EMUs and flight on Luna

[Der Anfang]

So, as everyone knows, in KSP, you can turn on the RCS and fly around on The Mun or any other low gravity body. Hell, with some effort, you could even fly on Duna if you so desired (or Moho, in that case). But my question is this: Is the EMU on Kerbal spacesuits over powered? My best guess is that they probably are, but it's still a burning question that I can't seem to find an answer to, even with any search online. So, I figured I'd ask here. Is it possible for standard issue EMU/IVA/MMU (whatever) suits to be able to "jetpack" on our Moon and be able to actually fly around?

Edited August 13, 2016 by Der Anfang

[Bill Phil]

The IRL counterpart of the EMU in KSP is the MMU (Manned Maneuvering Unit). There's also another maneuvering unit for emergencies in use on the ISS called SAFER, and there was an old design in the 60s that they never got to really test. The MMU had a Delta-V of about 25m/s. The only missions with it were in 84. And considering it's small DeltaV, small mass ratio, and the mass of the astronaut, I'd say no.

However, a small rocket chair could be made to work. But it would basically be a lander in its own right.

[Kryten]

This Martin guide to the MMU gives the translational acceleration capability as 0.3 feet per second, which translates to about 0.01g, less than a tenth of what you'd need to hover on the moon. KSP jetpacks do thirty times that.

[DDE]

KSP jetpack has around 600 m/s of dV, too, which is stupendously more than the MMU. However... the MMU uses cold gas thrusters, which are simple, but pretty derpy; this is because its predecessors were tested inside Skylab.

On the other hand, Gemini 9 and 12 were supposed to test the USAF AMU, which used peroxide monoprop and had a dV of 76.2 m/s (and came with woven steel pants).

[K^2]

Real mobility units have nowhere near enough thrust, because they simply don't need it, but you can certainly build one if you wanted to. Real jet packs using hydrogen peroxide as monoprop can lift a person on Earth and have about 300m/s of delta-V. That's not dramatically worse than KSP equivalent. And if you are happy using more caustic monoprops, similar to these used by space ships, you can almost certainly match the thrust and delta-V of KSP counterpart.

[p1t1o]

Remember a Kerbal [probably?] masses a lot less than an Earth-human!

If you put a Kerbal in one of our hydrogen peroxide Earth-rocketpacks, they would find it *highly* kerbal I think.

[DDE]

1 hour ago, WildLynx said:

How to draw a line between small lander and large jetpack?

Uhm... legs? A rocket chair - quite a few designs of which were explored to a great degree - is not worn directly on the back.

[Bill Phil]

5 minutes ago, DDE said:

Uhm... legs? A rocket chair - quite a few designs of which were explored to a great degree - is not worn directly on the back.

People have legs, too.

[magnemoe]

41 minutes ago, Bill Phil said:

People have legs, too.

Yes but an rocket chair has dedicated landing legs, yes you could land on your own legs however this would send you tumbling if you has some horizontal speed then landing and the legs would not weight much. 
Some designs I saw had you stand on an small platform and probably strapped in. 
Benefit is that you have an platform who always keep bottom down making it far easier to control. 

Yes at some point gravity become so weak its better to use an more powerful jet pack, Gilly in KSP is an place there gravity will pull you in one direction over time, it also has something called ground you don't want to crash into, just the same as an space station however its easier to hit. 

 

[K^2]

2 hours ago, DDE said:

Uhm... legs? A rocket chair - quite a few designs of which were explored to a great degree - is not worn directly on the back.

Majority of rocket packs have legs to help support them while landed/docked. So I don't think it's a distinguishing characteristic of a rocket pack. I would call anything with pilot enclosure a lander, and anything without either a rocket pack or a rocket stand, depending on how the pilot is attached.

[kerbiloid]

17 hours ago, p1t1o said:

Remember a Kerbal [probably?] masses a lot less than an Earth-human!

Not so much less, btw.
An equipped Kerbal weights 95 kg.
VA TKS can return either 3 persons + 50 kg, or 500 kg. So, 1 person (with chair) ~150 kg.

Kerbals are small, but full of ...  surprises.

10 hours ago, WildLynx said:

How to draw a line between small lander and large jetpack?

Gemini lander

Edited August 16, 2016 by kerbiloid

[p1t1o]

3 hours ago, kerbiloid said:

Not so much less, btw.
An equipped Kerbal weights 95 kg.
VA TKS can return either 3 persons + 50 kg, or 500 kg. So, 1 person (with chair) ~150 kg.

Kerbals are small, but full of ...  surprises.

Wow, that is pretty dense...

I just googled, and a modern spacesuit, with associated life support pack, masses around 300pounds (!) and thats without an astronaut in it, so you can double that 150kg figure I think, for a fully equipped space-walk-complete astronaut, though I think that is without a maneuvering pack.

 

[kerbiloid]

28 minutes ago, p1t1o said:

I just googled, and a modern spacesuit, with associated life support pack, masses around 300pounds (!) and thats without an astronaut in it, so you can double that 150kg figure I think, for a fully equipped space-walk-complete astronaut, though I think that is without a maneuvering pack.

There're two kinds of spacesuits: a lightweight rescue suit (to wear it inside the ship during the launch/landing) and a heavy EVA suit. Kerbals wear something intermediate.
Also they have 5 kg of fuel (with density ~5000 kg/m3) in its backpack. With deltaV ~600 m/s which means ISP ~1100 s.

[magnemoe]

1 hour ago, kerbiloid said:

There're two kinds of spacesuits: a lightweight rescue suit (to wear it inside the ship during the launch/landing) and a heavy EVA suit. Kerbals wear something intermediate.
Also they have 5 kg of fuel (with density ~5000 kg/m3) in its backpack. With deltaV ~600 m/s which means ISP ~1100 s.

1100 s, that pretty impressive, in short even if we had to bring eva fuel it would make sense to have kerbals push as the only better engine is the ion

[kerbiloid]

17 minutes ago, magnemoe said:

in short even if we had to bring eva fuel it would make sense to have kerbals push as the only better engine is the ion

Kerbal Space galley. A Kerbal who had crashed too expensive ship, get a new class: Oarsman.

Found an old topic about MMUs. The fuel amount depends on which mod and density we use.
If use a mod setting Monopropellant as EVA fuel, then 5 kg.
With stock (density is 4 kg/l) - 20 kg. Then ISP is ~300, but the fuel has density of titanium .

[magnemoe]

19 minutes ago, kerbiloid said:

Kerbal Space galley. A Kerbal who had crashed too expensive ship, get a new class: Oarsman.

Found an old topic about MMUs. The fuel amount depends on which mod and density we use.
If use a mod setting Monopropellant as EVA fuel, then 5 kg.
With stock (density is 4 kg/l) - 20 kg. Then ISP is ~300, but the fuel has density of titanium .

Kerbal weight does not go down as he use eva fuel, an throwback to the massless parts. 
It was some plan to have the eva pack use monopropelant who has to be refueled this is why the pod contains it. 
It was dropped, might be issues with conserving it. Kerbal leaves MK1 landing can who have 10 monoprop, he takes 5, he enter an landing can who hold 0 monoprop, then he exit he is out of it. less critical but still an issue Kerbal leaves pod one with 10 monoprop and move to landing can who also holds 10, pod will be left with 5 and landing can with 10, this was before crew transfer so it would be pretty easy to get critical low.