The thread for space cadets!

[warpus]

I agree that once humans start making a permanent appearance around the solar system, militaries will want to start making a show with their own manned missions. Until then, the prospects for human occupation are too dim and too distant for the military to spend much effort on it.

Oh come on, it's the U.S. government and military! They want to get ahead of the game and have well tested technology available to use that nobody else has, when the time comes. That means doing R&D right now.

You are probably right that they don't have any secret manned space stations, but I don't trust them to just sit around not figuring this stuff out, especially considering their budgets

 

[Thorgalaeg]

I have always wondered about how an interplanetary war would be in real world with real physics and technology. Ship-ship engagements at millions of kms of distance with ultra long range missiles, superslingshots launching asteroids to bomb planets, would lasers be used at all? Etc.

 

[hobbsyoyo]

Oh come on, it's the U.S. government and military! They want to get ahead of the game and have well tested technology available to use that nobody else has, when the time comes. That means doing R&D right now.

You are probably right that they don't have any secret manned space stations, but I don't trust them to just sit around not figuring this stuff out, especially considering their budgets

What is there to prepare for? Like I said, the prospect of manned interplanetary flights is so distant and improbable at this point that there's no reason to prepare to send out the Marines to do...stuff. It isn't even clear what they'd do since governments can't claim extraterrestrial territory. I guess all they could do is settle disputes or enforce property rights for corporations - and it's not even clear that corporations really can claim property either.

I have always wondered about how an interplanetary war would be in real world with real physics and technology. Ship-ship engagements at millions of kms of distance with ultra long range missiles, superslingshots launching asteroids to bomb planets, would lasers be used at all? Etc.

I think stealth missiles and asteroid bombings would be the way they'd go about space warfare. Probably lasers would be used too, as you can overcome reflective coatings by cranking up the intensity. I don't think ships would get close enough for traditional shells to be used but if they ever did get close then they would be quite useful.

 

[hobbsyoyo]

A US company launched four picosatellites without approval from the FCC. This company was trying out their new satellite platform that's about half the size of a 1U CubeSat (10x10x10 cm) and applied for a launch license with the FCC. The FCC said that below 1U in size, no one can really track the satellites reliably and asked them to mitigate this by adding radar reflectors and other changes. The company did make some modifications but went ahead with the launch (on an Indian vehicle) before they got final authorization to proceed. In retaliation, the FCC has denied their application for a follow-on launch and their will likely be more fallout.

What's really troubling is that the FCC has been playing nice with CubeSat operators up till now. The number of applications for launches they've received has skyrocketed with the advent of CubeSats and they're trying to figure out the best way forward for everyone just like the operators are. Unfortunately this development may make them take a more adversarial bent toward CubeSats which would be bad for everyone.

Moreover, American launches on Indian vehicles require a bureaucratic slight-of-hand to get around restrictions imposed on foreign launches. Basically, on paper, no one is supposed to launch on Indian vehicles but the government agencies like the FCC have been issuing waivers to let them go forward. This too may be changing going forward; it's hard to tell what the ultimate fallout will be but it could be very bad for the whole industry.


In other news, Congress passed a budget for NASA for the rest of the year that fully funds all of the missions (including climate science) that Trump tried to cut. Then they added something like an additional $2B that NASA didn't even ask for. So that's really good news!

 

[warpus]

What is there to prepare for? Like I said, the prospect of manned interplanetary flights is so distant and improbable at this point that there's no reason to prepare to send out the Marines to do...stuff. It isn't even clear what they'd do since governments can't claim extraterrestrial territory. I guess all they could do is settle disputes or enforce property rights for corporations - and it's not even clear that corporations really can claim property either.

Well.. it seems that we might have people flying to and from Mars on a regular basis in the next 10-20 years, and possibly the moon as well, and who knows where else.

I'm not sure what the U.S. government would want to be doing specifically with relation to that, but look at regular plane flight for instance. The U.S. military is always a step or two ahead of public companies, like airlines, in terms of the technology used. They're always working on some advanced airline technologies and rolling them out, like the stealth bomber all those years ago now. It seems that they're doing this because they know other powers are also developing their own technologies that will be more advanced than what public companies can offer, so they need to stay ahead of the game.

So it seems to me that if public companies start doing regular flights to Mars, the U.S. government and military will want to have at their disposal technologies more advanced than that, so that they have that projection of power, even if they do not need to (yet) use it. But for that to happen they need to be doing R&D right now. So I assume they are. Is it really possible that they're sitting back, not doing anything? That seems unlikely to me, but to be fair this is all guesswork

 

[Michkov]

I have always wondered about how an interplanetary war would be in real world with real physics and technology. Ship-ship engagements at millions of kms of distance with ultra long range missiles, superslingshots launching asteroids to bomb planets, would lasers be used at all? Etc.

