Mundane Mission

Mundane mission? Sure. The point of making a space transportation system is, somewhat unfortunately, to turn the wondrous adventure of space flight into a routine trip between work locations. Maybe someday we'll be able to train our kerbals to handle the everyday runs between celestial bodies, but today I'll handle it.

The next vehicle we need for our transportation system is a Tug to move things between planets and moons. I've already built a couple prototypes of these (and put them around Eve and Duna as a result of sending rovers there), but this one will be for the Kerbin System Routes... Kerbin-Minmus, Kerbin-Mün, Mün-Minmus. A simple design: A couple nuclear engines for efficiency, fuel tanks, RCS, lights and a probe body powered by an RTG, and front and aft docking ports. As long as I was launching the Tug, I also included a Crew Transfer Module (just one of the things that the Tug can move around). The Crew Transfer Module consists of a 2-kerbal cabin and a 4-kerbal hitchhiker container, plus some RCS to augment the Tug's RCS when attached. Also, since version 0.19 of KSP fixed the lighting bug, I'm also sending up a Lighting Rig to be attached to the space station so that docking can be done on the night side of Kerbin if desired. Below we see the payload being lifted by a Reusable Rocket.

The Reusable Rocket drops its recoverable side boosters at 18,000 meters, and then the rocket does its turnover.

Here's the payload in Kerbin orbit. You'll notice that I added some token radiation shielding ahead of the nuclear engines to limit the radiation exposure of any modules carried on the Tug's forward docking port (such as the Crew Module). On a typical interstellar mission, the nuclear engines may be used for less than 30 minutes of full-power runtime, and the reactor cores of those engines aren't going to build up a lot of highly-radioactive fission products in that time... but this Tug is intended to be reused over and over on repeated runs between Kerbin and its moons, so it may accumulate many hours (or even days) of engine runtime over its life... so radiation shielding becomes a more important issue. So these shields have high-Z material to absorb gamma radiation, as well as low-Z material to block neutron flux. Or so I imagine.

Oh! This is the first Reusable Rocket we've flown in version 0.19, so let's take a look at the reentry of the sustainer stage as it returns to KSC. We might need to include an inflatable heat shield if we want to use this rocket design once reentry heat damage is implemented.

With the Mün in the background, the sustainer lands on its rocket flame at KSC.

Meanwhile, back at the space station, the Tug has docked temporarily to the RCS-powered Mini-tug. This is to hand off the lighting rig.

The Mini-tug and lighting rig undock on both ends and scoot off to the side, leaving the Tug lined up for a quick docking directly to the space station.

The Mini-tug then docks the lighting rig to the end of one of the fuel tanks. This position gives the three high-intensity lights on the rig the best coverage of the station. The lighting rig also includes an RTG to power the lights. I'll be leaving the Mini-tug docked here for now until it's needed again.

Below we see the space station lit up in Kerbin's shadow. This lighting should make most of the docking ports useable when the station is in the shadow of the planet.

Now that I have the Kerbin System Tug and Crew Transfer Module in place, I decided to do a typical mission: Rotating the crew from the Minmus Moonbase with a replacement crew. In order to do this, I first had to build another vehicle: the Crew Cart. This is a simple rover that "launches" from the pad with three kerbals on board, and then rolls off the pad (beyond the drop-off bump that marks the pad boundary. This clears the pad so that we can bring out the next vehicle: a Crew Carrier 2 SSTO. Milski Kerman, Rodmy Kerman, and Dilger Kerman, all destined for moonbase duty, are the first to try out the Crew Cart.

Once the Crew Carrier 2 SSTO is on the pad, crewed by Nedmy Kerman, Rodgan Kerman, and Merfred Kerman (also slated for a stint on Minmus Moonbase), the Crew Cart drives back up onto the launch pad so that the other three kerbals can load up onto the SSTO.

Below we see Milski, Rodmy, and Dilger climbing the ladders to the hitchhiker container with its luxurious accommodations for their trip to Minmus.

The Crew Cart is rolled back under probe control to a safe distance (we want to re-use it, too), the SSTO lifts off with both its rocket and jet engines firing (although the rocket engines will be turned off very soon so that most of the first part of the boost can be handled by the jet engines).

The Crew Carrier SSTO successfully docks with the space station with 287 units of fuel left (and almost all of its RCS fuel), and then the six kerbals transfer over to the Crew Transfer Module attached to the Tug. Nedmy and Rodgan will be piloting the vehicle out to Minmus, so they transferred to the 2-kerbal cabin, and the others transferred to the hitchhiker container. The second picture below shows four kerbals on EVA, with Dilger having some extra fun floating around.

With its tanks topped up, the Tug blasts away to Minmus. The second picture shows them braking into Minmus orbit with Kerbin in the background.

There was a piece of legacy hardware in Minmus orbit, Tanker Station 5, so the Tug used that as a staging area. Note that for this mission I was trying out the Lazor Docking Camera mod, which actually worked out very well. You can see the docking camera display in the upper-left of the picture below. Nedmy and Rodgan seemed quite pleased with the new equipment. And let me tell you, it sure beats the heck out of panning the view back and forth and back and forth between side and top view to get and keep the ports lined up during docking.

With the Kerbin System Tug orbiting overhead, it was time for the Minmus Moonbase crew to roll out of bed and get moving. In the dawn picture below, we see that Aldner is the first one on the ladders of the Fido Mini 2 for the trip to the Moon Lander ships.

