Spaceplane to orbit with air breathing engines.

[JadeOfMaar]

7 hours ago, RavenpawKSP said:

The highest speed achieved was 41,232 m\s, which was achieved shortly after engine flameout before it stopped accelerating during the force glide on prograde.

A few heat shields and wing parts were lost due to the heat.

But a full orbit was achieved.

6 hours ago, RavenpawKSP said:

RCS can be used to rotate the craft in space but not to push the craft. A kerbal can be used to push only for small orbit changes, but not on prograde because that would ruin the point of the challenge.

Whiplashes die at about 1200m/s (give or take 100) and 17km altitude. So this challenge requires the masterful, controlled use of ancient krakens? I'm sorry dude but with criteria like this, this thread needs to be closed.

Edited January 16, 2017 by JadeOfMaar

[Stefano Balzarotti]

Achieve a stable orbit outside atmosphere it's impossible, but I was able to achieve an unstable orbit inside atmosphere.
Probably with enough speed and aerodynamic it's possible to maintain the orbit for many years.

Otherwise, you have to use a cheat, or you have taken advantage of a game glitch.

A my idea it's to use stack decoupler propulsion, apart from the fact that I don't know if it's possible, I'll broke the rules.
 

[Tex_NL]

34 minutes ago, Stefano Balzarotti said:

Probably with enough speed and aerodynamic it's possible to maintain the orbit for many years.

You are correct it is possible to raise your Pe above the ground in atmospheric flight. It's hard but it is indeed possible. Maintaining such an orbit for a prolonged duration however is not.
To maintain such an orbit you will need continuous thrust to fight off drag. Sooner or later you will run out of fuel.

However there IS a tiny loophole in this endeavour. Craft on rails do not experience drag in KSP. And only on rails craft below 23km are deleted. If you manage to switch away from a craft with both Ap and Pe between 23 and 70km in theory it is possible for such a craft to 'orbit' indefinitely.

No, Ravenpaw. This is NOT what you did! Do not try to claim this. If you actually did, you would have told it from the start.

[Mycroft]

On 1/10/2017 at 8:56 AM, RavenpawKSP said:

Get a space plane into a orbit (it doesn't have to be perfect) using only air breathing engines.

HINT:You can do a speed run in the stratopause and burn prograde just before you leave the atmosphere.

It can be a bit challenging to get enough speed to force glide on prograde long enough to complete your orbit.

Tell me if you have another idea of how to do this.

Insert screenshots or videos of your plane and its orbit!

Ok wow this is the hardest challenge that I've seen in a while, sadly not because it requires any special talent, just very good timing. But anyway I do find this intriguing, and I am tempted to try the Munar assist approach as that seems to be the only way to actually do it. But gee this is a hard challenge. Anyway it is kinda amusing how lots of the major KSP gurus immediately jumped on this {cough} RedIronCrown {cough} and everyone started basically accusing the OP of lying outright. Now as a reasonably experienced KSP player myself, I do not believe that the stock or any remotely realistic aero models allow for any way besides the SoI change method. But I think we could all afford to cool off a bit and stop hammering the point I'm sure everyone has gotten at least until we have solid evidence of this. Right now as @Vanamonde rightly pointed out, the accusations got out of hand a tad. I think we could all stand to back off for a sec, take a deep breath and tackle this sticky issue with tact and logic, not emotions. Emotional outbursts are not needed here in my humble opinion which you may certainly dismiss if you wish (it's not like I have any authority or influence). 

So to tackle this issue, we should take into account every variable possible that is known. 

First, I agree that most times the Whiplashes experience flameouts around 22-25 km. However I have seen many highly experienced players nurse stock engines to almost 40 km. I managed to reproduce it myself once. However it requires really nursing the throttle and is not at all easy. I was only able to do it once. 

Second, if the intent was for players to form a full orbit from inside the atmosphere, I'm afraid we will run into the fundamental issues with air breathing engines, namely that they need air to run. I can't say that I could see a vacuum operable jet. Sorry.

