aircraft construction

[Mister Spock]

Thanks for the suggestions on getting to Mach 1.  I don't have to do this contract now; I've got 65 days (and fortunately am not using KCT for this career).  So I'll work toward some better engines and try later.

This historical contract at issue is to fly the X-15 at Mach 1 over 10,000 meters.  Historically, a B-52 released the jet at altitude, and the pilots just rode the mustang for a minute before plunging to earth to land.  Still the fastest plane in history, yes?  Anyway, if I were really clever, I'd build a B-52 to carry my little X-15.  But then, I still need more tech to build the B-52, I imagine.

[TwilightWolfi]

On 5/23/2016 at 3:12 AM, Alshain said:

It's absolutely possible to build a working aircraft by the 4th tier.  This one flies beautifully in 1.0.5.

I made an exact replica of this plane, but it doesn't actually go anywhere.

Full throttle, start engines and it just starts rolling backwards. I even waited for it to reach maximum thrust while on brakes, but it still went nowhere.

Edited May 25, 2016 by TwilightWolfi

[AeroGav]

1 hour ago, TwilightWolfi said:

I made an exact replica of this plane, but it doesn't actually go anywhere.

Full throttle, start engines and it just starts rolling backwards. I even waited for it to reach maximum thrust while on brakes, but it still went nowhere.

I can only think  the game considers something to be in the exhaust path of the engines, hence they make no thrust.

If you press F3 to look at the flight logs is it showing the tailplane being "heated" by Juno engine? You might have to reposition it slightly.

 

[bewing]

Yes, if you look really carefully, the tail stabilizers on the original plane are raised up just a little bit, and they are not on yours.

[Rmack]

This is normal career mode.

 

Even though my aircraft are squirrelly, I've been pulling off crew report and temp reading contracts, even when they where on the other side of Kerbin!  Under altitude missions, anyway.  I can also usually pull off the higher than altitude missions.  Surface EVA reports are eluding me.  I don't think I could land my plane, but I might be able to parachute it in.

I've been experimenting with eight engine air breather horizontal flight vehicles, and it's not going to work.

 

How do I land on Kerbin?

[bewing]

46 minutes ago, Rmack said:

How do I land on Kerbin?

Are you still using the tier 4 wheels? You have to be really really good at building planes to be able to land one with LY01 and LY05 wheels in the wilderness.

If you upgrade the wheels to retractable ones, they can land in the wilderness easily. Sometimes you can get the retractable wheels on a contract.

[Rmack]

2 minutes ago, bewing said:

Are you still using the tier 4 wheels? You have to be really really good at building planes to be able to land one with LY01 and LY05 wheels in the wilderness.

If you upgrade the wheels to retractable ones, they can land in the wilderness easily. Sometimes you can get the retractable wheels on a contract.

I was thinking along those lines, but don't have enough science yet.  I noticed that you can turn on 'unlimited fuel' which I could use to do the first Munar missions.  Sad though, I so wanted to use fuel.

5 minutes ago, bewing said:

Are you still using the tier 4 wheels? You have to be really really good at building planes to be able to land one with LY01 and LY05 wheels in the wilderness.

If you upgrade the wheels to retractable ones, they can land in the wilderness easily. Sometimes you can get the retractable wheels on a contract.

I've been flopping my way there, taking the readings, then parachuting in, and getting recovered.  It works!

[bewing]

Alternately, if there is a lake near your destination, it is easy to land a plane in water. The tier 4 landing gear would survive that just fine.

[AeroGav]

It's a function of weight and landing speed, as to whether your low tier landing gear will survive a wilderness landing.    My "simple bird" I linked earlier in the thread has a stalling speed under 30m/s so can land anywhere.

The main problem i find with surface report type missions is being able to get back into the plane afterward.   I've tried offsetting the canards downward and setting some pitch trim before going EVA - that way you can make a "wheelchair ramp" for the pilot -  with varying success.  

It's like a breath of fresh air when you finally get the retractable gear though -that way your plane can "kneel" to let the crew back in.  

I'd definitely rehearse this kind of "embark/disembark" operation on the runway before flying half a world away.

ps. don't forget your parking brake.

