How far can you single stage?

[mr_yogurt]

For lack of a recent challenge on this topic, I present to you:

The single stage challenge

Pretty basic. Go as far as you can without removing bits of your craft from your craft.

Rules:

1. No parts may detach from your craft. (Including by explosion)
   
2. All stock, except for control/info mods such as MechJeb.
   
3. No debug menu or HyperEdit or 1337 haxoring.
   
4. No docking/refueling.
   
5. You cannot get out and push or have another craft come push.
   

Status on leaderboard is determined by average ÃŽâ€v to target. (Doubled on return). You must go to a target, Kerbol escapes are boring. Also, Assume Landing > Orbit > Crash/Flyby

Leaderboard

sdj64 - Duna landing, return - Interplanetary Expedition

Rodyle - Duna, return

Mesklin - Mun landing, Minmus landing, return - Extreme Munar

Awards:

Extreme Munar - Land on Mun and Minmus in the same mission and return

Interplanetary Expedition - Go to another planet, land, and return

1337 haxor - Land on Eve and return

Edited February 26, 2014 by mr_yogurt
Updating leaderboard

[Dave Kerbin]

Is this with jet engines (regular, turbo, rapier) or without?

[ihtoit]

Is this with jet engines (regular, turbo, rapier) or without?

see rule 2.

[1greywind]

Define "How far". My spaceplane has ~4400 m/s of dV after reaching stable orbit. Does it mean that, to win challenge I need to send my plane to orbit with largest possible semi-major axis (using gravity assists perhaps)?

[mhoram]

In my Delta-V Maximization Challenge tavert came up with a single stage roclet with 9124 dV.

Using Jet engines will of course get you further.

[PlonioFludrasco]

I think you have to prohibit Kraken drives.

[Rodyle]

Basically everywhere, I would say. Ion drives can get you anywhere, and with a small amount of oxidizer you can use a nuclear engine to land on most places as well.

Anyhoo: for non-ion driven vehicles: see the link in my signature. To Duna and back. As I mentioned: if you remove the payload and replace it with a large normal radius fuel tank, it should be able to get to Jool and back at least.

Edited February 23, 2014 by Rodyle

[mr_yogurt]

Is this with jet engines (regular, turbo, rapier) or without?

If there isn't a rule against it, assume it's allowed.

Define "How far". My spaceplane has ~4400 m/s of dV after reaching stable orbit. Does it mean that, to win challenge I need to send my plane to orbit with largest possible semi-major axis (using gravity assists perhaps)?

Edited main post to be more clear. Escaping Kerbol isn't much of an achievement compared to landing and returning from some places, and if you land and return from somewhere you get much higher leaderboard status than a flyby. Average ÃŽâ€v to target is what "how far" is defined as. Not having a target (Kerbol escape) is lame.

Basically everywhere, I would say. Ion drives can get you anywhere, and with a small amount of oxidizer you can use a nuclear engine to land on most places as well.

Anyhoo: for non-ion driven vehicles: see the link in my signature. To Duna and back. As I mentioned: if you remove the payload and replace it with a large normal radius fuel tank, it should be able to get to Jool and back at least.

If you have the patience to do a whole mission like this with ion drives, I would like to see. When you finish, post about it.

[kola2DONO]

Can i explode parts of my ship?

Also, can i use another rocket to push it without docking to it?

[Mesklin]

SSTO can reach anything, except Eve

Stochasty was everywhere on SSTO, see his post about flight to Moho as example. This craft has ~7500 m/s dV.

Also see links in my signature for Ikar (8300 m/s dV) and Dedal (flight to Tylo and back on SSTO).

[mr_yogurt]

Can i explode parts of my ship?

Also, can i use another rocket to push it without docking to it?

Nope and nope. I amended the rules to make this more clear

SSTO can reach anything, except Eve

Stochasty was everywhere on SSTO, see his post about flight to Moho as example. This craft has ~7500 m/s dV.

Also see links in my signature for Ikar (8300 m/s dV) and Dedal (flight to Tylo and back on SSTO).

