Where are the rocket SSTOs??!!

[hempa2]

I see a ton of SSTOs on the forums, and almost none of them are rockets!

Whats wrong with rocket SSTOs, why use plane 100t to orbit when you can rocket 100t into orbit?

[bsalis]

People do make them. They are just uncommon.... probably from the modest payload compared to a staged craft.

Some people have jet-assisted SSTO rockets too. Which I think are underappreciated.

[ecat]

Here's one I have to hand

And this remains one of my all time favourites in spite of its modest 6 jumbo payload

From http://forum.kerbalspaceprogram.com/threads/33503-Show-off-your-B9-Designs!/page14?p=508910&viewfull=1#post508910

[Jesrad]

I prefer to make rocket SSTOs instead of planes too !

I had two working vehicles of the sort before my har-drive crashed:

Plowfish, LKO-capable

Swordfish, which should be able to flyby Mun or Minmus. Maybe even land on Minmus and back ? I'll have to rebuild this one and try.

[Lilleman]

I made this thing while trying to answer this question: "What's the heaviest thing I can put in orbit?" (Bill for scale, next to the engine).

It weight 7600 tons, but technically it's a SSTO.

It even made it to Minmus!

Edit: Bill is allright!

Edited June 29, 2014 by Lilleman
100% stock!

[Pecan]

SSTOs are good for reusability but, usually, bad for payload ratio compared to staged rockets. The efficiency of jet engines, compared to rockets, makes them very attractive for SSTO construction and usually that means adding wings as well so you're back to a spaceplane design.

The first rocket in my tutorial is a very small SSTO while chapter 5 finishes with a larger one. Oddly enough, the simple SSTO rocket design in that chapter comes immediately after, and in contrast to, the most complex of asparagus designs ;-0

[Dispatcher]

It seems that the OP equates rocket only SSTOs with vertically launched craft. Here is a pic of my runway-launched SSTO spaceplane, which has only rocket engines (in this case, aerospikes):

Of course, most SSTOs seem to use a mix of rockets & jets (and more recently many use the RAPIER engine).

Edit: the pic is of an early version and my piloting skills, such as they are, left me without fuel. But the mono propellent allowed me to deorbit anyway.

Edit 2: I forgot that I also had to fire the separator at the nose (exposes the docking port); the orbit was highly elliptical and the maneuver was done at periapsis.

Edited July 5, 2014 by Dispatcher

[UmbralRaptor]

I use them fairly regularly for lofting small payloads. But most of the designs are distinctly uninteresting (1-2 tanks and an engine). The only interesting uses are 1) demonstrating that you can hit polar orbit with TL0 parts and no booster shenanigans in campaign, and 2) looking for ways to make a reusable VTVL. The latter tend to have poor payload fractions (5% starts to look good), but given how many jet SSTOs struggle to take a single pilot to orbit...*

My favorite would probably be this: (internal designation: Shantak 1U)

It has various clever design features that have been rendered obsolete by recent versions of KSP, though.

*Because of design issues. A well designed airbreathing SSTO can hit 70% payload fraction.

Edited June 29, 2014 by UmbralRaptor

[Blaster]

Rocket SSTO's are certainly doable.

This Reynard Rockets Rocket (called the RRRRR) makes orbit without dropping parts. However, it does need refueling to go anywhere after that.

And yes, the retro rockets are necessary for fine maneuvers.

Edited June 29, 2014 by Blaster

[Hodo]

I made a "rocket" SSTO, granted it uses SABREs and a rocket engine.

Javascript is disabled. View full album

This was built a long time ago.

[LethalDose]

I see a ton of SSTOs on the forums, and almost none of them are rockets!

Whats wrong with rocket SSTOs, why use plane 100t to orbit when you can rocket 100t into orbit?

Well, that depends on what you mean by "Rocket SSTO".

If "Rocket SSTO" means "SSTO that only use LF + Ox" engines, then it's because those rocket engines are extremely mass inefficient compared to air-breathing jet engines, and SSTO design is all about mass efficiency.

If "Rocket SSTO" means "SSTO that takes off vertically like a rocket", like the delta clipper, then it's two reasons. First, it's relatively inefficient to use thrust to accelerate straight up, in opposition to gravity, like a rocket because a substantial proportion of that thrust is lost to gravity, where aircraft thrust perpendicular to gravity and loose much less fuel to "gravity drag". Second, SSTOs are typically about reusability, hence controlled, precision landings are preferred so the SSTO can be reused. Planes are typically easier to land in a preset location, as long as that location is flat. In my experience, "Rocket SSTO's" by this definition are a total nightmare to land on Kerbin, planes are easier, after you get the hang of it.

