Scenario The ultimate great grand tour

downloaderfan

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Alright, it's been almost two and a half years since I've been active on orbiter forum. I usually fired up orbiter about once in two months. At some point, I came across Flytandem's various slingshot scenarios and was inspired by it.

So after planning a few basic slingshot maneuvers over the years, I finally decided to go for the ultimate slingshot plan - A tour through ALL the planets of the solar system. And after failing like 2-3 times in the past, I was finally able to come up with a complete solution over a course of 2 days.

It goes like this:

Earth-Venus-Mercury-Venus-Venus-Venus-Mars-Earth-Venus-Venus-Venus-Jupiter-Saturn-Uranus-Neptune

My plan was to reach jupiter around the voyager dates, so I first started my plan around 1965,66,67 but reached dead ends after almost a hour of planning.So I went even earlier and found a solution starting from 1962.

The first sling from venus to mercury has a Pe/Pl Rad of 0.973, despite my best efforts, I was not able to get it above 1, so I performed the sling with an altitude of 112 km (Venus) and was later able to correct the trajectory with a 150 dv burn just outside of the Venusian SOI. All the other slings have Pe/Pl Rad above 1. :)

Falling as low as mercury and then rising up again without utilizing any fuel (MCCs excluded) required 3 slings around venus to rendezvous with mars. Now, after mars, at least 2 slings around the earth were required to get my apogee as high as jupiter's. Due to my early launch date, I could raise my orbit as high as jupiter's and then wait an entire orbit to rendezvous with jupiter. So I first tried EVMeVVVMaEEJ, however, I was rendezvousing with jupiter only in 1980, which was too late to perform the sling to saturn. :shrug:

So I went back to venus again to change my trajectory and performed 3 continuous slings to raise my apogee above jupiter's & rendezvoused in early 1978.

The rest was pretty easy. (Of course) :p

Reached neptune in August of 1987. BTW, I also made a plan for Pluto after saturn which was actually Voyager 1's original mission and was able to reach pluto in september of 1986, before Neptune. :blink:

I've attached all the scenarios below, one folder purely for the plan & the other consists of the execution. I had to split the complete plan into 3 scenarios because after 14 stages of planning on earth, transX went nuts & the values began to fluctuate way too fast to plan further. So I had no other choice but to execute the path & plan further slings later, midcourse.

And of course :hailprobe:

View attachment Ultimate grand tour scenarios.zip
 
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Lmoy

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Reached neptune in August of 1987. BTW, I also made a plan for Pluto after saturn which was actually Voyager 1's original mission and was able to reach pluto in september of 1986, before Neptune. :blink:

Well, at the time, Pluto was closer to the Sun than Neptune was. Interesting that it's a whole year's difference though.

I like the sound of this plan, it's very clever and sounds like fun, especially for people who like to see Venus. :lol:
 
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PhantomCruiser

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Doesn't Pluto spend quite a few years inside the orbit of Neptune? Like 20 years or so...

OK, out of 250 years or so, 20 isn't a lot. But on a human scale timeline it's a good chunk of time.
 

PhantomCruiser

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I remember it being a big deal in science class when I was but a wee lad. When they switched back, not so much. When I mentioned it there were people who thought I was crazy (but Pluto was a planet back then, so...)
 

downloaderfan

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Well, at the time, Pluto was closer to the Sun than Neptune was. Interesting that it's a whole year's difference though.

Ah, forgot about that, pluto was indeed closer to the sun than neptune by about 0.5 AU.

However, being closer to the sun doesn't mean fastest to reach always.

Just before my saturn encounter, I noticed than pluto fell right where my trajectory was heading, along the hyperbolic line of my orbit. That meant that I was already heading to pluto and saturn was just in a way, due to which I had a high Pe/Pl Rad of about 10.4 to head to pluto from saturn. (High Pe/Pl Rad - Lesser trajectory change required)

Neptune on the other hand was about ≈45 degrees off from my trajectory which demanded a much closer pass from saturn(for a much higher trajectory change) which also meant a much larger distance to travel, to get to neptune...Not the mention the trip from Saturn to Uranus to neptune had a much higher average velocity relative to the sun compared to Saturn to Pluto

Take a look at the positions of pluto & neptune in the pic below to get a better idea :)

Image_2.png


especially for people who like to see Venus.

