Subs in Spaccccccccccce Query

[kerick]

Getting rid of excess heat in space is a real problem. IIRC when Skylab was first launched and the solar panels failed to deploy the interior got up to like 90 degrees F inside. And that was from just sunlight. That's when the makeshift umbrella sun shield saved the day. Hope this makes sense, I'm still on painkillers.

[kerick]

Also a fella had his own website with space model he had built which frequently started as airliner or sub hulls turned backwards and upside down.

[Scotaidh]

Getting rid of excess heat in space is a real problem. IIRC when Skylab was first launched and the solar panels failed to deploy the interior got up to like 90 degrees F inside. And that was from just sunlight. That's when the makeshift umbrella sun shield saved the day. Hope this makes sense, I'm still on painkillers.

Absolutely you're making sense.  A rocket scientist/engineer of my acquaintance said only method of disposing of heat works in space, and that's "black box".  He didn't go into specifics - I prolly couldn't have followed it anyway cuz I iz dum - but something about when there's no atmosphere white objects reflect heat (really absorb it much more slowly) and black ones emit heat.  It didn't really make sense to me, but then - see my previous disclaimer.

The ATCS link did make sense to me, though - it's kinda how I thought heat control would work in space.  [Outside of hull will be as cold as space; fluid in a closed loop heat-exchange system picks up heat with interior HEs and cycles out to hull-mounted HEs to become cool again.  ]

[zenrat]

That all might bw true in orbit or close to a star but what about out in deep space in the gaps between the stars?

[Old Wombat]

Internally there will be things generating heat, mostly people & electronics, which will need to be removed in a controlled manner.

Thermal insulation will prevent excessive emission of heat, black panels will be used to radiate excess heat.

I seem to recall a Science Fiction story (Arthur C. Clark? Jerry Pournelle? Robert Heinlein? ... I can't recall that bit.) where a space ship has some of its heat-exchangers damaged & things get pretty dicey, including the surviving HEs heating to the point where they start to glow red & reduce their efficiency at dissipating heat.

Can't remember how they fix it, either; just the heating up bit.

[kerick]

There are three ways to transfer heat, convection, conduction and radiation. The first two need some other form of mass to transfer the hear energy into. In space that is not available. This leaves radiation, not the most efficient method. I was working on a complete whiff starship for a long time and I included an excess heat exhaust port.
Just my $0.02.

[Rick Lowe]

There are three ways to transfer heat, convection, conduction and radiation. The first two need some other form of mass to transfer the hear energy into. In space that is not available. This leaves radiation, not the most efficient method. I was working on a complete whiff starship for a long time and I included an excess heat exhaust port.
Just my $0.02.

Just make sure it's adequately shielded from all them pesky 'snub' fighters...

[Weaver]

Hey Guys,i was doing a Little Research when a Question hit me:What If there was a Subspace Submarine for the Federation in Star Trek? I'd seen some Subspace Subs in Star Blazers and Thought What If some subs were Converted into Subspace Subs for Star Trek. What Subs would Work for this? What Say You? Thanks for Looking. Dan

As a kitbash shape-donor, a submarine is pretty useful. Converting an actual submarine to go into space would be pointless since it's far more heavily built than it needs to be. You'd have to have a ludicrous Space Battleship Yamoto style background to justify it: certainly not Star Trek!

The 'subspace sub' concept I always liked to think about was a spaceship that behaves in a manner analogous to a submarine. i.e. it lurks in subspace/hyperspace/whatever using some exotic, costly niche technologies and then bushwhacks passing 'normal' starships, perhaps using side-effects of the same technology.

[frank2056]

Isn't deep space very very cold?
So keeping warm might be the problem rather than cooling down.

A vacuum has no temperature, since temperature is the amount of heat energy in matter, and a vacuum by definition has no matter (or very little) in it. It's easier to generate heat than it is to radiate it quickly. In most cases, radiating excess heat in a vacuum is a Big Problem.

[Rick Lowe]

Isn't deep space very very cold?
So keeping warm might be the problem rather than cooling down.

A vacuum has no temperature, since temperature is the amount of heat energy in matter, and a vacuum by definition has no matter (or very little) in it. It's easier to generate heat than it is to radiate it quickly. In most cases, radiating excess heat in a vacuum is a Big Problem.

It's also a great big "Here I Am!" sign...

[zenrat]

I goggled "what temperature is space?".

The first result was this:
The temperature in outer space is generally 2.73 Kelvin (-270.42 Celsius, -454.75 Fahrenheit). This is actually the temperature of Cosmic Microwave Background Radiation, which is spread throughout the universe.
https://www.scienceabc.com/nature/universe/what-is-the-temperature-of-space.html

Sounds pretty cold to me.

[Old Wombat]

The "excess heat port" is a great idea ... if you have atmosphere to spare.

An "excess heat port" works by passing a medium (usually liquid or air) over a radiating surface & then pumping that medium away from the volume being cooled. This doesn't work in space because it can't, there's no medium to heat & eject, unless you're pumping out your water or air.

[frank2056]

I goggled "what temperature is space?".

The first result was this:
The temperature in outer space is generally 2.73 Kelvin (-270.42 Celsius, -454.75 Fahrenheit). This is actually the temperature of Cosmic Microwave Background Radiation, which is spread throughout the universe.
https://www.scienceabc.com/nature/universe/what-is-the-temperature-of-space.html

Sounds pretty cold to me.

That's the glow of the cosmic background radiation - the remnant of the Big Bang, when the universe was dense (ie, not a vacuum) and extremely hot. If you put an object in the vacuum of deep space. away from any source of heat, it will eventually radiate away its energy (glow)... but if it has people and machinery inside it's going to get extremely hot if it doesn't radiate away the excess heat.

A current example is the sunshield for the Webb Space telescope. The tennis court sized shield is just to get and keep the optics down to 50K. There's an instrument that needs to operate at 7K and it won't be able to get to that temperature without active cooling.

[zenrat]

If you are in deep space light years from the nearest star then surely it is better to conserve energy rather than radiate it out into space?

[Weaver]

If you are in deep space light years from the nearest star then surely it is better to conserve energy rather than radiate it out into space?

Okay in principle. Now, a) how are you going to store it? and b) How are you going to utilise it?