Question about manned Mars missions

Question

Moon missions are relatively easy, as the moon has low gravity and no atmosphere. Returning from the surface simply requires a small rocket, as there isn't much to overcome. However the problem with a manned Mars landing to me is how do they get back into orbit? Mars has significantly more gravity, as well as an atmosphere, so that means more weight and air resistance. Which means a bigger rocket.

So my question is what is NASA's plan for getting the astronauts back?

Answer 1

The previous poster talking about a 'pool of terminally ill volunteers' is obviously making that part up.

If Obama becomes president, he's already pledged to delay (if not outright cancel) Constellation, diverting the money to school reading programs. Never mind all the extra strain on the economy by putting Aerospace workers out of jobs, it will mean the US will be totally dependent upon the Russian Soyuz to ferry astronauts to the ISS and back. So much for wanting change.

Mars does not have significantly more gravity, being roughly between the moon and Earth, size-wise. and the atmosphere is much thinner than Earth. Yes, the lander will be more robust than the lunar module, but so what? They make it bigger. Problem solved.

Answer 2

You're pretty knowledgable on Mars!

Quite honestly, NASA really doesn't think that putting a man on Mars is a good idea, precisely for the reasons you've pointed out; however, President Bush would disagree and is already having them plan another manned lunar landing to prepare for a manned Mars landing.

And if the new President (be it Obama or McCain)  does not change this plan, NASA will most likely draw from a pool of terminally ill volunteers for whom there will be no return mission.

The only problem with this would be bad PR, even if the terminally ill people did volunteer.

Answer 3

You have to take the problem right back to Earth.  To get to the moon, they required a rocket (the Saturn V) 380  feet tall.  The reason is “payload”.  Once you start adding to the payload, you need bigger  and bigger rockets to take off, and of course the bigger rocket means more weight, and so it goes on.  

I understand that Mars missions will be launched from the moon, so the launcher will not have to be more massive that Saturn V.  However, you can’t spend 6 months going to Mars and then only be there 2 days like the moon missions.  

So, yes you need a larger rocket to get your larger Mars lander to Mars, but also your ship needs to support life for all those months, have enough life support for a decent stay on the planet, and then more life support for the return journey.  

Not a simple exercise, as I replied to the person last week who had the daftest question of the week “why can’t the Shuttle go to Mars?”

Answer 4

Exactly what you described, a bigger rocket =)

This is one of MANY troubles in a manned Mars mission. Radiation exposure is a major one, as well as what in the world (space?) the crew are going to do during the trip there and back. Another issue is planetary motion. Once you're at Mars, Earth has already gone by. You'll have to wait a year to get back to Earth.

So yes, they'll use bigger rockets.

As you can see, Mars missions... yeah those are going to be tough. We simply aren't ready for it yet.