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Attempting to go to space. With Canon... Re-ARMed!... An experiment report.


Tw1

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Danny2462 have made this with an "unique" part:

I though about that. I'd only add enough thrust to reach the orbit I want, but it just wouldn't be the same, you know?

Unless I managed to make the unique part cannon shaped, and use appropriate amounts of fuel...

Though the first thing I'll probably do in 0.20 is build put three mainsails really close together, with a seat in the middle, so I can control it using him.

I tried something like this earlier, just getting him stuck between the engines. But he just disappeared. There was no report of his death.

He may have gone flying out of render distance before I could switch control to him. They disappear when they do that.

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You could maybe make it into orbit on a lower gravity body. Perhaps if you set up a horizontal mainsail cannon on top of minmus' highest peak?

I might try this.

Newton's Cannonball at its finest :D

As for Minmus, the gravity might be low enough that even the slightest mass driver setting can send a kerbal in an escape velocity from it.

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Makes me think of pulse detonation engines... I prefer nuclear thermal.

It reminds me of a story that claims an American manhole cover was the first man made object in space.

It was supposedly put over a shaft in which a nuclear weapon was being tested/exploded, and inadvertently achieved Earth escape velocity.

Dr Karl (a well known Australian science communicator) talked about it as part of a show he did.

XKCD's "what if" section made mention of this, but..

1. If it really was initially going 66km/s (Mach 194), it would probably just disintegrate instantly from the drag force

2. Even if it did somehow not disintegrate, Newton's impact depth approximation tells us it wouldn't have gotten very close to space anyway

http://what-if.xkcd.com/35/

http://nfttu.blogspot.com/2006/01/nuclear-potato-cannon-part-2.html

http://en.wikipedia.org/wiki/Impact_depth

It's basically impossible to launch anything directly to space or orbit from the surface of Earth or Kerbin without continued thrust. In KSP you can use a bunch of stack separators to launch things at speeds of many km/s, but they don't get very far.

Here someone launches a probe at about 53 km/s, and it doesn't quite reach 13km altitude

http://forum.kerbalspaceprogram.com/showthread.php/27751-Stock-30-sec-Altitude-Challenge%21?p=341710&viewfull=1#post341710

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The horizontal cannon in that video is a bit like what my last experiment did.

I wanted to see if I could space the mainsails enough apart that they'd have an effect. I also wanted to see if I could use a horizontal and a vertical mainsail to achieve a 45 degree (approx) trajectory.

After a few failed designs, I ended up with this:

C6HPRs7.jpg

Bearly fit in the SPH. It also shows of my modified extra-long struts.

It made use on the mechanism that was to be used on the orbital canon. I call it the dropping platform.

ImojZQq.png

Melbald walked (down) the plank, glad that this was not my "real" save only a simulation.

m2Kfz77.jpg

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I tipped the platform, and whoosh!

What happened next was so fast, I didn't get any images.

As the earlier experiments predicted, he was accelerated by the first engine, but not the second.

Splat. Poor Melbald.

LHStkpz.png

But what was completely unexpected, was this:

SIo4O1S.jpg

I switched back to the cannon-vessel only to find it flying. Gravity soon did its thing, and we were going down again. Fast.

I decided to bail Deremy. Then a second strange thing happened.

SYy0xG3.png

He started heading skywards. Very fast. As you see, he reached an apoapsis of 6750 meters, far higher than any previous kerbal without using rockets. So that was some achievement then.

He did not enjoy his decent. I attempted to turn him so he'd land head first, as legend says they always land safely head first.

It's very tricky to reorient a kerbal using the jet pack. I'd prefer it if they could be controlled like spacecraft, WASD to turn, IJKL to translate.

I3svI3u.jpg

He did not land on his head, but still managed to bounce. At first he was terrified:

TnumPTd.png

Though this was soon replaced with a grin,

NC8xESl.png

It was all to soon, and he did not survive the landing.

d4n16pC.jpg

I was hoping to use this to fire then to the island with the runway. But perhaps a simpler approach, with a mainsail at 45°, is necessary.

Edited by Tw1
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Well... I don't get any higher by cheating.

Put 20 odd mainsails + tanks overlapping each other.