[bewing]

46 minutes ago, AeroGav said:

The main problem i find with surface report type missions is being able to get back into the plane afterward.

In previous versions, you could walk up the LY01 gears. That was fun!

In the current version you can't walk up the wheel struts anymore. But if you use an MK1 command pod with a small circular intake on the nose now, there is a new feature. You can actually jump from the ground and climb up the circular intake. You couldn't do that before.

But it's also true that you never need to get off the plane anymore, if you build it properly. On land, you can do all your surface reports standing on top of the plane. When splashed, you can get all the surface reports while grabbing a ladder.

Edited May 28, 2016 by bewing

[Pecan]

While you're all having fun - has anyone tried to build a tech 4 spaceplane in 1.1 yet?

[bewing]

8 minutes ago, Pecan said:

While you're all having fun - has anyone tried to build a tech 4 spaceplane in 1.1 yet?

Precisely what do you mean by "spaceplane"? An SSTO? 30 part count limit? Tier 1 runway limits?

Edited May 28, 2016 by bewing

[AeroGav]

5 hours ago, Pecan said:

While you're all having fun - has anyone tried to build a tech 4 spaceplane in 1.1 yet?

Ladies and Gentlemen, I present the Icarus..

https://kerbalx.com/AeroGav/Icarus

Something this basic raises the question, "what is a spaceplane?"

I'd say a spaceplane is something that

• can make orbit
• uses airbreathing engines at some point
• uses lift  rather than thrust to overcome gravity
• at least half of it comes back 

 

Not really economic though.   The Panther/Terrier "Hermes" on my KerbalX page is less wasteful, has better margins, and can bring a few tourists

 

[Pecan]

21 hours ago, bewing said:

Precisely what do you mean by "spaceplane"? An SSTO? 30 part count limit? Tier 1 runway limits?

SSTO spaceplane that, to quote and congratulate @AeroGav, "uses lift rather than thrust to overcome gravity".  A SSTO rocket (not using aerodynamic lift) is trivial from tech 1, the benefit I would look for in a spaceplane is that (in contradiction to him) all of it comes back.  As far as I know, such a (tech 4) rocket has never been possible, but a spaceplane used to be*.

*ETA: in 1.0.5

Edited May 29, 2016 by Pecan

[bewing]

13 minutes ago, Pecan said:

SSTO spaceplane that, to quote and congratulate @AeroGav, "uses lift rather than thrust to overcome gravity".  A SSTO rocket (not using aerodynamic lift) is trivial from tech 1, the benefit I would look for in a spaceplane is that (in contradiction to him) all of it comes back.  As far as I know, such a (tech 4) rocket has never been possible, but a spaceplane used to be*.

*ETA: in 1.0.5

Does that include runway accidents of wheels destroying themselves on takeoff or landing? Because I really doubt that those tier 4 wheels can support enough weight or speed to make it work. I think that will be the limiting factor.

[AeroGav]

2 minutes ago, Pecan said:

SSTO spaceplane that, to quote and congratulate @AeroGav, "uses lift rather than thrust to overcome gravity".  A SSTO rocket (not using aerodynamic lift) is trivial from tech 1, the benefit I would look for in a spaceplane is that (in contradiction to him) all of it comes back.  As far as I know, such a (tech 4) rocket has never been possible, but a spaceplane used to be*.

*ETA: in 1.0.5

An SSTO rocket is trivial from tech 1?   Well , rockets aren't really my area of expertise, but there is no way i could build an SSTO rocket with just flea boosters.   I did make a flea powered vehicle that could "escape the atmosphere" but it needed so many fleas, decouplers and fins to get working/keep stable it made the Icarus look cheap.   Then again, I've never tried an SSTO rocket.

The weakness of the Icarus is the 14 Juno engines that are discarded, along with their fuel tanks and intakes, every flight.   Perhaps if you replace them with underwing solid rocket booster pods, you could make the cost per flight competitive with disposable rockets.  The Junos take the Icarus up to mach 1.5 and 15km before igniting the Terrier, then get discarded at about 17km mach 1.9 when they flame out.  At this point it becomes a type of space shuttle, using solid rocket boosters and a liquid fuelled upper stage.  Where it differs (and improves upon) the NASA STS is that the wings are not merely payload on ascent, they actually produce lift and allow a lower TWR,  also the fuel tank is not discarded.  

