Could a manned mission to Mars (and back) be done NOW!?

[xRIEx]

Simpo Two said:

xRIEx said:

But if that input energy can be gathered from the sun via solar panels, then you don't have to carry it with you.

That's a point, but the amount of energy some portable solar panels can generate compared with the amount of energy needed to get a spacecraft off the ground and beyond escape velocity seem many orders of magnitude apart to me.

I have no idea of the maths involved, but I think they're suggesting the MAV would be sent there two years or so before any astronauts. It was in that NatGeo link above.

[MartG]

Simpo Two said:

xRIEx said:

But if that input energy can be gathered from the sun via solar panels, then you don't have to carry it with you.

That's a point, but the amount of energy some portable solar panels can generate compared with the amount of energy needed to get a spacecraft off the ground and beyond escape velocity seem many orders of magnitude apart to me.

A low rate of energy acquisition by solar panels over several months can easily equate to the high rate of energy expended during the short period of time of a launch

[NNH]

MartG said:

Simpo Two said:

xRIEx said:

But if that input energy can be gathered from the sun via solar panels, then you don't have to carry it with you.

That's a point, but the amount of energy some portable solar panels can generate compared with the amount of energy needed to get a spacecraft off the ground and beyond escape velocity seem many orders of magnitude apart to me.

A low rate of energy acquisition by solar panels over several months can easily equate to the high rate of energy expended during the short period of time of a launch

Another reason for the slow rate is that it works by using the very thin Martian atmosphere, rather than digging into rocks. The atmosphere is constant all over Mars, and only needs a simple inlet tube rather than a robotic drilling machine. By taking a small amount of hydrogen, you can split up Martian atmospheric carbon dioxide and use it to make methane (carbon plus 4 hydrogen atoms) and oxygen. For each tonne of hydrogen you take to Mars, you eventually get ~4 tonnes of methane ready to burn with ~16 tonnes of oxygen. But gathering those many tonnes of material from an atmosphere that is about 1% as thick as our own takes quite a while!

[MartG]

Looks like things may be moving on the nuclear propulsion front

http://www.foxnews.com/science/2017/11/10/how-vint...

[Einion Yrth]

MartG said:

Looks like things may be moving on the nuclear propulsion front

http://www.foxnews.com/science/2017/11/10/how-vint...

NERVA is, shall we say, somewhat politically sensitive; definitely an argument that needs having, but I wouldn't necessarily expect to win.

[Gandahar]

Pacman1978 said:

A question for the science section regulars. If funding was unlimited

yes

it isn't, governments prefer bombs

so

no

[AshVX220]

Gandahar said:

Pacman1978 said:

A question for the science section regulars. If funding was unlimited

yes

it isn't, governments prefer bombs

so

no

If governments transferred all defence spending to this, they still couldn't afford to go to Mars now, so your first point is er, pointless.

[RobDickinson]

AshVX220 said:

If governments transferred all defence spending to this, they still couldn't afford to go to Mars now, so your first point is er, pointless.

USA alone spends $600bn PA on their military.

At $2-3bn for each SLS launch, we already have $6bn for the orion crew vehicle, just need a large module for living and storage etc plus a lander.

I think $600bn for a few years would cover it.

[Simpo Two]

Gandahar said:

yes

it isn't, governments prefer bombs

so

no

Or to put it another way, 'governments choose first to be able to protect/defend their country'? I'll take national security ahead of Mars. The real culprit is financial waste and abuse of the welfare state.