Yeees... As does 'astroforce' - although that also sounds like a domestic cleaning product. :)

I think there are 3 good ways of naming futuristic military forces, each based on a different way of naming real-world forces.

 

1) You can go the Fascist route and just name them something scary/cool sounding, like Stormtroopers.

 

2) Figure out what real-world military force this futuristic force is evolved from and use the kinds of names that current branches use. For example, the US Army would probably call them something like Aerospace Infantry for boots, Aerospace Cavalry for mechanized forces of some sort, or Aerospace Artillery for fire support weapons. If the interplanetary/extraplanetary force was derived from the Navy the ground forces could be called a Marine Aerospace Expeditionary Force.

 

3) Don't describe them but alude to the government or organization that controls them. Since such government or organization is assumed to be inter-planetary/-stellar/-glactic/-whatever the force by extension becomes that characteristic without getting bogged down in names that sound like something from a cartoon. For example the name that was used in Aliens: Colonial Marines--not getting bogged down in spaceyness but instead identifying their relationship to the government they served, presumably the government encompassing Earth's collonies. Similarly a corporation which is known to have extraplanetary or interplanetary reach might have Asset Protection Team (defending material assets), a Real-estate Escalation Department (essentially a conventional paramilitary force), or a Resource Recovery Team (an HRT).

 

If you have to get into describing roles I'd suggest Aerospace for any force designed to operate in both orbital and atmospheric roles, especially since that is the term that seems to be already being used. For actual space troops, the question is tougher. Some good keywords could include Extravehicular for any force trained to operate outside a vehicle, Freefall or Microgravity could denote forces specially trained for combat in these environments.

How's this for a job description Microgravity Event Intervention Specialist?

Excellent suggestions Jeff_F_F.

 

I would add one distinction:

Actually the eventual fate of the Navy and the Marines is a good question. Most science fiction writers of the past envisioned the space force as a space-going Navy, hence the Marines (althought not literally *marine*) would be the landing force and shipboard combatants deployed aboard that space-going Navy. However the most likely route for the development of such a force in real life is as an extension of the Air Force, which will presumably eventually eclipse the Air Force entirely.

 

As such, it makes sense that the Army would go along for the ride to the stars. This kind of leaves the Marines in a lurch, and the seagoing Navy as well. The Marine Corps might be reconfigured as a spacegoing rapid deployment force. However since the Army of today already has air-mobile rapid deployment forces it seems inevitable that they would develop space-mobile rapid deployment forces as well. That basically just means two armies with essentially the same mission, and little real difference in capability, with the only real rationalle for keeping the Marine Corps being tradition. Of course, tradition might be sufficient cause to keep the Marines around, but it isn't a foregone conclusion.

 

On the other hand, there would almost certainly be need for naval actions to be fought, since any world worth fighting over--or colonizing in the first place--will no doubt be one with liquid water. The question is who will fight such actions? Will the space force transport Naval vessels to distant worlds? Or will the Army's already substantial fleet--more water craft than the Navy has!--expand its capabilities to include full-fledged naval action? Of course, if Navy vessels were transported to distant wars, the Marines would naturally go with them. And they would no boubt not restrict their activities to amphibious landings any more than they do in the real world.

Marines fight from ships.  Army travels on ships and fights principally from land (Normandy was an exception).  Therefore, if you have troops that board from ship to ship, or ship to station or deploy quickly from ships (think Aliens) they can legitimately be considered marines even if they do not develop in direct linage from the Marines.

 

Things that carry people between planets are ships, even if the service that develops them evolves from the Air Force.  (Tom Wolf's "The Right Stuff" described how the early atronauts chafed at going into space in 'capsules')  An Air Force derived Space Force could develop very navy-like characteristics because the Air Force has no history of people living on airplanes the way the Navy lives on ships.

In the Robotech/Macross anime series, for a time it was referred to as the "UN Spacy" (space force), sort of how we derived the word "navy" from the term "naval", or perhaps even "naval force". 

 

As to what do we call space-fairing infantry-type battle groups,

in the failed Star Trek Enterprise TV series, they had MACOs: Military Assault Command Operations, or just MACOs or commandos for short.

 

I'm sure we'll figure out something suitable, either a new catchy acronym, or maybe we'll invent a new word for it altogether.

Please, oh please oh please oh please tell me that by the time we are actually trying to name space troopers (and that's not a suggestion) that we have evolved beyond naming everything with an acronym.  Don't tell me the truth if we aren't.  Lie.

...in the fact that,

even if powered by nuclear reactors (the space "ships" would almost have to be, and hopefully fusion),

they'll have no more endurance than they can carry crew stores and other perishable supplies.

 

At least for the first few centuries until we get those replicator-like food makers such as Star Trek uses, ships aren't going to be able to carry a massive food-growing arena (?) that can allow the crew to subsist indefinitely on long duration missions (even though it should be expected that nutritionally-enhanced "space MREs" will be an obvious requirement on long missions, but just like today's personnel, don't expect them to subsist indefinitely, happily, on them).

Water and air reclamation will become much easier, but without access to food stuffs and other perishables, the space craft's duration would be no greater than many nuclear subs, needing to meet with replenishment craft every few months.

 

And besides, there will need to be considerable machine shop and parts fabrication facilities onboard the space craft: it won't be like just being able to surface, radio for assistance, or pull into the nearest port for repairs, which is only days, or at most, a few weeks away, and carrying so many just-in-case spares for the most likely components that could fail would end up needing too much additional bulk in the ship's design, just to carry adequate spare parts.

 

And until very fast travel speeds are achieveable (several 10's-100's km/sec, as Mach 10-20 just ain't gonna cut it),

as well as the obviously necessary decceleration (inertial dampers?) devices to rapidly slow down just as easily as they can accelerate,

space ships will have to be massive, at least as large as current CVNs, if only to be able to sustain crews for months on end with minimal,

if any,

resupply.

 

Low observable technologies and signature reduction will be a must, as such vessels won't be as maneuverable as Star Trek and Star Wars depict capital ships to be,

again,

at least not without inertial dampers, structural integrity field generators, particle & radiation shielding, and other cool techie stuff that looks & sounds so cool thanks to the special effects people, but,

let's face it,

is pretty much still light years away...at least so far as implementing them all into a workable design.

 

Perhaps by that time we'll have come up with the proper terminologies and colloquial jargon for space combat.

A space craft with endurance as long as its perishables? Like, a ship?