Posted on 12/24/2014 8:54:36 AM PST by BenLurkin
The premise of a ballistic capture: Instead of shooting for the location Mars will be in its orbit where the spacecraft will meet it, as is conventionally done with Hohmann transfers, a spacecraft is casually lobbed into a Mars-like orbit so that it flies ahead of the planet. Although launch and cruise costs remain the same, the big burn to slow down and hit the Martian bull's-eye—as in the Hohmann scenario—is done away with. For ballistic capture, the spacecraft cruises a bit slower than Mars itself as the planet runs its orbital lap around the sun. Mars eventually creeps up on the spacecraft, gravitationally snagging it into a planetary orbit
I remember the days when Scientific American was both.
I'm rusty on my orbital mechanics, but wouldn't slowing down the spacecraft cause it to fall inwards towards the Sun?
You would still need a lander. So I don’t see how you save anything anywhere.
Complex orbital manipulations so Mars catches up to you seems to me would extend the mission time significantly.
I really don’t know. Parallel parking is still a challenge for me.
But reading this, I thought of those asteroids that seem to follow the earth around the sun. Always wondered if that wasn’t a smarter way of putting something into “orbit” around a gravity well.
So, you get in front of Mars and wait for it to catch you. I do that with the bus. I get run over a lot. I’d hate to get run over by Mars. Probably doesn’t have any insurance.
Teleporter?
Getting to Mars in not the problem, it’s getting Home from Mars that makes it a complicated mission because we will need to send unmanned stuff there first that includes a self sufficient and fully automatic fuel manufacturing station... For when the astronauts show up later so they can get off the surface of Mars and back into orbit.
You slow it down by putting it in a higher orbit (out past Mars). When Mars approaches, you lower your orbit to allow speed matching.
Seems it would be far easier to launch toward a spot Mars will be in 6 months like we did for the moon missions.
Mars: low gravity Antarctica without oxygen. Have fun!
It’s a beater. Probably only has 15/30 at most.
The short answer is that it depends on which gravity well you are in (which is exerting the greater gravitational pull).
For fuel, perhaps those astronauts should be trained in fracking.
Why wouldn’t you launch to a point behind and a tad slower and let Mars gravity suck you up to speed?
Ballistic capture
http://en.wikipedia.org/wiki/Low-energy_transfer
I’m not interested in being sucked by Mars.
Venus maybe.
“I’m not interested in being sucked by Mars.
Venus maybe.”
NASA’s plan for an off-world colony: a floating city above Venus
http://wtkr.com/2014/12/23/nasas-plan-for-an-off-world-colony-a-floating-city-above-venus/
“I really don’t know. Parallel parking is still a challenge for me.”
Pull up next to car that would be in front of you till you are level with the rear light assembly. About 1.5 away.
Turn wheel all the way to the right while holding brake all the way down.
Begin backing up into space slowly with the wheel turned all the way to the right, letting that maneuver control the car.
When the car is all the way back as far as it can go without touching the curb begin turning the wheel slowly to the left and continue backing in slowly.
Straighten out and pull forward.
too true. Scientific American today is 50% global warming, 40% sociology, e.g. the advantages of diversity, maybe 10% hard science. Zite is much better.
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