I added Ikar to the Leaderboard. Did you go to the Mun and Minmus, return, and do it all over again without refueling? I wasn't too sure so I didn't add the second run to leaderboard. I will if you did.

Dedal doesn't count because you detached the Tylo lander from the rest of the ship.

Edited February 23, 2014 by mr_yogurt

[Rodyle]

If you have the patience to do a whole mission like this with ion drives, I would like to see. When you finish, post about it.

If I find the time to do something, I will. It will probably be a multi-day mission however, since my acceptance threshold of horribly slow burns is somewhat low. If I do something like that, mind if I post the intermediate steps here to keep myself motivated?

In the mean time, let's post some pictures. As I mentioned: full mission briefing can be found in my signature, but I thought the thread was rather empty at the moment.

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[Stochasty]

Ion drives are unnecessary for SSTO spaceplanes. You can make it to and from every target except Eve and Tylo using a nuke, and replacing the nuke with ions won't help for either of those. Eve cannot be done single stage, and Tylo requires stage-and-a-half (undocking a lander from the plane to take down to Tylo's surface, like what Mesklin did with his Dedal craft).

None of these trips are new, so they probably shouldn't count as official submissions, but to give you an idea of what is possible with SSTO craft here are the trips that I've made:

The Mun, twice.

Eve orbit, followed by Gilly and Minmus.

Duna and Ike.

Dres.

Laythe and Vall (simultaneous missions using two craft).

Eeloo.

Moho.

[Rodyle]

Ion drives are unnecessary for SSTO spaceplanes. You can make it to and from every target except Eve and Tylo using a nuke, and replacing the nuke with ions won't help for either of those. Eve cannot be done single stage, and Tylo requires stage-and-a-half (undocking a lander from the plane to take down to Tylo's surface, like what Mesklin did with his Dedal craft).

Sorry, but how do ion engines not help? I mean, you could replace nearly all liquid fuel and oxidizer meant for getting into orbit (may want to leave a little bit to actually get there) and replace all of it with a single ion engine, a single xenon tank and 20 generators. I can't believe that wouldn't increase your delta-v.

[John Crichton]

Sorry, but how do ion engines not help? I mean, you could replace nearly all liquid fuel and oxidizer meant for getting into orbit (may want to leave a little bit to actually get there) and replace all of it with a single ion engine, a single xenon tank and 20 generators. I can't believe that wouldn't increase your delta-v.

Oh, it will most definitely significantly increase your deltaV...but at the same time, your thrust goes out of the window

[Rodyle]

Oh, it will most definitely significantly increase your deltaV...but at the same time, your thrust goes out of the window

It was just the most extreme example. I'm at the moment doing some calculations of optimal(ish) amounts of batteries, generators and engines which would allow you to fire the engines in 500 seconds bursts at at least 0.5 m/s^2. Still not sure if it's possible though: you'd need eight engines for each 10 tonnes your craft weighs to get that half a meter per second squared acceleration. 8 engines draw roughly 120 E/s, so, given that batteries store 20E/kg, you'd need 5.8 kg of batteries for each second those engines are active (assuming you have no generators, which probably is not optimal). So to make them work for those 500 seconds, you'd need 2.9 tonnes of your 10 ton space craft to be battery.

That's not to mention the part count, by the by. Don't even get me started on that...

[Stochasty]

Sorry, but how do ion engines not help?

There are no targets that you can get to with ion engines that you cannot get to without ion engines. While ion engines give you increased delta-V for the transfer portion of your trip, they are useless (i.e., dead weight) during takeoff and landing. That dead weight is not trivial, and the efficiency loss during landing and takeoff can (and, for most targets in the Kerbal system, does) out weigh the efficiency gains of using ion engines for the transfer.

[Rodyle]

There are no targets that you can get to with ion engines that you cannot get to without ion engines. While ion engines give you increased delta-V for the transfer portion of your trip, they are useless (i.e., dead weight) during takeoff and landing. That dead weight is not trivial, and the efficiency loss during landing and takeoff can (and, for most targets in the Kerbal system, does) out weigh the efficiency gains of using ion engines for the transfer.

Meh. I'd say you could carry a small lander easily. It's not really single-stage any more, but you're still able to zip all over the solar system.