Well, the seven venusian slings were required to fall as low as mercury and then getting as high as jupiter at the right angle, I tried to keep the "Orbits to icept" as low as possible so that I'm not spending most of the time just watching the screen waiting to rendezvous, otherwise, this would been a much easier task, since, if I wait enough number of orbits, I would rendezvous at some point or the other given my orbit intersects the orbit of the target planet. Infact the highest 'Orbits to inept' was from mercury to venus which was 1.5, but the orbit period was lowest at this point due to my apogee being around venus & perigee around mercury. All the other slings have 1 or lower 'orbits to inept' :)
 

Lmoy

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Well, the seven venusian slings were required to fall as low as mercury and then getting as high as jupiter at the right angle,

I know that, and it's very clever trajectory planning by the way! I was just amused by how many times the spacecraft ends up swinging by Venus. I'm imagining advertisements for the trip now. "See the beautiful planet Venus with your very own eyes! Then see it again! And again! And again! And again! And again! And again! And also every other planet. And then die in the cold dark infinite expanse at the edge of the solar system!"

Come to think of it, how much delta-v would be required to come back to Earth after the Neptune flyby?
 

downloaderfan

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I know that, and it's very clever trajectory planning by the way! I was just amused by how many times the spacecraft ends up swinging by Venus. I'm imagining advertisements for the trip now. "See the beautiful planet Venus with your very own eyes! Then see it again! And again! And again! And again! And again! And again! And also every other planet. And then die in the cold dark infinite expanse at the edge of the solar system!"

:lol: :rofl:

Come to think of it, how much delta-v would be required to come back to Earth after the Neptune flyby?

Almost none via an aerosling(excluding MCCs), just successfully performed one by dropping as low as 500 km above the surface of neptune. The return trip to earth adds an additional 31.4 years to the journey and I don't see any faster way around it. :shrug:

This would make it a total of 56.2 years, literally a trip of a lifetime. :tiphat:
 
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Lmoy

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:lol: :rofl:



Almost none via an aerosling(excluding MCCs), just successfully performed one by dropping as low as 500 km above the surface of neptune. The return trip to earth adds an additional 31.4 years to the journey and I don't see any faster way around it. :shrug:

This would make it a total of 56.2 years, literally a trip of a lifetime. :tiphat:

I need to learn to use Trans X or IMFD so I can figure this kind of stuff out for myself. What's the speed upon returning to Earth? Does it make for a survivable reentry?
 

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What's the speed upon returning to Earth? Does it make for a survivable reentry?

My periapsis velocity upon returning to earth is 16.6km/s. Using dgatsoulis's Selecting the correct altitude for a given peak hull temp with the Ravenstar tutorial, I got a static pressure of 4.02 Pa which should theoretically keep the Ravenstar safe until it gets just below 72 km, which is low enough to maintain altitude required for the aerobrake. However, the XR2 wouldn't be able to survive the aerosling at neptune with 30 km/s + periapsis velocity.
The alternative would be a 7265 m/s dv burn at the neptunian periapsis of my orbit to get directly to earth. Getting to a planet nearer to neptune (to later perform slings to earth) would require a lower dv burn, however, that would dramatically increase the time of flight.
The standard delta glider would of course survive any condition. Don't know much about other ships.

I need to learn to use Trans X or IMFD so I can figure this kind of stuff out for myself.

Watching David courtney's videos would be a great place to start. :)
https://www.youtube.com/user/DavidWCourtney?&ab_channel=DavidCourtney

For more advanced maneuvers, check out Flytandem's turorials
http://orbiter-forum.com/showthread.php?t=16990
 
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