Boundary - semi realistic shooter in space

Looks like a shinier version of Shattered Horizon (https://en.m.wikipedia.org/wiki/Shattered_Horizon), which was an ace game that sadly died a death ten years ago - only available from key resellers these days but the bots are still fun to go against.

This also resembles some of the zero-G sections from Call of Duty Infinite Warfare, which I was surprised never made it to the multiplayer game.
 
Could be that recoil has to be countered by the player using the suit thrusters, in fact that could be interesting mechanic.
 

Viajero

Volunteer Moderator
Could be that recoil has to be countered by the player using the suit thrusters, in fact that could be interesting mechanic.
Yeah I had the same idea when watching the vid, most likely suit smart thrusters countering the recoil.
 
Wondering how can one make recoil-less projectile weapons that can actually have an impact - pun intended
Most of the weapons have recoil, but that would presumably be compensated for by thrusters. This would not be difficult as even the recoil from a .50 BMG is tiny in comparison to a 90kg person wearing 200+kg of gear and the heavier weapons seem to have recoil buffers.

Other weapons I saw (namely the one at 50 seconds) looked like they worked on the same principle of an RPG or recoiless rifle...most of the recoil is absorbed by a countermass, not the weapon itself, or what it's mounted to.

Fun fact - the higher the projectile velocity, the lower the momentum for a given energy. Maybe they are handheld railguns?
It's near future, mostly with weapons that already exist today. I see what looks like a carbine version of a Barret M82 and a modified AK-103 in the first minute.

Overall, I was very impressed with the gameplay footage shown, and I would not be at all surprised if there were rea scenarios playing out in 50 years for control of space-based assets or resources that looked a lot like this.
 
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the recoil from a .50 BMG is tiny in comparison to a 90kg person wearing 200+kg of gear and the heavier weapons seem to have recoil buffers.
I would not call the recoil form a .50 tiny. The dude in the linked video is shoulder firing a .50. And he's visibly shaken
Now imagine doing that while hanging out in Zero-G with no support points. No thrusters will be able to instantaneously counter that recoil.

It would be something like this but with more tumbling and cursing and laughing. A Benny Hill Show in space.
 
I would not call the recoil form a .50 tiny. The dude in the linked video is shoulder firing a .50. And he's visibly shaken
Now imagine doing that while hanging out in Zero-G with no support points. No thrusters will be able to instantaneously counter that recoil.
Nothing about zero-G changes the forces involved and a recoil momentum that would accelerate a person to few hundredths of a meter per second, if that, could easily compensated for. We aren't talking about eliminating the kick of the recoil, as clearly there is recoil in this game (the animations around the 1:17 mark look quite convincing to me), but nullifying the momentum transfer with respect to movement would be trivially easy.

Recoil from most portable firearms sending people flying is comic book stuff. Relative to a 300kg object (person, in a bulky space suit, covered in armor, with a large EMU thruster pack on) even the free recoil of something like an M82 (or the BFG-50A in your video) firing a .50 BMG (about 50 ft.lbs, which is less than a 12-gauge magnum slug fired from most shotguns, which I have experienced) is tiny.

The apparent M82 derived carbine in the video is most likely a smaller caliber (don't need the superior terminal ballistics of a .50 BMG in a vacuum or close quarters), possibly weighted (weapon mass is a huge factor in recoil), and definitely equipped with a muzzle break...but even if it was the lightest .50 BMG firearm that was practical to build and had no recoil mitigating features at all, it's not going to be tossing around a person, let alone one in that suit.

Again, upper limit of recoil (barring those weapons that are recoiless designs) for most anything depicted in the gameplay video is going to be ~50ft.lbs/~70 joules. At modest rates of fire, even the NASA MMU developed in the 1970s could match the degree of acceleration this would impart on a person wearing it. A combat version sixty years on should be able to provide a rock solid stable firing platform for any weapon that would be mounted to it, or that could be carried by the individual piloting it.

It would be something like this but with more tumbling and cursing and laughing. A Benny Hill Show in space.
This is a collection of people falling over mostly of their own accord, or barely braced weapons being accelerated to a few meters per second when discharged. You hold a weapon correctly an even ones known for punishing recoil are barely going to move you, even if you are completely unsupported. The amount of momentum we are talking about is simply not that huge.
 
Apparently russians fired a 14.5mm automatic gun in space. From a 20t space station (Almaz). And they had to use station thrusters to keep it into position.
Eventually they decided to abandon guns in space and go for missiles.

Now i would assume that a 20t station has some mean thrusters. More effective than one could fit on a 200 kilo Eva suit.
And the 14.5mm automatic gun is not sensibly bigger than a .50 BMG.

Edit: nice movie
 
Apparently russians fired a 14.5mm automatic gun in space. From a 20t space station (Almaz). And they had to use station thrusters to keep it into position.
Eventually they decided to abandon guns in space and go for missiles.

Now i would assume that a 20t station has some mean thrusters. More effective than one could fit on a 200 kilo Eva suit.
And the 14.5mm automatic gun is not sensibly bigger than a .50 BMG.

