The Zero Delta V Challenge

[ihtoit]

The Deceptively Simple Challenge: Using NO delta V whatsoever, achieve (or prove) an escape orbit from LKO.

THE RULES:

- ANY part mod valid (excluding partwelding).

- NO infinite fuel or other things that break classical physics (except stock massless parts and ASAS units).

- Engines must be shut off or better yet, jettisoned, before departing LKO. This includes warp drive, ion, monoprop, RCS, or any other form of thrusted or wave propulsion known or unknown.

SCORING:

1,000 points for supplying a proof.

1 point for changing (and circularising) orbit using your proof, score per km of delta-a (change in semi-major axis). Score achieved on completion of circularising manoeuvre only.

1,000 points for achieving escape trajectory.

(Before you come back with "It can't be done!", yes it can. You see the effect every single time you launch).

[BagelRabbit]

I flew a Launch Stability Enhancer to the orbit of Eve, once. I think that this entry merits a full 2,000 points... except for the fact that it does "break classical physics." Just a little bit...

(okay, maybe more than a little bit. Sorry.)

Proof!

[goduranus]

No, he meant you must start in Low Kerbin Orbit, infiniglider wing does not work there.

[sdj64]

Yes. Yes it can. Though not every launch, there are plenty of SSTOs. (note that enough to make orbit is enough to make it to escape if I started in LKO with this thing. I could also just make it bigger since it's masseless.) http://forum.kerbalspaceprogram.com/threads/83595-Project-Orion-decouplers-to-orbit

[Kasuha]

Delta v is change in velocity, it does not have to have anything to do with any particular kind of propulsion. If you change your velocity (direction or magnitude) in any way, you "used delta v".

Even if you start rotating your ship, then decouple/undock a part to send it on different orbit, you "used delta v" since you gave it an impulse and changed its velocity.

So I'm not really sure what is this challenge supposed to be about.

[goduranus]

Either explosions or decouplers. But hey, there is a way to move around without delta V, by exploiting center of mass issues during fuel transfers.

[chengong]

You can get off and push. And since I can do this forever cuz my kerbal doesn't get tired, I can circularise and ruin my orbit over and over, which gives me infinite points.

[KerikBalm]

Poorly explained challenge is poorly explained.

[Wanderfound]

Yup, 'tis rather vague at the moment.

You can certainly hit escape velocity without any orbital thrust, though:

[Pds314]

Essentially:

Decouplers are cheating because they have Delta-V.

Infiniglide won't work because you don't reach orbit.

The Manley fuel transfer dumbbell violates classical physics.

Kerbal-on-ladder violates classical physics.

Spinning up using ASAS and timewarping when your origin part is moving faster than your CoM violates classical physics.

Regular fuel or ion drives are cheating because they have Delta-v.

Kraken drives violate classical physics.

The only way I see of doing this is to make a ship which consists of a pile of SAS units and generators of some kind, and a giant tower of low-mass or massless parts and a fairly light pod or a massless ladder with a Kerbal on it, spin up the ship such that the speed of the pod will exceed escape velocity, then release, and let it go flying, uncontrolled, through the Kerbol system. This still, of course, by definition, has Delta-v, and is also one-use.

[Pds314]

If physics exploits were allowed, then Kerbal-on-ladder drives would be my instinct. Especially considering that there is no hypothetical upper limit to the acceleration of a massless cubic octagonal strut with a massless ladder attached and a Kerbal, who, while not massless in nature, is massless on a ladder, pushing it.

[r_rolo1]

Hum, Delta-V means literally change of velocity, NOT stored energy that can be transformed in movement. So the OP affirms that he can go from a LKO orbit to a escape velocity without changing speed (including direction ) and without violating the laws of classical physics ( quoting "except massless parts and ASAS units" ). That I can assure it is impossible.

But assuming that the dV thing is just misleading advertising, you can just make Jeb go out and push. Nothing in the challenge wording forbids it ...

[KerikBalm]

The Deceptively Simple Challenge: Using NO delta V whatsoever,

So anything that changes your velocity is forbidden

achieve (or prove) an escape orbit from LKO.

There is no such thing as an escape orbit. There are orbits, and there are escape trajectories, but not both.

Changing your orbit changes your velocity, and violates the prohibition against velocity changes

- ANY part mod valid (excluding partwelding).

So the alcubiere drive of Interstellar mod is allowed, that "warp drive" does not change velocity, it just translates through space.

Solved?

- NO infinite fuel or other things that break classical physics (except stock massless parts and ASAS units).

Aww, warp drives break "classical" physics. We're back in impossible challenge again.

- Engines must be shut off or better yet, jettisoned, before departing LKO. This includes warp drive, ion, monoprop, RCS, or any other form of thrusted or wave propulsion known or unknown.

Warp drive is a wave propulsion? why would it be allowed, it breaks classical physics (and is still highly speculative, and just becuase its not proven impossible doesn't mean.... well, I direct you to russel's teapot).

If you are in LKO, you cannot leave LKO without changing your velocity or position. To change your position without a change in velocity is essentially a warp drive, which you have forbidden, and violates classical physics, which you have also forbidden.

(Before you come back with "It can't be done!", yes it can. You see the effect every single time you launch).

Unsupported and clearly false assertion is unsupported and clearly false.

[goduranus]

You can change your orbit without changing your velocity!

Just trying it, go 3000m/s in the direction of prograde horizon at 70km altitude, and maintain that 3000m/s, see what happens to your orbit.

Hell, I know how to complete this challenge, it can be done.

[r_rolo1]

You can change your orbit without changing your velocity!

Just trying it, go 3000m/s in the direction of prograde horizon at 70km altitude, and maintain that 3000m/s, see what happens to your orbit.