Although this is a longshot from a canon (I mean, it is basically the same as trying to fire a bullet without the barrel)

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i have an idea, use a very large array of very large fuel tanks. point a mainsail directly at each one (think of it as a detonator). and have a platform with a kerbal suspended over it by a platform with a decoupler. set up the action groups to light the mainsails and release the kerbal bearing platform at the same time.

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i have an idea, use a very large array of very large fuel tanks. point a mainsail directly at each one (think of it as a detonator). and have a platform with a kerbal suspended over it by a platform with a decoupler. set up the action groups to light the mainsails and release the kerbal bearing platform at the same time.

So that the platform manages to get thrust from every mainsail? ? Maybe.

Platforms tend to be pretty light, this idea could have potential. But I'm all cannoned out for now. Maybe some other day.

These things are pretty quick to make, once you know about the hold Alt to copy trick. Testing and refining still takes a while.

If anyone else has a go, that'd be cool to see.

Edited by Tw1
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well the idea was to create a massive explosion and propel the kerbal with the kick. but your idea might work better.

i try to limit my ksp playing these days so i wont be board when the game hits final. i play the new version for a couple weeks then go do something else until the next version comes out.

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I swear this works, I even found the reddit challenge where people have done it!

http://www.reddit.com/r/KerbalSpaceProgram/comments/1cq5hz/weekly_challenge_katapult/

Here is a notable example of it working.

http://imgur.com/a/qVMDC#0

well, it isn't orbit, but it's a lot better than the 5km issue you seem to be having.

Edited by Splode
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That is strange. Perhaps the mainsails are closer? I've got to check that out.

Their craft looks not unlike the original concept I had...

Edited by Tw1
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PS, this may work on the moon?

Construction of the "Kannon" is undergo, and preliminary tests are encouraging. Only 4 prototypes self destructed, and the end result was a 1km launch of the debris... I mean payload.

knn.jpg

Edited by Technical Ben
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Loaded up this craft file from that reddit challenge.

It defied everything I'd previously found out.

Maybe this is how Einstein will feel one day if FTL is invented...

Should've stuck with threefold symmetry, like I'd intended, not four..

The reddit craft:

mmcXupM.png

jermRo4.png

The craft was certainly impressive. And achieved twice the height that I kept reaching.

yU3Nvwb.png

With a little help from the Jetpack.

I tested the bottom bit on its own, and it only got slightly higher than the single mainsail.

So it was definitely the stack above doing a lot of the work.

1Xij1tk.png

MjRCBR1.png

This design showed potential. But one drawback was it always fell apart during launch. Also, it needed to be bigger. Much bigger.

I put it through the roof. And the floor. And then the roof again.

r7dzJHf.jpg

It started to lag in the VAB, so I knew it was nearing its maximum potential for overbuilding.

When it finally loaded on the pad, it was certainly impressive.

And it was holding the one and only Jedediah Kerman.

z9OHQuV.jpg

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Don't you love the enthused look on Jeb's face? Put him in a 52 mainsail monster cannon, and he's like "Whatever this is all about, I'm so glad to be here."

His first task was to retrieve the parachute from the yellow box on the side.

9E078oX.png

Then it was time to descend to the bottom down a very long ladder. A turning area was added after one try, where Jeb tried to go down head first.

ff79uPp.jpg

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It's quite a long way down, a result of the construction technique, which involved moving the command pod to the very top, and building below it, and lowering it to the ground, and building above.

mkWdY9b.jpg

What's more scary, looking down, or looking up?

taT7mKk.png

Neither as far as Jeb's concerned , he's totally unflappable when there's rocketry to be done. He descended that 40m ladder with eager anticipation in his eyes.

jcWJjL3.png

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Well, this is it. Boom time.

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Not Jet packing this time, and got to a respectable 11.5km.

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But Jeb wasn't very well lined up. We could do better.

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Again with Jetpack?

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That's more like it. And again:

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17.3Km. That's pretty good. (I think Kerbin orbit is probably not feasible with these parts though.) I'm pretty happy with that. Jeb forgot his parachute that time, not that imminent death bothered him in the slightest.

vnKW7C9.png

Decided to see if I could squeeze a few more engines into the design. Bill was also back (from the dead) and wanted to have a go. But he wasn't very cooperative.

I had to send him back when he forgot to pick up a parachute.

