
Planetary Transfer Calculator - T-A
https://transfercalculator.com/
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rcuv
If you're interested in this kind of stuff, the NASA General Mission Analysis
Toolkit (GMAT) is open source and is actively used to do navigation analysis
for multiple missions which are currently flying.

[http://gmatcentral.org/](http://gmatcentral.org/)

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waynenilsen
A mouse over description for TMI MTO MCO and MOI would be great, those
acronyms are meaningless to me. Edit - found as labels under ΔV Breakdown
heading

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jessriedel
Could also use an explanation of what it means to "calculate a transfer".
Like, the ΔV? The travel time? All possible parameters? Frustrating that if
you click on "What It Does", it doesn't clarify.

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foxyv
Most orbital calculations are "optimizations." You are looking for either the
best time or most efficient orbit that your craft can achieve. Most of the
time you are guessing at initial conditions that will produce a desired orbit
and then moving down a gradient to a local optima.

Other times you are looking to predict the velocity and position of an orbital
body at a certain time. Since there are many large planets in the solar system
this requires non-linear differential equations that can only be solved (at
this time) using an approximate calculation using methods such as the Euler or
Runge-Kutta method in a computer.

[https://en.wikipedia.org/wiki/Runge%E2%80%93Kutta_methods](https://en.wikipedia.org/wiki/Runge%E2%80%93Kutta_methods)

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dpcx
I've often seen artist renditions of how our solar system looks, and a lot of
people complain that it isn't a flat disk, that all of the planets are
trailing behind the sun as it flies through our galaxy. What I've always been
interested in is what that then looks like in our section of the galaxy.
[https://www.youtube.com/watch?v=C4V-ooITrws](https://www.youtube.com/watch?v=C4V-ooITrws)
is probably the best example of the trailing nature that I've seen. Does
anyone have suggestions for the movement through the galaxy bit as well?

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crossman
That video has some flaws which are covered in this helpful article from Phil
Plait [https://slate.com/technology/2013/03/vortex-motion-viral-
vid...](https://slate.com/technology/2013/03/vortex-motion-viral-video-
showing-suns-motion-through-galaxy-is-wrong.html)

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jkubicek
> It’s wrong. And not just superficially; it’s deeply wrong, based on a very
> wrong premise.

If you read further down in Phil Plait’s article, the video is based on a
conspiracy-theory-style paper written by a crazy guy.

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wurst_case
I'm writing a Sci fi novel and I can use this to help me build narratives! So
cool!

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joshuak
Track Starman and his Tesla from the Falcon Heavy test, and the Monolith from
2001. Switch to "The Expanse" mode and calculate transfers with Epstein Drive.

A++

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odysseus011380
Greetings. I'm a complete idiot when it comes to space. Still trying to wrap
my head around "direction," navigation and just how to see or look in space.
Would love a portable version of this program. Finally, can someone offer up
the difference between Planetary Transfer Calculator and Space Engine? Thanks

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mpwoz
Someone already mentioned it upthread, but I highly recommend playing "Kerbal
Space Program" to gain a better intuition of orbital mechanics. I'm no rocket
scientist but that game really helped me wrap my head around how things like
orbital transfers work without actually learning any of the math behind it.

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odysseus011380
Thank you very kindly. I will take a look at it post haste.

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malms
Does that use the real trajectories of the planets (such as give by the JPL
ephemerides) or or eliptical approximations ?

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wdfx
Interestingly a transfer from Earth to Jupiter ends up with Jupiter coming up
on the ship from behind at twice it's velocity - I would never have guessed
that to be the case, one always imagines a ship arriving at a somewhat
relatively static object.

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drspacemonkey
Basically, everything in space is a moving target.

If you'd really like to nail home an almost intuitive understanding of orbital
mechanics, I recommend Kerbal Space Program. Imagine Minecraft NASA. You plan,
build, launch, and fly space missions using a simplified physics model. It's
insanely fun and addictive, as long as you can get past the frustrations of
early failures.

I cannot recommend this game enough. I've got hundreds of hours in, and I'm at
the point where I've got huge spreadsheets carefully planning out mission
parameters to spec the requirements for my new heavy launch platform to
colonize the solar system. I'm even assembling a long-term research station in
orbit that will eventually be parked around a gas giant.

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ahakki
What you actually want is KSP modded with Principia to give you an n-body
simulation of the solar system.

[https://github.com/mockingbirdnest/Principia](https://github.com/mockingbirdnest/Principia)

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rtkwe
The existing SOI model is still good enough to give a more intuitive
understanding of orbital mechanics. Also did they ever fix the Jool system in
Principia? Never played with it but iirc there was an issue with Jool where
one of the inner moons would very quickly be ejected from the system.

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pavel_lishin
Given that it's a toy solar system, it's entirely possible that there's no
stable configuration for Jool's system with its full set of moons :/

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fsagx
Fun! A way to add gravity assist and multiple gravity assists would be a great
feature.

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karthie
Still gotta wait for 11 years approx to reach Saturn even travelling in high
speed.Long wait will try to post a reply back from Saturn once i land there
safely.

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SketchySeaBeast
You know Saturn is a gas giant, right?

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cardiffspaceman
WFSMC? Working from Saturn's Metallic Core?

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app4soft
_Stellarium_ [0]

[0] [http://stellarium.org](http://stellarium.org)

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Sharlin
Stellarium is a planetarium software. It doesn't help you calculate
interplanetary transfers, so if you're just mentioning it because it's a
tangentially related and undeniably great piece of software, you might want to
elaborate a bit.