[Stochasty]

It's not really single-stage any more.

QED.

You want to build multi-stage, and use ions for the transfer? Sure, they're great, if you can tolerate long burns. But if that's what you want to do, why are you talking about it in a thread devoted to the capabilities of single stage craft? I was quite explicit in my above post: ion engines are unnecessary for single stage craft.

[Rodyle]

QED.

You want to build multi-stage, and use ions for the transfer? Sure, they're great, if you can tolerate long burns. But if that's what you want to do, why are you talking about it in a thread devoted to the capabilities of single stage craft? I was quite explicit in my above post: ion engines are unnecessary for single stage craft.

If you want to land: no. However, nowhere in this challenge does it say you need to land at every target. It'd perfectly allowed to zip out of the Kerbin Atmosphere and do a flyby of each moon and planet. Still an SSTO, still perfectly within challenge parameters, perfectly good use of ion engines. To use your words: QED.

[Stochasty]

You can do a flyby of anywhere using nukes, too. Better yet, you can do a flyby, land, and return using nukes on every target except Tylo and Eve, and ions don't help with either of those. So there is no reason whatsoever to use ion engines on an SSTO as the game currently stands; they are unnecessary. Which was my point to begin with.

[Rodyle]

You can do a flyby of anywhere using nukes, too. Better yet, you can do a flyby, land, and return using nukes on every target except Tylo and Eve, and ions don't help with either of those. So there is no reason whatsoever to use ion engines on an SSTO as the game currently stands; they are unnecessary. Which was my point to begin with.

I think we're talking past each other. You can make a decent SSTO capable of going past, hell, even orbiting them should be doable, all possible targets in the game and then return to Kerbin using ion engines. Sure, that's still possible with nukes (ish, I don't know. Maximum possible with the nuke is 17 km/s, which might be too little, even if you perfectly plan the route and do every manoeuvre perfectly), but it's a lot easier with ion engines.

[sdj64]

I have an entry, to Duna, and 2 cents to add to the ions/nukes debate. The main advantage of ions is to make a really small interplanetary SSTO. I don't think I could make a duna-capable plane much smaller without ions. Though you would still need another engine to land, probably a 48-7s. For a large SSTO nukes are pretty much necessary for your sanity, time, and part count, regardless of what capabilities ions have on paper. How long will it take you to take your theoretical ion SSTO to get to all of those targets?

Pictures!

[mr_yogurt]

If I find the time to do something, I will. It will probably be a multi-day mission however, since my acceptance threshold of horribly slow burns is somewhat low. If I do something like that, mind if I post the intermediate steps here to keep myself motivated?

In the mean time, let's post some pictures. As I mentioned: full mission briefing can be found in my signature, but I thought the thread was rather empty at the moment.

-snip-

Cool. I assumed that the probes you detached did not help the ship in any way. I might need to amend the rules so people know that payloads are allowed. Also, I originally assumed that you landed on Duna, but upon closer inspection it appears you did not. Sorry for the confusion.

Edited February 26, 2014 by mr_yogurt

[Rodyle]

Cool. I assumed that the probes you detached did not help the ship in any way. I might need to amend the rules so people know that payloads are allowed. Also, I originally assumed that you landed on Duna, but upon closer inspection it appears you did not. Sorry for the confusion.

Nah. None of the probes helped in any way, and neither did the scooter (I should've let that horrible thing burn up in the Dunar atmosphere...). I indeed did not land on Duna. It would've been nice, but the delta-v budget would've been awfully tight, and even more importantly: the thing weighed around 40 to 35 tonnes while in Dunar orbit, if it wasn't closer to 50. No way a single nuclear engine would have gotten if back into space.

As for the SSTO Ion thingy: still in development. I've pretty much given up on anything resembling a spaceplane, since it'd both look like arse and be impossible to fly anyhow. I'm currently still doing a lot of tryouts on how to get enough ion engines to get at least half a m/s^2 acceleration, while still having enough RTGs and batteries to give it at least 500 m/s bursts of thrust. And, if at all possible, I'd also like it to have 500 parts or less.

Let's just say that it's complicated. XD