed, more fulfilled, and more equal planet.

  • mschuster91 3 hours ago

    > Or even what we fund Israel's 2/3 of all their weapons are bought by US

    And all of the money the US gives to Israel is earmarked for American products.

    • amanaplanacanal 2 hours ago

      Just more American tax dollars going to American defense contractors.

  • chris_money202 3 hours ago

    Or hear me out, we improve life here on Earth...

  • throw48842975 3 hours ago

    The US gives Israel $3.8B a year (and 2/3 of their weapons are _sold_ by the US not bought). The budget of Nasa is $25B.

    But by antisemite math and logic says we’ll get 10% light speed.

    • amanaplanacanal 3 hours ago

      Being against military aid to Israel isn't necessarily antisemitic.

    • ck2 3 hours ago

      anti-israel-warmongering != antisemite but nice try

      US has given Israel over $20 Billion directly since 2023 alone

      Since 2023 NINETY THOUSAND TONS OF WEAPONS

      Enough already

      Israel has universal health care, let them buy build their own weaspons

      US must only sell Iron-Dome ONLY, defense only, they are warmongers

  • zer00eyz 3 hours ago

    > Can we swap the US Military and NASA budgets for just one year please?

    It would be nice.

    There is a pretty well known interview of Admiral Grace Hopper by David Letterman, where she talks about her famous "nanosecond" and explaining (to Generals) why it takes so long to get a message to a satellite. https://www.youtube.com/watch?v=oE2uls6iIEU (As an aside, Grace was a name she lived up to in a way few others could, if you have never seen that interview it is well worth a watch!)

    The valuable and well understood lesson is that latency is tyrannical, and unavoidable. The only real customer for "data centers in space" is spacex for war fighting. You don't want that data, and it's analysis going back around the world. You don't want to put compute close to the front lines, and you certainly cant deploy it for the kinds of "special operations" that the US has been doing for the last two decades.

    Is there a civilian use? Maybe. Ships, oil platforms, and remote locations could all see a use for this, but it isnt going to be that impactful.

    Realistically, getting military spend back to more "dual use" applications would be great. We have a LONG history of this in the USA. Tons of Army core of engineers projects. The interstate highway system was born out of a need for better logistics. NASA was about missiles, space was incidental. The US computing industry's foundations fell out of the navy code breaking efforts of WWII. The internet (ARPANET) was a DARPA project to start with. Spread Spectrum and its roots in Torpedos (navy again). GPS, the auto injector (epi pens).

    Most of these are far in the past, recently the biggest thing we have gotten out military investments is TOR (and one could argue its in decline).

    I think we don't see as much coming out of the modern military because it is grossly mismanaged. It's become reliant on private industry to "innovate" and that has a relentless focus on the bottom line.

    Yes it would be nice if we did that spending swap, but it will never happen realistically. I think a change of leadership, of intent could result in far less waste and much more benefit for the American public. We have proof we can, we just need to figure out how and make it happen.

    • lstodd 2 hours ago

      Durum-burum latency. In fact, internets slowed down compared to 2010s, and CDNs helped only to delay that.

      LEO orbit latency is nothing compared to what you lose to stuffing your link with useless web crap.

  • rendx 1 hour ago

    Can we swap the US Military and child care budgets for just one year please?

    Just one year

    It would be AMAZING