ChrisSpace's planetary alignment trajectory question/challenge

[ChrisSpace]

Okay, so i'm working on a project relating to space movies and fictional timelines, and I need your help with something. Specifically, I need to know 'when' Space Odyssey: Voyage To The Planets takes place. Specifically, I need to know if there is a way the 'grand tour' can take place with a launch date in the 21st century. Here is what I can find so far about the voyage depicted in the film:

The spacecraft 'Pegasus' is a fusion-powered vessel that begins its voyage with a 41-day trajectory to Venus, followed by another trajectory out to Mars. This is then followed by the spacecraft refueling in Mars orbit and then dropping to within 5 million miles of the sun, where it accelerates to nearly 300km/s. This slingshot takes it out to Jupiter where Pegasus endures a long aero braking manuver to get it on an elliptical orbit intercepting Io, where it enters orbit for a brief period of time before moving out to Europa, and then leaving the Jupiter system altogether. The vessel reaches Saturn and, after a less intense aero brake, enters a stable orbit in the Cassini Division before moving outwards to Titan, where it refuels and leaves for Pluto. After entering orbit around pluto the spacecraft returns to Earth (it also had a rendezvous with a comet but since said comet doesn't actually exist it can't be taken into account).

More info about the spacecraft: http://www.bbc.co.uk/sn/tvradio/programmes/spaceodyssey/pegasus.shtml

Extra rep for the first person to find a working planetary alignment and can hence put a date on when the events of the film take place.

[GeneralVeers]

Pluto is a good way to figure it out: in the first episode, when the map traces out the ship's path and the planned flight path reaches Pluto, Pluto (yes, it's a PLANET, dammit!) is shown as having crossed Neptune's orbit a short but noticeable while before, perhaps ten to fifteen years.

That's right about where Pluto is today. So that means the mission was projected to reach Pluto right around 2015. If the mission took 41 days to reach Venus, I'd say the mission from launch to Pluto took around five years.

[ChrisSpace]

Oh, another thing I forgot to mention is that the entire film is available on youtube. It often shows what day into the mission something happens (eg it shows that the Jupiter aerobrake happens on day 411) so that might be useful.

[GeneralVeers]

Yeah, found Part 1 on YouTube when I wrote my first post.

Next cheesy trick: I re-watched the mission animation they showed early in the episode; this scene lasted about 24 seconds from Earth to Pluto, and the flight line reached Jupiter about 15 seconds in. So, 15 seconds for 411 days = 27.4 days per second, or 657.6 days for the full trip to Pluto. Meaning, if the ship reached Pluto in 2015, it launched just under two years before, therefore sometime in 2013.

However, any method used will be a guess, because it's still a TV show and I'm pretty sure they took some creative license somewhere, even if they did base it on fact.

[Shpaget]

Speaking without actually watching the movie, if it takes only 41 days to get to Venus, they are not using Hohmann transfer orbits, but rather something much more direct and less energy efficient, meaning they can launch pretty much any time, so there is little need for planetary alignment.

[YNM]

Depends on what kind of thrusters is used.

Assuming no continuous thrust, one thing that can become the key is the transfer between Mars and Jupiter, given perihelium distance and perihelium velocity. This way we can tell the angles in between, while also being able to calculate the whole transit time and type of orbit.

[ChrisSpace]

All the actual 'mission time' dates are shown in the film, so things like how long it took to get from X to Y are mostly known. The book also has lots of extra info.

[ChrisSpace]

Okay, I have come up with a plan. In the intro they show Pegasus' trajectory out to pluto. If I were to download a clip of that bit I could triangulate exactly where the 'camera' is at different parts of that trajectory scene, and using the amazingness of SpaceEngine I could find out exactly when the planets are in that position. There is one problem: My current video-downloading software can't handle videos of more than 20 minutes or so, and the only clips from the film that have that part that I can find are 57-59 minutes long. So that leaves us with two options: Either we find a shorter clip from the film with the trajectory scene in it, or someone with better video-downloading software can download it and shorten it to just that scene, then give me the shorter clip file. I like the first idea better but I can't find any short clips with the scene, so this is where I need your help.

[Mr Shifty]

There have been several discussions of this over in the Orbiter forums over the years. Here's probably the most relevant:

http://orbiter-forum.com/showthread.php?t=34352

Near the end, user dgatsoulis posts a set of scenarios that are as close as possible to what you see on the show.

[ChrisSpace]

There have been several discussions of this over in the Orbiter forums over the years. Here's probably the most relevant:

http://orbiter-forum.com/showthread.php?t=34352

Near the end, user dgatsoulis posts a set of scenarios that are as close as possible to what you see on the show.

Extremely valuable source is extremely valuable. Thanks!

[ChrisSpace]

Okay, it turns out the only really notable thing I got from that source was this image:

This image includes everything we need to know: Important dates and the relative positions of the planets at certain times. The 8th frame, for example, shows the relative positions of Venus, Earth and Mars, as does the 12th. It should be possible to find when these planets are in this relative configuration, and at what times the configuration is compatible with the positions of the other planets shown. I imagine that SpaceEngine, Universe Sandbox2 or Celestia has some feature where you can see this. I have tried but so far I haven't found any alignments. First to do this gets lots of rep!

[cantab]

This is then followed by the spacecraft refueling in Mars orbit and then dropping to within 5 million miles of the sun, where it accelerates to nearly 300km/s.

This made me do a double-take. If your aim is low fuel usage and you want to go from one satellite to another you should just transfer between them. Dropping to a low periapsis over the primary is only relevant if you want to escape it altogether. But when time is a concern as in the described scenario, then there *may* be cases where whipping round the Sun is worthwhile.

[ChrisSpace]

This made me do a double-take. If your aim is low fuel usage and you want to go from one satellite to another you should just transfer between them. Dropping to a low periapsis over the primary is only relevant if you want to escape it altogether. But when time is a concern as in the described scenario, then there *may* be cases where whipping round the Sun is worthwhile.

I'm just going off exactly what happens in the film. I don't know how efficient it is.

[ChrisSpace]

Okay, so far I haven't had any luck finding a date when Venus, Earth, Mars and Jupiter are in the positions shown in the image above. I really need help. Bonus rep to the first person to find this.