Ultralight challenge: Lowest launchpad mass to orbit and beyond

[flashcactus]

The goal of this challenge is very simple:

Build a spacecraft with as low a launchpad mass as you can manage and then achieve a stable (with an above-atmosphere periapsis) kerbocentric orbit with it.

Whoa, whoa, don't run off to the VAB just yet. We have some rules, too.

First: Stock parts only. The only exception is MJ/KER or other info/autopilot parts.

Second: Physicsless parts DO count toward the final mass (Note that MechJeb, KER and the info window in Map View do not count most or even all of them towards the shown value).

These physicsless parts are irrelevant to the challenge, and so may be used without being counted towards the total mass:

• Communotron 16
  
• Communotron 88-88
  
• 2HOT Thermometer
  
• Double-C Seismic Accelerometer
  
• GRAVMAX Negative Gravioli Detector
  
• PresMat Barometer
  
• Illuminator Mk1
  
• Illuminator Mk2
  

The ladders are not counted on unmanned craft only:

• Pegasus I Mobility Enhancer
  
• Telus Mobility Enhancer
  
• Telus-LV Bay Mobility Enhancer
  

The whole list of massless parts as of the current version of KSP can be found here.

If someone makes something that is significantly lighter than everything else when physicsless parts don't count, though, I might set up a separate leaderboard for those, too. Ask for it if you want it.

Third: The thing that achieves orbit must be controllable (to prevent silly things such as sepratron-driven octagonal struts)

Fourth: If you use ferram's atmosphere mods, be a man even if you're a woman and use FAR. No NEAR-silliness.

There are separate leaderboards for FAR and stock atmosphere, as well as craft that contain Tweakscaled parts and those which don't.

A .craft file and three screenshots are required from each contestant for the entry to be included: (1) craft in VAB/SPH, (2) map mode with periapsis node highlighted and (3) craft in orbit.

Optionally, tell how to fly that thing to orbit and other interesting tips.

Tips:

1. The craft does not have to be manned and does not have to return from orbit, either.

2. It also doesn't need to be able to stay in orbit indefinitely.

3. If you do make it manned, "get out and push" is a valid tactic (Okay, let's restrict this: No more than 2 kerbalfuls of EVA fuel could be spent on pushing).

4. Launch clamps and other stuff that (a) stays on the ground and ( does not exert any force upon the ship does not count towards the final mass.

But getting to orbit is only the beginning. Getting to orbit with less than a ton of launchpad mass is cool but you probably won't be able to go anywhere else after that. So we have separate tiers for ultralight spacecraft that do more than just get an orbit.

Exploration Mode: Minmus. Go to Minmus and land in one piece (again, the requirement is that it has to be controllable).

Exploration Mode: Mün: Same as above, but land on the Mün.

[EDIT] As SkyRender helpfully pointed out, Ion drives are a problem here, so designs using them have a separate scoreboard.

And if you want to go even further, the Interplanetary Mode is for you! It is slightly different though:

1. No scoring. There's no winners or losers here, as there's just too many places one can go to and too many different kinds of missions, and I don't want to enforce any particular body or kind of mission.

2. Part mods are allowed, but every entrant must provide the full list of installed mods. Entries may be segregated based on the subjective "overpoweredness" rating I give each of them.

For the more hardcore of you, we have Hardcore Mode, which is the same as the base challenge, but you'll have to launch from Eve with the starting point no higher than 1km ASL. You are free to hyperedit the craft there, and an additional screenshot of it sitting on the body in question with a mass readout (or that and a map view with the ship info window open if you don't have or want to use a mass-measuring mod) is required for the entry to count.

