Landing the Shuttle

[Raptor9]

Jebediah and Valentina, the intrepid pilots from the Kerbal Space Center, are attempting to land the first Shuttle after re-entering the Kerbin atmosphere...

 

Edited December 20, 2015 by Raptor9
Re-uploaded video due to a bad frame

[winged]

Nice shots.

[SnakyLeVrai]

Nice job

Speaking of landing the space shuttle, do you have a reliable method to pinpoint your landing site? Even with the use of the Trajectories mod, I have huge inaccuracies (due to the fact that I angle the shuttle 40° from prograde , until I get slower that mach 3.5, to avoid overheating).

[Raptor9]

7 hours ago, SnakyLeVrai said:

Speaking of landing the space shuttle, do you have a reliable method to pinpoint your landing site? Even with the use of the Trajectories mod, I have huge inaccuracies (due to the fact that I angle the shuttle 40° from prograde , until I get slower that mach 3.5, to avoid overheating).

I execute my retro-burn on the "exact" (or best as I can tell in the map view ) opposite side of Kerbin from the KSC.  From there I bring the periapsis to somewhere between 30 and 40 km altitude.  Each spaceplane I have has a target altitude I aim for, due to differences in weight and inertia.  For my Shuttle, I use 40km; for my smallest light spaceplane, 30 km.  After I get into the atmosphere, it's just a matter of managing the pitch of my spaceplane to adjust heat, drag, and lift.  It's one of those things that I've just practiced many times so I don't have to rely on the Trajectories mod.  To help with my Shuttle monstrosity, I have a small probe core mounted at an angle in the cargo bay that I use for attitude control during OMS burns due to the offset alignment of the Mk55 "Thud" engines.  I also use this during reentry for attitude control.

Bottom line, do a few test runs to find your target periapsis location, and then find that good pitch attitude for upper atmo flight.  Everything else is Kerbal-style hand-flying.

The one caveat I will say is the orbit altitude you're reentering from will also affect your atmo entry angle and entry speed.  I've only tested my Shuttle coming in from 70-100 km altitude.  Other missions I've stepped my higher orbits down to these lower orbital planes prior to reentry.

Edited December 20, 2015 by Raptor9
typo

[SnakyLeVrai]

I see. You followed the Kerbal Training Manual by the letter

My shuttle design doesn't have a specially purposed OMS. I designed the main 3 engines in a way that the two bottom ones are centered and aligned with the CoM & cockpit. I just disable the top engine and it works like a charm, though it doesn't look like the real deal then... (pics here). I guess I'll have to make more flight tests and write a manual for my Kerbals then... Thanks for confirming my fears 

Nice shots in your video. I assume you used camera tools?

[Raptor9]

2 hours ago, SnakyLeVrai said:

Nice shots in your video. I assume you used camera tools?

Yep, sure did.  And thanks for the compliments.  A shuttle itself isn't the hardest thing to make (SSTO spaceplanes have that honor), but it can be a serious engineering endeavor requiring many, many tests to make sure it flies and performs just right throughout all phases of flight.  Launching, staging, orbital maneuvers, hypersonic reentry, landing; the whole setup is so asymmetrical.  Even RCS thruster placement and scaling required several tests in orbit to get them tweaked just right, but then again, I'm a bit of a perfectionist.

[SnakyLeVrai]

It is indeed a complex thing. The RCS Build Aid mod is a wonderful aid for RCS balancing (and also main engine alignment). Not only it will show you the effect with the current CoM, it will also show you the effect around the DCoM (Dry CoM = with empty tanks), so you can fine tune it between the two CoM.

[MrMeeb]

Amazing!  

[Raptor9]

4 hours ago, SnakyLeVrai said:

Not only it will show you the effect with the current CoM, it will also show you the effect around the DCoM (Dry CoM = with empty tanks), so you can fine tune it between the two CoM.

Yep, while I don't use that mod, i always drain all my tanks to see where the dry CoM is, especially on aircraft.  You never know if the thing will fly right as it burns off fuel.