The USS Pennsylvania: What A Manned Interplanetary Mission Might Look Like

[The Jedi Master]

The USS Pennsylvania is the US Navy's largest submarine. It carries nuclear missiles, and patrols the Pacific ocean as a deterrent to a nuclear attack. It also carries 155 crew (15 officers, 140 enlisted). Ignoring the fact that a submarine doesn't really work like a spaceship, it can provide a window into how living on one might feel.

First up: the psychology. The crew must be able to handle living underwater with 154 other people for months at a time. As such, they have to be psychologically conditioned. This is basic knowledge for many of you, of course, but it shows that the way that, say, Mars One is recruiting isn't going to cut it. They will need to go through a military-like training program to be properly conditioned. They need to know how to follow orders. This may seem a bit harsh, but if we tried a Mars One type recruitment program for the Pennsylvania, things would fall apart fairly quickly.

Of course, a mission probably isn't going to have as many people as the Pennsylvania, so that helps somewhat. But the large crew brings up another thing: supplies. Now, of course, the submarine gets it's air from the water, so we'll ignore oxygen. Food is a bigger concern for the purposes of this post. Anyone who's been in the military or even has remotely studied life in the military will tell you that food is provided through Meals Ready To Eat, or MREs. These things don't taste very good, generally, but they are small, compact and light. Now, if we combine this with the food designed for space we already have, we get a food supply perfect for long distance interplanetary travel.

There are many other things that make long distance space travel problematic which the Pennsylvania solves. And any Mars capsule is going to be a fair bit lighter than the sub, even taking into account oxygen and materials. So, I ask you: do you think we should take the example of the Pennsylvania? Or is there a fatal flaw to this plan? I'm curious to see the answers!

[SuperWeegee4000]

I certainly agree. Certainly, our first manned interplanetary mission won't have 155 people aboard; most likely six at the most (the capacity of the Orion capsule). It is likely that Martian astronauts could remain mentally stable over months at a time, though you must take into account the thought of just how alone you and your two to five colleagues are out in the cosmos, away from anything they can call home.

Mars One worries me because it proposes a permanent settlement - the people chosen, if the mission proceeds, will remain on Mars for the rest of their lives, which - and this may just be me here - doesn't sound particularly appealing. Keep in mind that nothing has ever returned from Mars, so that's another technological innovation NASA can add to its growing list. And really, anything beyond Mars seems too far away.

[Motokid600]

Absolutely submarines are a great analogue for life in a spacecraft, but SuperWeegee is right. Space travel and exploration is amazing, but at the same time its the most terrifying thing I can think of. My worst fear is open water. So I cant possibly imagine the thought of being stuck in a tin can so far away from Earth that it can barely be distinguished from the stars in the background. I don't think Mars One will have to live on Mars indefinably, but atleast the length of the trip to get out there. Although I admit im having a hard time imagining a Martian ascent vehicle. Don't think the LEM would cut it:sticktongue:

[Savage117]

@The Jedi Master,

I think you are missing a key psychological factor here that would effect the crew of a Mars bound spacecraft but not the crew of a submarine. The inability to surface. Now I know subs can stay underwater almost indefinitely, but they can surface at any time they wish, barring war time maneuvers or equipment malfunction, and this is a very big psychological boon to the crew, they know they can surface any time they want.

A crew aboard a spacecraft can never "Surface" they will be in an extremely hostile environment in a vehicle that trades vessel integrity and stability for less mass, its practically a metal balloon. Add on to that, any piece of galactic debris moving at a sufficient speed could be the equivalent of a cannon ball hitting your metal balloon, and you might feel better standing in the middle of a live firing range at an army base than in a spaceship for a year or more. Not to mention if something goes wrong on the spacecraft, there will be no rescue. At least with a sub there is a chance the crew can be salvaged should something horrible go wrong with the sub and they cant surface.

So I say sub life is probably a cake walk compared to that, except during war time, im betting then its pretty much the same or worse because you are so much closer to home. Im just kinda being the Devils Advocate here, I agree with you, a sub is probably the closest we will get to a real manned interplanetary flight and how its crew should be trained.

[Nibb31]

A submarine is also always less than a week or two from a friendly base at all times. It can be reached by support ship or aircraft at any time. They can surface, bail out, and be rescued if necessary. There are also physiological factors, like the lack of microgravity and the quality of food (you can afford a proper galley and larger shorter-life food supplies on a submarine, whereas space crew will have to eat zero-g rations with a long shelf-life). And as already stated, the psychological pressure between a crew of 150 and a crew of 6 is totally different.

