Slingshot Moon vs Direct flight

[perseus]

Compared with a direct flight. What would be saving delta V using slingshot on the Moon to get to Mars, Venus, Jupiter?

 

[Pioneer]

Compared with a direct flight. What would be saving delta V using slingshot on the Moon to get to Mars, Venus, Jupiter?

I assume that you will gain dV, but I'm not sure how to do such a flyby using the default TransX and IMFD :shrug:

 

[blixel]

Compared with a direct flight. What would be saving delta V using slingshot on the Moon to get to Mars, Venus, Jupiter?

The Trans-Mars Injection burn from LEO to Mars will typically cost you just under 3600 m/s.

Earlier this year, I spent quite a bit of time with dgatsoulis learning how to make the trip to Mars (or other planet) by starting off on the moon, dropping to a low periapsis at Earth, and then performing a burn to then go out to Mars (or some other planet.)

In one of my recorded flights, my Trans-Mars Injection burn cost me 434.5 m/s. And I'm still new at this kind of flight, so I don't think that's even as good as it gets. In another recorded flight, it cost me close to 600 m/s. I don't recall what the problem was in that case, but generally it shouldn't be that expensive.

You do have to add in the cost of first getting up into orbit around the moon and then doing the burn to get back to Earth. But when you add everything together, the total cost is still lower than the TMi burn from LEO to Mars. (Though, you have to already be on the moon in the first place. It certainly won't save you anything to start on Earth, go out to the moon, and then come back and go to Mars.)

If you're curious how this flight works, I have 3 recorded examples on my YT channel. Though, the last one is the best just due to the fact that I had more experience by the time I got around to recording it for the third time.

 

[BrianJ]

It might be of interest to look at the"Nozomi" mission trajectory which squeezed as much dV as possible from 2 Lunar and 1 Earth gravity assists. Can be reproduced in Orbiter but I found that course corrections between 1st and 2nd Lunar flybys ate up as much fuel as it saved.

Nozomi Mission Abstract .pdf
http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/16823/1/99-0227.pdf

 

[RGClark]

The Trans-Mars Injection burn from LEO to Mars will typically cost you just under 3600 m/s.

Earlier this year, I spent quite a bit of time with dgatsoulis learning how to make the trip to Mars (or other planet) by starting off on the moon, dropping to a low periapsis at Earth, and then performing a burn to then go out to Mars (or some other planet.)

In one of my recorded flights, my Trans-Mars Injection burn cost me 434.5 m/s. And I'm still new at this kind of flight, so I don't think that's even as good as it gets. In another recorded flight, it cost me close to 600 m/s. I don't recall what the problem was in that case, but generally it shouldn't be that expensive.

You do have to add in the cost of first getting up into orbit around the moon and then doing the burn to get back to Earth. But when you add everything together, the total cost is still lower than the TMi burn from LEO to Mars. (Though, you have to already be on the moon in the first place. It certainly won't save you anything to start on Earth, go out to the moon, and then come back and go to Mars.)
...

Thanks for that. You've discovered why so many Mars enthusiasts want us also to return to the Moon. The recent NRC report that advised NASA should return to the Moon as a prelude to a Mars mission was a good step in this direction. But it did not note the most important reason for this: the degree to which a Mars mission becomes simplified by setting up propellant depots in lunar orbit using lunar-derived propellant and launching the Mars mission from there.


Bob Clark