Flight Question To Mars after a Venus sling?

[fullarmor2]

I was watching a documentary about Mars missions the other day and they were discussing possible upcoming flights to Mars. And one scenario that they were seriously considering was a flight to Mars that included a Venus sling. Have you ever heard anything like that being considered? I think they said it would actually be cheaper on fuel to do that. But then they ruled it out as being too risky. Because if they miss the sling somehow then they are lost.
Has anyone done a flight from Earth, and sling Venus, and then out to Mars? If so, What date did you use for beginning at Earth? I'm having some trouble at finding a date that works for this.

 

[Pipcard]

Well, there's an alternate history novel by Stephen Baxter titled "Voyage" in which NASA launches a manned mission to Mars in the 1980s using a Venus slingshot.

 

[perseus]

The advantage of the flyby is to bring the launch window to return, without having to wait too long on Mars.

 

[BruceJohnJennerLawso]

It sounds like a decent idea, but I dont know how realistic it would be. Slingshot windows like that arent terribly common, its not hard to imagine a mission like that missing its launch window due to technical and/or development problems.

I could definitely see it being done with a lunar slingshot while leaving Earth though.

If you want to check for slingshot courses, setting up a TransX plan while in Earth orbit should work fine.

 

[dgatsoulis]

Has anyone done a flight from Earth, and sling Venus, and then out to Mars? If so, What date did you use for beginning at Earth? I'm having some trouble at finding a date that works for this.

Earth Mars Earth short mission duration
Excellent set of Earth→Venus→Mars TransX plans from flytandem. All launch on the same date and you can choose between 2 free returns (short and long) or a short stay (~1 month) on Mars.

Tito's 501 day EME free return journey in TransX

Tito's plan is similar but the other way around. You go to Mars fast, sling to drop below Venus' distance from the Sun, but there's no second sling; Venus won't be there. Then you arrive back to Earth.
In the same thread you can also find an EVME plan, that has been optimised to have approximately the same flight-time, and a survivable arrival velocity at Earth.

 

[boogabooga]

I recommend this tool for all of your slingshot planning needs:

[ame="http://www.orbithangar.com/searchid.php?ID=5419"]Trajectory Optimization Tool v2.1 - No MATLAB Compiler Runtime[/ame]


Once you practice with it, you can use it to search for a good trajectory. This should save some time relative to looking for it yourself in TransX. Plus, TOT looks for an optimized trajectory; while you can find some trajectory in TransX, it's a lot tougher to tell if it is the optimal one.

You just have to recognize that sometimes TOT gives a junk solution, and you have to run several times to get a good result.

 

[fullarmor2]

There is also a video on Youtube in which a guy is doing a flight in Orbiter from Mars and slinging Venus and back to Earth. Its a good demonstration of how to use Trans X for doing sling shots. It helped me quite a lot, as this is my first attempt at an IP flight involving a planetary sling. I'll post a link in case anyone else reading this is new to this type of flight so you can see it demonstrated. Especially how to set up Trans X.

https://www.youtube.com/watch?v=R7z4vfZAVYQ&list=PLPu_SHPaJzs7Vjg2VqnjfqJADIirNeiMq

 

[Astro SG Wise]

Yeah, full armor, I didn't get it either. This video is an orbiter mission to Mars using the Venus slingshot.

https://www.youtube.com/watch?v=rrbvM5HuQRE

Also, I heard that NASA wants to fly their Orion Mars missions in the 2030s, because Mars is closer then. Can't it be done any time they want? Is there a big difference?

 

[boogabooga]

There is also a video on Youtube in which a guy is doing a flight in Orbiter from Mars and slinging Venus ...

https://www.youtube.com/watch?v=R7z4vfZAVYQ&list=PLPu_SHPaJzs7Vjg2VqnjfqJADIirNeiMq

It's not just a guy.

That's O-F's own, the one and only, blixel. :tiphat:

He would be good to p-m if you have questions.