Lightest SSTO

[CalMacDa]

Who can make the lightest stock SSTO? That's what this challenge is for.

The rules are very very simple. Make the lightest SSTO purely with stock parts, no using debug menu, and orbit must be stable (Pe > 70km)

This isn't a spaceplanes competition! This is an SSTO competition!

3 required screenshots:

Ship with weight in tons visible

Map view, in orbit

In orbit, not map view

Kudos if you get below 2 tons. That is the tough number to get below.

Thanks, and let's see those SSTOs!

RANKINGS:

Foxster: 0.674 tons

chengong: 0.8 tons

gm573: 0.803 tons

Cat Biscuits: 0.826 tons

SRV Ron: 1.33 tons

cantab: 1.395 tons

Red Iron Crown: 1.992 tons

Captain Vlad: 5.2

Captain Sierra: 6.72 tons

Edited January 16, 2015 by CalMacDa
Adding entry to rankings

[chengong]

below 20 tones is incredibly easy, try 2 tones instead.

[CalMacDa]

below 20 tones is incredibly easy, try 2 tones instead.

Oops... That's what I meant...

[chengong]

Oops... That's what I meant...

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

0.7t

Edited January 11, 2015 by chengong

[Captain Sierra]

While hardly a contender to beat the above post, its probably the lightest SSTO you can make with minimal part clipping and a Mk2 cockpit.

The arrowhead here weighs in at 6.72 tons on the pad with enough fuel to rendezvous up to 150km and de-orbit.

Currently using a clipped turbojet-909 combo, I have a variant of it (not yet certified) with a RAPIER engine which weighs in at under 6 tons.

[Foxster]

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

Assuming you used 31.5/38.5 in the FL-T100 then that doesn't seem enough dv for a stable orbit. What's the secret?

[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

cheng, your orbit is not stable... I can't rank you with that

[numerobis]

With just one oscar, you get 0.77t assuming a QBE. That gives you 4500 m/s vacuum, which might just be enough.

But the spacecraft as pictured has two oscars, so it's a bit fishy. Did you mean 0.85t?

CalMacDa: chengong's orbit as pictured is in fact stable.

[chengong]

yea maybe it was 0.8t, I don't remember because I quickly did it in 5 minutes. Also why I had two tiny tanks, just in case I don't get the perfect launch first time around.

The secret is that dv counter is not entirely accurate when you do things like physics wrap, and fire engines at extremely low thrust just to turn because you have no torque.

Contrary to poplar belief, the atmosphere ends at 69,000m not 70,000.

[numerobis]

69078m to be precise.

[Foxster]

CalMacDa: chengong's orbit as pictured is in fact stable.

Its stable, but periapsis isn't over 70K as per the rules.

[numerobis]

Ah, indeed. Still, the spacecraft is clearly capable.

I wonder if the single FL-T100 is enough on its own, with a sufficiently well crafted flight path.

[Captain Vlad]

I was fiddling around with my little 'fly for fun' jet last night and switched its basic jet engine with a turbojet and ended up in a vertical climb and a apoapsis of 72,000 meters. Figured a Rapier and a different fuel tank would put her in orbit. I was correct.

Weight at launch is 5.2 tons. Made a 100,000 km orbit and landed back at KSC on about 17 (whatever fuel units it uses) left, so not really a 'to the Mun' type of plane, but still...kinda happy with her. She's all stock, with no clipping (not that I care about clipping; everyone else just seems to like to specify).

Edit: Forgot to get a map view shot...is the one with the Ap/Per data displayed with Kerbal Engineer sufficient or should I fly her back up again?

Edited January 11, 2015 by Captain Vlad
Added Screenshot and asked question.

[hoioh]

Not quite as light as Cheng's , but still pretty light. Has a lot more DV, is completely stock, doesn't clip anything and it's periapsis is over 70K. And to make it in any way useful I added some science instruments on the sides.

Javascript is disabled. View full album

[GoSlash27]

I'm surprised nobody's mentioned this yet:

[hoioh]

Didn't you make an even lighter krakendrive powered craft that was basically a winglet on a strut, Slash?

[Red Iron Crown]

I did something similar for a micro-SSTO challenge back in April, pretty sure none of the parts' stats have changed since then:

Javascript is disabled. View full album

Turbojet/ion hybrid, under two tons and makes orbit with a pile of dV remaining. Probably not eligible as it has a MechJeb module edited into the pod and thus is not 100% stock, but may serve as inspiration for others (this design is beatable, I had more than enough LF and xenon as well as an extra probe core for flying backwards on ions).

I took the liberty of editing the OP and poll to match the OP's intentions.

Edited January 11, 2015 by Red Iron Crown

[Red Iron Crown]

Great entry, Foxster, not a gram of engine mass in that design!

[CalMacDa]

yea maybe it was 0.8t, I don't remember because I quickly did it in 5 minutes. Also why I had two tiny tanks, just in case I don't get the perfect launch first time around.

The secret is that dv counter is not entirely accurate when you do things like physics wrap, and fire engines at extremely low thrust just to turn because you have no torque.

Contrary to poplar belief, the atmosphere ends at 69,000m not 70,000.

just checked the wiki. You're right. Sorry cheng! You will be ranked at 0.8tons

- - - Updated - - -

Not quite as light as Cheng's , but still pretty light. Has a lot more DV, is completely stock, doesn't clip anything and it's periapsis is over 70K. And to make it in any way useful I added some science instruments on the sides.

http://imgur.com/a/VQd12

Cant see the mass. Please edit the post to show it

[SRV Ron]

With Kerbal Engineering and combining three other screenshots into one, here is all the data required on my SSTO probe from KSP 0.90 Beta

Launch Weight

Orbit weight

Orbital stats, way over 70,000 meters.

Cost, could be reduced by using only one OxStat or none.

[CalMacDa]

With Kerbal Engineering and combining three other screenshots into one, here is all the data required on my SSTO probe from KSP 0.90 Beta

Launch Weight

Orbit weight

Orbital stats, way over 70,000 meters.

Cost, could be reduced by using only one OxStat or none.

http://i.imgur.com/4uhpWdq.jpg

I can't see launch weight... Is it the 0.34?

[SRV Ron]

I can't see launch weight... Is it the 0.34?

Look to the readout on the left which is the prelaunch stats. It is 1.33 tons. Orbit weight is 0.34 tons on the right.

[CalMacDa]

Oh, sorry. Missed that. Thanks. I'll rank yah!

[GoSlash27]

Didn't you make an even lighter krakendrive powered craft that was basically a winglet on a strut, Slash?

Oh, heavens no!

I can't take credit for that.

I did make a kraken drive infiniglider, but that was heavier and I had a lot of help. The winglet-on-a-strut was around long before I ever came on the scene.

Best,

-Slashy

[hoioh]

just checked the wiki. You're right. Sorry cheng! You will be ranked at 0.8tons

- - - Updated - - -

Cant see the mass. Please edit the post to show it

Mass is shown in the bottom right hand corner of the first screenshot, green text in the little box. just view full res and zoom in on it.