Kerbal-X to Mun, Minmus, and Back Without Refueling

[PLAD]

The performance of the stock Kerbal-X that comes with KSP has changed quite a bit over the years, as the weight of its parts and the iSp of its engines change from version to version. Here is what Mechjeb has told me are its numbers ready-to-launch:

(Note that the numbers may vary a bit depending on what method you use to measuere them and whether you measure in the VAB or on the pad.)

Version........total vacuum dV............total weight on launchpad

0.22..............6832 m/s......................131.67 tons

0.23.5...........6818............................131.44

0.24.2...........7333............................131.24

0.25, 0.90......7333............................130.94

1.0x..............6428............................129.22

It was not possible to launch from the KSC, land on Mun, and return to Kerbin before version 24.2. From then through .90 a Mun landing mission was moderately difficult but quite possible. You might think it became impossible again in 1.0x, what with the loss of 905 m/s in dV, but thanks to the new atmosphere model it takes about 1000m/s less to get into orbit than it took in the earlier versions. In fact it can now get to an LKO and have about 135m/s more available than it did in the earlier versions. This makes a mission to take of from Kerbin, land the ship on Mun and Minmus, and return to Kerbin without refueling possible. Barely.

Here it is! Note that I was chicken and took the monopropellant out of the command pod before launch, giving the ship and extra 35m/s of dV. I did this in 1.02, the new versions came out while I was doing it but I don't think they change any of the space manuevers at all.

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I made about 30-40m/s of mistakes in this mission, so the K-X can do this mission in 1.02 and have about 80-90m/s left over. I now have to see if the K-X can get to a 72x72km orbit for no more than about 3430m/s with version 1.04, if so this mission is still possible.

EDIT:I just tested it, and the new atmosphere model in 1.0.4 makes it possible to get the Kerbal X to a 72x72km orbit with only 3274m/s, which is 74m/s less than in 1.0.2. So a Kerbin-Mun-Minmus-Kerbin mission can now be done even without my fancy method of getting to Mun.

Edited July 1, 2015 by PLAD
New info

[Scotius]

Interesting. I wonder if K-X can make it to Duna?

[PLAD]

Interesting. I wonder if K-X can make it to Duna?

It could in version 0.90. I haven't tried the new Duna atmosphere though, to get the K-X to Duna's surface and back Duna's atmosphere has to do almost all of your braking, and I hear it's a lot thinner now...

[Geschosskopf]

It could in version 0.90. I haven't tried the new Duna atmosphere though, to get the K-X to Duna's surface and back Duna's atmosphere has to do almost all of your braking, and I hear it's a lot thinner now...

I haven't been to Duna in 1.0.4. In 1.0.2, however, it's atmosphere was a paradise. It aerocaptured you without flames at whatever Ap you wanted, it filled your chutes so that you could land on high ground from steep descents with not many more chutes than needed on Kerbin, and yet impeded your launch way less and before. You could fly a heavy plane with little wing to nearly 20km where such a thing would have been unable to take off at all previously. In 1.0.2, Duna's air had everything you wanted and nothing you didn't.