Third, I believe that this is actually possible via the Munar gravity assist discussed above. I have done similar things for the heck of it before and I would put it in the realm of hard but possible. 

Fourth, I will deliberately tip my hat to this player if he knows how to do this. But I would like to see a video of it. Because on the forums I found we have a forum rule of 'pics or it didn't happen' merely because it is so easy to fudge things if no one knows how to verify it.  

Fifth, @RavenpawKSP I would like to be one of the first to welcome you officially to the KSP forums! What a first post!  I'm sorry that people on this thread are being less than nice, and thanks are due to @Vanamonde for keeping it from boiling over. I do hope that in general, the forums are nicer to you than in this particular thread, and sincerely wish you the best of luck in sorting this stuff out!

On 1/15/2017 at 11:03 AM, RavenpawKSP said:

The highest speed achieved was 41,232 m\s, which was achieved shortly after engine flameout before it stopped accelerating during the force glide on prograde.

A few heat shields and wing parts were lost due to the heat.

But a full orbit was achieved.

Ok so I was wondering if perhaps this was a typo. I could kinda see 4.1 km/sec, though gee whiz I am not sure that this is in the realm of feasibility for me in stock. That would more than give you a Munar encounter. Kraken drives do do this kind of speed as a few have pointed out. All you gotta do is show the Kerbal what a Kraken looks like up close and he will be so terrified that they usually run away at near light speed . Especially Bill and Bob. But on the whole I am intrigued by the idea and hope nobody's feelings get too hurt.

[tseitsei89]

2 hours ago, Mycroft said:

First, I agree that most times the Whiplashes experience flameouts around 22-25 km. However I have seen many highly experienced players nurse stock engines to almost 40 km. I managed to reproduce it myself once. However it requires really nursing the throttle and is not at all easy. I was only able to do it once. 

Interesting. How did you manage that? In my experience they always flame out at 20something kilometres.

2 hours ago, Mycroft said:

Third, I believe that this is actually possible via the Munar gravity assist discussed above. I have done similar things for the heck of it before and I would put it in the realm of hard but possible. 

How can you get apoapsis to munar height with only jets? IMO a more feasible way (although probably still quite impossible) would be to use a "centrifugal catapult" since nobody said this needed to be SSTO.

So

1. Have a plane to get ap out of atmosphere. 

2. Decouple the "catapult" which is just a long stick with command pod on the other end and lots of reaction wheels + EC on the other end.

3. Spin. Fast. Like really fast.

4. Decouple the pod at the right moment so it will fly prograde and hopefully be enough to raise pe to > 70km

But yeah even that would be amazingly hard since jets just dont get enough speed to get periapsis and apoapsis high enough for a "catapult" like this could finish the circularization (I would love to be proven wrong though...)

2 hours ago, Mycroft said:

Ok so I was wondering if perhaps this was a typo. I could kinda see 4.1 km/sec, though gee whiz I am not sure that this is in the realm of feasibility for me in stock. That would more than give you a Munar encounter. Kraken drives do do this kind of speed as a few have pointed out. All you gotta do is show the Kerbal what a Kraken looks like up close and he will be so terrified that they usually run away at near light speed . Especially Bill and Bob. But on the whole I am intrigued by the idea and hope nobody's feelings get too hurt.

Even if it was a typo it probably still didn't happen (the 4.1km/s run with jets I mean). Since in this thread we have achieved ~2km/s and there have been some quite competent people trying. So either he somehow "broke" the game physics with some new trick or he is just lying...

Edited January 17, 2017 by tseitsei89

[Hodari]

Depending on exactly how you define the rules and whether or not there is some bug or exploit you could use, there may be some very SMALL chance that there is some way to do this "challenge", but there is certainly no way to do it that actually complies with the spirit of it. 

[Jarin]

Step 1: make absurd claim
Step 2: refuse to back up claim or address any criticisms
Step 3: ???
Step 4: No profit, go directly to jail, to not pass Go, do not collect kudos.

