Why are rockets so easy and planes so hard?!

[Sharpy]

18 minutes ago, Corona688 said:

Do I hear a goalpost being moved?  I do believe I hear a golapost being moved.

Insisting on the most complicated just because that's the only way your argument makes sense is entirely arbitrary.

So we're left at the unmeasurable 'rockets doing rockety things and airplanes doing airplaney things'. Unless you can suggest a reasonable metrics.

[wumpus]

16 minutes ago, Corona688 said:

Do I hear a goalpost being moved?  I do believe I hear a golapost being moved.

Insisting on the most complicated just because that's the only way your argument makes sense is entirely arbitrary.

In KSP it is wildly easier to send a rocket into space (presumably something a newbie player can do in a few missions) than building a plane to hop over to the nearby island and land on the runway.  IRL such things were done with aircraft by at least 1910ish, while Yuri Gagarin didn't fly until 1961*, and unmanned space flight was closer to 1961 than 1910.  The obvious reasons that planes are harder in KSP is that it is a rocket simulation that has planes grafted on after the fact.

* sure, he hit orbit which it obviously much harder than "get into space".   But he certainly couldn't make it into space much before 1958 or so, which would only give Korolev a short time to build a rocket "merely" capable of going to space.

[The_Rocketeer]

3 minutes ago, wumpus said:

In KSP it is wildly easier to send a rocket into space (presumably something a newbie player can do in a few missions) than building a plane to hop over to the nearby island and land on the runway.  IRL such things were done with aircraft by at least 1910ish, while Yuri Gagarin didn't fly until 1961*, and unmanned space flight was closer to 1961 than 1910.  The obvious reasons that planes are harder in KSP is that it is a rocket simulation that has planes grafted on after the fact.

* sure, he hit orbit which it obviously much harder than "get into space".   But he certainly couldn't make it into space much before 1958 or so, which would only give Korolev a short time to build a rocket "merely" capable of going to space.

While this is true, it's also true that fundamental physics of rocket propulsion were understood and applied centuries before the fundamental physics of aerodynamic flight were first applied, and they are mathematically considerably simpler. It's also true that it took over 50 years for powered flight just to break the sound barrier, compared with only around 15 years for rockets to go from the V2 to landing on the moon.

[Sharpy]

8 minutes ago, wumpus said:

In KSP it is wildly easier to send a rocket into space (presumably something a newbie player can do in a few missions) than building a plane to hop over to the nearby island and land on the runway.  IRL such things were done with aircraft by at least 1910ish, while Yuri Gagarin didn't fly until 1961*, and unmanned space flight was closer to 1961 than 1910.  The obvious reasons that planes are harder in KSP is that it is a rocket simulation that has planes grafted on after the fact.

Sputnik-1, 4 October 1957

V-2, breaching Karman Line, 1944.

 

[tater]

45 minutes ago, Sharpy said:

Name a bicycle that has achieved LEO. There, we have a proof that bicycles are harder to make IRL than rockets.

Making a bicycle capable of reaching LEO would indeed be vastly more complicated than a rocket.

People have talked about spaceplanes for a long, long time. None have happened.

The current contender for the most plausible (but still entirely unrealized) spaceplane is what, Skylon? If they ever make it work, it will barely achieve LEO with a cost to orbit that's basically competitive (?) with existing LVs.

I think the basic fact is that while rockets have to move through the regime where most all the aero problems aircraft face happen, they do so very quickly, and the solution to the problems in that narrow regime is easier given the goal (spaceflight). If this were not true, we'd have spaceplanes already. Basically they hit max Q in under 2 minutes, the it's downhill from there. Any spaceplane concept lives in that regime for a while.

 

[The_Rocketeer]

I think perhaps we're getting lost in a tangent here.

In KSP (even career-mode) we're not really evolving jet propulsion technology, we're jumping in at a certain tech-level and having instant access to reliable equipment. Most things are scale-able - with the technology to build a plane to reach the island runway, one can also build a plane capable of multiple circumnavigations. Equally with technology to reach the Mun, players can go interplanetary.

