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Comment by simonh | Hacker News Reader

New Shepard far too big, with far too much delta V for a moon lander. It’s design parameters are all wrong. Also SpaceX has a perfectly suitable propulsion system in the SuperDracos.

The truth is none of the existing or currently planned systems, other than BFR, would make any sense as lunar landers. They’re just not designed for it. Dragon and Orion are Apollo Command Module replacements, not LEM replacements. For lunar landings and excursions we’d need a new vehicle along the lines of the LEM. Lightweight, vacuum only, reusable and refuelable with an ‘infinitely’ restartable engine. SLS would be perfectly capable of launching such a vehicle, in fact that’s exactly the sort of thing it’s designed for.

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You mistook my point. Not that New Shepherd can be used "as is", but merely that Blue Origin and SpaceX have developed propulsion-based landing technology and NASA/Boeing have not. There's a much shorter development path from New Shepherd/Dragon 2-->LEM, than from Orion.

And of course SLS could launch a LEM. The problem there is that it costs $2 billion/launch. That's "just a bit" of a price premium relative to Falcon Heavy, or whatever the fully reusable generation of rockets is going to cost.

Why not just use the Saturn V designs? Are they that bad?

As magnificent as the Apollo program was, and the Saturn V in particular, it was an incredibly expensive and complex launch system, unsustainably so.

Additionally, even if you did want to recreate a Saturn V, the designs themselves aren't going to get you very far. Most of the tooling has been lost likely along with much of the institutional know how, especially on the technician side of things. I'd be very surprised if you could recreate a functioning Saturn V for a lower cost than designing an entirely new launch system.

https://en.wikipedia.org/wiki/Rocketdyne_F-1#F-1B_booster

> As part of the Space Launch System (SLS) program, NASA had been running the Advanced Booster Competition, which was scheduled to end with the selection of a winning booster configuration in 2015. In 2012, Pratt & Whitney Rocketdyne (PWR) proposed using a derivative of the F-1 engine in the competition as a liquid rocket booster ... The F-1B engine has a design goal to be at least as powerful as the un-flight-tested F-1A, while also being more cost effective.

https://en.wikipedia.org/wiki/Saturn_C-3#Pyrios

> Developed during the later stages of the Apollo program, the F-1A was test fired, but never flew. Several were crated and stored by Rocketdyne (later Pratt & Whitney Rocketdyne). The company has also maintained an F-1/F-1A knowledge retention program for its engineers for the entire period the engine has been mothballed.

Also, https://arstechnica.com/science/2013/04/new-f-1b-rocket-engi... .

And this engine lost the SLS competition to the SSME+solids. So yes, it's an interesting point that the Saturn V engine might still be buildable, but it's not cost effective today, and it's not the Saturn V rocket.

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