 

Seriously though, impossible in stock. Barely possible with any semi-reasonable mods. Maybe doable with a mod scramjet and some kind of physics cheat at AP. Meaningless as a challenge without defining mods, though.

Okay, I went back and reread that triple-post with the video and I'm starting to suspect he meant that he got his AP out of the atmosphere and came back to where he started on a ballistic trajectory, thus "orbiting". Less physically impossible, just implausible. 

Edited January 17, 2017 by Jarin

[theend3r]

1 hour ago, Jarin said:

Step 1: make absurd claim
Step 2: refuse to back up claim or address any criticisms
Step 3: ???
Step 4: No profit, go directly to jail, to not pass Go, do not collect kudos.

 

Seriously though, impossible in stock. Barely possible with any semi-reasonable mods. Maybe doable with a mod scramjet and some kind of physics cheat at AP. Meaningless as a challenge without defining mods, though.

Okay, I went back and reread that triple-post with the video and I'm starting to suspect he meant that he got his AP out of the atmosphere and came back to where he started on a ballistic trajectory, thus "orbiting". Less physically impossible, just implausible. 

Like I wrote before, it is definitely possible since he only forbade rocket engine and nothing else. You can:

1. Decouple things to get rid of weight (including engines after you no longer need them in points 2. and 3.)
2. Use decouplers for propulsion
3. Use centrifugal force with decouplers to make a space catapult
4. Get hit by an asteroid or debris, intentionally or not

[Hodari]

7 minutes ago, theend3r said:

Like I wrote before, it is definitely possible since he only forbade rocket engine and nothing else. You can:

1. Decouple things to get rid of weight (including engines after you no longer need them in points 2. and 3.)
2. Use decouplers for propulsion
3. Use centrifugal force with decouplers to make a space catapult
4. Get hit by an asteroid or debris, intentionally or not

Actually, no....that is NOT what the challenge said.   It was

"Get a space plane into a orbit (it doesn't have to be perfect) using only air breathing engines. "

Now, if you DO allow those other methods you mentioned AND if you can get your Ap high enough first, I'll agree that it might be possible.  Not sure you actually can get the Ap high enough though for just decouplers to be enough and either way...

2 hours ago, Hodari said:

Depending on exactly how you define the rules and whether or not there is some bug or exploit you could use, there may be some very SMALL chance that there is some way to do this "challenge", but there is certainly no way to do it that actually complies with the spirit of it. 

 

[theend3r]

57 minutes ago, Hodari said:

Actually, no....that is NOT what the challenge said.   It was

"Get a space plane into a orbit (it doesn't have to be perfect) using only air breathing engines. "

Now, if you DO allow those other methods you mentioned AND if you can get your Ap high enough first, I'll agree that it might be possible.  Not sure you actually can get the Ap high enough though for just decouplers to be enough and either way...

 

Ah, ok then. I understood it this way: "Get a space plane into a orbit (it doesn't have to be perfect) using only air breathing engines. "

[Firemetal]

Ok. I honestly believe we are dealing with a troll. He first posts an impossible challenge. Then he cannot post a video of him doing it. Then he tells Red Iron Crown that he is unable to use the computer and keeps throwing his video at him. We all know that to get a Mun assist, you need to be going at 3000 m/s in the atmosphere and you'd need a very small plane with lots of decouplers to get into orbit that way.

So mods. This is clearly impossible. Please close post? Thanks.

Fire

[Vanamonde]

Once again, if you do not like the terms of a challenge, skip it. Do not throw around accusations of trolling. There's no call to get angry about this kind of thing. 

[Mister Dilsby]

Ah...nothing like a good old impossible challenge thread!

Well, it only says spaceplane, it does not say SSTO. So, maybe you could get enough velocity in air to get out of the atmosphere, and then abuse reaction wheels to fling a small capsule the rest of the way. I seem to remember doing something like that a long, long time ago...