KWcZUeW.jpg

He wanted to try parachuting down the middle, with me putting the engines on while he was airborne, so he'd get extra lift. Unfortunately, he descended too rapidly for that, and ended up on the ground.

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Hit F9, tried again. This time, he parachuted right down the middle, and landed safely on the step-off platform. Kinda.

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Ok. Bill's acting weird. Perhaps he hit his head too hard..

Decided to go a head with the launch. Bill didn't move. It was reassuring that my version of the kannon didn't pull it self to bits under prolonged thrust, but odd that Bill wasn't going anywhere. I even tried standing him on the side engines instead of the middle.

htlp0as.jpg

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Nup. Not going flying today.

That's enough canons for me. I'll finish up with this epic picture, Bill, in the smoke of 58 mainsails, looking up through an engine's bell.

OV3WS8s.jpg

And that's the end of that.

Edited by Tw1
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Doing that from Kerbin is impossible, I once had a thread before the '013 disaster where we tried to get a Kerbal into orbit with cannons but max was 10km(due to drag). However, try deorbiting kerbals, it's really fun. You launch a cannon into orbit( the engines must be pointing opposite from each other so the craft stays in place. Go to the retrograde pointing engine, fire the engines and enjoy! You can easily make a Mun cannon too and shoot Kerbals into Kerbin

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I wonder if angling the thrusters more as you continue down the line would provide better thrust, (Effectively, your vertex changes to match the speed at which the kerbal is moving)

The problem is STILL that without a barrel you're losing so much of the force. (Hence why your initial attempts were humourous, but futile)

But as the Reddit design clearly is a "faux barrel", supplying the "expanding force" (I was trying to do so just by launching a 10x mainsail rocket rear with 1x mainsail forward with limited success [mostly, I kept losing the kerbal]).

Honestly though... I feel that a GIANT (as in 10x the VAB) catapult could supply better results. The problem is that the kerbal just isn't under the influence of the thrusters for a long enough time (Barrel, Gun, etc).

A Catapult (not a Teeter-Totter) works by transfer of momentum, so until the abrupt stop the kerbal should remain in the "catapult seat" and hence retain most of the force.

*But, of course, the physics system would tear the thing to pieces and the joints won't be nearly strong enough to provide the 100% transfer

Edited by Fel
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I think there is a Manley video about using a rocket exhaust boost to EVA a stranded Kerbal into Munar orbit, now that I think about it.

yes, there is a;so one of him returning with only eva from gily.

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I did a few more experiments.

uNYyS3T.png

rqc0rTF.png

None of them really got anywhere, but they looked cool.

These ones used the "it doesn't notice collisions" principle.

v25d3Ro.png

044BAeZ.png

If you look closely, there are engines missing where kerbals "collided" with them. Seems the game only checks for collisions every few fractions of a second, leaving a little room to work around. This means spacing is very important.

I attempted to recreate one from that Reddit thread, but it didn't match its claimed 20Km.

So I them turned on part clipping.

This wasn't the final one, but:

UIkWYJs.jpg

EHuC1Uf.png

Well, it worked, just that happened once of twice.

I got some strange effects, similar to a video posted earlier in this thread:

G0OmKpW.jpg

I never got anywhere near the station, but I certainly gave some kerbals a great time.

zOxtBXp.jpg

I think I'll make an SSTO instead....

Edited by Tw1
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I think I'll make an SSTO instead....

You mean a SSTO Canon, right?

/me curses about the attachment nodes being the only way to "store energy" but being far too rubbery to provide a 100% transfer

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A space trampoline. :P

Actually, I was thinking a sling shot type thing would be pretty cool. I was experimenting with modified KAS cables the other day. If I set the cable really long, and the retract speed really fast, with the right set up, I could possibly propel anything I like into space.

As long as:

1. I get the angle correct, so it fires properly, rather than swinging like crazy.

2. The forces aren't so huge that everything gets pulled apart. (I don't want to have to edit parts, if that can be avoided.)

3. I can get a kerbal or object to stay in the bucket bit without him falling out too soon, or flying out too late.

Experiments I did the other day with KAS suggest it's feasible. But I'm not going to be playing for a while because of uni exams, and won't be trying it any time soon.

Edited by Tw1
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