Hell, I know how to complete this challenge, it can be done.

Major confusion there. For doing that you will need to trade kinetic energy to overcome the higher potential energy of a higher position in the Kerbin gravity well ( in other words , you will need to get higher because you are keeping the same velocity, including direction vector BTW same numerical speed with a different direction implies dV different of zero ). A higher position with the same speed is equivalent to you first getting to the higher position ( with a decreased speed, by definition ) and then change speed to match the previous speed at lower altitude. Thus it implies a dV change

[Nao]

@goduranus haha, nice one... going further with this:

Accelerating an object with a force that is always perpendicular to direction of movement will never actually change the velocity of the object itself, only it's direction of motion. (Just like how circular orbits work, with gravity as constant acceleration).

So i would just burn straight up from LKO keeping attitude on 90deg angle to velocity vector... any changes in actual velocity can be blamed on orbital mechanics (like the one that occurs when going around elliptic orbits).

It could be said that accelerating an object this way would never change it's velocity by itself, no change in velocity no "delta v"... problem solved... where i can contact NASA, these guys are doing it all wrong!

[Wanderfound]

Incidentally, if read sufficiently literally, the rules don't explicitly forbid Hyperedit. Ain't nothing "physics-breaking" about simulated teleportation.

[goduranus]

To beat this challenge involves no engines, decouplers, explosion, or GOTP maneuvers. I saw this at Scott Manley's btw

Start your ship with a probe core, connect several long girders in front and several long girders in the back to make it as long as possible. Then connect a fully loaded fuel tank in front, and an empty fuel tank in the back. Add some reaction wheels for turning and struts to keep it together.

E----------C----------F

(E=Empty Tank, C= Core, F= Full Tank, - = girders)

Now hyper edit it into kerbin orbit.

At apoapsis, point the full tank towards Kerbin, and transfer fuel into empty tank. Notice your apoapsis has changed. Now turn 180 degrees and do it again, apoapsis has changes again. Repeat until escape trajectory.

Edited September 18, 2014 by goduranus

[r_rolo1]

That breaks classical physics You can only do that because KSP does not fully follow RL physics when you change fuel around a ship ( it does not ask you for energy input to change fuel of place, but changes it anyway, leading to potential energy coming out of nowhere ). That is a pet gripe of mine so old as the ability of transferring fuel

[wasmic]

To beat this challenge involves no engines, decouplers, explosion, or GOTP maneuvers.

Start your ship with a probe core, connect several long girders in front and several long girders in the back to make it as long as possible. Then connect a fully loaded fuel tank in front, and an empty fuel tank in the back. Add some reaction wheels for turning and struts to keep it together.

E----------C----------F

(E=Empty Tank, C= Core, F= Full Tank, - = girders)

Now hyper edit it into kerbin orbit.

At apoapsis, point the full tank towards Kerbin, and transfer fuel into empty. Notice your apoapsis has changed. Now turn 180 degrees and do it again, apoapsis has changes again. Repeat until escape trajectory.

However, you will change your velocity by doing this. Therefore you use Delta-V. You just don't get the Delta-V from a reaction drive. Oh, and your design also violates classical physics.

[BagelRabbit]

No, he meant you must start in Low Kerbin Orbit, infiniglider wing does not work there.

I still think that flying a Launch Stability Enhancer is the only way to change an orbit using no reaction mass, "getting out and pushing," or using a K-drive (which is forbidden under the rules, as it counts as a form of propulsion IMO). Launch Stability Enhancers don't use propulsion... they're basically just rendered physicsless (and gravity-less) because they're not designed to be used this way. Once they're in space, they simply maintain their velocity. They are, to make a long story short, true "massless parts..." which means that this is the only method that works so far. Again, because the rules are so vague, I may be completely wrong.

The only thing that would be a problem is that I don't get to LKO first, but I don't really see a way that I could get a Launch Stability Enhancer into orbit, even with HyperEdit...

[cantab]

This seems more of a puzzle than a challenge per se.

There's a simple and physically valid but cheaty way to escape Kerbin with no change in velocity whatsoever from when you launch. Ship on a launch clamp and edit the craft or save file so it's really really high, beyond stationary orbit. Release it from the clamp and off it goes! The real-life equivalent is of course a space elevator. However you're never in LKO with this approach.

[goduranus]

However, you will change your velocity by doing this. Therefore you use Delta-V. You just don't get the Delta-V from a reaction drive. Oh, and your design also violates classical physics.

The ship velocity does not change, you can check it on the velocity readings.

It happens because of a bug with KSP center of mass calculations. Where the center of mass moves relatives to frame of reference coordinates when you transfer fuel.

Edited September 18, 2014 by goduranus

[r_rolo1]

@UpsilonAerospace

Note that the wording of the OP does not disallow going out and pushing. A Kerbal is not a engine and you don't need infinite fuel option on to going out and push. More, if I do so, I'm not using thrust in the challenge ship, I'm using it in the Kerbal ( so , in other words using other ship to push the challenge ship is also not disallowed by the rules )

Anyway, I'm waiting to see the OP try on this. In fact it is required for a challenge in this forum that the OP provides proof that is possible , right ? :/

Edited September 18, 2014 by r_rolo1

[r_rolo1]

The ship velocity does not change, you can check it on the velocity readings.

It happens because of a bug with KSP center of mass calculations. Where the center of mass moves relatives to frame of reference coordinates when you transfer fuel.

If you have a different orbit the velocity changes, period. If the module of the velocity stays the same ( that is perfectly possible ) the direction of the velocity ( again, velocity is a vectorial variable: it has a module ( aka "intensity", the thing you see in the velocity readings ) and a direction ) must have changed, otherwise you would still be in the same orbit. If the velocity changed in either module or direction, Delta v has to be different of zero...