The question isn't really why the technology is easier to apply, it's how easy it is to learn what's required. Once you have that knowledge, interplanetary rockets and circumnavigational/spaceplanes are equally easy/hard - it's just a matter of checking your dV and putting things together properly.

So, on that basis, in KSP rockets are easier to learn because:

• they're simpler to understand and require considerably less calibration
• they can be made from just 3 parts (planes require a minimum of 5, and that requires some intelligent design to work - much more comfortable with at least 15+).
• KSP penalises planes more than rockets in various ways (e.g. usefulness of tier 1 runway vs tier 1 launchpad, SAS isn't well-suited to atmospheric flight, etc)
• air-breathing planes won't work in vacuum without auxiliary thrust systems
• landing rockets usually means parachutes, landing planes means pilot skillz
• low-tech rockets are expected to go straight to space - low-tech planes are expected to stay on Kerbin for a long while
  • because of this, for new players, rockets seem to progress faster and are initially more rewarding

Edited September 2, 2016 by The_Rocketeer

[Yemo]

Planes are not hard once you understand how they work.

Kind of like getting to orbit. Once you understand how it works, it is quite simple.

[The_Rocketeer]

19 minutes ago, Yemo said:

Planes are not hard once you understand how they work.

ahem

58 minutes ago, The_Rocketeer said:

The question isn't really why the technology is easier to apply, it's how easy it is to learn what's required.

 

[Corona688]

Part of what makes this so confusing is recovery...  Most rockets are disposable, most aircraft aren't, and their roles are very different.  The vast majority of rockets aren't manned, and most aircraft are.

General complexity isn't a good metric either...  In some ways they're getting simpler as time goes on, and there's always going to be a bigger rocket and always going to be a more expensive jet fighter.  It's also quite difficult to define -- how about the Osprey tiltrotor, one of the most sophisticated aircraft to ply the skies?  Is it a fair comparison or not?  etc, etc, ad infinitum.  We can one-up each other all day.

There will be multiple answers for different roles, anyway.

Making a craft manned means the sky's the limit on complexity, also.  So, if I had to pick a criteria for "fair" answers, it'd be pretty specific:  Two unmanned, expendable craft from the same era, with similar roles.  How about:

A) The V-2 rocket, grandfather of modern rocketry

B) The British remote-controlled aircraft which was pressed into use as a suicide bomber.

They had smaller drone aircraft, too, but they weren't comparable in size or function, being mainly things designed to loiter in the air and be shot at, not hit targets themselves.

Edited September 2, 2016 by Corona688

[Yemo]

@The_Rocketeer

Well, I also dont think it is harder to learn than orbiting.

.	Orbit	Flight
1.	enough TWR to overcome gravity	enough TWR to fly
2.	not too much TWR to not burn up	enough lift to fly
3.	you need "sideway" velocity for orbit	your CoL needs to be behind your CoM
4.	right amount of control eg gimbal	right amount of control eg surfaces

 

Pretty simple.

 

If you have too much control on your rocket it starts to wiggle with SAS, same for your plane.

Edited September 2, 2016 by Yemo

[The_Rocketeer]

26 minutes ago, Yemo said:

Well, I also dont think it is harder to learn than orbiting.

I agree with this, but orbiting applies to spaceplanes and rockets equally. When starting your first game, as someone who doesn't know what they heck they're doing, it's still easier to reach orbit with rockets than planes. The point I'm making is in KSP learning to design and fly rockets is a more accessible, simpler, and gives more short-term-rewards experience than learning to design and fly winged aircraft.

