Suggestion: Off-center force for decoupler

[Fraktal]

Thinking of KSP recently, I remembered that the biggest issue with using an aerodynamic nosecone instead of a fairing is that even if you stage off the nosecone with a decoupler upon reaching a high enough altitude where aero isn't a problem, the now-unpropelled nosecone immediately collides right back into the still-propelled rocket, potentially breaking stuff if you don't have the time and fuel to briefly thrust radial-out to avoid it. I had to scrap a Duna mission once due to the nosecone I used to cover the command module's docking ring having smashed into and broken the antenna when I staged it off during circularization.

So I thought, what if there was a decoupler variant that's still mounted inline but when staged, applies force diagonally instead of exclusively on the fore-aft axis, specifically to fling stuff staged off the front of the rocket out of the way? Because using a Sepratron for a mere nose cone is a bit of an overkill, not to mention draggy, costly and heavy enough to defeat the whole point of using a nosecone instead of a fairing..

[Fierce Wolf]

I have bumped (see what i did there?) into this problem before. If i ever jettison my nose cones i simply turn left a little bit, decouple, point forward again and burn. But i'm always in for more parts. A nose cone with carring capabilities that could be opened, closed and jettisoned, for example, would be super cool to have.

[pandaman]

3 hours ago, Fierce Wolf said:

A nose cone with carring capabilities that could be opened, closed and jettisoned, for example, would be super cool to have.

You mean like a symmetrical version of the Mk3 liading ramp?

Yes, good idea.

[dnbattley]

While it might ruin your aesthetic sensibilities, I'm pretty sure that simply offsetting and rotating the decoupler, then offsetting and rotating the nose cone "back into place" won't adversely affect the aerodynamic model and would achieve the effect you are looking for...

[Pds314]

You could add a seperatron to decouple the cone. Although that will hurt aerodymamics.

Another option is to briefly disengage engine thrust. Since you probably shouldn't be decouplibg a nosecone in thick atmosphere and nosecones are usually more aerodynamic than empty nodes anyway (although a lot lighter).

Edited November 16, 2019 by Pds314

[Pds314]

On 11/15/2019 at 9:10 PM, dnbattley said:

While it might ruin your aesthetic sensibilities, I'm pretty sure that simply offsetting and rotating the decoupler, then offsetting and rotating the nose cone "back into place" won't adversely affect the aerodynamic model and would achieve the effect you are looking for...

Not sure this is true. Having anything sideways in the airstream is pretty unaerodynamic. It would be considerably more aerodynamic at that point to forego the nosecone and decoupler entirely, then flip the topmost fuel tank or whatnot upside down and translate it back up so no forward nodes nor sides of a part are exposed. At least in the stockosphere. This technique allows, e.g. very supersonic mk1 planes with a single juno. Especially if the resulting empty rear-facing node is used for something like a second tail.

Edited November 17, 2019 by Pds314

[dnbattley]

1 hour ago, Pds314 said:

Not sure this is true.

For science!

I did some testing, and you are right about the rotation having an adverse impact on the aero model, however the offset alone works, producing an almost negligible drag impact, thus:

Both (otherwise identical) vessels have achieved an approximately equal height

However, the offset decoupler successfully clears the nose cone away from the impact zone even at moderate speeds.

 

You are right that there are other ways of gaming the aero model, however, I did not incorporate these into this "A-B" experiment

[Pds314]

1 hour ago, dnbattley said:

For science!

I did some testing, and you are right about the rotation having an adverse impact on the aero model, however the offset alone works, producing an almost negligible drag impact, thus:

Both (otherwise identical) vessels have achieved an approximately equal height

However, the offset decoupler successfully clears the nose cone away from the impact zone even at moderate speeds.

 

You are right that there are other ways of gaming the aero model, however, I did not incorporate these into this "A-B" experiment

Yeah offset should have no effect on the aero model but significant rotation should.

[paul23]

On 11/15/2019 at 4:27 PM, Fraktal said:

Thinking of KSP recently, I remembered that the biggest issue with using an aerodynamic nosecone instead of a fairing is that even if you stage off the nosecone with a decoupler upon reaching a high enough altitude where aero isn't a problem, the now-unpropelled nosecone immediately collides right back into the still-propelled rocket, potentially breaking stuff if you don't have the time and fuel to briefly thrust radial-out to avoid it. I had to scrap a Duna mission once due to the nosecone I used to cover the command module's docking ring having smashed into and broken the antenna when I staged it off during circularization.

So I thought, what if there was a decoupler variant that's still mounted inline but when staged, applies force diagonally instead of exclusively on the fore-aft axis, specifically to fling stuff staged off the front of the rocket out of the way? Because using a Sepratron for a mere nose cone is a bit of an overkill, not to mention draggy, costly and heavy enough to defeat the whole point of using a nosecone instead of a fairing..

This is exactly where seperatrons (notice name) are designed for.

[HvP]

Embed a small weight on just one side of the nosecone. Not near the tip, you want it near the base so that you can move it as far off the center-line as possible for maximum torque.

A Mk-12-R radial drogue chute seems to work well. It's not so heavy that SAS can't compensate for the off center weight, but it's heavy enough that it will torque the nosecone to one side when you eject it.

Edited November 24, 2019 by HvP