3 ship mun mission with docking

[Temstar]

So recently I've been playing around with both Erkle and ORDA docking mods with the goal of developing techniques for interplanetary landing and return trips, particularly for the harder targets like Eve and Laythe. The test Mun mission turned out to be a great success. Here's a run through:

At the start of the mission, an Olympus class orbital propellant depot is already waiting on orbit with one crewmen. (prototype shown above with two spacecraft docked) The depot holds a large quantity of both regular and RCS fuel and will function as an orbital base in the future for Mun missions. The other ship involved in the mission is the lander, here it's taking off with the two remaining crew to join with the depot.

At LKO, the two ships join up. For this occasion I picked the aft docking port of the Olympus to dock the lander, you will see in a moment why.

Time for trans-munar injection. While Olympus has plenty of fuel and thrust for TMI it's radial engines have awful Isp. So instead I elected to use the lander's highly efficient nuclear thermals rockets for the TMI burn to push the entire combined spacecraft into munar orbit. There's a trick to this: the two spacecraft's navigation must be in agreement with each other, otherwise they will fight each other for steering and cause the combination to spin out of control.. For this burn I set both spacecraft to R&D > ATT> HOLD. This makes both ships try to keep their heading at the moment the HOLD command was switched on.

Although efficient, the low thrust of the nuclear thermals rockets ment an unusually long burn. During the burn I did some fuel transfer test - turns out the fuel transfer rate between Erkle docking claw is quite high. Here we can see it's way higher than the burn rate of three nuclear rockets. Also interesting is the fact that fuel feed will continue after the receiving ship's tanks are filled if it's burning fuel - the transfer will just drop to equal to the burn rate.

8 hours later, the two ships arrive above Mun. The crew turn the combined spacecraft around and fire the nuclear thermals rockets again to slow down and settle down into a munar orbit.

While orbiting the moon, the lander crew fully fuel the lander and wait for the go for PDI.

Word from KSC is a go and Apokee Lander undocks from Olympus and begins powered descent initiate.

Apokee Lander successfully lands on the Mun! Commander Tombree climbs down first with lander pilot Gilfurt right behind him.

Tombree does his Peter Pan thing with his MMU

EVA is over and the crew gets back inside and lifts off and head back meet up with Olympus

Having linked back up again. Gilfurt gets out to work the RCS fuel lines to refuel the lander. Much like the ISS and its docked Soyuz the Apokee Lander function as a lifeboat for Olympus. Should it be necessary the crew can evacuate from the depot using the lander and escape to either a different orbit or Munar surface to wait for rescue. Thus it's a safety requirement that the lander is loaded with full fuel when docked.

Neither Olympus or Apokee Lander are intended for re-entry for this mission (though Olympus have the capability). Instead they are intended as a permanent Mun presence. To get our heroes back a new crew is launched from KSC in an Apokee II cis-munar spacecraft and heads for the Mun

The three ships join together above the Mun while the two crews exchange greetings and conduct handover. Apokee II arrives with more fuel and RCS fuel than required to get back so the additional fuel are pumped into Olympus's hold.

With the crew exchange complete the original crew undocks Apokee II from Olympus and fires its engine for TKI to take them back home.

Apokee II successfully re-enters atmosphere. Since the nose of the spacecraft is taken up by the docking port Apokee II does not have an XL parachute. Instead it mounts three regular Mk16 parachutes.

Splash down and a heroes welcome for the crew!

You can find the craft files and link to the mods here:

http://kerbalspaceprogram.com/forum/showthread.php/22560-0-17-Erkle-ORDA-Orbital-Propellant-Depot-Olympus

Edited October 6, 2012 by Temstar