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LEADERBOARDS

Mass without physicsless parts is also provided [in purple small text] if different

Base challenge:

1. Foxster's tweak of the Timmy Tiny, 0.789t [0.784t physicsless]
   
2. gm537's Timmy Tiny, 0.803t [0.798t physicsless]
   
3. Cat Biscuits, 0.826t
   
4. Heimdall5008's MonoOrbiter, 0.865t [0.685t physicsless]
   
5. [sSTO] ihtoit, 0.905t [0.865t physicsless]
   
6. [sSTO] UmbralRaptor's Project 9745, 1.0045t [0.9745t physicsless]
   
7. [sSTO] [iON] Mesklin's Neutrino light, 2.39(?)t [0.580t physicsless] [.craft file not provided]
   

1. flashcactus' Silly3, 0.884t
   
2. [iON] SkyRender, 1.93(?)t [1.66t physicsless] [.craft file not provided]
   

None at the moment. Worth a try!

1. flashcactus' SillyJ, 0.327 t
   

Exploration Mode:

1. Foxster's Tom Thumb(Minmus edition), 1.471t [1.446t physicsless]
   

1. Foxster's Tom Thumb(Mün edition), 1.885t [1.859t physicsless]
   

1. SkyRender, 1.93(?)t [1.66t physicsless] [.craft file not provided]
   
2. [sSTO] Mesklin's Neutrino, 2.55(?)t [0.740t physicsless] [.craft file not provided]
   

Interplanetary Mode:

[spoiler=]

Ziv, Almost-grand-tour(No Eve landing), 9.983 t at launchpad.

Edited August 18, 2014 by flashcactus
Updated the leaderboards

[UmbralRaptor]

Project 9745, submitted for easy mode (and stock aerodynamics):

If physicsless parts didn't count, it would be 0.9745 t. Since they do, 1.0045 t. (grr...)

Actual flying is pretty boring. Full throttle until you hit terminal velocity, then back off to keep it. Pitchover begins at ~4 km.

And the .craft.

Edited August 15, 2014 by UmbralRaptor
Made compliant.

[SkyRender]

There's just one small problem to this challenge...

Ion engines.

This little bugger has enough dV and thrust to reach, circularize, land on, return to orbit around, and leave the Mun, easily. It could then do the whole routine again and stop by Minmus as well just for kicks. You're looking at ~7000dV in that tiny package, and even if it does top out at 50% thrust under ideal sunlight, that's still 1.5 TWR on the Mun (meaning a midday landing there would be entirely doable).

Here's how it looks at launch. FAR is installed, because FAR.

[Sirine]

Lowest mass to orbit achieves, end of challenge for this thread..

[flashcactus]

My own entry. With FAR, without tweakscale, 0.884t, no physicsless parts at all (except MJ, but it has 0 mass anyway).

This is simply the smallest rocket I could manage, and it beats all my previous elaborate attempts by a sizeable margin.

Flight profile: Floor it, get apo above atmosphere, turn to horizon until MECO (or throttle down at about 10k and wait for your velocity vector to drop a bit before continuing a proper gravity turn (I feel silly just saying that about this stack of pancakes) to get that apo at MECO), decouple&continue at full throttle, as the TWR of the top stage is just enough to circularize without falling back. Optional: use the leftover fuel to deorbit before electric charge runs out and watch the dead probe survive reentry and fall to its splashy/crashy doom.

The .craft file

[flashcactus]

There's just one small problem to this challenge..

Ion engines.

This little bugger has enough dV and thrust to reach, circularize, land on, return to orbit around, and leave the Mun, easily. It could then do the whole routine again and stop by Minmus as well just for kicks. You're looking at ~7000dV in that tiny package, and even if it does top out at 50% thrust under ideal sunlight, that's still 1.5 TWR on the Mun (meaning a midday landing there would be entirely doable).

Here's how it looks at launch. FAR is installed, because FAR.

Well, that is cool and all, it is probably the ultimate solution to the hard modes, but it does not actually provide the lowest launchpad mass for just an orbit and nothing else (at least your design does not), so the base challenge still stands.

And I challenge you, personally, to beat my 0.884t with ions.

[EDIT] Added a note about ions and a separate category for them. Also added that craft from your post as an entry, hope you don't mind.

Edited August 15, 2014 by flashcactus

[SkyRender]

Well, that is cool and all, it is probably the ultimate solution to the hard modes, but it does not actually provide the lowest launchpad mass for just an orbit and nothing else (at least your design does not), so the base challenge still stands.

