Smallest, Lightest SSTO?

[PanzerAce]

I keep seeing these monstrosities that people are building to loft cargo and the like into orbit, and for some reason I can never get my larger SSTO's to actually achieve the O part with any kind of remaining delta. So I went the other direction:

 

 

15 parts, 11.5 tons. And un-used LF in orbit (wish there was an easy way to adjust fuel tank ratios). Honestly, the hardest thing to deal with for me is the ~1300-1400 m/s limit due to heating while in atmosphere. If we could get a cockpit that'd survive the heating up to ~1700 or more, I bet I could make this even better.

Launch procedure is absurdly simple. Full throttle, nose b/w 15-20 degrees above the horizon (very little lift, so actual flight path with be ~5 degrees shallower until high mach numbers), hit SAS. Once at altitude, close intakes and go to closed cycle mode just before velocity stops going up. Full burn till ~75km apo, then burn to circularize.

I also *might* be able to go from a V tail to a single vertical stabilizer and run it pure delta-wing style, and I might be able to drop an intake and move it underneath the ship, which would lose me some weight and drag. Too tired to do that right now though, and got work today.

 

 

UPDATE:

Yes, I can ditch the V tail for a single stabilizer, and go to one intake. Same flight profile as before. Ends up having almost triple the delta V at the end (58.80 units of Oxidizer in almost the same orbit), along with a bit more LF (272 units vs. 202). 13 parts and 11.4 tons on the runway at that point. No pictures because I forgot to take any while doing it, and I don't feel like re-launching KSP now, since I've got to get up for work soon

Edited January 25, 2016 by PanzerAce

[Evanitis]

In my experience, the smaller the plane is the easier it gets to design and fly them. That's the most compact one I ever built:

It's designed to fit in an mk3 cargobay. I was planing to build a big SSTO that carries this to orbit, but the project is on hold until I can think of a just slightly plausable sounding reason to do so that I can tell my investors.

Though I won't even dig for it's detailed numbers, as I know it's nowhere near the smallest this thread will see. If you forget the notion that it should be kerbaled and should be able to dock, the only payload you need is a probe core. Slap on some fuel, a tiny rocket engine and 2-3 of the smallest elevons and it can probably fit in even an Mk 2 cargobay.

I should take the project that spawned this plane even further: A huge SSTO that carries a smaller one to orbit that has an even smaller one inside it. sstoception!

 

(BTW, closing the intakes changes nothing in the current version)

Edited January 25, 2016 by Evanitis

[katateochi]

In 0.25 I built a little fleet of mini SSTO's, one of which was able to reach Mun, land and return without refueling, but since the changes in Aero that fleet has been grounded! (but you can still see/download them here http://kerbalx.com/hangars/142). (I think the "Executive" variant still works as it was rather OP anyway).

In 1.0.5 I've made this one.  Not quite as small as either of the two above, but my aim was to have something with a reasonable room for error.  It's fast a very easy to fly and can also handle an aggressive re entry without overheating (not actually sure how it manages that...err...I mean...that's was part of it's design).  Glides very nicely too.

 

1 hour ago, PanzerAce said:

No pictures because I forgot to take any while doing it, and I don't feel like re-launching KSP now, since I've got to get up for work soon

What is this, the "groggily post your SSTO before work" thread!? That's exactly where I'm at too OP! Happy Monday to all! (*groans)
I'll (try to remember to) post the craft file and put some of it's stats once I'm done with work today.

 

 

Edited January 25, 2016 by katateochi

[Val]

I have 2 candidates.

1. J-2 Muna at 9.25 t including a small Mun/Minmus lander as payload. (Craft)
   
    
2. J-1 Gulf at 8.5-ish t. My own interpretation of @UpsilonAerospace's Cute SSTO (Craft)

    

[Levelord]

My entire pre-1.0 fleet of SSTOs were retired. But I had designed a few new ones for 1.0.5. I have a few SSTOs functioning, but the latest one I'm working on doesn't have all the comforts of a normal cockpit, but it does feature an ejection seat.

 

 

 

It's max cruising speed is at 1,500 m/s at an altitude of 24,000m

 

 

 

This is the craft in a 70km/70km orbit. Kerbal engineer is bugged at the moment showing 0dV, but you can see its remaining fuel.

