Learstar Launch: wing keel

[Lohan2008]

G'day, any advice on launching the *new space plane = Learstar ? It pulls over too steeply at 20 k if I "turn" at 10 km; what position should the plane be in on ?

top, bottom, side ??

Edited October 9, 2014 by Lohan2008

[Lohan2008]

I really need help ! Why can I not get into orbit ???

Edited October 8, 2014 by Lohan2008

[Lohan2008]

Helpplease

[el_coyoto]

Typical ascent profile goes like this (you mileage WILL vary) :

• 20° or 25° ascent from the runway. Watch your speed, don't go faster than terminal velocity, you would lose speed to drag
  
• When reaching 10 or 15 km, orient to the nose to keep a constant vertical speed (I usually go with 200 m/s) and build up horizontal speed. Drag and terminal velocity stop being a problem at the altitudes
  
• When your air intakes start being close to empty, try to reduce thrust (to reduce air consumption) and make sure your speed is still increasing : you will accelerate despite the lower throttle setting because there will be less and less drag to slow you down.
  
• Keep the "reduce thrust-build horizontal speed-keep vertical speed positive" cycle going until you cannot throttle down without slowing or throttle up without starving your engines. You should be rather fast (1000 m/s, 1500 m/s) : time to punch the rocket mode and get to orbit!
  

Fly safe!

EDIT : I haven't checked the new stock planes, and slowly started to realize that the Learstar is stock... Never mind the question about a picture of the plane. People may also come up with much better ascent profiles specifically for this plane...

Edited October 8, 2014 by el_coyoto

[Taki117]

In general you want to be going as fast as possible before jet engine flame out (This may require pointing your nose DOWN to account for the curvature of Kerbin) jMy usual space plane ascent is 45 degrees to 10km, then keep my velocity indicator 5 degrees above the horizon (This usually puts my nose at about 20 to 25 degrees) then once my apoapsis is about 1 minute, or my indicated altitude is about 36km (When the navball switches to orbit mode) I point my nose prograde and go until just before flameout, then I switch over to my rockets and make orbit.

[Lohan2008]

I should HAVE put in that I am asking about the Learstar A1 (stock) that launches VERTICALLY.

When you reach 50 km the wings don't give lift and it becomes unbalanced.

Edited October 8, 2014 by Lohan2008

[ratchet freak]

that's why reaction wheels and gimballed engines exist, if they don't work then you are out of power

[Rhomphaia]

that's why reaction wheels and gimballed engines exist, if they don't work then you are out of power

None of the stock engines in KSP have enough gimbal authority for this kind of craft. I didn't get much time with 0.25 and am away until tomorrow night but IIRC the Learstar only has the rection wheels in the cockpit. to overcome it's imbalance it would probably need dozens of reaction wheels.

It is not very well built at all. when I get home I plan on seeing if I can get it to orbit without adding or removing any parts. But I doubt it can be done without tweaking or repositioning things.

[Henshaw]

Got it into orbit and back, manually adjusting thrust and making the engines on the plane part less restricted

[LethalDose]

Pics of craft are hugely helpful when trouble-shooting. Post pictures of your vessel and problems as they occur will get you more help faster in the future.

[tg626]

I got it drunkenly to orbit by reducing thrust when it tried to flip. When it got to the point that any thrust wanted to cause it to flip I set the thrust of the planes engines up to 100%.

Landing was a disaster however, even with the jet engine full on it sank like_ a stone.

[Pecan]

All the stock vehicles have 'issues', Squad said they didn't want to give people perfect vehicles and discourage them from making their own.

Building rockets is easy. Flying stock ones is harder. When you've built a few of your own you can spot what's wrong with Squad's.

Building 'shuttles' is HARD. All the ones I know rely on mods or config editing. Don't expect anything much of Squad's.

[Taki117]

Ok, here's my flight profile (I misunderstood earlier)

Straight up as much as you can until about 5km, be sure to roll "heads down"(Shuttle on the bottom)

After you jettison the SRBs (They should be out by about 6km) begin to pitch over SLOWLY! if you are mashing the keyboard turn on RCS.

At about 25km adjust the thrust limiter on the shuttle engines to 100%, throttle back as needed to prevent uncontrolled flip. (I was at about 50% throttle at just over 20km)

Once you have made the adjustment throttle up and watch for flipping.

Once you get your desired apoapsis drop the main tank, shut down the LFO engines on the shuttle and turn on the monoprop engines. Don't forget to turn on the flow for the aft most RCS tank.

Plot your maneuver and circularize.

Edited October 8, 2014 by Taki117

[Heimdall5008]

I (almost) made it to orbit with the same tactics discussed here (run out of fuel before I could lift the Pe enough):

- use RCS from lift off on

- increase thrust on the orbiter engines

- decrease thrust on the main engine

And the trap with the disabled RCS tank is really evil...

[Lohan2008]

I fixed the launch by putting wings on opposite side to make a winged keel

[Taki117]

And the trap with the disabled RCS tank is really evil...

It is like that so you have enough fuel for your RCS engines to deorbit.

[tg626]

I fixed the launch by putting wings on opposite side to make a winged keel

http://i.imgur.com/J0uLrA3.png

That is FREAKING brilliant@!!!