The six kerbals got somewhat disarrayed during the 2.4 km trip to the landers, but nobody fell off. These Moon Landers were originally meant to carry the station crew back to Kerbin, but this legacy hardware is now part of the Space Transportation System and will handle crew transfer between surface and orbit. They are parked 2.4 km from the moonbase to reduce lag at the base. It was at this point in the mission that I ran into a problem: The program would not let me switch to any of the kerbals on the ladders of the Fido. The [ and ] keys could only switch from the Fido to the landers, and would not allow switching to the kerbals (it just gave the error message, "Can't switch view while kerbal is on ladder"). Normally when I get this error warning, I can use the other opposite bracket key to switch...but it wasn't taking it this time. So...I switched to the Fido, forced on physical time warp (with the alt key), and began spinning the the Fido faster and faster around its vertical center axis...and soon all the kerbals flew off the ladders and drifted down in Minmus's weak gravity. Then I could switch to the kerbals.

Below we see the dispersion of kerbals after they were flung off of the ladders. I suppose it might have worked to switch to the Tracking Station and then see if I could switch back to the individual kerbals...but the spin trick was more fun.

The boys clambered aboard the two ships, and Aldner, Ludger, and Bobgan led the way in Moon Lander 1 (or "Reusable Minmus Transfer and Emergency Kerbin Return Ship 1" as it is called in the official documents now), blasting off (in the background of the picture below) to head for Tanker Station 5.

Below, Aldner has docked the Moon Lander 1 (er...RMTaEKRS 1) to the Tanker Station. I had a bit of a problem doing the crew transfer: One two occasions when I sent a kerbal on EVA out of the Tug's crew module, he went shooting off at high speed and it took a while to get his rocket pack turned on (it wouldn't respond at first) and stabilized. I had to fly them back from about half a kilometer away. Weird bug. Or maybe the boys were just being rowdy.

Once Nedmy, Rodmy, and Rodgan transferred over to Moon Lander 1 (or whatever), they topped off its tanks from the Tanker, then separated it from the station and plotted a return trajectory to the landing area south of Minmus Moonbase (remember to lead your landing point, kiddies, to account for Minmus's rotation).

Below we see Moon Lander 1 coming in about 370 meters south of its liftoff spot (to put it a little farther from the moonbase), with Moon Lander 2 and the Fido Mini in the near background. After landing, Thombles in the Moon Lander 2 officially transferred control of the Minmus Moonbase complex to Nedmy in Moon Lander 1.

Now relieved of duty and ensuring the unbroken habitation of Minmus by kerbalkind, Thombles, Nelemy, and Corfrey took off in the Moon Lander 2, heading for the Tanker Station.

Boost. Rendezvous. Dock. Crew transfer. Been there. Done that. Did it again anyway.

Milski, Dilger, and Merfred set the Moon Lander 2 down less than 100 meters from Moon Lander 1, and the boys all piled out to enjoy the low gravity funtime that is Minmus while waiting for the Fido to drive over.

Fido successfully drops off another load of kerbals at Minmus Moonbase.

The New Crew lines up for a photo (with Merfred on top of Rodgan), and then they all rush inside to pick out a bunk in one of the twelve habitation modules of the moonbase.

Back at the Tanker Station, Aldner offloads most of the fuel from the Tug into the Tanker (much to Ludger's chagrin... but now that the energy was spent it hauling it up here, it might as well get left behind where it can be used by the Moon Landers and other ships that will come to Minmus). They kept all of their RCS fuel, however, since Nedmy reported that the Tug ate a lot of it at times. Then they burned for Kerbin around the backside of Minmus, and headed home.

To save fuel, they did an aerobraking in Kerbin's atmosphere at an altitude of 33 km, which captured the ship into an orbit with an apoapsis of 146 km. Then they maneuvered to make rendezvous with the Space Station. They docked with over half of the fuel they left Minmus with still in their tanks, so Ludger approved of Aldner's piloting.

Aldner transferred over to the SSTO Crew Carrier first so he could grab the pilot seat, and the rest of the boys filled the capsule and hitchhiker container seats.

Below: Computer-guided reentry back to KSC with version 0.19 flame effects.

There was insufficient fuel for a rocket flame landing, so the chutes were popped out in sequence, and the remaining fuel was used to slow the ship more just before touchdown.

All of the crew disembark down the long ladders.

One last picture of the Old Minmus Crew before they head off to do whatever it is that kerbals do after being cooped up on a moon for an extended period of time.

The Tug worked well, but there were times when it seemed to be eating RCS fuel like crazy when SAS was on, and other times when it did NOT in almost identical circumstances. Odd. For the moment, the Crew Module is strutted to the front of the Tug, but once the Tug has to do some other job, the Crew Module will be undocked, and any future trips will have it un-strutted. I've tried this out, and it seems quite stable (and this was a case where it was using LESS RCS fuel... when I would have expected the extra wobbliness to make the RCS problem worse). Maybe whenever the ship seems to be eating lots of RCS, I should switch back to the Tracking Station to see if that settles it down.

The same Tug and Crew Module could be used to transfer crews on interplanetary trips (perhaps with an extra fuel tank connected to the rear docking port). Maybe I'll set up a base on Laythe and see how one of the SSTO rockets work there. But I don't want to do too much until I see how resources will be implemented, since that will affect strategy. And if heat damage is added and is nasty, probably all of my reusable liftoff/landing ships may need to be scrapped.