And I challenge you, personally, to beat my 0.884t with ions.

[EDIT] Added a note about ions and a separate category for them. Also added that craft from your post as an entry, hope you don't mind.

That would be wise, given how overpowered an ion drive is once it's in orbit.

[gm537]

Here is my entry the "Timmy Tiny". VAB KER shot says mass of 0.798 and since KER doesn't count physics-less panel that gives a launch mass of 0.803 tons.

[flashcactus]

Here is my entry the "Timmy Tiny". VAB KER shot says mass of 0.798 and since KER doesn't count physics-less panel that gives a launch mass of 0.803 tons.

Nice one, thanks for the entry.

Can you also provide the .craft file?

This is FAR-less, if I understand correctly?

[gm537]

Haha yep missed that requirement. And indeed that is FAR-less. (how do you make the link not say the unpleasant looking link name?)

https://drive.google.com/file/d/0Bzw1y5VWJ9wVWGJSM0VGTE9pdFk/edit?usp=sharing

[flashcactus]

(how do you make the link not say the unpleasant looking link name?)

The format is [ url="<actual_address>"]<link_name>. If you're using the editor to insert those tags, either type the link name first, highlight it, mash that button&paste that link, or replace the stuff between them afterwards.

And thanks for the file!

[ihtoit]

0.243t dry - with useful payload - 0.865t on the pad and a Rockomax stock engine, gets into 70x70 orbit on 4370m/s dV. You're welcome.

No FAR, by the way. All entirely stock.

[Ziv]

I know there's no category for a Grand Tour or big long missions but maybe this mission worth to look at:

9.983 tons on launchpad and it landed a Kerbal on all the bodies, except Eve.

http://forum.kerbalspaceprogram.com/threads/57197-The-Ultimate-Jool-5-Challenge-land-Kerbals-on-all-moons-and-return-in-one-big-mission?p=1313730&viewfull=1#post1313730

[flashcactus]

0.243t dry - with useful payload - 0.865t on the pad and a Rockomax stock engine, gets into 70x70 orbit on 4370m/s dV. You're welcome.

No FAR, by the way. All entirely stock.

That's pretty nice, but I need 2 more pictures: craft in VAB and map view(well okay, you could drop that one, the MJ window is evidence enough) plus the .craft file to officially add your entry to the scoreboards.

Also, what's that antenna on the side?

-----------------------------------------------

I know there's no category for a Grand Tour or big long missions but maybe this mission worth to look at:

9.983 tons on launchpad and it landed a Kerbal on all the bodies, except Eve.

http://forum.kerbalspaceprogram.com/threads/57197-The-Ultimate-Jool-5-Challenge-land-Kerbals-on-all-moons-and-return-in-one-big-mission?p=1313730&viewfull=1#post1313730

Well, while that is cool and just under 10t is very light for a grand tour, I'll have to think whether to expand this challenge to interplanetary levels. Thanks for the idea, though.

[ihtoit]

the antenna's just a short range dipole because I use RemoteTech (which requires a GC connection or a Kerbal onboard). The tanks are Oscars and the larger one is an FL-T100. Four static panels and 4 of the small batteries, and what do you need a .craft for? It's less than 20 parts!

[flashcactus]

the antenna's just a short range dipole because I use RemoteTech (which requires a GC connection or a Kerbal onboard). The tanks are Oscars and the larger one is an FL-T100. Four static panels and 4 of the small batteries, and what do you need a .craft for? It's less than 20 parts!

I need a way of measuring the craft's weight precisely. One way to do this is to look at the VAB picture with a mass-measuring mod. Another way would be to load your .craft file and measure it myself. You provided neither. Assembling a replica of your craft by the picture is also not something I'd like to do.

I've no idea whether the mass you posted includes physicsless parts (the panels and batteries and possibly also the antenna) and that's gonna determine where your entry goes in the scoreboards.

[ihtoit]

if you really insist...

