'Earwig' Transport Erector Launcher with mün rocket

[sgt_flyer]

Hi, i presented it in the TEL thread a few days ago, here's the files for my Transport Erector Launcher and it's mün rocket ! (because, if you want to launch a mün mission away from ksc, you can now ! )

also contain the mün rocket alone, if you just want to test out the rocket itself.

i spent quite some time working on a way to verticalize the rocket with stock parts without needing to use difficult timings on separatrons or rocket engines - and why bother with a simple rocket ? it's more fun to do it with a mün capable rocket ! - so i ended creating a mün rocket lightweight and resilient enough to withstand the transition from horizontal to vertical.

before anything else, here is the mission album (note, the lander has been slightly modified since these pictures, to have slightly more delta-v and illuminators (for nightside mün landings):

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now, the big part : ground and flight instructions !

Action Groups :

abort key : separate the command pod from the rocket, and ignite the escape tower to make the pod veer away from the rocket (it also disables the pod's torque to prevent the torque from messing with the offcentered thrust of the escape tower)

key 1 : shutdown the lander's engine (to use after mün landing, in preparation for mün liftoff)

key 2 : reactivate the lander's engine, and decouple the drop tanks and landing legs. (for liftoff from mün)

key 3 : toggle the lander's solar panels

key 4 : toggle the vehicle's rear landing gear (the ones who serves as claws)

key 5 : toggle the support structure's legs

key 9 : deploy the parachute

key 0 : decouple the escape tower from the command pod (only for use after an abort)

Ground Operations (if you only took the rocket, you can switch directly to the ascent profile):

the launch system consist of 3 elements, all carried by the vehicle until in position for launch :

the rocket (with a launching pad attached to it's engines, and axles on each side for resting on the support structure)

the support structure (which has an RTG and a probe core in order to manoeuver it's landing legs)

the vehicle itself, which has rear 'claws' which are used when raising the rocket.

there's not enough RTG's to power permanently the wheels, but there's large batteries to sustain long trips. (and if you need to quickly recharge the batteries, you have two solar panels for that when you stop the vehicle - do not try to use those on the move

before trying to roll the vehicle out of the runway, raise the rear claws (key 4) to prevent the claws from hitting the ground. (note, KSC's buildings pads are too step to climb up safely with the vehicle, it's easy to snap a wheel on those - although you could go down from them without much problem)

raising the rocket :

once you are in the position you wanted, you can start to raise the rocket as follow :

1 - make sure that you rear 'claws' are down (key 4), and engage the parking brakes.

2 - deploy the support structure landing legs (key 5) (they have the clearance to deploy on each side of the vehicle)

3 - hit spacebar once, for decoupling the rocket from the vehicle. (at this point, the rocket will simply rest onto the support structure, as the articulation point is at the COM of the rocket)

4 - switch to have the focus on the vehicle itself, and click on the forwardmost clamp'o'tron to decouple it. (the second clamp'o'tron should decouple at the same time, if not, simply click it and 'undock' it).

(at this point, the rocket will entirely rest onto it's support structure)

5 - with the vehicle in focus, disable the parking brakes, and start moving forward. the rear claws will catch the rocket's pad I-beams, and this will start to rotate the rocket

(don't go too slow nor too fast, to not break or pass through the claws).

6 - once the rocket is in vertical position, engage the vehicle's parking brakes, and switch to the support structure to toggle it's landing legs (G or key 5 at this point) - the support structure will lower the rocket to the ground.

(at this point, the rocket will rest onto it's launch pad)

7 - switch back to the vehicle, raise the rear claws (G or key 4), and drive forward to get out of the support structure.

