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View Full Version : Question about Earth to Mars Free-Return Orbital-Mechanics



LoneTree1941
2014-Jan-06, 10:18 PM
I was reading just now about Dennis Tito's Inspiration Mars Foundation proposed Mars flyby. It seems to me that a Mars flyby mission would have to follow an orbital path just outside Mars surface rather than inside so that the face of Mars seen at the moments of the flyby would be its night side.

Is that the case?

It's an interesting question, and if my thinking is accurate that would be an extreme downside for the crew of two (a man and a woman; married I'd assume) to be so deprived of an actual face-on view of Mars' Surface.

I've found a You-tube VIDEO (http://www.youtube.com/watch?v=lBGlYNd2tmA) sponsored by the Inspiration Mars Foundation which shows that result.

ToSeek
2014-Jan-07, 04:07 PM
Well, they should get a pretty good view on the approach, but, yes, they'd be on the far side of Mars from the Sun when they're closest, so it would be dark.

EDIT: If you scroll down on this writeup (http://spaceflightnow.com/news/n1302/27tito/#.Uswod3cnZ7o), you'll see an artist's depiction of the flyby.

LoneTree1941
2014-Jan-07, 09:54 PM
Thanks much ToSeek.
Here is something else I was wondering about which you gave me the answer to:
"Then comes the harrowing re-entry, plowing into the atmosphere at a staggering 31,800 mph, an unprecedented speed for a manned spacecraft"
I wonder just how doable that is. I would assume that's a little less than about twice the normal re-entry velocity.

ravens_cry
2014-Jan-08, 01:06 AM
It's more than Apollo 11's approximately 25,054 mph, but, with more ablative protection and the right re-entry corridor, I don't see it as too impossible. Maybe doing multiple passes might help.