What is a VTOL and a SSTO?

[lukeoftheaura]

people are talking about VTOL and SSTO and I don't know what one is!

can any1 tell me?

Edited October 11, 2014 by kerbingamer376

[Rhomphaia]

Vertical Take-Off and Landing

Single Stage To Orbit

[Overfloater]

SSTO means Single Stage To Orbit - no decoupling stuff to reach orbit.

VTOL - Vertical take off & landing - referring to jump jet aircraft.

VTVL - Vertical take-off & vertical landing rockets

[AlexinTokyo]

VTOL stands for Vertical Take Off and Landing, and usually means a plane with downward facing engines allowing it to take off and land with no forward motion, and to hover.

SSTO stands for Single Stage To Orbit, and means a vehicle capable of achieving orbit (around Kerbin in the game) without staging. Many (if not most) people use it to refer to a winged vehicle (space plane) that can reach orbit, but strictly any vehicle, including a rocket, that doesn't separate any parts can be considered an SSTO.

Ninja'd. And to (pedantically) answer your actual question, "yes."

[Red Iron Crown]

Here's a useful thread to bookmark, helps understand all the acronyms we throw around here a lot.

VTOL - Vertical take off & landing - referring to jump jet aircraft.

VTVL - Vertical take-off & vertical landing rockets

I can't say I've ever seen that distinction made. In my mind VTOL and VTVL are interchangeable.

[Sophistry]

I can't say I've ever seen that distinction made. In my mind VTOL and VTVL are interchangeable.

I have to say, this just makes me interested in what a horizontal take-off and landing rocket looks like! (Rocket-powered aircraft aside, of course)

Edited October 11, 2014 by Sophistry

[cantab]

Air-launched rockets and missiles often ignite when horizontal. On the ground most military rockets and missiles are launched at an angle.

As for landing, a spent stage descending on chutes may well land horizontally.

[Overfloater]

I can't say I've ever seen that distinction made. In my mind VTOL and VTVL are interchangeable.

Yeah the names don't even imply anything... I got that from wikipedia :-p

[Pecan]

Yeah the names don't even imply anything... I got that from wikipedia :-p

I'm glad you did though - I hadn't heard of VTVL before either but it might be handy for making the distinction between something that is meant to launch/land and fly 'vertically' and something that can launch/land vertically but fly horizontally. (... until 45-degrees of course, then I'm just stuck again ^^)

[Red Iron Crown]

I'm glad you did though - I hadn't heard of VTVL before either but it might be handy for making the distinction between something that is meant to launch/land and fly 'vertically' and something that can launch/land vertically but fly horizontally. (... until 45-degrees of course, then I'm just stuck again ^^)

Same here. I just had a look at the wiki articles, it's an easy way to distinguish the two types.

[O-Doc]

I have to say, this just makes me interested in what a horizontal take-off and landing rocket looks like! (Rocket-powered aircraft aside, of course)

The V1 was the first and only HOTOL I know of. The Skylon will technically be HOTOL as it is an air-breathing rocket with a closed cycle.

[Red Iron Crown]

The V1 wasn't really a rocket though, it was an airbreather.

A C-130 using JATO might qualify, it essentially uses SRBs to get up to takeoff speed quickly.

[nine_iron]

VTOL = Very Tardy Oily Lady

SSTO = Silly String Too Old

[Pecan]

SSTO = Somewhat Simpler Tall Object.

[Javster]

Shameless plug for my abbreviations guide! http://forum.kerbalspaceprogram.com/threads/73063-A-newbie-s-guide-to-abbreviations

[capi3101]

Too late to join in the conversation?

VTOL - vertical take off and landing. Basically a craft that takes off without rolling down the runway to do so. Usually the term is applied to a craft that would ordinarily roll down a runway to take off. Helicopters are the classic VTOL craft. Some airplanes, however, fall in the VTOL category; the A-10 Warthog for instance, takes off and lands vertically while in flight it handles like a normal airplane. You can build craft that function similarly to the A-10 in KSP by setting up some engines to face downward and some in a normal position. Designing a successfully functioning VTOL that doesn't immediately careen into the ground is challenging and flying them is fun.

SSTO - single stage to orbit, i.e. any craft that leaves the launchpad or runway and arrives in orbit with the exact same number of parts. No staging events whatsoever. Generally when folks are talking about SSTOs around here, they mean spaceplane - something that rolls off the runway, flies up to about 25000 meters and gains orbital velocity while still in atmosphere. SSTO rockets are rarer but still possible; they're generally good for lighter payloads (a Kerbin-orbiting satellite consisting of a Stayputnik, thermometer, antenna and solar panels can easily be put into orbit with an FL-T400 and a 48-7S; that's a fully functional SSTO rocket) but folks have gotten some fairly substantial payloads into orbit with them. The part count is much lower than, say, an asparagus-design as a rule and the designs are simpler, but you have to be willing to fiddle with the throttle as you fly and the payload fraction is lousy as a rule.

DocMoriarty has an awesome guide on how to build VTOLs and SSTO spaceplanes - he uses his spaceplanes to deliver substantial payloads to orbit.

[Pecan]

..the A-10 Warthog for instance, takes off and lands vertically...

Huh?

Do you mean the Harrier family such as the AV-8B?

...SSTO rockets are rarer but still possible; they're generally good for lighter payloads ... The part count is much lower than, say, an asparagus-design ... but you have to be willing to fiddle with the throttle as you fly ...

SSTO rockets are not just possible, they're easier.

They're good for a much wider range of payloads - especially things too heavy for 'planes to handle without exrensive mods and/or thousands of parts.

The part count is way lower than a spaceplane for an equivalent payload (except where the payload is very light).

There is absolutely no need to fiddle with the throttle. Even if there were they'd still be a hundred times less difficult to fly than spaceplanes ^^.

..the payload fraction is lousy as a rule....

Spot-on there though. SSTO rockets absolutely drink fuel. My standard 100t-payload SSTO rocket only manages 13.5%. Of course, if you build a VTVL SSTO with jets you get all the fuel-benefits that spaceplanes do and still don't have to drag all those extra, massy, useless parts (like wings) along with you so you get the best payload ratio possible.

[capi3101]

Huh?

Do you mean the Harrier family such as the AV-8B?

Yeah, I had a brain fart there. My bad.