Using the symmetry of interstellar flight dynamics to manage the journey to a distant object

[Andrew Linton]

Take a look at these two charts which display observations of speed, distance, and time made during the Chalker Landing Community Goal back in March, 3302.

Spoiler

The symmetry of the speed profile shows, I believe, that the journey time to reach the mid-point of a long transit like this is equal to the time taken to travel from the mid-point to the destination.

This predictability, at its best when there are only two stars in a system with no other object disturbing the gravity field, makes it possible to create a Voice Attack profile to manage the second half of the journey. Provided you can stay alert and can mark your passage through the mid-point of the journey, the profile I've created will manage your arrival at the distant object i.e. it will stop your ship before you overshoot. (I'm not saying you won't crash into an icy moon before you get to the star, but that's not an issue when there's only one object at the destination)

This video shows the profile in action:

Spoiler

[video=youtube_share;aB_JjkYF5LA]https://youtu.be/aB_JjkYF5LA[/video]

You have to tell the profile when you're at the mid-point of the flight; I use a spare key, bound to a Voice Attack command, to flag up the event; you can either observe the moment of maximum velocity, or use the range information in the navigation panel to spot when the destination star jumps to the top of the display, indicating it is closer than the departure point.

If you want to try the profile, I've attached it as a .txt file which you could rename as .vap: View attachment Managed Interstellar Flight.txt

 

[mls]

but the midpoint is shifting towards the heavier astronomical object. the greater the difference between the masses, the more the shifting. this will probably only work when you have just two similar heavy objects.

just fyi

 

[dognosh]

I dunno mls, I have noticed my speed increasing until I hit mid distance many dozens of times, then speed starts dropping ? You sure gravity plays a part in that ?

 

[mls]

at least i remember being fastest when closer to the smaller object. dunno if thats changed. but i'm pretty sure

Edit: didn't want to break your spirit, just don't want you to faceplant that O-Type ;-)

 

[Andrew Linton]

I dunno mls, I have noticed my speed increasing until I hit mid distance many dozens of times, then speed starts dropping ? You sure gravity plays a part in that ?

That's my experience, too. What can spoil this approach is a clutch of planets round the departure star, or having to fly past a far-flung icy world on the way to the destination. Anything that slows the initial acceleration can increase the time to the mid-point, with the corresponding risk of overshooting at the destination - hence my proviso in the OP about the profile working best with only two bodies in the system.