What kind of military spacecraft can we create with current technology?

[peadar1987]

I did think that. If they were able to put massive objects from the Kuiper Belt into an earth insertion orbit, surely the best thing to have done (especially for their second wave) would have just been to slam 10 or so big impactors into earth, which would cripple our industrial capacity at the very least, then move in and mop up the survivors.

[SemiaCloud]

What about the PKA spaceplane?

[YNM]

Why ? They're interstellar, which means comes at least on escape velocity. Also, if they can reach us to battle/annihilate/colonize instead of just a probe's lucky dash (we do that - Voyagers), probably their propulsion systems are greeat, and making chaos to hevenly orbits shouldn't be a problem. Nudge Sedna into the right orbit and you get a moon - sized object slamming to Earth. At near escape velocity (of Sun).

[hawkinator]

What if the aliens' mission is to make us all slaves?

[KSK]

This sounds very Footfall to me.

To answer OP's question, probably an Orion powered ship loaded up with all manner of nuclear nasties. Whether we'd ever get a chance to deploy it before it gets clobbered with a rods-from-god kinetic weapon, is another question.

[Darnok]

What if the aliens' mission is to make us all slaves?

I would say they are late

[YNM]

What if the aliens' mission is to make us all slaves?

Why would you need slaves when you can create robots ?

[Kibble]

Why would you need slaves when you can create robots ?

Once I conjectured an invasion by intelligent extraterrestrial aliens who were like those extreme deep sea fish with huge gaping mouths that hang motionless waiting for prey - not a good body plan for making anything! (They co-evolved to symbiosis with another, somewhat more physically-able fish, which is how they had any civilization at all.) But then they find humans, and our magnificently dexterous appendages! The obvious choice is to move their entire civilization to Earth with an invasion to assert dominance, and have us humans build giant bathysphere habitats for them.

[Alias72]

full of tons and tons of chlorine....

I still think carpet nuking Earth is our best defense plan. What would be a good name for it though?

[Bill Phil]

full of tons and tons of chlorine....

I still think carpet nuking Earth is our best defense plan. What would be a good name for it though?

Scorched Earth?

[Pixel of Life]

Nuclear surface-to-orbit cannon.

1) Dig a hole.

2) Fill hole with nuclear explosives.

3) Seal hole with steel or any other strong material. This will be the projectile.

4) Detonate explosives.

5) ???

6) Profit!

[Darnok]

Why would you need slaves when you can create robots ?

Because robots costs and you have to care about them, while slaves don't cost and you always can get more for free, just wait 9 months.

[Tex_NL]

Nuclear surface-to-orbit cannon.

1) Dig a hole.

2) Fill hole with nuclear explosives.

3) Seal hole with steel or any other strong material. This will be the projectile.

4) Detonate explosives.

5) ???

6) Profit!

Almost.

1) Dig a deep hole.

2) Fill the hole with water.

3) Drop in a single nuke.

4) Cap the hole with a heavy steel plate.

5) Detonate the nuke.

6) The water will absorb all radiation and turn to steam, blasting the multi tonne steel plate to orbit. Also known as a thunder well.

Propulsion of steel plate cap

---

During the Pascal-B nuclear test, a 900-kilogram (2,000 lb) steel plate cap (a piece of armor plate) was blasted off the top of a test shaft at a speed of more than 66 kilometres per second (41 mi/s). Before the test, experimental designer Dr. Brownlee had estimated that the nuclear explosion, combined with the specific design of the shaft, would accelerate the plate to approximately six times escape velocity. The plate was never found, but Dr. Brownlee believes that the plate never left the atmosphere, as it may even have been vaporized by compression heating of the atmosphere due to its high speed. The calculated velocity was sufficiently interesting that the crew trained a high-speed camera on the plate, which unfortunately only appeared in one frame, but this nevertheless gave a very high lower bound for the speed. After the event, Dr. Robert R. Brownlee described the best estimate of the cover's speed from the photographic evidence as "going like a bat out of hell!" The use of a subterranean shaft and nuclear device to propel an object to escape velocity has since been termed a "thunder well".

This incident was reputedly used as part of the technical justification for the Orion project for possible use of nuclear blasts for outer-space propulsion.

http://en.wikipedia.org/wiki/Operation_Plumbbob

[Pixel of Life]

*snip*

Yes, that's exactly what I was thinking of.

[YNM]

Once I conjectured an invasion by intelligent extraterrestrial aliens who were like those extreme deep sea fish with huge gaping mouths that hang motionless waiting for prey - not a good body plan for making anything! (They co-evolved to symbiosis with another, somewhat more physically-able fish, which is how they had any civilization at all.) But then they find humans, and our magnificently dexterous appendages! The obvious choice is to move their entire civilization to Earth with an invasion to assert dominance, and have us humans build giant bathysphere habitats for them.