[Xyphos]

On 9/1/2016 at 7:53 AM, Sharpy said:

Yes, but the whole idea is to do as much on efficient air-breathing engines, and as little as possible on rockets, which by definition must carry a lot of (reaction) mass. And ram rise means that merely developing better, faster, stronger air-breathers is insufficient. Some people like to picture spaceplanes as "gain orbital speed in the atmosphere, then perform a token circularization burn with RCS." This is why that approach is impossible.

yeah, I don't see that happening any time this century.
just shave off as much dV as possible in air-breathing mode then switch to rockets. it's more practical that way, and our current technology will allow for it.
everyone's looking for the holy grail, but nobody will take a single step forward.

[Corona688]

1 hour ago, Xyphos said:

everyone's looking for the holy grail, but nobody will take a single step forward.

It's...  difficult.  It'd be nice to carry cargo instead of all that dead weight.  The US has something close to SSTO now, but it's not useful for bulk cargo.

Edited September 2, 2016 by Corona688

[Sharpy]

15 hours ago, Corona688 said:

It's...  difficult.  It'd be nice to carry cargo instead of all that dead weight.  The US has something close to SSTO now, but it's not useful for bulk cargo.

Personally, I believe SSTO IRL is a misguided endeavor. Hauling jet engines to orbit? Just no.

The approach with airborne launch platform makes much more sense. Make the thing staged, but make the stages fully, and easily recoverable. Not like Shuttle's SRBs which need to be fished out, and refurbished in a process that costs as much as new ones. But, say, stage 1: turn around, glide back to launchpad on wings, refuel. Take maybe three hours to attach a new stack of upper stages - something like cargo airplane. Stage two: finish an almost-orbit, after losing reentry speed glide with small aid of (small, light!) jet engines (or even plain old propellers) back to the landing pad, coming in from the opposite direction as stage 1. Stage 3 would be custo-tailored to the needs, and mostly non-recoverable.

[magnemoe]

18 hours ago, Xyphos said:

yeah, I don't see that happening any time this century.
just shave off as much dV as possible in air-breathing mode then switch to rockets. it's more practical that way, and our current technology will allow for it.
everyone's looking for the holy grail, but nobody will take a single step forward.

Scramjets looks like is close to this performance then optimized. Yes hey have their own problems like require to be high supersonic before igniting. 

[Sharpy]

3 minutes ago, magnemoe said:

Scramjets looks like is close to this performance then optimized. Yes hey have their own problems like require to be high supersonic before igniting. 

If you missed the discussion, it's not the power of the airbreathers that makes accelerating to orbital speeds impossible.

[GoSlash27]

23 hours ago, wumpus said:

In KSP it is wildly easier to send a rocket into space (presumably something a newbie player can do in a few missions) than building a plane to hop over to the nearby island and land on the runway.  IRL such things were done with aircraft by at least 1910ish, while Yuri Gagarin didn't fly until 1961*, and unmanned space flight was closer to 1961 than 1910.  The obvious reasons that planes are harder in KSP is that it is a rocket simulation that has planes grafted on after the fact.

I think it's more accurate to say that all the difficult bits of "rocket science" have already been done for you in KSP, No mucking about with the difficulties of special alloys or fabrication techniques. No worrying about turbopumps and diffuser plates. No careful formulation and storage of specialized rocket fuels, and nothing ever fails.
 Given all this, how could one *not* succeed in getting to space?? It's just "click a tank on a controller and an engine on a tank" and kaphoomph... you have a rocket.

When someone hands you the building blocks that comprise a rocket, it's easy to make a rocket out of them. Pointy end up, hot end down. When someone hands you the pieces that comprise an airplane, making an airplane out of them is a much more difficult task. You still have to arrange all the parts in such a way that all the forces are in balance so it flies properly.

TL/DR; Airplanes are, necessarily, more complex beasts than rockets. That's not KSP's fault.
 

[howardwolowitz]

set your flying controls (roll pitch yaw) to fine with caps lock when taking off, you will notice the dials turn blue instead of red like normally, makes it alot easier to turn on the runway during takeoff

[Kerbal101]

Welcome to the forums, @howardwolowitz !!
Thats a great advice! Although from my personal experience its better to forget turning altogether once the engines are running and until in the air. But it maybe just me