No, there really isn't much in common between a submarine and a spacecraft.

[Motokid600]

Well if were going farther then Mars the craft would be assembled in orbit so weight wouldn't be an issue id think. And the craft would be large like a sub and fairly spacious. The crew quarters would no dout be a centrifuge for artificial gravity. And why not good meals? A plate of roast beef, green beans and mashed potatoes be a good morale boost. That's the thing with sending humans into space. Until we find a way to make a stasis module ( probably a must for anything beyong Mars ) we have to make fairly comfortable space craft. Either that or just find a way to get them out there quicker.

[Moon Goddess]

Anyone who's been in the military or even has remotely studied life in the military will tell you that food is provided through Meals Ready To Eat, or MREs.

Crew aboard a submarine (or in general most of military life) don't actually eat MREs most of the time. A sub has a galley, and cooks, it has supplies and prepares meals same as if you were at a army or navy base.

If a space mission were to 4-10 people I'd expect they'd eat things similar to what they eat on ISS right now. (which has vastly improved from the apollo days)

Now if we were going send a space mission with 155 people, I am CERTAIN that there would be provisions, and a cook and some form of zero g galley.

[Dkmdlb]

Although I admit im having a hard time imagining a Martian ascent vehicle. Don't think the LEM would cut it:sticktongue:

I just looked up on the ol' Wikipedia. The LEM had about 4,600 m/s delta v, and to get to LMO requires about 4,400 m/s. Of course, the LEM ascent stage only had about 2,200 m/s, and had a lower TWR than is required to achieve Martian orbit, but still - a Mars ascent stage might not be that much larger than the LEM.

Edited August 19, 2013 by Dkmdlb
spelling

[TheSaint]

Ex-submariner here. No, the Navy does not serve sailors MREs (although it has been discussed to reduce crew requirements). but MREs would be a great model to base space food on. They have a shelf life of at least seven years if stored properly, and if you strip it down to the bare essentials (just the food, no spoon, heaters, TP, etc.) you can bring the weight down to about 1.5 pounds per meal. And they're not that bad, they taste about like a microwaved TV dinner. Although after a couple months I'd probably be craving a salad.

As for psychological conditioning, the only thing they have for submariners is that it is an all-volunteer force. They can't make you serve on a sub. That seems to weed out most of the head cases, although you still get some guys who think they can take it but decide later that they can't. They just get psych evals and wind up elsewhere. Or they end up cracking and taking a swing at someone (which I saw happen only once in four years on the boat). Then they get knocked down a rank, lose a lot of money, and wind up elsewhere.

I think that the most important thing they could do for astronauts on long-term missions is to keep them busy. On the boat we always had something that needed doing. Watchstanding, operating the plant, training, emergency drills, paperwork, doing minor maintenance underway, planning major maintenance when we got in port, etc. When I had free time I either read in my bunk or watched a movie. I'm sure today I'd bring a laptop along and be playing video games all day. But keeping busy helped keep your mind off of where you actually were.

I also think that an important morale booster for long-term missions would be to keep their mind on the goal. Living in a Winnebago and eating nothing but MREs for six months for no reason at all would be unbearable. But if that Winnebago was on its way to Mars, that would be a whole other ballgame.

[LaydeeDem]

I certainly agree. Certainly, our first manned interplanetary mission won't have 155 people aboard; most likely six at the most (the capacity of the Orion capsule). It is likely that Martian astronauts could remain mentally stable over months at a time, though you must take into account the thought of just how alone you and your two to five colleagues are out in the cosmos, away from anything they can call home.

Mars One worries me because it proposes a permanent settlement - the people chosen, if the mission proceeds, will remain on Mars for the rest of their lives, which - and this may just be me here - doesn't sound particularly appealing. Keep in mind that nothing has ever returned from Mars, so that's another technological innovation NASA can add to its growing list. And really, anything beyond Mars seems too far away.

Well good thing Mars One is a complete BS scam.

But back on topic, life one a submarine is actually very similar to an interplanetary voyage. IIRC; Nasa actually trains their astronauts in an underwater base.

[Nibb31]

But back on topic, life one a submarine is actually very similar to an interplanetary voyage. IIRC; Nasa actually trains their astronauts in an underwater base.

Yes, they train them in a dedicated underwater astronaut training facility, not on a nuclear sub. Totally different environments.

[Jackissimus]

Ex-submariner here.

I love this forum.