My First Realism Overhaul Moon Landing!

[jandcando]

Hello everyone! I just did something that I'm very proud of and I thought I would share it here. I landed a probe on The Moon in Realism Overhaul with a probe of my own design riding on a rocket of my own design. There are tons of mods involved, so I won't be posting the craft files (unless you REALLY want them.)

So lets begin with the probe design. I has 4 generic pressure-fed engines that provide 1kN each. Its 2 solar panels provide power for the reaction wheel, a long range dish, and 2 omnidirectional antennae. The probe on its own has 3,879 m/s of delta-v that takes 10 minutes and 58 seconds to burn.

The probe has an attached service module that provides power for final orbital insertion and the Lunar transfer orbit. The lower tank contains about 100 liters of hydrazine for its RCS, along with the normal fuel for its engine. The engine is a pressure-fed EADS Astrium Aestus II. This stage provides 4,161 m/s of delta-v and burns for 13 minutes and 38 seconds.

The upper stage of the rocket I have titled "Medium Lifter" is powered by a Rocketdyne J-2 engine and provides 4,592 m/s of delta-v that burns over a duration of 4 minutes and 23 seconds. Inside the interstage fairing, there are 2 solid rocket motors for ullage (settling the fuel at the bottom of the tank.) These motors burn first, and then the J-2 main engine ignites.

The lower stage of this rocket is powered by an NPO Energomash RD-180 engine. This stage provides 3,637 m/s of delta-v and burns for 2 minutes and 42 seconds. This stage has fins for atmospheric stability. The fins are not necessary for roll control, since the engine has 2 nozzles and can simple gimbal them in opposite directions to roll. The fins just help with the gravity turn not happening too fast. On the very bottom, 4 separation motors can be seen that quickly and cleanly separate the lower stage from the upper stage, preventing the J-2 engine from colliding with the interstage shroud.

This rocket as a whole contains 16,275 m/s of delta-v.

I went on a strange path that I'm not so sure is normal to do when setting up a Lunar transfer in real life. What I did is burn prograde at the ascending node until the apogee was a little higher than the Moon's altitude. This is the point where the service module detaches and the lander's engines start being utilized. I coasted to apogee and matched my inclination relative to the Moon. Then I burned about 200 m/s prograde. It didn't circularize my orbit, but it was helpful for getting a Lunar encounter.

I ended up landing in the Sea of Crises, with only about 200 m/s of delta-v left to spare.

Looking back on that, it would appear I subconsciously named it "Mun Probe" instead of "Moon Probe"

Here is the Imgur album for the whole mission:

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Edited December 27, 2015 by jandcando
Clarified my maneuver.

[Wallygator]

Very nice. Well Done! Have a rep snack.

Frankly just getting into orbit was a wonderful success for me. Haven't made it to the Moon yet. Working on it...

(Except OS X doesn't like RSS and associated mods very much...)

[jandcando]

Very nice. Well Done! Have a rep snack.

Frankly just getting into orbit was a wonderful success for me. Haven't made it to the Moon yet. Working on it...

(Except OS X doesn't like RSS and associated mods very much...)

Thanks! And good luck on playing Realism Overhaul, it is pretty challenging.

[dafidge9898]

Did you have to worry about throttling during landing? That's a problem for me. I can't find any good throttleable engines to use for landing

[jandcando]

Did you have to worry about throttling during landing? That's a problem for me. I can't find any good throttleable engines to use for landing

The engines I used don't throttle, but I can restart them as many times as I want since they are pressure-fed hypergolic thrusters. So instead of throttling, I just turned them on and off again at different frequencies to almost "emulate" throttling. But this would not work if I had RemoteTech installed due to signal delay. I would've had to do a pre-programmed suicide burn instead.

[Curiosity7907]

Which ksp version where you playing?

Craft download?

Is there a github or forum which has a guide how to land spacecraft on the moon in RSS?

[Geschosskopf]

Bravo!  I played Orbiter for many years prior to finding KSP so I know how hard it is to play that way.  Even though I now play KSP instead of Orbiter because all that RSS stuff ain't my cup of tea, I salute you.

[jandcando]

On 12/24/2015 at 9:39 AM, Curiosity7907 said:

Which ksp version where you playing?

Craft download?

Is there a github or forum which has a guide how to land spacecraft on the moon in RSS?

If you can land on the Mun on stock KSP, it isn't much different. Except you need to make an inclination change, sort of like getting to Minmus. The major difference is you have to time your launch correctly, and make sure your Lunar orbit is as low as possible.

As for craft download, it is a little late for that because Realism Overhaul has changed a lot since this mission.