Our real club rocket launch got cancelled due to bad weather, so I played Kerbal Space Program instead. I spent a few hours exploding some large rockets before I realized that their structures simply could not take the beating the massive engines were giving them. The secret: Throttle down the engines to 3/4 power for most of the boost, and do a more vertical launch trajectory to get out of the atmosphere quicker (less stress on the airframe). I tried adding lots of bracing, but that seems to cause it's own problems by making the physics engine stress out with all the extra parts. Once I got the uprated launch vehicle tweaked and boosting well, I had a nice Mark Twain spacecraft in orbit... so I took it to Duna (the Kerbin system's Mars equivalent).
The Mark Twain series of spacecraft (so named because they carry two landers each, which are named the Lewis and Clark), was made with stock KSP version 0.18 parts. The crew are carried up in the main 3-kerbal capsule, then two of them can transfer to the lander capsules to control those spacecraft. The first Mark Twain was tested in Kerbin orbit, just to practice separating and docking (the landers moved off half a kilometer and returned to dock). The second Mark Twain (chemically-fueled, like the first) was tested on a mission to the Mun. Each lander successfully landed on the Mun, lifted off and rendezvoused and docked with the Twain. My first orbital rendezvous missions; I was so proud. The third Mark Twain series spacecraft incorporate nuclear engines to make the interplanetary transfer.
Below is the Mark Twain 3c2 rocket: Twelve solid rocket boosters, firing in 8 and 4 sequence. Five "Mainsail" engines are under the stacks that each use four of the big fuel tanks. Must keep these engines at around 75% power, or they rattle the rocket apart. The side stacks feed the center engine until they drop off. Small "Sepratron" solid motors help get the side stacks clear when the drop off. Big opportunity for smashing the central core there. Central core finally does the tip-over from vertical to 45 degrees, then horizontal at the very end. Gets real squirrelly near the end of burn. The four nuclear engines on the Mark Twain mothership finish the trip to orbit. The nukes are fed by four small side tanks and two big drums in the center (one of which can be jettisoned when empty...it has feed lines running to the engines and gets drained first). The three-kerbal crew rides up in the main capsule.
The crew for this mission: Kelby Kerman, the designated pilot of the Lewis 3c2 lander for the Duna landing attempt; Lembart Kerman, pilot of the Clark 3c2 for the landing on Duna's moon Ike; and the guy who has to stay in the Twain mothership and doesn't get to land anywhere...my regards to Captain Dunsel Kerman. Here they are in orbit around Duna, with the red planet and its moon Ike in the background. The interplanetary transfer wasn't too bad once I figured out how to use the maneuver node feature of KSP 0.18. I also used an online calculator to find the proper planet orientations for the trip.
My initial entry orbit was inclined and eccentric (you can see where it is because I jettisoned one of the fuel tanks there). You can see the final 1,000-km base-of-operations orbit after I circularized and plane-shifted in to equatorial. (On the way back to Kerbin later, I noticed that the jettisoned tank was no longer in Duna orbit, but had been ejected into orbit around Kerbol (the sun of the system)... it must have had a close encounter with Ike that flung it out of the Duna system.)
Kelby Kerman made his space walk to the Lewis lander on the side of the Twain, then separated for the landing attempt on Duna. The Twain is off in the distance behind his ship.
Duna has a thicker atmosphere than Mars, so parachutes can be used to assist in landing...but I used rocket breaking as well. Came in on an arcing orbit and let the atmosphere help slow the ship (but a lot of rocket breaking was needed, too), and then the chutes popped out and help slow the Lewis a lot...and helped even more in getting it to descend vertically. Final touchdown was on rocket flame.
After a safe landing, Kelby cavorts on the surface of Duna.
The rocket-packs have a tough time on Duna, but they were good enough to lift Kelby to the top of the Lewis for this shot with Duna's moon Ike in the background.
It was actually kind of a plain landing site. No cool rocks or anything.
The landing site marked on Duna:
Litfoff from Duna. The rocket did not struggle at all to leave Duna's gravity. I noticed that the side tanks were empty during the boost to orbit, so I dropped them. Many of the parts of the lander have to be operated by right-clicking on them and clicking a button, which is inconvenient...but KSP version 0.18 has "action groupings" that can be used to assign various actions to keys...and I really should figure out how to use those.
Back in orbit around Duna. Next came the stressful life-and-death rendezvous with the Twain mothership.
The Lewis lander safely docked back to the Mark Twain, and Kelby is safe back aboard the mothership after an short space walk.
Lembart Kerman's turn! He took the Clark 3c2 lander out from the operational orbit to Duna's rather large asteroidal moon Ike for an attempted landing. Here is the Clark descending to the surface. Ike has no atmosphere, so it's an all-rocket-motor landing. I did a stop-dead-in-orbit-and-fall-straight-down approach (not the most fuel efficient way, but easiest).
Safe landing! Lembart does an EVA to check out the rather plain airless surface.
Ike's gravity is low, but not as low as it is on Minmus. Here Lembart jumps as high as the top of the Clark lander (this was not assisted by rocket-pack).
Lembart safely returns and docks with the Twain. He kept his side tanks on the Clark, but they were empty by the time he got back to the mothership. He's still in the Clark for this picture.
The Lewis and Clark landers were left in Duna orbit (each with about half a tank of fuel). Here we see the Mark Twain mothership burning for home on nuclear fire.
Below we see the Twain heading in for an aerobreaking return to Kerbin. I aimed it in at a height of just under 20 km, and that slowed it up nicely. The four nukes got dropped into the drink. I suppose I should put separators and parachutes on the nukes to bring them in safely for re-use (I gather that the program will pop the chute automatically for discarded pieces).
The heroes return to a safe twilight landing in the ocean!