Remember that not every spaceplane is an SSTO , and not every SSTO is a spaceplane.   I'm quite willing to throw stuff away if it makes the spaceplane easier to fly or improves its useful payload/range.

As you can see from the video the Icarus does not require godlike piloting skills and got to orbit despite some errors.  That launch video was the first flight of the final design and also the first  flight to go supersonic (all the others were aborted due to inability to cross sound barrier - had to keep adding more junos - or due to discovering staging errors etc. soon after liftoff).

 

[FullMetalMachinist]

1 minute ago, AeroGav said:

An SSTO rocket is trivial from tech 1?   Well , rockets aren't really my area of expertise, but there is no way i could build an SSTO rocket with just flea boosters.

I thought "tech 1" was the next column to the right, and the single one you start with was "tech 0"? 

[Pecan]

Just now, FullMetalMachinist said:

I thought "tech 1" was the next column to the right, and the single one you start with was "tech 0"? 

And to @AeroGav, this is also how I count it.

@bewing - yes, I also think the wheels are (very much) the weak point.  Bugs aside, it should not be an issue but skids either way (even parachute stop) are acceptable.  I'm not doing a challenge here though, just asking what low-tech people have, are working with or is possible.

The definition of SSTO is anything designed to reach (Kerbin) orbit in a single stage - nothing jettisoned.  For what it's worth (which isn't much), my definition of a spaceplane is something that flies to space primarily using wings for lift, regardless of whether it uses a rocket or air-breathing engine for thrust.  A reusable SSTO has to survive re-entry and landing as well, all without jettisoning anything, although refuelling and repacking chutes is fine - again only in my opinion.

My original question was, therefore, whether anyone had made something fly to orbit with tech 4 (or lower) using aerodynamic lift rather than pure thrust.  SSTO is a bonus, reusable SSTO doubly so :-)

Edited May 29, 2016 by Pecan

[AeroGav]

1 minute ago, Pecan said:

And to @AeroGav, this is also how I count it.

@bewing - yes, I also think the wheels are (very much) the weak point.  Bugs aside, it should not be an issue but skids either way (even parachute stop) are acceptable.  I'm not doing a challenge here though, just asking what low-tech people have, are working with or is possible.

Honestly I don't think the wheels are that much of an issue.  The Icarus has a radial decoupler on the bottom of each wing, to which is attached a mk0 intake/lf fuel tank/juno.   The fixed gear are attached to the bottom of this engine nacelle, and three more juno pods are attached to the central one left and right of it, for a total of 7 engines per wing.

Let's just repeat this - the gear are attached to a mk0 fuselage, which are attached to a decoupler, which is attached to the wing, which is in turn attached to the fuselage.

With 14 junos, 1 terrier and 3 ft400 tanks of rocket fuel i was convinced it would blow up without ever leaving the ground  - but in fact it takes off fine,  just set pitch trim to obscure the "I" on the "Pitch" axis display , start your engines, and it will fly itself off.

Misaligned gear, not using angle snap and absolute rotation mode is what is causing much of these problem.s

[Pecan]

Just now, AeroGav said:

...Misaligned gear, not using angle snap and absolute rotation mode is what is causing much of these problem.s

Thanks for that.  I am not playing KSP as much as I used to (RL is such an intruder!) and haven't tried horizontal launch/landing at all since 1.1 came out so I've not dealt with wheels much and only have forum comments to go on.

[AeroGav]

4 hours ago, Pecan said:

Thanks for that.  I am not playing KSP as much as I used to (RL is such an intruder!) and haven't tried horizontal launch/landing at all since 1.1 came out so I've not dealt with wheels much and only have forum comments to go on.

In my experience,  landing gear are actually pretty stable in 1.1.     Here we have gear attached to a wing - oh noes !

 

..and this is us coming in to Minmus.   Used to be more skittish, liable to skid and flip over, than it is now in 1.1.  Braking action still very poor though, but what do you expect on a planet made of ice cream.