Space ship Vs Mars

ScumLord

I know the world is mad to get to mars but I'm wondering is it really the best use of our time and resources?

Would building a spaceship that could accommodate a fairly large crew (maybe 60+), something like an upgrade to the international space station but something that's able to move around and could do trips to the moon for instance, or even a prolonged trip to mars. It could also cover some of it's cost by taking billionaires on trips.

I would have thought it would help develop more useful science because spaceships have more benefits. It can go to places like mars or an asteroid and deploy colonies and stick around to make sure everything ok rather than just go there with no way of getting home.

Is it mainly a radiation issue? Is it just point to point is cheaper? No way of fueling it?

I just think if the cost would come in somewhere around the same as a Mars trip Nasa and the likes should be seriously considering a spaceship instead.

Capt'n Midnight

We have plenty of rockets that can launch about 20 tonnes modules into LEO. We have the technology to assemble those modules.

Fuel is easy. Use some modules as fuel tanks, they can be sent up ahead to the Lagrange points using electric engines.


We should be sending things like solar sail cube sats to investigate asteroids

ScumLord

Just doing a basic search on costs, the international space station cost $100 billion. But I don't know if that's a, to date number. Or what it cost to build not including maintenance.
Current estimates for the mars mission are at €100 billion and if the ISS is anything to go by that could balloon to ten times that size.

I would think that if we built another station today it would cost a good bit less than it did in the past.

Having a ship permanently based in space that could routinely do trips to the moon ferrying people and equipment seems like it would be more worthwhile. Or even do the odd long range mission to an asteroid if the conditions allowed.

Mars just seems like to much effort for little reward at this stage. Even just replacing the ISS with something more up to date would probably have more real world benefits than a trip to mars.

Capt'n Midnight

ScumLord wrote: »

Just doing a basic search on costs, the international space station cost $100 billion. But I don't know if that's a, to date number. Or what it cost to build not including maintenance.
Current estimates for the mars mission are at €100 billion and if the ISS is anything to go by that could balloon to ten times that size.

Rough rule of thumb divide NASA costs by ten to see what it would cost others. Mir cost about $5-10 Billion

NASA spend on the SLS is very roughly what the Russians or Chinese spend on space.

I would think that if we built another station today it would cost a good bit less than it did in the past.

As above Mir cost a fraction of what the ISS did. Skylab was a single launch. Lookup Wet Workshop for a way of getting more habitable space easily. Insulated and easily able to take one atmosphere of pressure.

Having a ship permanently based in space that could routinely do trips to the moon ferrying people and equipment seems like it would be more worthwhile. Or even do the odd long range mission to an asteroid if the conditions allowed.

Mars just seems like to much effort for little reward at this stage. Even just replacing the ISS with something more up to date would probably have more real world benefits than a trip to mars.

From https://en.wikipedia.org/wiki/Delta-v_budget

Escape orbit (C3), Geostationary orbit (GEO), Geostationary transfer orbit (GTO), Earth–Moon L5 Lagrangian point (L5), low Earth orbit (LEO).

Getting to Moons of Mars or the asteroid belt doesn't take much more energy than going to the moon. Just takes a lot longer. But you can use electric drive or solar sail. Going down into the gravity well of Mars and back out is a completely different ballgame, you need heat shields and parachutes and rockets so you need to carry lots of extra single use kit and way more fuel.

Reati

If we're in the realm of spending mad money, I'd love to see them upgrade the ISS and move it to lunar orbit instead of a deorbit burn up. Even if they leave it there unmanned to test out how long all the stuff can work for as a test into how well a space ship station would last in travel. Pipe dream but would be great to see.

Anyway, we should go to Mars. We need to develop the tech to live untethered from the earth long term. Mars has many of the resources we need to do this. A space ship wouldn't be self sufficient (depending on what the plan for it is).

There was a great BBC documentry years ago about a NASA "Missions" kind of like the OP describes where a crew fly a Grand Tour of the planets. Space Odyssey: Voyage to the Planets was the name.

Capt'n Midnight

Reati wrote: »

If we're in the realm of spending mad money, I'd love to see them upgrade the ISS and move it to lunar orbit instead of a deorbit burn up. Even if they leave it there unmanned to test out how long all the stuff can work for as a test into how well a space ship station would last in travel. Pipe dream but would be great to see.

The Russians plan to
decouple their modules when the love-in finishes up and keep them as a going concern.

Without constant supplies of fuel it will de-orbit like Skylab did. It would take a lot of fuel to between the Van Allen radiation belts. And they vary in size too. Also would take more fuel to visit and de-orbit.

Anyway, we should go to Mars. We need to develop the tech to live untethered from the earth long term. Mars has many of the resources we need to do this. A space ship wouldn't be self sufficient (depending on what the plan for it is).

But Mars is at the bottom of a gravity well.

There was a great BBC documentry years ago about a NASA "Missions" kind of like the OP describes where a crew fly a Grand Tour of the planets. Space Odyssey: Voyage to the Planets was the name.

That would take ages because the planets won't align for a long time.

Reati

Capt'n Midnight wrote: »

The Russians plan to
decouple their modules when the love-in finishes up and keep them as a going concern.

Without constant supplies of fuel it will de-orbit like Skylab did. It would take a lot of fuel to between the Van Allen radiation belts. And they vary in size too. Also would take more fuel to visit and de-orbit.

Agree - this why i called it a pipe dream with endless money required

Capt'n Midnight wrote: »

But Mars is at the bottom of a gravity well.

Don't really follow you on this one.

Capt'n Midnight wrote: »

That would take ages because the planets won't align for a long time.

Agree - it's just an interesting watch. I don't think it's ever be a viable mission tbh even if the planets did a align.

ScumLord

Reati wrote: »

Don't really follow you on this one.

Like earth mars has a lot of gravity, as far as I know the biggest energy cost of any mission from earth is just getting off the planet. The same would be true of mars, getting on and off the planet would require a lot of fuel. The moon would require much smaller amounts of to get on and off the surface. I think that's why the one way mission idea gained traction. It eliminates the need to send a load of return fuel.

Capt'n Midnight

Curiosity is a rover on Mars. The rocket used to get there had a mass of 540 tonnes. Most of which was used to break out of Earth's gravity well.

But at Mars lots more mass was shed on the way down.
2,401Kg of landing systems for an 899Kg rover.

So let's be generous and say for every tonne you want to land on Mars you need 500 tonnes of Rocket.