Cargo delivery cost savings

[Ice30]

So I am using TAC life support, MKS for building bases capable of sustaining life and DRE, Realchutes, FAR etc. I have been building a huge space station that I am sending to the Joolian system that will provide life support and beamed power for many years while I fully explore all the moons. I have been trying to build most components of the main lifters retrievable, in addition to using SSTO space planes.

My latest mission involved sending up ~100 tonnes of cargo including replacement parts and emergency supplies to the station, all the cargo containers would not be going with the space station so this mission presented a unique problem to me. I had a craft that at the launch pad cost about a million credits, but nearly all components could be retrieved if I could figure out a way of doing it. I decided the shape of the payload was too long and tall to survive a landing without toppling over and crashing into the surface, so the best way to retrieve the payload was to split it up in sections while it fell towards Kerbin and have parachutes on each module. The main lifter stage would be put on a suborbital trajectory so it could parachute down safely wherever it could, another stage would circularise the payload, help it dock with the station and then be used to de-orbit the payload.

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For the main stage, I used an inline chute containing a drogue and a main chute, covered with fairings to protect the chutes if the main stage started tumbling during re-entry, before the main drogue was able to kick in. When I actually did this, the main stage actually tumbled quite a lot because it was aerodynamically unstable in a retrograde trajectory, luckily my fairings managed to shield most of the heat until the drogue kicked in so overall the chute design here was a success. When the main stage landed (on a small slope) it fell over and unfortunately damaged one of the four engines, but the rest were okay so I accepted that as a reasonable result given the size of the main stage.

For the payload I attached chutes radially on each module and covered with an ablative shield to protect the chute during re-entry, the engine would allow me to maneuver close to the space centre for this which increased my cost retrieval. The main docking port is attached to a decoupler to reveal the drogue chutes (2 off). I had a complex action group arrangement to decouple the modules, ablative shield, deploy landing gears and parachutes module by module. This didn't work on my first run through (thank god for quick load). I changed my deployment so that the top module decoupled first, then the lower ones one by one. This reduced the chance of the lower stages colliding with the upper stages during decoupling. I stuffed up my chutes however, I somehow made them uneven so the modules didn't glide down in a balanced way. Luckily the touchdown speed was low enough that I retrieved 3/4 modules (the fourth one disappeared ~300m from the ground just as I was trying to centre my focus on it to make sure it landed okay but oh well).

Overall the mission went OK. I retrieved roughly 70% of my cost. I am still learning how to set up real chutes correctly so hopefully I wont make that mistake again

[Immashift]

Nice idea for a thread. I'd also like to save on cost with a pile of mods installed. Getting lower stages to successfully land without either disappearing or exploding seems to be a challenge for me. Orange tanks and mainsails really dig into my funds right now, especially when I drop them 2300m up and they go poof.. I've been resorting to spaceplanes and SSTO's for smaller lifts due to costs.

Scott Manley put up a good video on cost savings, in case you haven't seen it:

Long ago in modland there was the Lazor system, capable of extending craft despawn range with voodoo magic. This functionality would be extremely useful in career now, cause then I needn't worry about stuff going away and could just recover everything after a launch.

As a side question, what are those soyuz-looking boosters from? Can't be Bobcat's Russian pack right? To my knowledge that hasn't been updated in ages.

Edited August 7, 2014 by Immashift

[Ice30]

Thanks. That orange fuel tank is actually a scaled up version of the ordinary one, note the KR-2L engine attached... I found the best way to get the launcher stage to be retrievable (with DRE) is to have enough fuel to get it into a reasonable suborbital trajectory (using far) with a periapsis of between -50,000m->35,000m and have enough batteries (make sure they are turned off until you need to use them) to turn the stage and perform any burns\parachute deployment that may be necissary. I actually really think the control that real chutes gives you is a fantastic mod to use with DRE...

I used to use a mod that extended the physics range but it still randomly crashed and destroyed landed\landing space craft so I dont think theres a way around it besides making sure all components land very close to each other and to centre your view on each craft as it touches down...

To answer your question those parts are from KW rocketry.