Newtons Cannonball on the Mun

[1greywind]

Point of challenge is to build contraption, that is able to fire uncontrolled projectiles fast enough, so they can travel around the Mun and hit close to starting location. Best possible score is to hit yourself with projectile that made full orbit.

Rules:

1

Build cannon using stock KSP or any mods (I don't see big advantages of mods in this case so we start with single score board).

2

Get it to the Mun's surface - hyperedit, infinite fule, anything counts. (Hint - use Kerbal maps to eyeball good shooting location).

3

Fire projectile (rocket is projectile too) in any direction (but East of West are obvious - more chances that projectile comes back to you). Projectile can have pod or robotics core, but no active control inputs, staging events or scripting (kOS) are allowed while on trajectory - no "cluster bomb" or "guided missiles". You can use any kind of engine to propel projectile - solid fuel, liquid fuel, mass driver, etc. But do not use RCS and lock gimbal on engine(s). Projectile should travel at least half of Moon's circumference before impact (so "fire straight up" does not counts). Projectile impulse duration (engines work time) is not limited, but you should not control projectile (or rocket) during flight.

4

Provide screenshots or video with your score record. You need to show: cannon, starting location on map, moment of projectiles separation, map view of projectile's orbit, impact location on map (optional) and distance to starting location (required - mouse over cannon's marker - it will show distance).

5

Score is distance between projectile's impact location and starting point in kilometers.

Score board:

[table=width: 500, class: grid, align: center]

[tr]

[td]Name[/td]

[td]Name[/td]

[td]Score[/td]

[/tr]

[tr]

[td]1[/td]

[td]1greywind[/td]

[td]11.8[/td]

[/tr]

[tr]

[td]2[/td]

[td]-[/td]

[td]-[/td]

[/tr]

[tr]

[td]3[/td]

[td]-[/td]

[td]-[/td]

[/tr]

[tr]

[td]4[/td]

[td]-[/td]

[td]-[/td]

[/tr]

[tr]

[td]5[/td]

[td]-[/td]

[td]-[/td]

[/tr]

[/table]

- - - Updated - - -

My entry:

Starting location:

Impact:

score = 11.8

Download link to savegame with my contraption ready to fire on Mun. Just start "Newtons_cannon" save and load quicksave.

Edited October 1, 2015 by 1greywind
rules clarification

[Azimech]

ÃŒnteresting. Might give it a go.

Sorry if I'm being a .... but in that video you're using a missile launcher, not a cannon ;-)

Edited October 1, 2015 by Azimech

[Superfluous J]

(I don't see big advantages of mods in this case so we start with singe score board)

Best. Typo. Ever.

[1greywind]

@Azimech: Well, yes, "cannon" is more figure of speach here. Anyway we don't have gas physics in KSP and even throwing kerabl into rocket engine exhaust is not a true "kerbal cannonball" show.

@5thHorseman: Best. Typo. Ever. fixed

Edited October 1, 2015 by 1greywind

[Dunbaratu]

How does one officially define a "projectile" versus a "rocket" given that it will always take some time to get the 'bullet' up to speed? i.e. is a 'bullet' that took 5 minutes to get up to orbital speed before you cut the engines out a "projectile"? If not, then how short does the impulse need to be? Will 30 seconds be good enough? How about 45? etc.

Edited October 1, 2015 by Steven Mading

[1greywind]

How does one officially define a "projectile" versus a "rocket" given that it will always take some time to get the 'bullet' up to speed? i.e. is a 'bullet' that took 5 minutes to get up to orbital speed before you cut the engines out a "projectile"? If not, then how short does the impulse need to be? Will 30 seconds be good enough? How about 45? etc.

Ok, I'll add clarification to rules. Wiki states, that "a projectile is any object thrown into space (empty or not) by the exertion of a force". So rocket also is projectile. I don't think that we need to limit lmulse duration - main point is that you should not control rocket during flight.

Edited October 1, 2015 by 1greywind

[Superfluous J]

I think "SAS off, one spacebar hit is the only control input you're allowed" is fair, no?

Once landed on Mun, of course.

[1greywind]

I think "SAS off, one spacebar hit is the only control input you're allowed" is fair, no?

Once landed on Mun, of course.

One space bar hit. SAS can be turned on (but only for torque, no RCS).

[Clear Air Turbulence]

I am instantly thinking: railgun.

No idea how to build one, though.

[1greywind]

I am instantly thinking: railgun.

No idea how to build one, though.

Look for mods - As I remember few weapon mods with railguns and mass-drivers. Something like this - http://forum.kerbalspaceprogram.com/threads/103511-Pre-Release-0-90-FIXED-Netherdyne-Mass-Driver-Mod can work

[Dunbaratu]

Ok, I'll add clarification to rules. Wiki states, that "a projectile is any object thrown into space (empty or not) by the exertion of a force". So rocket also is projectile. I don't think that we need to limit lmulse duration - main point is that you should not control rocket during flight.

The point being it's not a projectile until *after* the engines are off. During the time that the engines are on, that's pre-projectile. Thus rules about what you can and can't do once it's a projectile differ from what you can and can't do *before* it's a projectile. Obviously you can aim it before you launch it. Obviously you can control it before you launch it. An obviously it is being measured from the point where the launcher is, not from the point where it became a projectile (where the thrust stopped).

The need for the clarification is over when the control has to stop. i.e. can you steer it during it's 20 second burn just prior to it being a projectile, but after detaching from the launcher. That's the edge case that needed clarification, not what happens after the thrust is done.

[1greywind]

can you steer it during it's 20 second burn just prior to it being a projectile, but after detaching from the launcher.

No. All you can do is to hit Space bar once

[Foxster]

Be a lot easier just to make what is fired unpowered i.e. a cannon and not a rocket launcher. Like this (apart from the screwed-up wheels, of course)...

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...and a little video of firing it...

• http://www.youtube.com/watch?v=StnH2tqkZYwI
  

Edited October 1, 2015 by Foxster

[Slam_Jones]

Is it possible to reverse the magnetic values of docking ports, and arrange them to launch another docking port at high speed? Closest to a railgun that I can think of, sans mods.

[Azimech]

In theory, yes. A lot of things can be modified. You can give a rocket engine a negative heat value, the blast will cool instead of heat up. Give a rocket engine a negative thrust value, then it will have a thrust vector pointed in itself.