Slingshot

[pippo]

I watched a documentary on the BBC not so long ago about the Voyager probes and how they managed to send them so far out whitout any fuel issue. They used the gravity pull of the planets in our solar system to slingshot around them and be catapulted further away.
I'm sure that for most of you, this isn't a big discovery, but it was to me.
Now, I was well aware of the gravity pull role of planetary bodies in Elite Dangerous while traveling near a planet in super cruise (i.e. that slows you down). But since then, didn't quite understand why I would over shoot some of my destination yet always in the "blue zone/sweet spot" speed. Now I understand, and my piloting is greatly improved, and actually a lot more enjoyable.
I love this game to bits, especially when one of these bits turns out to be a great yet "silent" gameplay feature.

I just felt like sharing...

 

[pippo]

The context is something like you're compressing space around your ship to move faster than light using your normal engine capability. However you can only compress space so much in the presence of a gravity well. The stronger the well the less you can compress thus the slower you move through space. Actual gravitational pull isn't being taken into account at all because the space compression is way more powerful than the affect of gravity and your ships computer automatically put you in a stable orbit around planets (i.e. your frame of reference) anyway. Thus the only factor that controls your speed is how much space is being compressed and what throttle you set your ship too.

Now I know how wrong I was.

 

[Twelvefield]

Right and wrong, friend. The game is a game, so gravity isn't simulated, although it's suggested from time to time.

Slingshot trajectories are extremely important to build speed in space, provided that fuel and mass are limits to spacecraft construction (they aren't in ED), and that you don't mind travelling at very much below sublight speeds (exceeding C is common in ED). Adding a gravitational slingshot to motion in ED space would be a bit like using a hamster wheel as a boost for your Formula 1 Ferarri: the effect is so negligible compared to the delta-vee capable by the least of the craft that you needn't bother to factor it into the game.

Planetary motion seems to be governed by just by setting an orbit and having the object move in its track. Real relativistic motion is certainly possible, see Universe Sandbox Simulator, but it would cause the game to grind to a halt.

As for overshoot, if you or anyone else is wondering, follow the James Bond Rule: make the time counter read 007. That seems to be reasonably efficient while avoiding most overshoots. Not my rule, some other helpful CMDR passed that on to me.

 

[pippo]

Adding a gravitational slingshot to motion in ED space would be a bit like using a hamster wheel as a boost for your Formula 1 Ferarri

True unless…

Spoiler

 

[digitalscream]

Adding a gravitational slingshot to motion in ED space would be a bit like using a hamster wheel as a boost for your Formula 1 Ferarri: the effect is so negligible compared to the delta-vee capable by the least of the craft that you needn't bother to factor it into the game.

Tell that to Spock et al.

 

[pippo]

On a more serious note Twelvefield, I did overshoot targets yet always being in the blue zone, and I'm also fully aware of the 7sec (6sec?) rule of thumb yet it really did feel, like stated in the first post, that I was somewhat being "slingshot" out of the planet or star's gravity pull.
The reason why I quoted M.Evans is that now, I'm confused again.

 

[Lobstris]

To make you even more confused, have a look at what was in the DDA's regarding slingshots and microjumps (second post in the thread). https://forums.frontier.co.uk/showthread.php?t=7892.

Also note this from Sandro Sammarco:

Although the FSD locally distorts space, effectively shrinking distances, it does not affect gravity, so the effect results in apparently massively increased gravitational forces:

• Gravitational influence from locations is significantly extended in both range and strength, dragging the commander’s vessel off course, but also allowing skilful slingshots around massive bodies.

.
Somewhat contradictory to the Mike Evan's quote.

 

[pippo]

To make you even more confused, have a look at what was in the DDA's regarding slingshots and microjumps (second post in the thread). https://forums.frontier.co.uk/showthread.php?t=7892.

Also note this from Sandro Sammarco:
.
Somewhat contradictory to the Mike Evan's quote.

I don't know if I should say thank you anymore...

 

[Lobstris]

I don't know if I should say thank you anymore...

I believe the correct response is to shed a single tear at what the game could have been, before getting on and enjoying what's there anyway.

 

[Bortas]

I watched a documentary on the BBC not so long ago about the Voyager probes and how they managed to send them so far out whitout any fuel issue. They used the gravity pull of the planets in our solar system to slingshot around them and be catapulted further away.
I'm sure that for most of you, this isn't a big discovery, but it was to me.
Now, I was well aware of the gravity pull role of planetary bodies in Elite Dangerous while traveling near a planet in super cruise (i.e. that slows you down). But since then, didn't quite understand why I would over shoot some of my destination yet always in the "blue zone/sweet spot" speed. Now I understand, and my piloting is greatly improved, and actually a lot more enjoyable.
I love this game to bits, especially when one of these bits turns out to be a great yet "silent" gameplay feature.

