Lightest SSTO

[cantab]

Here's a FAR entry, 1.4 tons.

I know what you're thinking, "Hey! That's not fair! It takes less delta-V to make orbit in FAR!". Hold your horses, it's not that simple. Very small rockets experience proportionately more drag than normal-size ones, so the delta-V needs go up. Short and fat 1.25m diameter designs have stability problems while skinnier 0.625m designs suffer from the poor mass fraction of the tanks, and either way the aerodynamic parts like nosecones and fins are heavy on such a little rocket.

So I think it's an open question as to whether stock aerodynamics or FAR will permit the lighter mass to orbit. Certainly mine is nowhere near the best.

In the VAB:

Orbit attained:

More pics: https://flic.kr/s/aHsk4784jP

Non-map orbit shot can be grabbed if you really need it.

[EdFred]

1.06t

No screen shots, but easy enough to make. QBE + FLT200 + 48-7S with the -200 with 72Liquid Fuel and 88Oxidizer.

That's it. 3 parts.

Edit: You actually need the massless solar panels in order to get the craft to turn. Still 1.06t though.

Edited January 13, 2015 by EdFred

[flashcactus]

Hey, that's… pretty similar to the challenge I did a while ago(see sig). Nice to see all that continued.

Of note is that the runner-up for lowest achieved physicsless mass (in the orbit, no-tweakscale, stock atmo tier) went as low as .685 t, being of roughly the same design as the winner here. (and, interestingly, foxster provided the winning craft there, as well). Still, in *that* respect, Mesklin's Neutrino Light beats everything here by a considerable margin (Even the vanilla Neutrino does, but that's another story)

How about importing my results (the rules were stricter, so they're compatible) here, so they won't be lost?

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]
   

- - - Updated - - -

Actually, is tweakscale permitted here? It's not technically non-stock parts…

If it is, … *rubs hands*

[CalMacDa]

Flash, i'm sorry, but the screenshots required are required... If you could rebuild those ships or get the builders to send pics then I would be happy to, but there isn't any proof. People would start to get whiny about that.

[smartech]

I've played around with the optimal rocket tool here: http://garycourt.github.io/korc/, and it looks like Foxster has pretty much nailed it, so the challenge is basically over . The lightest SSTO it finds with 4500m/s is 0.682t. Interestingly, going to multiple stages it goes down to only 0.652t with 2 stages because the decouplers are very heavy relative to the rocket.

[Foxster]

I've played around with the optimal rocket tool here: http://garycourt.github.io/korc/, and it looks like Foxster has pretty much nailed it, so the challenge is basically over . The lightest SSTO it finds with 4500m/s is 0.682t. Interestingly, going to multiple stages it goes down to only 0.652t with 2 stages because the decouplers are very heavy relative to the rocket.

Ah but there are a few things that otherwise excellent calculator does not account for.

[Tsevion]

Can I abuse infiniglide? If so I've got an SSTO you can see here that can make orbit weighing about 300kg. Although loading it up in 0.90, it appears that the weight of the small control surfaces has changed... so it's heavier and may need a redesign... hrmmm.

Edited January 14, 2015 by Tsevion

[flashcactus]

Flash, i'm sorry, but the screenshots required are required... If you could rebuild those ships or get the builders to send pics then I would be happy to, but there isn't any proof. People would start to get whiny about that.

Lurk around the thread (the button in my sig), every entry was required to have the same screenshots you're asking for to be included into the scoreboard. .craft files are also available for all contestants except the last one.

- - - Updated - - -

And you didn't answer my tweakscale question.

Also, call me Cactus

Edited January 15, 2015 by flashcactus

[CalMacDa]

if that's what you meant then why did you also make the same mistake in the votes?

0.7t

http://i.imgur.com/9XAduFp.jpg

what I meant by "that's what I meant" was that I just thought it was 20 tons, but then realized that it was 2

[SRV Ron]

Some testing;

Built the 0.7 ton design, It came out to 0.88 tons. Due to the remote pod in use, it has no stability other then when powered. Tough to orbit but has the Delta V according to Kerbal Engineering.

Now, I shaved some weight off of my design by using that pod with the small SAS. Delta V is higher, However, due to the increased drag of the additional part, performance was slightly worse.

[xendelaar]

Nice Challenge! Here's my entry for version 1.0.4:

I was aiming for a 1.0t SSTO vehicle but that sadly didn't work out. So now I'm stuck with this 1.1t piece of junk . With some better flying skills, I bet it would be possible with less fuel.

We're good to go! Counting down...

We're right on track

Apoapisis of 75km... 413 dV left... I think we're gonna make it.

Setting up final node

Starting burn

Mission accomplished! We have a stable orbit. Here's the money shot

[Nefrums]

There is a 1.0 thread for this challande: http://forum.kerbalspaceprogram.com/threads/124055-Smallest-SSTO-for-1-0-challenge%21