If their bodyplan suppress designing, how in the heck they get here first ? Also, co-evolving means coming in together as well (else, no work for coming here I guess). Now you get two alien forms.

Because robots costs and you have to care about them, while slaves don't cost and you always can get more for free, just wait 9 months.

Except than humans are ******* friggin good revolters. You just need to stop working, then you'll better be dead. And if you want to mention mind control, may as well we are totally defenseless against them.

Hence why, if any were to occur, may as well we all be ignorant.

Edited June 5, 2015 by YNM

[J.Random]

Let's see. We're a mumbo-jumbo clan living on a single small island in a vast ocean. Suddenly, there's an aircraft carrier on a horizon. What are we going to do? What can we do? We can throw spears at it, I guess. But there won't even be a conflict. The only reasonable thing we could do is to shout very loud so that they don't accidentally step on us while passing by.

[Jmm85]

I think a lot of comments missed the point of the original question. He placed a very specific if unrealistic senario, with intent to get info on what the most out there space battle weapons and tactics could be employed without having to come up with any new fundamental technologies.  

Yes,  given need to and worldwide support we could in short period launch some bigger items.   Cost is what limits payload most at this point of world comes together with a real goal could overcome that, to a large extent.   US military budget already dwarfs NASA's.  The space shuttle is scrape now, the airforce takes deliveries directly into airfcraft grave yards.  Also it started they set up an invasion head quartets on the moon, this implies they want the world intact.   No information on if inhabitants are an issuse or consern.  Just pointing out this out because senario implies that global destruction was never goal. 

To address the topic.  If a hostile mom base was constructed, best feasible course of action would be loads up every launch vehicle capable of high earth orbit with biggest h bomb they could carry and launch in waves towards moon.   Hope some get thru. 

 

[Nibb31]

1 hour ago, Jmm85 said:

To address the topic.  If a hostile mom base was constructed, best feasible course of action would be loads up every launch vehicle capable of high earth orbit with biggest h bomb they could carry and launch in waves towards moon.   Hope some get thru.

Besides the fact that it would take months to prepare those rockets, it would take 3 days after launch for your nukes to reach the Moon. Any hostile "aliens" that have interstellar travel would probably have a good laugh and swat them out of existence.

There is no such thing as space warfare, because any technology that allows you to bend the laws of physics enough to make interstellar travel practical will also have corollary technologies that enable insta-kill of just about any threat.

[Bill Phil]

43 minutes ago, Nibb31 said:

Besides the fact that it would take months to prepare those rockets, it would take 3 days after launch for your nukes to reach the Moon. Any hostile "aliens" that have interstellar travel would probably have a good laugh and swat them out of existence.

There is no such thing as space warfare, because any technology that allows you to bend the laws of physics enough to make interstellar travel practical will also have corollary technologies that enable insta-kill of just about any threat.

New Horizons passed the Moon's orbit in a matter of hours. 

[Jmm85]

While i agree that it is not a realistic senario,  realistically there is no response possible.   

The context of what are discussing matters though.  Most hypotheticals can be broken by looking at only through practicality.   

[RainDreamer]

Well, this topic has been dead for a while, but I guess I should change the scenario again so it makes more (actually less) sense:

Imagine the USA becoming a rogue nation under the control of  a crazy president (I won't say who or how the Americans decide to follow that person) who aims to conquer the world. The same crazy president decide to militarize space.

What kind of crazy military spacecraft will the poor scientists working there will come up with?

Edited September 16, 2016 by RainDreamer

[Kryten]

Define 'militarise space'.

[Mitchz95]

A constellation of laser satellites that can fry airborne nukes would probably be the most likely.

[Jmm85]

I would guess, the most likey powerful without inventing any new tech would be either laser arrays, or rods of good concept tungsten kneck energy bombs.  Armed, updated x-33 drone would be interesting, have it go into rest mode basically as a satellite wake it up with massively higher speed,  have to look at how large a piece of tungsten would need to be to survive re-entry but something along lines of space based punt gun with hyper velocity could wreak serious havoc. 

[DDE]

OP, have you ever considered Children of a Dead Earth? It fits your mandate for "proven technology only".

However, trying to control LEO will be incredibly annoying. I'm pretty sure Russia has a bunch of Naryad ASATs in some old warehouse, and China, well, who knows. Overall, thanks to ground clutter and the complexity of putting anything massive into orbit, it's very easy to counter any attempts to set up a hostile presence in space.