I just felt like sharing...

Slingshot meneuvers are useful for spacecraft travelling at very low speeds, like our present probes. In ED we are travelling with some kind of "warp"-drive compressing space-time in front of us and expanding it behind us, enabling us to travel with up to ~2000c. Slingshot meneuvers would be absolutely ridiculous for such drives. In fact, as we all know, the presence of strong gravitational fields interferes with the FSD in ED, so passing celestial bodies at close distances actually slows us down.

 

[Loskene]

Tell that to Spock et al.

Let's get crossover. The Tipler slingshot manoeuvre first performed by Spock and the Enterprise crew relies on using the Cochrane warp drive to bend spacetime to an extreme degree in an area where it's already being warped by a large mass, generating a constructive interference pattern and allowing you to travel through time as a physical dimension. Hence looping around a star at maximum warp. Unfortunately the frameshift drive generates a destructive interference pattern with natural gravity wells and becomes less effective in the regions where enough spacetime bending would pull you through time. The upshot is that this flavour of spacebending allows hyperspace jumps across vast distances, instead of having to go as the crow flies at significant but not instant velocities. Until significant breakthroughs are made in frameshift engine theory, you won't be sending your Orca back in time to rescue any humpback whales from 1980s san francisco.

 

[who?]

Slingshotting would be very cool to include in the game (turn off safeties, aim for the planet, get a near miss swing around and come around the other side at 2,001c!)

Well, after reading up about slingshotting it seems doesn't really work like that. Slingshotting can speed up or slow you down depending on the celestial body's orbital velocity relative to your craft. In order to model slingshotting properly you'd have to be able to determine the direction in which the planet is travelling and adjust your approach accordingly, you can't just "slingshot on demand" in any direction you want.

Here's a cool piece I learnt though - slingshotting can slow the body you're swinging around (very, very minutely, because of the relative difference in mass). Imagine having a really, really evil Community Goal, where the goal was to have lots and lots of craft repeatedly slingshotting around a planet and thus slow it down enough to drop out of orbit and into its sun. I think that would be pretty popular.. some people really want to see a world burn!

 

[pippo]

Slingshot meneuvers are useful for spacecraft travelling at very low speeds, like our present probes. In ED we are travelling with some kind of "warp"-drive compressing space-time in front of us and expanding it behind us, enabling us to travel with up to ~2000c. Slingshot meneuvers would be absolutely ridiculous for such drives. In fact, as we all know, the presence of strong gravitational fields interferes with the FSD in ED, so passing celestial bodies at close distances actually slows us down.

No nitpicking here, but I'm not sure I understand where you're getting at…
I think I understand now the trivial slingshot effect relative to the space-time compression that you, Twelvefield and Mike Evans are on about. But the question remains (unless I am completely missing the point, will you excuse me as I am not english) Why oh why do our ship gets catapulted out of a gravitational field?

In fact, as we all know, the presence of strong gravitational fields interferes with the FSD in ED

This is what I don't get… In fact, I don't know.

 

[pippo]

Imagine having a really, really evil Community Goal, where the goal was to have lots and lots of craft repeatedly slingshotting around a planet and thus slow it down enough to drop out of orbit and into its sun.

Or out of orbit not into the sun but into interstellar space, which unless undiscovered is something that I wish was in the game, but I'm digressing here...

 

[Zplintz]

It's a simple mechanic where the closer you get to a gravity well and stronger that effect, the lower your max speed.

It may be that Sandro' s proposal was just too much to cope with on current technologies or unplayable by the majority of players.

I believe the correct response is to shed a single tear at what the game could have been, before getting on and enjoying what's there anyway.

No tears necessary - there is plenty more to come and plenty of time to extend physics and mechanics during the process.

I am definitely not crying at what (I believe) was a proposal of what FD were considering not what would definitely be in game at launch or even ever.

In the land of pipe dreams not everything you imagine is practical or feasible.

 

[Lheim]

Jupiter accelerated the voyager space probe a few kilometers a second, over the course of days.

Your absolute bare minimum speed in supercruise is 30 kps; but you're usually in the vicinity of large planets for moments. The hamster wheel analogy is exact.