Spaceplane reentry Thread

[Kroslev Kerman]

Tired of your craft not pointing this degrees because the SAS suks or are you too lazy to do it well i have the answer to that using Lazy Method! method!

First get a probe core/Docking Port(any) and rotate this -amount of degrees IT HAS TO BE - OR IT WILL NOT WORK now control from that point and press prograde and watch your spaceplane reentry gracefully and not hopefully burn up on reentry 

Do you have any more ideas how to reenter your craft comment if you know any more!

Ok lets get to the Reentry Part!

Long reentrys

Advantages

Fuel efficient

Good for Low TWR Craft like space shuttles with monoprop engines

Realistic

Low G Force on your Kerbals

Disadvantages

You have a chance to burn up

Yeh thats all i could think off

Short reentrys

Advantages

its easy to aim where you are going to land

Easy to do

Dont have to worry about burning up

Disadvantages

VERY HIGH G FORCES

Very fuel inefficent

 

Edited November 29, 2018 by Kroslev Kerman

[Rocket In My Pocket]

I typically just go radial out and let it try it's best. It can't ever maintain it so it ends up at about a 30-40 degree tilt which is fine.

Also didn't we just have a thread about this somewhere?

Anyways I'll add the same tip here I did there; docking port's work just as well for the probe core method.

Edited November 28, 2018 by Rocket In My Pocket

[Atkara]

1 hour ago, Rocket In My Pocket said:

Also didn't we just have a thread about this somewhere?

I remember that one, yeah.

[Guest]

I don't use tricks like this but I certainly have techniques.

Design

• Make it as CoM invariant as possible, with CoM shift forward if at all.
• Don't place CoM too far forward of CoL. This makes the AoA controllable all through the descent; otherwise you'll be forced nose-down earlier than you'd want to.
• Give it a sharp nose. A blunt nose will cause it to tumble when it hits thick air.
• Place tanks both well forward and aft.
• Give it enough wing. A big wing means effective braking higher up which means less thermal load.

Technique

• Find a good corridor. From LKO I find 55 km to 50 km Pe is about right.
• Initiate re-entry holding radial out.
• Watch the pitch control. It will start moving.
  • If it goes below 0, you're in danger: pump remaining ballast into the forward tank until it's above 0.
  • if it goes above 0.5, pump ballast back until it's back there or you're low and slow enough to transition to level flight. 
• Depending on your craft, transition from radial out to 60 degrees, then 45 degrees around when you hit the plasma phase.
• Once at a safe speed (ca 1200 m/s or so), nose down to transition to aerodynamic flight.

Edit: if your craft is well designed (pointy nose, CoM not too far forward of CoL, a small amount of ballast that you can pump back and forth) then you shouldn't need tricks like the tilted probe core, as normal SAS with minor nudges should be enough to hold attitude where you want it until you're ready to go level.

Edited November 28, 2018 by Guest

[Pthigrivi]

1 hour ago, Brikoleur said:

I don't use tricks like this but I certainly have techniques.

Design

• Make it as CoM invariant as possible, with CoM shift forward if at all.
• Don't place CoM too far forward of CoL. This makes the AoA controllable all through the descent; otherwise you'll be forced nose-down earlier than you'd want to.
• Give it a sharp nose. A blunt nose will cause it to tumble when it hits thick air.
• Place tanks both well forward and aft.
• Give it enough wing. A big wing means effective braking higher up which means less thermal load.

Technique

• Find a good corridor. From LKO I find 55 km to 50 km Pe is about right.
• Initiate re-entry holding radial out.
• Watch the pitch control. It will start moving.
  • If it goes below 0, you're in danger: pump remaining ballast into the forward tank until it's above 0.
  • if it goes above 0.5, pump ballast back until it's back there or you're low and slow enough to transition to level flight. 
• Depending on your craft, transition from radial out to 60 degrees, then 45 degrees around when you hit the plasma phase.
• Once at a safe speed (ca 1200 m/s or so), nose down to transition to aerodynamic flight.

This is almost exactly what I do. Is this a standard method we both learned or is it convergent evolution?

[Guest]

1 hour ago, Pthigrivi said:

This is almost exactly what I do. Is this a standard method we both learned or is it convergent evolution?

Certainly convergent evolution. I arrived this after a lot of trial and error. Especially error.

[Cavscout74]

1 hour ago, Brikoleur said:

Certainly convergent evolution. I arrived this after a lot of trial and error. Especially error.

Probably depends on when people started playing - in my case, its certainly learned from others.  Although I did have a fair amount error before looking up what the experts did. 

[Kroslev Kerman]

Am adding more stuff and that other topic about the probe core method was also done by me this is just a more toturially thread for reentering spaceplanes

[Chel]

When I'm re-entering, I always angle my plane upwards, and do small spins. Sometimes I will even deploy airbrakes to slow down while still going through the atmosphere. I remember once how I just went straight down through the atmosphere, and pulled up with about 200 meters to spare from hitting the ground. 

Fun

: )

[I_Killed_Jeb]

I'm sorry but I don't at all see the utility in this probe core method.

[Rover 6428]

My method is to have a plane tilted up a little (10 degrees or so) and tilt up and down to distribute heat and adjust my trajectory. If I seem to overshoot, I turn my plane 180 degrees and pitch up (It creates more Gs, but not much if done right)

[Kroslev Kerman]

11 hours ago, I_Killed_Jeb said:

I'm sorry but I don't at all see the utility in this probe core method.

well it does the angling automaticly and you dont have to set it up your self

[Wilds]

I found the hardest reentry is when the plane is essentially out of fuel, as the load balance could potentially be very messed up. I set up fuel priorites so my CoM and CoL is always very close together. I like to test by turning off SAS at high speeds in atmo and see what happens.

If the plane stays nice and level with SAS off (at all fuel levels), then it is very safe imo. When making a plane, I like to also test unsafe reentries at high speeds. Say 300km Apoapsis and a steep 0km Periapsis. I sure as heck won't do that on a real mission with a crew, but I always need to know the limits!

Edited November 30, 2018 by Wilds