If you want to read up on spacwearfare, there is Atomic Rockets Which goes into quite some detail.

There is also Children of a Dead Earth which supposedly lets you play out realistic space battles

 

[hobbsyoyo]

Well.. it seems that we might have people flying to and from Mars on a regular basis in the next 10-20 years, and possibly the moon as well, and who knows where else.

I'm not sure what the U.S. government would want to be doing specifically with relation to that, but look at regular plane flight for instance. The U.S. military is always a step or two ahead of public companies, like airlines, in terms of the technology used. They're always working on some advanced airline technologies and rolling them out, like the stealth bomber all those years ago now. It seems that they're doing this because they know other powers are also developing their own technologies that will be more advanced than what public companies can offer, so they need to stay ahead of the game.

So it seems to me that if public companies start doing regular flights to Mars, the U.S. government and military will want to have at their disposal technologies more advanced than that, so that they have that projection of power, even if they do not need to (yet) use it. But for that to happen they need to be doing R&D right now. So I assume they are. Is it really possible that they're sitting back, not doing anything? That seems unlikely to me, but to be fair this is all guesswork

The military does not have advanced airline technologies. The requirements are so wildly divergent between commercial and military aviation that there isn't a lot of cross-over. The most you can say is that the general advancements in military aviation sometimes spill over into the private sector but not really a whole lot. Advancements in military aviation really stopped being directly applicable to airlines and commercial aviation in the 60's-70's when jet engines became fully mature and wide body airliners started flying. Before that, bombers were directly applicable to commercial aviation but since then there's been very little they have in common any more.

NASA does a much, much better job of helping commercial aviation - they regularly fly test beds that contain prototype wings and engines and control systems that are meant to be commercialized. Stealth bombers have no utility as airliners, the most they might help with is navigation and control systems but those systems would be so classified they won't see the light of day until they're already obsolete by advancements in the private sector + X years.

And right now, the only way they could get out 'ahead' of the private sector when it comes to manned flights is to develop their own launchers (which they haven't done since the 60's) or their own capsules (which they have never really done). Preparing for manned force projection in outer space is not something the military is looking into right now because there is no reason to do so.

 

[uppi]

I think stealth missiles and asteroid bombings would be the way they'd go about space warfare. Probably lasers would be used too, as you can overcome reflective coatings by cranking up the intensity. I don't think ships would get close enough for traditional shells to be used but if they ever did get close then they would be quite useful.

Increasing the intensity is easier said than done. Lasers are not the most efficient devices and if you increase the power, you increase the waste heat that you have to transfer away. If you select armor in such a way that the laser damage is mostly thermal, a battle between an attacker with a laser and a defender would mostly come down to who has the better cooling system. This has the attacker at quite a disadvantage, because most lasers generate much more heat than light and the defender can reflect at least some of the light into space. I once failed to even put so much as a scratch to a material, despite using intensities exceeding 10 MW/cm^2. Meanwhile the air conditioning system of the lab had trouble keeping up. Lasers could still be used as precision weapon against vulnerable system, but trying to burn through armor that has been designed to withstand laser weapons is most likely going to fail.

I think the weapons would be most likely gravitational. You would lob small chunks of materials into orbits that would intersect the orbit of the defender at high speeds. It would not matter much if the defender could see them coming and dodge them, because he would need to spend fuel to do and would run out of fuel if you do it often enough. The battle would be about maneuvering into favorable orbits that would allow you to have many opportunities to shell your opponent without inviting return fire.

 

[warpus]

The military does not have advanced airline technologies.

Maybe I'm pointing to the wrong technologies? What about all those xth generation fighters and advanced stealth bombers, I thought there were a lot of technologies in use in these aircraft that other countries can't right now even duplicate.

 

[Broken_Erika]

Oh come on, it's the U.S. government and military! They want to get ahead of the game and have well tested technology available to use that nobody else has, when the time comes. That means doing R&D right now.

You are probably right that they don't have any secret manned space stations, but I don't trust them to just sit around not figuring this stuff out, especially considering their budgets

One day all that technology will be needed when the Moon Nazi's attack! Or to defend us from an invasion of the Libruul Commie-Nazi's from Uranus!

 

[warpus]

It's all about control and power projection for them. Maybe I'm talking out of my butt though

 

[Cutlass]

Maybe I'm pointing to the wrong technologies? What about all those xth generation fighters and advanced stealth bombers, I thought there were a lot of technologies in use in these aircraft that other countries can't right now even duplicate.

