5 ms·

Planetary Transfer Calculator

99 points by T-A 7y ago

wurst_case 7y ago
I'm writing a Sci fi novel and I can use this to help me build narratives! So cool!
malms 7y ago
Does that use the real trajectories of the planets (such as give by the JPL ephemerides) or or eliptical approximations ?
waynenilsen 7y ago
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
- jessriedel 7y ago
  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.
  - foxyv 7y ago
    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
app4soft 7y ago
Stellarium[0] [0] http://stellarium.org http://stellarium.org
- Sharlin 7y ago
  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.
karthie 7y ago
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.
- SketchySeaBeast 7y ago
  You know Saturn is a gas giant, right?
  - cardiffspaceman 7y ago
    WFSMC? Working from Saturn's Metallic Core?
rcuv 7y ago
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/
dpcx 7y ago
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?
- crossman 7y ago
  That video has some flaws which are covered in this helpful article from Phil Plait https://slate.com/technology/2013/03/vortex-motion-viral-video-showing-suns-motion-through-galaxy-is-wrong.html https://slate.com/technology/2013/03/vortex-motion-viral-vid...
  - jkubicek 7y ago
    > 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.
    - woah-theories 7y ago
      The paper may be written by a crazy guy, but it's not a conspiracy theory unless there's a threat of real harm and abject paranoia of danger. So the paper may be a crackpot hypothesis, but if it's there to present a bogus idea, but isn't designed to foment anxiety of a secret enemy, there's nothing related to conspiracies. Paranormal magical thinking may specify fictious alien races, some good and some bad, and present conflict among made up aliens, with some of them being evil villains, but then it's just supernatural musticism with a science fiction angle, and not conspiracy theories. Even if it pushed an idea that the movie They Live was based on fact, it wouldn't be a conspiracy theory until drawing the major focus on connections to real world events, and hijacking the readers focus to recruit believers of a fear oriented narrative. If that's not the case, it wouldn't be particularly correct to categorize the ramblings of some freak as conspiracy theories. So get your terminology straightened out.
fsagx 7y ago
Fun! A way to add gravity assist and multiple gravity assists would be a great feature.
joshuak 7y ago
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++
wdfx 7y ago
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.
- drspacemonkey 7y ago
  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.
  - ahakki 7y ago
    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
    - rtkwe 7y ago
      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.
      - pavel_lishin 7y ago
        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 :/
deleted 7y ago
[deleted]
odysseus011380 7y ago
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
- mpwoz 7y ago
  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.
  - odysseus011380 7y ago
    Thank you very kindly. I will take a look at it post haste.

99 points by T-A 7y ago

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

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

waynenilsen 7y ago

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

jessriedel 7y ago
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.
- foxyv 7y ago
  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

app4soft 7y ago

Stellarium[0] [0] http://stellarium.org http://stellarium.org

Sharlin 7y ago
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.

karthie 7y ago

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.

SketchySeaBeast 7y ago
You know Saturn is a gas giant, right?
- cardiffspaceman 7y ago
  WFSMC? Working from Saturn's Metallic Core?

rcuv 7y ago

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/

dpcx 7y ago

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?

crossman 7y ago
That video has some flaws which are covered in this helpful article from Phil Plait https://slate.com/technology/2013/03/vortex-motion-viral-video-showing-suns-motion-through-galaxy-is-wrong.html https://slate.com/technology/2013/03/vortex-motion-viral-vid...
- jkubicek 7y ago
  > 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.
  - woah-theories 7y ago
    The paper may be written by a crazy guy, but it's not a conspiracy theory unless there's a threat of real harm and abject paranoia of danger. So the paper may be a crackpot hypothesis, but if it's there to present a bogus idea, but isn't designed to foment anxiety of a secret enemy, there's nothing related to conspiracies. Paranormal magical thinking may specify fictious alien races, some good and some bad, and present conflict among made up aliens, with some of them being evil villains, but then it's just supernatural musticism with a science fiction angle, and not conspiracy theories. Even if it pushed an idea that the movie They Live was based on fact, it wouldn't be a conspiracy theory until drawing the major focus on connections to real world events, and hijacking the readers focus to recruit believers of a fear oriented narrative. If that's not the case, it wouldn't be particularly correct to categorize the ramblings of some freak as conspiracy theories. So get your terminology straightened out.

fsagx 7y ago

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

joshuak 7y ago

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++

wdfx 7y ago

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.

drspacemonkey 7y ago
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.
- ahakki 7y ago
  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
  - rtkwe 7y ago
    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.
    - pavel_lishin 7y ago
      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 :/

deleted 7y ago

[deleted]

odysseus011380 7y ago

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

mpwoz 7y ago
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.
- odysseus011380 7y ago
  Thank you very kindly. I will take a look at it post haste.