No, not really. Seriously my concerns are, pressure integrity,canvas diving suit keeping air in, would the suits air pumps work properly, that sort of thing.
It’s for my next Call of Cthulhu game, my turn to GM. I’d like to make things seem as most non space-suity as possible for when they… Actually i always write myself a brief elevator pitch at the start of any game notes to focus my thoughts. It’ll make things clearer if i quote it.
* Britain, the summer of 1954 the party have been brought together for an job, an eclectic bunch united a the mysterious goverment agency because conventional methods have failed. Official secrets acts are signed, but very little details are provided.
After a brief period of unusual training, they are sent through a Gate recently unearthed in the depths of a Welsh coal mine. On the other side they find themselves in a mysterious and seemingly abandoned outpost upon the surface of Mars.
They must strive to find out the secrets of the place as first it’s ancient builders defences awaken, then the builders themselves are summoned back. To complicate matters there is yet one more secret the party will discover. The gate transferred them across 15 years of time as well as 50 million miles of space, they’re now back in 1939. A scientist already present lost everyone he loved during the war and he sees a second chance. He’s going to contact Earth and change the past, no matter what it does to the future and however many he has to kill to achieve his goal in the present."*
…so I need something non space-suity as possible so as not to give the game away until they step through the gate for maximum impact.
And yes i do have players who will argue the toss and nitpick about a diving suit being practical on Mars (Me for one if our other usual Gm was running this) , which is why i ask.
Not a chance - these diving suits were not sealed - they are essentially a small diving bell that accommodates the head of the diver, loosely mounted on top of a suit that provides physical protection for the body (only keeping the water out because the helmet is plopped on the top.
So more like Atmospheric diving suit - Wikipedia then which i assume if it can handle multiple atmospheres on the outside could handle near vaccum as well. Yes?
There’s no reason you couldn’t use something that looks like a diving suit, though. If none of your players’ characters are divers, say “It appears to be a diving suit”. If one of them is, say “It looks sort of like a diving suit, but with some modifications”, and if pressed on the nature of those modifications, “The fabric seems to be reinforced, and the seals are all much tighter-fitting”.
The problem with spacesuits is mobility. If you use something like a canvas diving suit, even with proper seals, the pressure inside the suit is going to blow it up like a balloon and make it very difficult to flex in any way.
There is air on Mars, so you shouldn’t need something as airtight as would be necessary on, say, the moon. The problem is that the pressure in general, as well as the partial pressure of oxygen, is just too low to walk around casually. Maybe having sufficient positive pressure in the helmet would be good enough. I seem to recall reading something about humans possibly being able to survive on the surface of Mars with just modern SCUBA gear.
One option could be to have the travelers come out of the gate into a pressurized base on Mars where they don’t instantly die. Then, maybe they find space suits there that have been conveniently left there by prior explorers, or maybe they can radio back through the gate and receive a shipment of real space suits.
From a game perspective, this is what I’d recommend.
In fact, since the OP wants a big reveal that they’re on Mars - I’d let them spend much of the first adventure exploring a strange alien temple. How could something like that be on Earth and no one has seen it yet? Let them get a sense of how alien the place is and then… Oh… wait… now that you’ve found a window, you’re looking at Mons Olympus. (And if I was doing the GMing, at this point, they’d also find a set of suits that can be modified to fit humans by cutting off the extra arms.)
I think the pressurized home base is necessary anyway. Even with a properly sealed suit, you can’t live in there for very long. Unless this adventure has to play out in a matter of hours, the characters need a place to de-suit and take care of needs like using the bathroom. It’s hard to feel heroic on day three of using the same adult diaper…
There’s not much practical difference between 99% less atmosphere and 100% less atmosphere. If you had a Martian atmosphere in a lab on Earth, we’d call it a vacuum.
While I wouldn’t discount the problem of the temperature entirely, this is going to be easier to overcome than the air problem. A nice day on Mars is warm enough without much insulation. Not only is an airtight suit is already going a long way toward keeping your body heat in but you can always add more layers of clothing or blankets if it’s too cold. People on Earth can stand temperatures well into the negatives with the right gear, and that gear is less complicated than a space suit.
You’d want to do the mission in the summer, though. And the night-time lows do reinforce the importance of either having some kind of airtight shelter or making it a very short mission.