8 - switch to the rocket, engage it's ASAS, and hit space once to eject the two axles.

at this moment, the rocket can now lift off any time for the mün mission

Rocket Ascent profile / mün mission:

climb straight up until 8000m, then start tilting the rocket and make a smooth eastward curve to reach : 45° at 20000m, 30° at 30000m, 20° at 40000, and 0° around 50000m, then continue burning at a 0° angle until your apoapsis is around 80000m. at this point, shut down the engines and let the rocket coast until you are near apoapsis, then circularize.

eject the first and second stage as they are emptied, the lander's fairing will be ejected with the first stage, and the escape tower with the second stage. the third stage is used to finish the ascent, and then to make the mün transfer.

once in space, you can deploy the solar panels (key 3) to replenish your batteries (no RTG onboard ).

mün transfer : the third stage should have enough fuel to make a Free return trajectory : place your manoeuver node near the correct ejection point for a mün transfer, modify the manoeuver's orbit with the prograde handle until the apoapsis is a bit higher than the mün, then click on the manoeuver node's ring and drag it along your orbit until you have something which looks like a Free return trajectory.

(try to have a mün periapsis near or under 40000m, and that the return path just end up in kerbin.) make your transfer, then eject the lander from the third stage. (the third stage will move with you, and then continue past the moon to come back to burn in kerbin's atmosphere - or you can switch to the third stage and use the onboard core probe and make a burn to crash the third stage in the Mün with the remaining fuel )

when you are around 25 / 30s before your mün periapsis, start burning retrograde to circularize around the mün (if coming from a free return trajectory).

for landing, the most efficient way remains Kosmo-not mün landing profile : drop your mün periapsis to around 4000m, then kill your horizontal velocity when you arrive near your periapsis. (as the speed drops, start tilting the lander in order to not lose altitude too fast - keep an eye on the vertical speed indicator left of the altitude indicator), once all horizontal speed has been killed, finish your descent vertically and make a slow & nice landing . once landed, shutdown the lander's engine. (key 1)

mün ascent : push your throttle up to 2/3rd, then hit the key '2' to separate the return spacecraft from the landing legs and reignite the engine for ascent.

(i usually do my turn towards when ascending from mün 270°) - almost as soon after liftoff turn to go 45° above horizon, and once you are over 4000m, start going for 0° above horizon, and burn until your apoapsis is near 20000m - then shut your engine, and coast until you reach your apoapsis to circularize. once in mün orbit, place your manoeuver node, use the prograde handle, and then grab the ring to check for the least delta-v transfer back to kerbin (you can deploy your solar panels for the trip back).

when reaching kerbin, the reentry landing is a traditional one. (you should even have enough delta-v remaining in the spacecraft for circularizing after an aerobrake)

here are the .craft files (both for the spaceplane hangar):

'Earwig' TEL with the mün rocket (515 parts): http://www./download/ufmcbiz8vsy7o0o/Earwig_TEL_Mun_rocket.craft

mün rocket alone : (228 parts) : http://www./download/qut7hg4q1mxkgf6/Mun_rocket_alone.craft

Have fun !

[GusTurbo]

Absolutely spectacular -- easily thread of the month. How long did it take to create this?

[sgt_flyer]

Well, i wanted to create a TEL system since quite some time, but a standard TEL rocket launcher was not motivating enough, so i wanted it to carry a mün capable rocket - which i built first, using several of my techniques to try to build it lightweight and sturdy enough to withstand the horizontal to vertical transition.

Then, the vehicle design itself was made in a lot of iterations, including trying to raise the rocket with rocket engines on the support structure, but that ended to require a too careful timing to be easily used (due to the sheer momentum carried by the rocket) or too destructive for the support structure.

Also tried out having the articulation point ahead of the rocket's center of mass, which proved to be difficult to control.

This carrier vehicle is maybe the fourth or fith concept i toyed with, each one giving me hints on how to improve the later versions so it took the equivalent of a few days building and refining it on the game, but even more time outside the game thinking about the concept mechanics

[Woopert]

Awesome design. Far more complex than what I use!

[team.leit]

Thanks for releasing the mun rocket now I can have fun:D

[Prof. Endwalker]

One word: Wow.