TheJeeronian t1_je1wvdz wrote
There is an extraordinary amount of math involved. They plan out the exact path of the vessel, as well as the paths of all planets involved.
The approximate path of the vessel is calculated with conic sections (ellipses and hyperbolas) around a planet or star.
The best way to predict a path, albeit with an extraordinary amount of math, is actually very simple. We use the conic sections to predict planets' orbits, since they don't tend to change much, and then we do a very simple calculation to see how much they each tug on the vessel. We then add all of these tugs together and see what direction it is pulled overall. We move it a tiny forward, and repeat the calculation again. Move it again. Calculate, move, calculate. Over and over ten billion times to get a good prediction of the path the vessel will follow. Computers are great for that.
Pokinator t1_je1yhwd wrote
OP's question also brings to mind the story of the Curiosity Opportunity rover on mars.
It's original tenure was only supposed to be a 90 day mission on the surface, but through a combination of good construction and non-catastrophic conditions, it instead served for 14 years. It didn't stop until a harsh dust storm knocked out its ability to recharge.
Similarly, something like the Voyager is a combination of "let's get it as far as we can" and "let's see how far it will go". With enough computation and simulation, a path can be plotted out of our star system so that it doesn't hit Pluto and crash. However the farther it goes, the more Chaotic Entropy comes into play. We can project paths of celestial bodies, but longer predictions bring on more deviations until it stops being viable.
Once Voyager cleared the system, it was reasonable to say "alright, we've set it up as best we can, let's see where it goes" and keep collecting data as long as it transmits
arcosapphire t1_je2201g wrote
> OP's question also brings to mind the story of the Curiosity rover on mars.
> It's original tenure was only supposed to be a 90 day mission on the surface, but through a combination of good construction and non-catastrophic conditions, it instead served for 14 years. It didn't stop until a harsh dust storm knocked out its ability to recharge.
You're referring to Opportunity, not Curiosity. Curiosity was activated under 11 years ago, is still operational, and doesn't recharge because it uses an RTG.
Opportunity was deployed for 14 years and relied on solar power.
remorsefulDownfall OP t1_je1zsgb wrote
I don't know how to give best answer of if that's even a power that I have on my post but this is definitely it so far, thank you! This is exactly the type of comprehensive breakdown that I was looking for.
remarkablemayonaise t1_je2h616 wrote
I'm not sure which of us is confused. Conic sections are solutions to two body problems or similar (the Earth is orbiting the centre of mass of the solar system, not the sun itself).
Three body problems rely on second by second force simulations. Instantaneous force simulations lead to accelerations which lead to changes in velocity and location, which feedback to the force simulations.
Euler's method and similar are ways to solve differential equations like above.
TheJeeronian t1_je2u1zk wrote
Conic sections are just an approximation. The fairly minimal tidal gradient makes stitched together conical sections a decent approximation - when you're near Earth you follow a conic around Earth and your path around the sun otherwise mimics that of Earth.
The Earth orbits the solar system's barycenter, which approximates fairly nicely to the sun but if we ignore the sun and patch our conics around the barycenter it works even better.
The method is aptly named "patched conics".
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