Launch Abort & Escape Kit

[Moach]

well, well...

every now and then, we feel a kerbal's life could be spared from ending violently in a fireball of terror and mayhem....

but who hasn't faced that dreadful situation in which a decoupler has not enough 'pop' to clear away from a ruthlessly murderous flaming stack?

the solution? - MORE POWAH! 8)

i devised a simple little 'abort kit', containing the following parts:

* Launch Escape Tower - a thruster that pulls the pod away from the doom-dealing madness below

* Blast Cone Decoupler - a decoupler designed to fit around the mk1 command pod and protect it from the abort jets exhaust

* Mk20 parachute - a modified and larger chute with a structural hardpoint on top

* try to ignore the crappyness of this picture

so to build a functioning launch escape system (LES)

* add the mk20 chute to the top of your pod

* put the cone decoupler on top of it

* attach the escape tower to the top of the blast cone

and now, just to set up your stages right....

the proper staging order is:

- stage 0 -

pod

heatshield (if available)

- stage 1 -

parachute

- stage 2 -

cone decoupler

- stage 3 -

escape tower ignition

pod or heatshield lower decoupler

this setup allows you to use the escape system in two ways - 'eject' or 'jettison'

the default is to eject, then stage 3 is fired, the pod will separate and the tower will pull it up - you can then eject the tower from the cone decoupler (which has enough 'pop' to clear it into a safe distance) and open your parachute (i'd advise you keep your heatshield, if available , just in case...)

the alternative is to 'jettison' - if you pull down the cone decoupler stage so it fires before the LES, it'll jettison the tower - leaving the lower decoupler all set up for a nominal ejection-free separation

watch your nose attitude when jettisoning the tower during burn - it could possibly hit you in the face as you speed past it :

models were made with all due care for poly count and texture size economy, since not everyone has a killer video card to play with... - FPS tests on a GPU-challenged PC have proven quite satisfactory

get the LES kit here! - your kerbonauts will thank you! :cheers:

[jrsteensen]

Can't wait to get home to try this out.

[rdfox]

Aw yeah, I've wanted a BPC ever since the first LES tower showed up!

[cd7890]

awesome

[Andras]

I put the blast shield off to the side in the VAB and can't pick it back up. Is there something that can be done to increase the 'clickable' area?

[sirmonkey]

I put the blast shield off to the side in the VAB and can't pick it back up. Is there something that can be done to increase the 'clickable' area?

try clicking near the connection point, usually works for me or i just grab another one, it'll disappear when you launch and come back to the VAB anyways.

[Moach]

the clickable area is quite small, im afraid... it's around the rim near the top... this is due to a limitation in the current ways of the collision check system, anything larger and it thinks the cone is colliding with the pod...

i've notified HarvesteR already... seems like an easy fix, if he does as i suggested - to simply ignore collisions on parts that are not detached... this should ease up some of the load on the physics engine too....

:cheers:

[eggrobin]

A wonderful BPC indeed, and a neat parachute. May I however suggest allowing surface attachments on the escape tower ---[tt] attachRules = 1,0,1,1,0 [/tt]---, thus enabling more control over the LES, e.g., through the use of Safer Development boosters as pitch control motors (no symmetry) and tower jettison motors (2-fold symmetry) ?

My trials with this alteration yielded a highly reliable LES, the escape tower being more self-contained than in my previous model (Pod - NovaSilisko's Mk3 - Safer Decoupler - Sunday's Punch-out - Safer Structural, bearing the aforementioned motor setup - Safer Aeropart), which, unless subtly adjusted, would send the capsule crashing right into the ground during pad aborts...

One could argue, though, that if an escape tower is frowned upon, jettison and pitch control motors would be rejected outright by Jebediah. Who would want to board a rocket without there being a chance of being crushed by the life-saving systems, or even landing a bit closer to that splendid explosion below? 8)

Thanks for those good-looking parts,

eggrobin

[Volt]

Woo, I love it! When individual separate abort and jettison buttons are made for LESs, this will be even more epic!

One problem I just experienced, though... I was deorbit burning a standard LVT-40 engine and when I was at about 1100 m/s, the parachute module exploded. Now my kerbals are doomed to death. (well, the trajectory took it to the dark side but you know what I mean.) Care to explain what happened and write Mrs. Kerman a condolence letter?

EDIT: Post-mortem catastrophic failure report says that Mk20 parachute exploded due to overheating. There was an LFT, a Mini-decoupler and the pod between the engine and the chute.

[Moach]

how much flame can you put on a parachute before it catches on fire?...

yes, the Mk20 is quite sensitive to heat... i tried to make it a little more on the realistic side, since the mk17 can take more heat than a regular heatshield.... but i guess the thermodynamics model is somewhat strange and has the pod transfer way too much heat to stuff above it....

anyways, if you can manage to keep the parachute away from open flames it should be fine... i hope...

or i might have to do something about that, tho... : - what's the cfg parameter for heat conductivity again?

[Volt]

Well, this was during deorbit burn - the parachute should have been inside its shroud, since its stage wasn't activated yet. Graphically, and in the stage display, it was undeployed. Anyway, I wouldn't say that the parachute should be taking any damage during deorbit burn, because really there isn't much of an alternative to deorbit burning.

[McLuv]

I'd just like to say that I love this piece o' kit. I set it up as my second stage sequence, so that if my first stage is going haywire, my CM decouples and flys way out of the way before disconnecting the LET and opening the chute.

Of course, if everything is nominal I simply rearrange both decoupler and tower to the top of the stack.

This type of system will be even better when an option for a a dedicated escape stage is implemented.

[alberro+]

Jesus, this has been dead for 9 years! How come it hasn't been closed yet?

[Geonovast]

Let's not needlessly bump threads, please.  We don't lock threads just because they're old when they're quietly sitting around.  Please only bring back old threads if you have something to contribute.