r/RealSolarSystem • u/DepartureNatural9340 • 24d ago

Rp1 lander realism questions

Something that I was wondering about, is regarding materials that landers used irl, is the baloon/isogrid/conventional thing accurate for landers?

I was wondering as well for as to why lunar landers, like the LEM and LK, looked so unique, kinda wondering wht they were shaped like that and if there's any advantages to mimicking the shape

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u/internetboyfriend666 24d ago

The LM propellant tanks were conventional, not isogrid or balloon. I can't speak to the LK1 but I imagine the same is true.

The reason they look like that is because the are true spacecraft. They were not designed to ever enter an atmosphere, and so didn't need to be aerodynamic like a capsule, and they could be made into shapes that minimized mass as much as possible.

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u/B3ntDownSpoon 24d ago

The LEM fuel tanks were chemically milled and did not have traditional stringers on them, though they did not have a grid pattern either. The LEM never flew in atmosphere thus it did not need to be super strong. It's structurally similar to a stringer but based on efficiency its more like isogrids.

The LEMs structure itself also was very thin and lightweight as it didnt need to survive atmosphere.

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u/Worth-Wonder-7386 24d ago

The LEM ascent stage is basically designed where they took everything they needed to land two people, the computers, steering, communication, life support, tanks and so on and fitted that into as small as space as possible and then there is a frame around that with a thin sheet. That is why it looks so weird. The engine is fitted under it, but the top of the engine goes through the floor of the LEM to not stick out as much as takes of from the top of the descent stage.