.craft file

VAB view:

[Mesklin]

Here is two my entries with stock only, no FAR:

1. Minimal SSTO with name "Neutrino light" orbit reach only and some fuel for return, only ion power, 0.580 t on runway

Javascript is disabled. View full album

2. Similar design "Neutrino", more heavy - 0.740 t on runway, but made Mun+Minmus round-trip (4100...4400 m/s dV on LKO)

Javascript is disabled. View full album

[flashcactus]

Here is two my entries with stock only, no FAR:

1. Minimal SSTO with name "Neutrino light" orbit reach only and some fuel for return, only ion power, 0.580 t on runway

2. Similar design "Neutrino", more heavy - 0.740 t on runway, but made Mun+Minmus round-trip (4100...4400 m/s dV on LKO)

Thanks! I've seen those in the K-prize thread and hoped you'd come here. I need you to upload their .craft files for them to be added to the leaderboards, though, as MJ does not count the physicsless OX-STATs&Z-400s, of which you have plenty, towards the shown vessel mass. I'd also advise you to remove all the mission-irrelevant physicsless stuff (scientific instruments,antennae,etc) from the published versions of the craft, as otherwise they will be included in the final mass too.

[edit] Note that the landing gear bays are massless too, and nominally weigh 0.5t each, so if you could remove them while retaining capability to reach orbit (raised launch clamps to start with a glide, a couple sepratrons to kick you up, you name it), that'd obviously benefit your final score.

On a side note, what navball mod are you using?

Edited August 16, 2014 by flashcactus

[flashcactus]

Another entry, the SillyJ. Still with FAR, but tweakscaled this time.

.craft file

This one weighs 327kg and does not contain any physicsless parts aside from MJ and KER (KER removed from the published .craft file)

As you can see, the first stage is an engine nacelle and turbojet, both scaled to 0.625m diameter. The fuel in the nacelle is also tweaked to â…• the original amount. The top stage uses a downsized FL-T100 for its superior mass ratio and a downsized large nosecone(as it is much lighter) and rockomax decoupler (for the exact same reason). The staging (jet and clamps in the same stage) is deliberate, as it allows to pitchover the craft without experiencing RUD by aerodynamic forces.

Flying this is a bit nontrivial. First, some preflight preparations: set full throttle, activate SAS, switch MJ SASS to ADV/SURFACE_VELOCITY/FORWARD but don't activate it.

Activate the first stage and as the craft stops falling and starts going up, pitchover to about 75°, activate SmartASS and let go of the attitude controls. Just before you start passing mach 1 (~350m/s), throttle to about ⅓ to avoid aerodynamic RUD. When you hit 10km altitude, throttle back to full and watch this little thing shoot up at a ridiculous acceleration.

Once intake air starts decreasing, get ready to stage. Leave the throttle at full until flameout. Air runs out at about the same moment fuel does, so monitoring the fuel is also an option.

When the jet flames out, stage immediately, because the intake gets a crazy amount of drag with the engine off. The upper stage will try to tumble, so turn ASAS back on after decoupling. Coast to apoapsis&circularize, and you have an orbit! Don't forget to deorbit before the batteries run out!, as leaving trash in space is not nice.

[Cat Biscuits]

This is mine, all stock weighing in at 826 kg I reckon I probably could have drained some fuel out if I were a better pilot though.

.craft

It is pretty easy to get into orbit, just have to be mindful of terminal velocity's, This all being said the types of craft that can be built lightly to get to a kerbin orbit are limited, may be worth extending the challenge to other SOI's

Edited August 16, 2014 by Cat Biscuits

[ihtoit]

Another entry, the SillyJ. Still with FAR, but tweakscaled this time.

.craft file

This one weighs 327kg and does not contain any physicsless parts aside from MJ and KER (KER removed from the published .craft file)

http://legion.flashcact.us/img/pub/ksp/lowestmass20rbit/sillyj_vab.png

As you can see, the first stage is an engine nacelle and turbojet, both scaled to 0.625m diameter. The fuel in the nacelle is also tweaked to â…• the original amount. The top stage uses a downsized FL-T100 for its superior mass ratio and a downsized large nosecone(as it is much lighter) and rockomax decoupler (for the exact same reason). The staging (jet and clamps in the same stage) is deliberate, as it allows to pitchover the craft without experiencing RUD by aerodynamic forces.

http://legion.flashcact.us/img/pub/ksp/lowestmass20rbit/sillyj_launchpad.png

Flying this is a bit nontrivial. First, some preflight preparations: set full throttle, activate SAS, switch MJ SASS to ADV/SURFACE_VELOCITY/FORWARD but don't activate it.

