Around the World in Eighty Years
February 7, 2019 7:46 AM   Subscribe

Start with a small spaceship having a mass of 1500 kg from earth with a low start delta velocity of maximal 2.5 km/s, visit all nine planets of the solar system using only about 550 kg propellant in at most 80 years. Sounds crazy? Watch a short animation of such a "Jules Verne Tour," or if you like details, read all about how it was computed.
posted by Wolfdog (14 comments total) 17 users marked this as a favorite
 
"nine planets"
posted by pracowity at 8:32 AM on February 7 [2 favorites]


“we agree with Planet Pluto Definition
posted by Segundus at 9:03 AM on February 7


I hadn't heard of the GCMA-ES algorithm, it looks like it could be kind of neat if it works as they describe it. Optimising interplanetary orbits on a single commercially available PC rather than on a server rack would make it way more accessible, that is, if you're into designing space missions for fun.

> "nine planets"

Positively seething with passive-aggressiveness would be one possible description of the astrophysics community.
posted by Eleven at 9:04 AM on February 7 [1 favorite]


Nice!

I notice that the start date is on October 3rd, 2035. I wonder how common good start dates for something like this are - is this a once-in-a-century opportunity, or are there lots of options for start dates that'd work?

Somebody should make this happen, either way. Anybody want to tweet this at Elon Musk?
posted by clawsoon at 9:19 AM on February 7


Sounds crazy?

The same principles have been used successfully to reduce fuel requirements for single-planet missions, but the example mission itself is impractical. You can't expect a probe built today to last 80 years without any equipment failure, or for the technology used in the probe not to be hopelessly outclassed long before the mission is complete.
posted by cardboard at 9:31 AM on February 7


Don't count if you don't set foot...
posted by sammyo at 9:43 AM on February 7 [1 favorite]


Is this similar to / the same as the (fascinating) Interplanetary Transport Network?
posted by chappell, ambrose at 9:54 AM on February 7


If we remove the "clears its orbit" part of the definition as they argue, then this mission plan misses one of the ten planets.
posted by rhamphorhynchus at 10:27 AM on February 7


cardboard: or for the technology used in the probe not to be hopelessly outclassed long before the mission is complete.

That is surely true of Voyager I, and yet:
In a further testament to the robustness of Voyager 1, the Voyager team completed a successful test of the spacecraft's trajectory correction maneuver (TCM) thrusters in late 2017 (the first time these thrusters were fired since 1980), a project enabling the mission to be extended by two to three years.

Voyager 1's extended mission is expected to continue until about 2025 when its radioisotope thermoelectric generators will no longer supply enough electric power to operate its scientific instruments.
If I'm doing my math correctly, Voyager has been up there for 40+ years. That's not 80 years, but perhaps by 2035 we'll have bumped into the limits of Moore's Law anyway and there won't be nearly as much difference between 2035 tech and 2115 tech as there is between 1977 tech and 2017 tech.
posted by clawsoon at 12:03 PM on February 7 [5 favorites]


And when we're talking about "planned mission lifetime" Spirit and Opportunity would like to have a word too.
posted by DreamerFi at 12:37 PM on February 7 [2 favorites]


A cool project but how hard would the computation be to find the optimal launch date in the future to minimize all the factors, that is is there (in the next few centuries) a configuration of the orbits of the planets that shaves off significant time?

getting cold in German November 2018, but not in my flat as long as my AMD TR 2990WX is running full thrust utilizing all 64 threads.

But perhaps a better use would be how to optimize a speed survey of potential water bearing asteroids. One great find (cough... and the small factory to convert water to rocket fuel) could make rocketing around the solar system using fast 0.1G continuous thrust which puts the trip to mars at weeks rather than months/years. It's a bootstrap problem, very expensive to boost to orbit but if there was a depot the entire equation changes and we can go anywhere.

So much better to heat an apartment with orbits than bitcoins.
posted by sammyo at 1:24 PM on February 7 [1 favorite]


If we remove the "clears its orbit" part of the definition as they argue, then this mission plan misses one of the ten planets.

Actually at that scale, you're closer to 19 or 20 planets (so far). Which I'm fine with.

"Clears its orbit" is a weird, un-physical description. It was basically added purely to exclude Pluto and keep the list short for nostalgic reasons, otherwise there could be dozens of planets, and that would apparently be a bad thing.

If the chemists were as benightedly stupid as to make a similar call as the IAU, they'd limit the definition of an element with something equally weird, like "must have at least one stable isotope" just so the list would be shorter.

Then they turned around and said people objecting to the new definition only wanted to keep Pluto as a planet for nostalgia reasons, in almost textbook projection.
posted by tclark at 2:10 PM on February 7 [5 favorites]


Actually at that scale, you're closer to 19 or 20 planets (so far). Which I'm fine with.
Cool. I wasn't sure how many other objects in the solar system fit the definition, but I figured Ceres would, since it was a planet long before Pluto was. Now I check, though, Wikipedia says it's only the 33rd largest known object in the solar system!

"Clears its orbit" is a weird, un-physical description. It was basically added purely to exclude Pluto
I guess, but it was also an informal version of this rule that excluded Ceres for being part of the belt.

there could be dozens of planets
And thousands of exoplanets already!
posted by rhamphorhynchus at 8:16 PM on February 7


And thousands of exoplanets already!

But have they cleared their orbital neighborhood of debris?

The existence of exoplanets at the quantity we've found them puts this weird criterion even more into stupid territory. It's irrelevant.
posted by tclark at 3:58 PM on February 8 [2 favorites]


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