I think you will see a sample return
from Mars before we actually land humans
on Mars Sunday the first Rover we landed
on Mars was called Pathfinder it was a
very small Rover Spirit and Opportunity
were larger curiosity much larger but
when we're talking about getting humans
to Mars we'll have to have even larger
spacecraft with larger air shells and
larger parachutes and larger engines to
be able to get that equipment and the
things that those people would need to
the surface of Mars in one piece
humans need a lot of things to live air
and water and food so you know starting
off you need a lot more mass to get to
the planet so what you would probably do
to get some humans there you would
probably land some spacecraft there
ahead of time maybe a return craft
actually the next Rover that's going to
go up in 2020 is going to take an
instrument package that will try to make
hydrogen and oxygen and water from the
components of Mars to prove that we can
do that so you would probably land a
spacecraft there unmanned that could
make its own oxygen and hydrogen for for
rocket engines and make its own water
and have that already so that you would
send a manned spacecraft that wouldn't
have to carry all that with them so they
could land since we know how to land
close to other objects we could land
nearby and the astronauts could walk
over there some of the things you have
to worry about on a manned mission to
Mars it's just the distance of Mars is
close but not that close we're talking
about it probably a two three year
journey to get there and what if there
was a problem board the spacecraft what
if you had your appendix burst on the
way that could be a problem you can't
just turn the spacecraft around and head
home the other thing is in radiation you
know on earth we are protected by our
atmosphere from a lot of the radiation
from cosmic rays for example when
curiosity went to Mars even cocooned in
its heat shield it received enough
radiation in that cocoon - that was more
radiation than a Hugh
yet in their lifetime so we'll have to
come up with shielding to protect
astronauts just from the radiation to
get there now you're traveling to Mars
and you've been in weightless
environment for a while
so when you get to Mars you're you have
some gravity it's not as much on earth
as Earth but you do have some gravity so
you'll have to get used to walking now
we'll probably mitigate that by having
astronauts do exercises we could spend
part of the spacecraft to create some
artificial gravity on the way one of the
technologies who are working on ours are
better engines that maybe could provide
small thrust but thrust over time that
could cut a trip to Mars down from you
know six months to maybe six weeks so as
that technology evolves I think it'll
make it easier to send humans to Mars
but it is always going to be a risky
proposition it's risky enough to get off
of the earth and let alone out in space
but you know NASA it's getting out of
the near-earth environment we're leaving
that to to private companies and we're
starting to actually get the exploration
business again go back to the moon
hopefully in a few years go to Mars go
visit an asteroid and they can explore