Activate the first stage and as the craft stops falling and starts going up, pitchover to about 75°, activate SmartASS and let go of the attitude controls. Just before you start passing mach 1 (~350m/s), throttle to about ⅓ to avoid aerodynamic RUD. When you hit 10km altitude, throttle back to full and watch this little thing shoot up at a ridiculous acceleration.

http://legion.flashcact.us/img/pub/ksp/lowestmass20rbit/sillyj_hot.png

Once intake air starts decreasing, get ready to stage. Leave the throttle at full until flameout. Air runs out at about the same moment fuel does, so monitoring the fuel is also an option.

http://legion.flashcact.us/img/pub/ksp/lowestmass20rbit/sillyj_flmout.png

When the jet flames out, stage immediately, because the intake gets a crazy amount of drag with the engine off. The upper stage will try to tumble, so turn ASAS back on after decoupling. Coast to apoapsis&circularize, and you have an orbit! Don't forget to deorbit before the batteries run out!, as leaving trash in space is not nice.

http://legion.flashcact.us/img/pub/ksp/lowestmass20rbit/sillyj_orb.png

http://legion.flashcact.us/img/pub/ksp/lowestmass20rbit/sillyj_map.png

uh... scaled parts=non-stock.

Or I call "Shenanigans".

[Mesklin]

Thanks! I've seen those in the K-prize thread and hoped you'd come here. I need you to upload their .craft files for them to be added to the leaderboards, though, as MJ does not count the physicsless OX-STATs&Z-400s, of which you have plenty, towards the shown vessel mass. I'd also advise you to remove all the mission-irrelevant physicsless stuff (scientific instruments,antennae,etc) from the published versions of the craft, as otherwise they will be included in the final mass too.

[edit] Note that the landing gear bays are massless too, and nominally weigh 0.5t each, so if you could remove them while retaining capability to reach orbit (raised launch clamps to start with a glide, a couple sepratrons to kick you up, you name it), that'd obviously benefit your final score.

On a side note, what navball mod are you using?

About navball, I am using mod from this thread

And about my entry, I will be busy till next Thursday, and all modification for my entry will be after this date

[Foxster]

Not really an entry as its just a tweak to the Timmy Tiny by swapping out the Oscar-Bs for a Round-8 and adjusting the fuel in the FL-T100. Gives a bit more dV and reduces the weight a little.

I make it 0.784+0.005=0.789t.

MechJeb will put it into a stable 71K orbit.

(Unless its different enough to count as an entry...)

Edited August 17, 2014 by Foxster

[flashcactus]

This is mine, all stock weighing in at 826 kg I reckon I probably could have drained some fuel out if I were a better pilot though.

It is pretty easy to get into orbit, just have to be mindful of terminal velocity's, This all being said the types of craft that can be built lightly to get to a kerbin orbit are limited, may be worth extending the challenge to other SOI's

Thanks for the entry. There's a little problem with it though: I cannot verify that you actually got a stable orbit, as you have neither the KER window open, nor the periapsis node highlighted in your map shot.

As for the limitedness, we still have the "go to mün/go to minmus" non-ion categories. Adding more for different bodies looks interesting but unnecessary right now, and I can't think of a ruleset that would make them more interesting than "base challenge lite", if the body in question is not Eve or Tylo.

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uh... scaled parts=non-stock.

Or I call "Shenanigans".

They aren't exactly non-stock, but they do allow building stuff that's several times lighter. Because of that, they have a separate leaderboard.

---------------------------------------------

About navball, I am using mod from this thread

And about my entry, I will be busy till next Thursday, and all modification for my entry will be after this date

Thanks! I can definitely wait for it.