 

Edited January 25, 2016 by Levelord
Images not showing up

[Evanitis]

17 minutes ago, Val said:

 

Dang, it's disappointing to hear you. I always read your posts in the mental voice of Delphi (Sea Reaper princess in Citizen Kabuto). Blame the avatar.

Edited January 25, 2016 by Evanitis

[Val]

5 minutes ago, Evanitis said:

Dang, it's disappointing to hear you. I always read your posts in the mental voice of Delphi (Sea Reaper princess in Citizen Kabuto). Blame the avatar.

It's not my voice in the video. That's @UpsilonAerospace.

I didn't have any pics of my craft, so I linked his video, since that was the inspiration for my craft.

[RokRoland]

3 hours ago, PanzerAce said:

15 parts, 11.5 tons. And un-used LF in orbit (wish there was an easy way to adjust fuel tank ratios).

 

Yes, there is a way that is easy for me at least. Right-click your fuel tank when building your craft. From there, you can remove LF or OX from the tank. However, for whatever reason the adjustment seems to be stepped, so if you have several tanks the smallest one has the best granularity. Based on your remaining LF at orbit, reduce it as appropriate.

Anyway, I decided to build a SSTO based on a rover which had the transport experience Rapid Unplanned Disassembly at an apoapsis of 65 km. Jeb climbed into the rover and made it down safely. The Kerbal Steering Board mandated this platform to be used for all future SSTO efforts. It's a long story and I may write up about it later in the K-Prize thread, however here it is in a few poor quality pictures (the third picture features the Rover the SSTO is based on along with detachable Science Trailer roving about the Mun).

The Ben Rover Go-Jetter 4c features two Whiplashes, a Terrier and a Twitch and orbits quite simply by pointing nose at 45 degrees, then after switching to rockets following prograde, and finally by thrusting towards apoapsis prograde at 70k+. It also lands in one piece and can be equipped with a jettisonable no-walk system for Val, which means she can directly EVA to the command chair, has a 70% chance of not damaging the ship and 95% survival rate for the pilot - a fair trade-off for saving a few paces!

Cargo? It lifts a Kerbal. Mission accomplished!

 

One notable drawback of the platform has been the symmetry of girders forming the base has been replaced by manual precision engineering measurements due to faulty building aids. Some pilots have complained about the tendency of the plane to pull slightly left. The pilots have been told they have been equipped with controls designed to compensate this issue, namely "yaw".

[BagelRabbit]

2 hours ago, Val said:

J-1 Gulf at 8.5-ish t. My own interpretation of @UpsilonAerospace's Cute SSTO (Craft)

Thanks, Val! I'm positive this little guy isn't the smallest SSTO made in KSP so far, because more than half the design choices I made favored aesthetics over functionality. There's plenty of room at the bottom!

...and yes, @Evanitis, the voice you hear on the video is mine. You may now resume believing that Val's voice is whatever you want it to be. 

-Upsilon

[Choctofliatrio2.0]

My smallest SSTO has 0 parts, because I have never successfully built an SSTO

[Spartwo]

Needed something to fit in a cargo bay. Doesn't now because of the cockpit replacement,

Edited January 25, 2016 by Spartwo

[Foxster]

You are gonna need to deliver a payload if you are making a little SSTO...

Edited January 25, 2016 by Foxster

[KerikBalm]

I don't see many monstrosities... maybe I haven't been looking in the right place... IMO, if the cargo fits in a mk3 cargobay, its not a monstrosity... the one that is my avatar... that is a monstrosity...

I've tried to do smaller Juno powered ones, but I could never quite make them work on Kerbin - maybe if I used part clipping and had the junos and a 480772 in the same stack and clipper so that the juna doesnt block the 48-7s exhaust, then the drag advantages of inline vs radial + the small Isp advantage and TWR advantage of the 48-7s over the 24-77 would make it work... still not going to get a kerbain in a command seat on there though:

I had tried a single stack version with 1 juno and radial 24-77 motors... but it didn't even make it that close.

The 0.625 diameter rockets are pretty bad in comparison to the larger sizes, the radials are just terrible. The Juno is in theory better than the goliath or whiplash, but those are both terrible for SSTOs as well.