Edit: nice movie
Nothing credible I've ever heard about the Almaz autocannon test indicated that recoil spinning or moving the station was a serious issue; the math certainly doesn't back it up. The weapon being on a fixed mount and needing to move the entire spacecraft to aim could have been a concern, however.

Ultimately it's thrust vs. counterthrust. The amount of thrust produced by man portable weapons is quite low...the whole point of a firearm is to channel as much energy as possible into the projectile, while minimizing the momentum of the weapon itself. Even the largest fully-automatic man-portable weapons do not produce much thrust.

Motion sensors certainly exist (I have ten year old laptop harddrives, that cost 40 dollars when they were new, that have ones that would work) that could detect the moment a weapon was fired, and the impulse it applied, then react to apply counter force with reaction wheels and thrusters far faster than a human would perceive. Indeed, I'd expect the weapons themselves to be linked to the suit and the momentum compensation to begin as soon as the propellant was ignited, way before the operator's arm even started moving back, eliminating even that small latency.

We wouldn't be using nitrogen thrusters like the old MMU, we'd be using propellants with much higher thrust, both for greater mobility and for increased combat radius/duration. They'd have no issues accelerating the entire mass, against sustained recoil, quickly enough to risk harming the occupant, without any limiters in place. This stuff also already exists.

We also wouldn't be using thrusters at all for countering rotational forces (except as an emergency backup), because reaction-wheels (gyroscopes) could easily handle the forces involved and don't need to deplete valuable reaction mass to do so. Again, old tech.

The center of mass of the entire system would be very close to the point of recoil, namely the right shoulder (and the suits in the game's video look like this was already taken into account to at least some degree), when possible, to minimize the rotational forces on suit and save battery power that would otherwise be wasted on running the reaction-wheels harder than necessary.

Hell, give me enough money and I'll design a zero-g combat MMU that offers stability, while firing an automatic shotgun or semi-automatic .50 BMG anti-materiel rifle, that you wouldn't be able to distinguish from being strapped to a cement pillar with a seven-point harness. I'm sure the professionals could do much better. I'm equally sure anyone taking plausibility seriously in the design of a game like this has access to both much better talent than I and took good advantage of it in the conceptual stages of their product.
 
We wouldn't be using nitrogen thrusters like the old MMU, we'd be using propellants with much higher thrust, both for greater mobility and for increased combat radius/duration. They'd have no issues accelerating the entire mass, against sustained recoil, quickly enough to risk harming the occupant, without any limiters in place.
I don't know about that actually. If we're talking near future, so no dramatically new propulsion tech in play, cold gas thrusters are probably still the best option for a MMU. The only real alternative would be a hypergolic monopropellant system, but those leave nasty toxic residue that you wouldn't want to be tracking back into a space station. That said, modern gas thrusters certainly have adequate thrust for this scenario, although the available propellant might be a gating factor on how much ammunition you bring.
We also wouldn't be using thrusters at all for countering rotational forces (except as an emergency backup), because reaction-wheels (gyroscopes) could easily handle the forces involved and don't need to deplete valuable reaction mass to do so.
I doubt a combat MMU would bother with reaction wheels actually. In real space applications they are only used to provide tiny torques for stabilizing craft that experience very small forces or pointing things that need precision but not speed. Mainly because they are very heavy for the torque they produce. I do imagine training for space combat would encourage firing through your center of mass to minimize torque, but even so I think you'd wind up with a thrusters-only system.
 
I don't know about that actually. If we're talking near future, so no dramatically new propulsion tech in play, cold gas thrusters are probably still the best option for a MMU. The only real alternative would be a hypergolic monopropellant system, but those leave nasty toxic residue that you wouldn't want to be tracking back into a space station. That said, modern gas thrusters certainly have adequate thrust for this scenario, although the available propellant might be a gating factor on how much ammunition you bring.
"Green" monopropellants like AF-M315E, which has been in use for more than a decade, can have upwards four times the specific impulse of nitrogen gas and are significantly superior to even hydrazine in volumetric performance. Toxicity concerns, which these propellants strive to minimize, would also not be a priority for a combat-oriented MMU...giving your astronaut-soldiers a competitive edge against others would.

The issue is less one of raw thrust, though quick bursts of acceleration would certainly be beneficial in combat, and more one of endurance. the MMU cannot actively manuver for long, but you replace it's 40 pounds of pressurized nitrogen with 100+ pounds of a high-performance chemical monopropellant, and you can dramatically increase combat time/radius and have much larger peak thust when you need it.

I doubt a combat MMU would bother with reaction wheels actually. In real space applications they are only used to provide tiny torques for stabilizing craft that experience very small forces or pointing things that need precision but not speed. Mainly because they are very heavy for the torque they produce. I do imagine training for space combat would encourage firing through your center of mass to minimize torque, but even so I think you'd wind up with a thrusters-only system.
I'm also looking at maximizing fuel efficiency with the use of reaction wheels, but you may be right in the mass being counter productive. I'd think it would be advantageous for attitude keeping and absorbing the small rotational impulses of recoil, but perhaps I'm overestimating their performance/mass ratio. Maybe no reactionwheels and smaller batteries would let one carry more than enough extra fuel to overcome the increased thruster use.
 
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