OHM Gravity Controller MFD

[OrbitHangar]

Author: wizard1073

INTRODUCTION
This MFD is designed to modify the gravitational effect on any vessel via a simple mechanism of using a virtual thruster to affect gravitational force.  The MFD is written in LUA and implemented through the ScriptMFD.  The motivation for this MFD is to make any vessel able to liftoff from Earth with or without thrusters.  It has far more applications than this, which will be evident to anyone who has been looking for this functionality.

The gravitational setting can be made stronger, weaker, or negative.  This corresponds to field strength modifiers greater than 1, less than 1, and less than 0.

POSSIBLE USES
o  Allow vessels with normally insufficient hover thrusters to liftoff vertically.
o  Allow vessels to land and stay landed on low-gravity moons and other such bodies.
o  Modify effectiveness of slingshot maneuvers by increasing/reducing effective gravitational force.
o  Reduce amount of thrust required to complete an orbital maneuver close to a gravity well.
o  Test a vessel's aerodynamic configuration for stability under differing gravitational force scenarios.
o  Allow creation of a vessel that chiefly uses stronger and weaker gravitational effects to maneuver.  (I am reminded here of a vessel mentioned in the third(?) book in the Foundation series by Isaac Asimov.  It was equipped with anti-gravity and hyperspace engines.)

HOW IT WORKS
The MFD creates an invisible thruster and a small propellant source when engaged.  It then uses this thruster to add or subtract from gravity's effect.  The gravitational modification is proportional to the total force exerted by gravity on the vessel. 

CREDITS
1) Isaac Asimov and the Foundation series.  The brief description in the third book of a ship having anti-gravity and hyperspace engines and how it was used smoothly leave the planet surface to reach a jump point fascinated me completely.
2) Artlav, developer of WarpDriveMFD Mk2 R1.  I use the anti-gravity feature far more than the warp drive feature.  My only complaints are that it is not persistent to the vessel (i.e., when focus is changed to another vessel, gravity suddenly returns), and that it does not allow variable effect.

3) DanSteph and his mission scenario "Beautiful landing on Phobos".  I stuck the first landing, but wondered how I could do it if I had less skill.  With this MFD, an increased gravity effect helps a little.
4) Martin Schweiger, developer of Orbiter.  I've been having fun since Orbiter 2006, and the LUA interface has been a real window of opportunity to tailor the simulator even further.

REVISION HISTORY
1.0, 1 April 2011, Initial Release


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[Scruce]

Very good addon, been testing it and i have seen no problems. :thumbup:

 

[wizard1073]

Stability under time compression

I tested it at the highest time compressions and it was stable, thank God! There's some angular instability if you use high time compression within atmosphere, but that is not related (I believe) to the MFD mechanism. That problem seems to be aerodynamic.

The fun part was avoiding the pole at zero modification (full gravity). Apparently one cannot set an engine's Isp to zero. :lol: That took me a week to figure out.

The DLL version should be easier, as there is an addForce() function. It should eliminate the virtual engine entirely.

 

[Scruce]

With it i was able to start to build MIR in the atmosphere:

 

[Stevodoran]

Set gravity to zero and you have unlimited fun :thumbup:

 

[Scruce]

Set gravity to zero and you have unlimited fun :thumbup:

But remember to set docked vessels gravity to zero aswell. Yep, MIR-2 ended up like its predecessor :lol:.

 

[jangofett287]

Anti-gravity makes for a good launch tool!

 

[Stevodoran]

I took the space shuttle for a fly around ksc :lol:

And try this, Open orbiter use the DGIV and eject while on earth with gravity at zero, This happens

 

[jangofett287]

Load up any vessel, do nothing, just set your grav to O, and wait for it to reach that. Your vessel will start to slowly float upwards. Anyone else noticing that?

 

[Stevodoran]

Load up any vessel, do nothing, just set your grav to O, and wait for it to reach that. Your vessel will start to slowly float upwards. Anyone else noticing that?

Yup

 

[jangofett287]

I've had a brilliant idea. Anyone up for a game of 0-Grav football with DGIVS?

 

[Scruce]

Load up any vessel, do nothing, just set your grav to O, and wait for it to reach that. Your vessel will start to slowly float upwards. Anyone else noticing that?

Its because of two reasons:

1) The rotation of Earth,
2) The movement of Earth (orbiting the Sun).

 

[Bonanza123d]

I want to do this. I think it will be very fun and enjoyable.

 

[Jamesep3]

What are the effects on space flight? does it allow the whowly unrealistic ability to slow down and speed up with engines engaged like in most sci-fi movies?:shrug:

 

[martins]

Load up any vessel, do nothing, just set your grav to O, and wait for it to reach that. Your vessel will start to slowly float upwards. Anyone else noticing that?

If you disable gravity for vessels, but not for anything else, you will get all sorts of pseudo forces which can manifest themselves in effects like this. In this particular case, it may be atmospheric friction that imparts a tangential impulse on your vessel, and slowly slings it away from the planet.

If you really want to get rid of gravity, then you need to do it a bit more extensively to avoid this kind of unpredictable behaviour. At the very least, you should

• disable atmospheres for all planets (they won't be able to hang on to them)
• disable orbital trajecories for all planets and moons, and let them escape in straight lines from the point they were when gravity disappeared.
• disable the sun (as a radiation source), since fusion in the core will stop without the required gravity-induced pressure
• eventually probably remove the sun and all other bodies altogether since they would dissipate/fall apart without gravity.

Somehow, life without gravity doesn't sound that exciting.

 

[Istochnikov]

Required for Vorchan, Primus, Sharlin/Shargotti/Sharaal/Valen'tha, and Warlock class spaceships from B5

 

[wizard1073]

Two potential improvements

1) I thought of this for airplanes, but it would work just fine for spacecraft: A safety setting that uses antigravity to prevent crashes. This would be useful for mothership-based launches, where the autopilot is not necessarily to be relied upon. Gravity would only be altered to create a two or three gee deceleration, resulting in a hover just above the surface.

2) A counter-drag setting that only mitigates gravitational drag. This would permit (I think) normal launch autopilots to work, as the gravity controller would reduce the affect as centripetal acceleration increases with the horizontal velocity. Once in circular orbit, there would be no further gravitational drag.

Martin is right about the need for gravity. It's not just a good idea... It's the Law. :lol:

 

[Keatah]

Ok good. Now, what add-on is the right one to use? The HiggsFieldController or Gravity Controller?

 

[jangofett287]

What are the effects on space flight? does it allow the whowly unrealistic ability to slow down and speed up with engines engaged like in most sci-fi movies?:shrug:

No, it does not. To do that you would have to get rid of conservation of energy and/or conservation of momentum.

 

[Izack]

No, it does not. To do that you would have to get rid of conservation of energy and/or conservation of momentum.

Well, that can't be all that hard to do, if we can already repeal the law of gravitation.

Speaking of that, I'm dubbing this tool RhinoMFD.