What does the "jettison" button on a heat shield do?

[RedsBone]

If I right click on a heat shield in-flight, there is a "jettison" button that I can only press once (then it doesn't show up any more). But it doesn't seem to do anything while the shield still has the fairing, nor when it doesn't have the fairing any more. So what's the button for?

Edited May 16, 2015 by RedsBone
Ghramah

[Xkay7]

rocket engines also have this feature, but like them it does nothing.

[SRV Ron]

Some of the mods have ejection capability built into their heat shields. It is a way to shed useless weight once the shields have done their job. Currently, such staging is not part of the stock heat shields. Most likely, it is a placeholder for some future update.

[Nutter]

I think it has something to do with the interstage fairings that appear on them and some rocket engines if you attach an object (like a decoupler) underneath them.

At the very least, they seem to be the only times you can observe it, but I think you can only actually see it used on the LV-N with it's two-part fairing that doesn't attach to the decoupler.

[NathanKell]

Correct. Jettison means jettison the shroud, like what happens when you have an engine above a decoupler and then decouple.

[match]

A couple years ago I spent a couple hours trying to jettison a couple engines using that button.

I thought my download was borked and downloaded it fresh. Nope... I gave up.

A couple days later I had a couple new ideas to try to decouple those engines.

Again, No dice.

I almost quit playing KSP over that... I felt both cheated and stupid.

Ignorance coupled with pride is an impossible burden.

Good thing I came to this forum and lightened my burden!

When I was fourteen, my father was so ignorant I could hardly stand to have him around. When I got to be twenty-one, I was astonished at how much he had learned in seven years. ~Twain

[surge]

A shroud for a heat shield needs special treatment?!

Or even exists?

Uh-huh.

[moogoob]

AH, so that's what that mysterious jettison button I've been seeing on and off since 0.23.5 was about. Wondered why it did nothing.

[James M]

Okay the only real reason to jettison a heat shield is to either shed weight or to reenter with a thruster attached to the bottom of the lander. You'd have the heat shield under that to protect it and then jettison right before you start your landing burn.

[LN400]

One thing I found was a heat shield out of ablators offers less drag than the Mk I pod. I don't know if it's one of the mods I use or if it's stock behaviour but I usually stage the HS so that when it runs out (or if), I drop it for a higher acceleration down to safe parachute deployment speed. Also the weight loss helps.

Edited August 5, 2016 by LN400

[Laie]

On 5/17/2015 at 0:37 AM, moogoob said:

AH, so that's what that mysterious jettison button I've been seeing on and off since 0.23.5 was about. Wondered why it did nothing.

Can't say that I used it often, but in Nervas and in 0.90 it worked.

[Sharpy]

Actually, you definitely want to shed weight when landing, to save up on active braking or reduce speed when parachuting, so jettisoning the heatshield is entirely possible.

As of 1.1.3, not sure whether that's KIS/KAS or stock, you can jettison the shroud, and the shield independently. You can also include it in the staging sequence.

[Corona688]

This is a necropost.

The OP is now inaccurate, you can definitely jettison heat shields now.