The panther is widely held as the minimum for a airbreathing SSTO... but thats with the afterburner.... without it, I've still got craft over over 673 m/s in atmospheric flight above 4km... though I haven't tried to SSTO one it without using the afterburner.

The Juno is... just... terrible for SSTOs unfortunately. It should work for a laythe SSTO however.

Its a shame, I really wanted to take a kerbal to orbit like this:

In the end, I just have them as personal jets for going around laythe... water landings only.

They get to orbit of kerbin in a single stage... as the payload

 

Edited January 25, 2016 by KerikBalm

[PanzerAce]

8 hours ago, RokRoland said:

Yes, there is a way that is easy for me at least. Right-click your fuel tank when building your craft. From there, you can remove LF or OX from the tank. However, for whatever reason the adjustment seems to be stepped, so if you have several tanks the smallest one has the best granularity. Based on your remaining LF at orbit, reduce it as appropriate.

Sorry, I meant the ability to adjust the ratio of LF/O without any empty tank space. It just feels wasteful to me. 

[pasukaru76]

Payload? What is payload? 

7 parts including the launch clamp, 6.2 tons.

[magnemoe]

On 25.1.2016 at 7:22 PM, Foxster said:

You are gonna need to deliver a payload if you are making a little SSTO...

 

Don't agree, one major niche for tiny SSTO is rescue and transport of one kerbal to and from LEO. Still I loved you plane and the cute probe
How much dV does it have? 

[Nich]

Yes sorry I just don't like little SSTOs too much work for 1 kerbal.  I have a scooter .3t to rescue kerbals from LOK and when I get 5 at a staion I retrieve them.

 

Edited January 27, 2016 by Nich

[Miravlix]

11 hours ago, pasukaru76 said:

Payload? What is payload? 

7 parts including the launch clamp, 6.2 tons.

Seriously overdesigned. You don't need the battery.

 

I do find it to be wrong to launch anything without an antenna, so I can't actually beat your design, since I have to replace the battery with an antenna.

[Wjolcz]

Way too big, guys. Way too big...

[adsii1970]

This sounds fun - and I'm going to accept this challenge.  I'll post pictures when I am done!

On a related note: I thought that here, a SSTO referred to craft that were horizontally launched from the airfield runway. I've noticed that a few of the contenders here are nothing more than single staged rockets... Not trying to pick a fight but looking for a more complete understanding of the acronym...

[KerikBalm]

Well, it seems bigger than my single stack juno spaceplane, maybe even bigger than my triple juno spaceplane... certainly uses more fuel... but my juno designs can't make orbit on Kerbin (they should make it on laythe), they end up about 200 m/s short.

[FancyMouse]

36 minutes ago, adsii1970 said:

On a related note: I thought that here, a SSTO referred to craft that were horizontally launched from the airfield runway. I've noticed that a few of the contenders here are nothing more than single staged rockets... Not trying to pick a fight but looking for a more complete understanding of the acronym...

I know someone is eventually going to say this so I'll say it. Nope they're legit SSTO - they are Single-Stage-To-Orbit. The thing you're talking about should be called (SSTO) spaceplane. Being an SSTO has nothing to do with whether it's a spaceplane or rocket.

[FlyingPete]

10 minutes ago, FancyMouse said:

I know someone is eventually going to say this so I'll say it. Nope they're legit SSTO - they are Single-Stage-To-Orbit. The thing you're talking about should be called (SSTO) spaceplane. Being an SSTO has nothing to do with whether it's a spaceplane or rocket.

You can also have spaceplanes that aren't SSTO, like this experiment I did:

 

The drop tanks, carrying the air intakes and a couple of jet engines, get left behind and (theoretically) recovered.

 

Edited January 27, 2016 by FlyingPete

[Armisael]

Someone (not me) managed it in under a ton. It was in 1.0.2, but I'm not aware of any cbanges to KSP since then that would cripple it.

Edited January 27, 2016 by Armisael

[RizzoTheRat]

8 minutes ago, FlyingPete said:

You can also have spaceplanes that aren't SSTO, like this experiment I did:

And in real life all space planes so far have been multi stage (Shuttle/Burran/X-37 taking off as rockets, X-15/Space-Ship-1 dropped from launch aircraft)