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A US military exercise to launch a satellite on short notice

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Re: A US military exercise to launch a satellite on short notice

#41

Post by laughing_man »

manoDev wrote: post #35
WarmWash wrote: post #10

Earlier quoted context omitted.

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.

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

Bretton Woods was formally terminated in 1973.

Re: A US military exercise to launch a satellite on short notice

#42

Post by kimixa »

blauditore wrote: post #33
kimixa wrote: post #23

Earlier quoted context omitted.

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 impu…

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.

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.

Re: A US military exercise to launch a satellite on short notice

#43

Post by AyyEye »

senthil_rajasek wrote: post #26

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...

Joe and Buzz Aerospace Supply

https://www.youtube.com/watch?v=KB-ZCmvFIXo "accents"

https://www.youtube.com/watch?v=keKDA7523_c "Nerdneck"

Re: A US military exercise to launch a satellite on short notice

#44

Post by laughing_man »

ck2 wrote: post #18
cg5280 wrote: post #8

Earlier quoted context omitted.

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.

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…

>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.

Re: A US military exercise to launch a satellite on short notice

#45

Post by throw48842975 »

amanaplanacanal wrote: post #27
throw48842975 wrote: post #21

Earlier quoted context omitted.

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.

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

[dead]

Re: A US military exercise to launch a satellite on short notice

#46

Post by tatjam »

kimixa wrote: post #31
zer00eyz wrote: post #28

Earlier quoted context omitted.

> 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.

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 t…

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 :)

Re: A US military exercise to launch a satellite on short notice

#47

Post by PaulDavisThe1st »

jocaal wrote: post #34
cg5280 wrote: post #8

Earlier quoted context omitted.

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.

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.

> 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.

Re: A US military exercise to launch a satellite on short notice

#48

Post by kimixa »

tatjam wrote: post #46
kimixa wrote: post #31

Earlier quoted context omitted.

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 t…

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 :)

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.

Re: A US military exercise to launch a satellite on short notice

#49

Post by mrguyorama »

kccqzy wrote: post #25
ck2 wrote: post #18

Earlier quoted context omitted.

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…

> 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…

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.

Re: A US military exercise to launch a satellite on short notice

#50

Post by rayiner »

cg5280 wrote: post #8
ck2 wrote: post #4

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

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.

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.

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