Overall, if you're not building a vessel with reusability in mind, there's just not that much of a reason to make it an SSTO.

[magnemoe]

I use just pure rocket ssto, granted some of the designs use SRB who would land back at pad with parachutes if not killed by game.

Various designs from 3 man up to 120 ton SSTO. (200 ton with SRB)

[GoSlash27]

This rover is designed to act as an SSTO for most bodies in the system, as well as an ATV, scout, payload hauler, construction equipment, and jerrycan. It falls a little over 400M/sec short of being SSTO from Kerbin.

I haven't bothered to create an SSTO from Kerbin because 1) I don't need one and 2) there's no benefit to it. This one serves the function from most other bodies because 1) I *do* need one and 2) There are all sorts of benefits to it.

Best,

-Slashy

[edit] I wonder if I could put one in orbit from a mountaintop. Hmm...[/edit]

Edited June 29, 2014 by GoSlash27

[Jouni]

Second, SSTOs are typically about reusability, hence controlled, precision landings are preferred so the SSTO can be reused. Planes are typically easier to land in a preset location, as long as that location is flat. In my experience, "Rocket SSTO's" by this definition are a total nightmare to land on Kerbin, planes are easier, after you get the hang of it.

[Whackjob]

Something tells me I'll be posting something in here later today.

[magnemoe]

While we wait for wackjob I post my 120 ton cargo to LKO SSTO.

7 stacks of this rocket who takes 18 ton to orbit.

7 man SSTO

the small radial engines is the escape system, also to give soft landings the hitchhiker can survive. Another version of the rocket is a 10 ton SSTO, that is the smallest model I have.

[GoSlash27]

After tweaking the rover design, it is now SSTO capable from the pad at KSC. Now to see if it will keep this capability after adding docking ports...

[MarvinKitFox]

Bah.

When we had real engines, it needed a miracle to put 20% of your launch mass in orbit, even with a staged rocket.

Back then SSTO rockets simply weren't practical.

With the new engine imports from Krypton, My 156.5t on launchpad gets to orbit with 63 tons of it remaining, SSTO!

[cantab]

I guess generally speaking there's not much call for them, apart from the jetrocket designs. Staging is simple enough to understand, enables the same size rocket to launch a bigger payload, and makes it feel more like a real rocket.

[McFarnsworth]

You mean things like this?

[UmbralRaptor]

Bah.

When we had real engines, it needed a miracle to put 20% of your launch mass in orbit, even with a staged rocket.

Back then SSTO rockets simply weren't practical.

With the new engine imports from Krypton, My 156.5t on launchpad gets to orbit with 63 tons of it remaining, SSTO!

20% payload fractions were just about doable with SSTOs based around the pre-Isp LV-T30. (call it 0.13 - 0.15.2) Probably moreso with the 0.15 aerospike.

0.16 Was... special.

The 0.17.x aerospike probably would have topped out around 13-17% for an SSTO, so I would expect 20% out of an asparagus design. Certainly a launcher of mine from that era that used jets as boosters hit ~33%.

I guess one could count 0.18 - 0.21 as "real engines" (The 48-7S post-buff allowed for... interesting things).

[Caelib]

You can use the new engines from the ARM patch to achieve orbit in a single stage with a small payload.

[qromodynmc]

I was making experiments with rocket sstos recently,but none of them had enough fuel to do something at orbit,some 1 jet,2 rocket designs worked better but,really they are useless for heavy payloads,Only use is sending kerbals to space stations.

[LethalDose]

In my experience, jet-boosted rockets are the easiest choice for precision landings. The lack of wings makes atmospheric reentry safe and easy with stock aerodynamics. Jet engines allow you to reach the intended landing zone. In the final landing sequence, parachutes are used to kill the horizontal speed and to keep the vertical speed below 20 m/s, while jet engines slow the rocket down to a safe landing speed.

Pure rocket SSTOs are a bit harder, because you can't fly around looking for a good landing zone.

[iMAGES CLIPPED]

I think a major difference is that I use FAR & DER. I probably should have said "In my experience, landing rockets like that is a nightmare." I've tried landing these with RAPIERs and 'chutes, it just never seems to go well. And the efficiency issue remains with vertical thrust. It took me quite a while to figure out how to land aircraft with FAR, but it goes much easier now that I figured it out, at least on the KSC runway. I still can't land on that d@mned island.

Regardless, different players, different play-styles.

[Torham234]

With the new engine imports from Krypton, My 156.5t on launchpad gets to orbit with 63 tons of it remaining, SSTO!

Fixed that for you