Sure there are. But many of those techs don't translate well to civilian use. That said, I think Hobbs overstated the extent to which they don't. Synthetic materials as parts of the airframe, body, and wings has led to lighter weight construction of planes such as the 787 Dreamliner. Electronic controls have taken over from analog. The basic layout of civilian airliners is the same, but has been refined, so as to need electronic controls, but to be more efficient in use. However, in some cases the civil aviation world is ahead of the military one. New high fuel efficient engines came out of civilian projects, not military ones. The military is playing catch-up on that. But since the civilian engines and the military engines are all made by the same companies, there's cross fertilization.

That said, you can't take the comparison too far. There's no need for stealth in civil aircraft. In fact it wouldn't be allowed. And there's no call for supersonic civil aircraft. While some people would want that, it's just not cost effective.

 

[Zkribbler]

I can't find the article now, but apparently a star came within 1 million miles of Earth 50,000 years ago. It passed through the Oort Cloud. Comets, etc. still show the evidence of its passing.

I wonder if any Neanderthals noticed.

Edit: Found it. Oops, 70,000 years ago.

http://earthsky.org/space/scholzs-star-disturbed-comets-in-prehistory

 

[red_elk]

A million miles?
Must be a mistake, I don't think anybody would survive that.

 

[Thorgalaeg]

Solar system wouldn't survive that.

It is more like half a light year, which is more in the trillion of miles ballpark.

 

[Zkribbler]

Solar system wouldn't survive that.

It is more like half a light year, which is more in the trillion of miles ballpark.

The first article I saw probably said 1 trillion, and I mis-remembered. This article says: "the team’s simulations suggest that Scholz´s star approached even more closely than the 0.6 light-years pointed out in the 2015 study as the lower limit."

 

[GinandTonic]

I think the weapons would be most likely gravitational. You would lob small chunks of materials into orbits that would intersect the orbit of the defender at high speeds. It would not matter much if the defender could see them coming and dodge them, because he would need to spend fuel to do and would run out of fuel if you do it often enough. The battle would be about maneuvering into favorable orbits that would allow you to have many opportunities to shell your opponent without inviting return fire.

Yeah. At the kind of speeds that space combat would happen conventional warheads are significantly less deadly that inert mass. As I see it the projectile of choice would either be the smallest possible somewhat self-guiding impactor or more likely a lead sphere the size of a bb pellet. A couple of pellets is more than enough to wreck a spaceship given the velocities involved. Just make a magnetic induction rail the length of the ship and flick thousands of pellets down range. As accurate as you try to be at the distances involved it's a shotgun. Where one pellet will wreck a missile and two or three will wreck a ship.

Given how easy it would be to take out a missile in this way, at a fraction of the mass and cost, I dont see warheads of any kind being viable. Given how lasers disperse over the distances involved I dont see how they would be viable. As I see it, space warfare would be about flicking tiny pellets at each other and forcing the other guy to expend propellant to get out of the way. Whoever runs out of propellant or pellets first looses.

In the age of sail ships would surrender without a shot being fired when they knew they had been out manoeuvred. If those battles were chess on water then chess in vacuum would be the same but more so.

 

[uppi]

Given how easy it would be to take out a missile in this way, at a fraction of the mass and cost, I dont see warheads of any kind being viable. Given how lasers disperse over the distances involved I dont see how they would be viable. As I see it, space warfare would be about flicking tiny pellets at each other and forcing the other guy to expend propellant to get out of the way. Whoever runs out of propellant or pellets first looses.

Against such pellets, lasers would be useful as point defenses to vaporize stray ones and to force the opponent to flick enough pellets to overwhelm these defenses.

 

[GinandTonic]

Yes, but the lasers wouldnt be effective until they were relatively close. Couple of kilometres to have the power to vaporise lead? So the lasers would have a fraction of a second, a second tops, to vaporise the incoming pellets. Computers would have a huge advantage of being able to track exactly which pellets needed to be taken out, but it still shouldnt take too many to overwhelm a laser point defence. Lasers need a lot of power. Generating enough power to make one work with capacitors is one thing, generating enough power to fire fifty or a hundred shots in a fraction of a second would require orders of magnitude more power. Or a ship basically built out of super-capacitors.

 

[Zkribbler]

You're assuming that you can even detect an enemy space ship.

Sure, you can find them in orbit, but the space between planets is gi-normous. Plot a non-straight-line course between planets, and no one will see you coming.