Mun/Minimus There And Back Again 22 Tourist Design

[Carl]

NOTE: Although i used mechjeb for my flying and it's present in all the screenshots it is not present on the version of the craft file i uploaded. So it's pure stock compatible.

 

So i've allready posted my little boy tourist to Kerbin Orbit and back previously. Using that Experience and unlocked parts i built this. With 3kps of d/v upon reaching orbit it's quite capable of doing Mun or Minimum Orbital Tours, (well i hope, i haven't tested it but the d/v is more than enough and there's no stability or power issues so it should work just fine). I was limited by my unlocked parts to Skippers, no Mainsails or Twin Boars unfortunately. And the d/v requirement of the actual on orbit stage at 3kps combined with enough TWR in it to make practical maneuvers created some challanges. After trying a poodle i just felt the TWR was too low for the whole thing so i went to a Skipper, but the lowered ISP, and a few tons of weight gain (and the extra drag), from the chutes required and the solar's and adjusting batteries and what not raised the final payload to orbit which required more tankage for teh on orbit stage and the final total payload to orbit climbed to a massive 91 tons. Lifting that like my old design with liquid side along boosters lifted off the pad by SRB side alongs just wasn't practical in the slightest, i tried combo builds but in the end i had to go to a dual liquid booster setup with side along SRB for the extra TWR with the SRB's burning out and jettisoning a few seconds before the liquid boosters. Then once the anemic decouplers and chutes have got all that clear the main liquids kick in, tilt over and burn her to orbit.

 

But she isn't cheap 275k credits goes up and just under 50k credits comes back down, giving her a per tourist cost of just over 10.2 k a kerbal. It's not great but i'm working with some harsh tech limits. And whilst i haven't picked any up yet, (i'm designing in anticipation, the same on orbit engine stage coupled to a different payload stack will be used for the manned flyby's by the science team), i expect the mun contracts to pay proportionally better than the mere orbit ones. Later i'm going to modify it and use it for ferrying tourists plus fuel to a space station where a tourist mun/minimus lander will meet up and refuel off it. But thats going to need better monoprop tanks, and docking ports and a bigger stack separator than i currently have.

Flying her should be simple even without mechjeb, just remember, don;t pitch till you jettison the first stage liquids and allow a 3 second delay before igniting the 2nd stage liquids after you hit the decoupler for the 1st stage ons, or things will go boom. Getting her down just means initiating the deorbit burn, then locking her retrograde till the chutes becomes available, deploy chutes, release SAS, let her drop and the chutes will do the rest. Don't worry if she swings out on reentry at around 23km, thats supposed to happen, as long as it dosen;t happen before that she shouldn;t burn up, just don;t try doing an aerobrake straight from mun return, put her into an 80km orbit before de-orbiting. 

One Minor Note, added a comm antenna after flight but before the VAB screenshot, so the recovery value ommits that, only 900 credits though.

EDIT NOTE: The pics are slightly outdated, the updated version in the craft file has the heat shield on the bottom and a different battery config, though you can't see the batteries in the screenshots.

Craft File.

Pictures:

Edited January 5, 2017 by Carl

[Aerospike]

Does it really take so many chutes to slow this thing down for landing? Seems a bit excessive, but I have to look up the weight of the Hitchhiker containers.

[Carl]

Yes, Yes it does. Look a the third screenshot up from the bottom, 4.5m/s, which is abou the upper limit for advisable impact velocities IMO.. I've allready dropped a suggestion thread for bigger 2.5m compatible chutes so you don't need to decoratively plate the damm thing in them.

Edited January 3, 2017 by Carl

[StrandedonEarth]

I have a 23-seat Space Camp (contract pack) bus capable of dropping into and burning back out of Mun orbit, then landing on Minmus' Flats (usually dropping at least a quarter tank of propellants on the way down), then burning out to solar orbit before turning around and landing back at Kerbin, again with plenty of propellant (useful as ballast) remaining. 

TL;DR, it's a 23 seat three-star trainer with plenty of reserve dV. With a load of science instruments, it runs about 410kon the pad. The airbrakes work together with the RCS to keep it from wandering too far off  during re-entry. It tends to topple and demolish the HH during water landings, but that can be avoided by being quick on the recover button (or landing on land).

I could slim down the boosters a little, but that seemed like too much wok. And with that many seats, I figured the reserve was warranted. It also allows for stacking a commsat on top for another contract. And yeah, it's stock.

Edited January 4, 2017 by StrandedonEarth