Travel time to mars?

I believe with chemical propulsion its commonly believed to be about a
year each way. thats a long time

What if aerobreaking were used?

The manned portion would detach and dive perhaps repeatedly into the
atmosphere to slow for landing.

This would mean the transit vehicle would only accelerate on its way
to mars cutting travel time.

on a return from mars to earth could a capsule be built like apollo to
survive a full speed return?

On Jan 12, 11:24*am, " wrote:
What if aerobreaking were used?

The manned portion would detach and dive perhaps repeatedly into the
atmosphere to slow for landing.

This would mean the transit vehicle would only accelerate on its way
to mars cutting travel time.

So you've got a launch vehicle that flies past Mars at top speed,
drops off the crew capsule (which lands safely by aerobraking), and
then keeps going?

On Jan 14, 5:47*pm, Fred J. McCall wrote:
Damien Valentine wrote:
On Jan 12, 11:24 am, " wrote:
What if aerobreaking were used?

The manned portion would detach and dive perhaps repeatedly into the
atmosphere to slow for landing.

This would mean the transit vehicle would only accelerate on its way
to mars cutting travel time.

So you've got a launch vehicle that flies past Mars at top speed,
drops off the crew capsule (which lands safely by aerobraking), and
then keeps going?

It feels to me like there is something VERY wrong with his physics,
unless his goal is for his "manned portion" to make a really deep
smoking hole on Mars.

--
"We come into the world and take our chances.
*Fate is just the weight of circumstances.
*That's the way that Lady Luck dances.
*Roll the bones...."
* * * * * * * * * * -- "Roll The Bones", Rush

Didnt some earlier unmanned missions use aerobraking?

and just how robust of a heat shield would be necessary?

the now not needed manned stage could be abandoned to exit the solar
system at high speed, perhaps with some experiments.

or have it slingshot brake and do a slow or muliti year return to
earth.

dont think of it as wasted, think of it as used up

On Jan 14, 6:50*pm, Fred J. McCall wrote:
" wrote:
On Jan 14, 5:47*pm, Fred J. McCall wrote:
Damien Valentine wrote:
On Jan 12, 11:24 am, " wrote:
What if aerobreaking were used?

The manned portion would detach and dive perhaps repeatedly into the
atmosphere to slow for landing.

This would mean the transit vehicle would only accelerate on its way
to mars cutting travel time.

So you've got a launch vehicle that flies past Mars at top speed,
drops off the crew capsule (which lands safely by aerobraking), and
then keeps going?

It feels to me like there is something VERY wrong with his physics,
unless his goal is for his "manned portion" to make a really deep
smoking hole on Mars.

Didnt some earlier unmanned missions use aerobraking?

and just how robust of a heat shield would be necessary?

The problem isn't the heat shield. *The problem is you don't get much
drag from Mars' atmosphere. *I believe there was at least one
successful unmanned aerobraking probe. *These probes are relatively
small. *The aerobraking maneuver on Mars is VERY tricky. *You're not
going to do it if you're accelerating all the way there.



the now not needed manned stage could be abandoned to exit the solar
system at high speed, perhaps with some experiments.

Freudian slip on your part. *I suspect you meant that the UNmanned
stage was not needed and could be abandoned.



or have it slingshot brake and do a slow or muliti year return to
earth.

dont think of it as wasted, think of it as used up

I'm more concerned about the smoking hole your people made by not
doing any deceleration until they reached Mars.

--
"Rule Number One for Slayers - Don't die." *
* * * * * * * * * * -- Buffy, the Vampire Slayer- Hide quoted text -

- Show quoted text -

yep the no longer manned stage would be considered waste, or
slingshotted slowly back to earth.

think out of the box, since the box isnt your friend........

how about a small crew capsule, very robust with a large inflatable
transhab breaking or parachute?

if the capsule is low weight, its speed high might be compensated for
by a large drag to slow re entry.

obviously for this type mission robots will have set up a base camp,
or perhaps camps in advance.....

in prep for peole arriving.

obviously for this type mission robots will have set up a base camp,
or perhaps camps in advance.....

in prep for peole arriving.

Then it'll never happen. *Robots are just barely smart enough to move
around. *Even with supervision they get stuck in the sand.


Artificial intelligence is the future of robotics, one day they will
do all the dirty risky jobs more efficently than people.

robots will work in groups if one gets stuck others will come to its
rescue

On Jan 15, 2:01*am, Fred J. McCall wrote:
" wrote:

obviously for this type mission robots will have set up a base camp,
or perhaps camps in advance.....

in prep for peole arriving.

Then it'll never happen. Robots are just barely smart enough to move
around. Even with supervision they get stuck in the sand.

Artificial intelligence is the future of robotics, one day they will
do all the dirty risky jobs more efficently than people.

I've been hearing people say this for 30 years now, always talking
about how it's right around the corner. *So where is it?

Yeah, I know, "right around the corner"...



robots will work in groups if one gets stuck others will come to its
rescue

Which will lead to a whole bunch of them stuck together rather than
just one of them stuck.

--
"Ignorance is preferable to error, and he is less remote from the
*truth who believes nothing than he who believes what is wrong."
* * * * * * * * * * * * * * * *-- Thomas Jefferson

well look how far robotics have come on earth, and consider the very
best chess player is unable to beat a computer at chess.

now poor nasas manned space budget into robotics and AI, and license
all advancements to private industry, with the proceeds going back to
space exploration.

then watch AI take off.

on stuch robotic explorers send hundreds if not thousands, and accept
a big attrition rate.

plus groups of robotic crawlers could call for human help if they get
stuck too bad. sure it may be slow going, but think of the rewards

http://www.engadget.com/2011/01/13/i...opardy-pract/#

smarter than either of the two greatest jeopardy champions.

certinally a computer can run robotic explorers......

On Jan 12, 10:24*am, " wrote:
I believe with chemical propulsion its commonly believed to be about a
year each way. thats a long time

What if aerobreaking were used?

The manned portion would detach and dive perhaps repeatedly into the
atmosphere to slow for landing.

This would mean the transit vehicle would only accelerate on its way
to mars cutting travel time.

on a return from mars to earth could a capsule be built like apollo to
survive a full speed return?

Mars Hohmann is about a 8.5 month trip. Or about 250 days.

Mars Global Surveyor and Mars Reconnaissance orbiter each used
hundreds of drag passes over 4 to 5 months to achieve Mars orbital
insertion.
http://spacecraftkits.com/MGSFacts.html
http://www.spaceref.com/news/viewpr.html?pid=20710
http://hop41.deviantart.com/gallery/7438029#/d23v2fq

There is a Mars Semi Direct scheme that employs two aggressive drag
passes to achieve Low Mars Orbit.
http://www.marsdrive.com/Libraries/D...Mars.sflb.ashx
Trip time is somewhat shorter than a standard Hohmann, 200 days
instead of 250 days.