The Altair lunar module was part of the wonderful Constellation program cancelled in 2010; just the Orion spacecraft has been retained which is to deliver a crew into lunar orbit. The new carrier rocket will be the SLS (to replace Ares I and Ares V) but the lunar lander is to be replaced too. Why, as a matter of fact? Why don't they just again aspire to build the Altair LM from the Constellation program, or even go a step farther and rebuild the Apollo LM, just with upgraded instruments and a digital navigation system, as well as a way to match into the SLS stage?

According to Wikipedia, Artemis 3 is to land two astronauts on the surface while the other two crew members stay in orbit or at the lunar gateway station. So the Apollo LM could be reused at first. And if the Altair would be built, all four astronauts could land on the surface.

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    $\begingroup$ I think they finally found fixed price contracts with private companies are faster and cheaper. Technological progress is quite fast and lunar lander today can look very different than 10 or definitely 50 years ago. Rebuilding a 50 year old spacecraft the same way it was done 50 years ago just does not make sense and would end up being ridiculously expensive. 10 years old maybe but even there you get a penalty. Think of 3D printing from metal for example. $\endgroup$
    – Kozuch
    Commented Jan 17, 2021 at 12:33

1 Answer 1


Apart from the $12B development cost, Altair required Ares V to launch it and its Earth Departure Stage, without which it would never have gotten close to the moon. SLS doesn't have the capability to launch it. Even Ares V wasn't enough for everything, which is why they came up with Ares I and spent years and billions of dollars trying to figure out how to launch people on top of a Shuttle-derived SRB without killing them.

The Apollo LM was designed and built half a century ago. Its plans are all microfilm and physical blueprints, the people who understood them are largely dead of old age, the materials and construction methods are decades out of date, and most of the companies that supplied parts and did the construction are long gone. It would not be a shortcut to anything, and would be useless without the CSM...Orion and its service module would not be sufficient to deliver it to the moon.

Both Altair and the Apollo LM were two-stage vehicles, with a small ascent stage that leaves the majority of the vehicle abandoned on the surface. That's the only component that could even theoretically be reused.

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    $\begingroup$ "most of the companies that supplied parts and did the construction are long gone" – And several of the ones that survived are part of the HLS competition. $\endgroup$ Commented Jan 17, 2021 at 14:43
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    $\begingroup$ @JörgWMittag Lockheed Martin and Northrop Grumman alone account for probably a couple dozen of them after all the mergers and acquisitions, not that they can really be considered the same companies after all that...the companies today are several corporate generations removed from the ones that built Apollo. $\endgroup$ Commented Jan 17, 2021 at 15:19
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    $\begingroup$ I am pretty sure Constellation lunar missions required both an Ares I and V launch. SLS =/= Constellation. $\endgroup$ Commented Jan 17, 2021 at 15:31
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    $\begingroup$ ? They wanted to separate crew and cargo for launch to orbit, and that's what they planned to do. How is that not adhering to it? $\endgroup$ Commented Jan 17, 2021 at 15:38
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    $\begingroup$ I'm impressed to learn that you were in the planning sessions! $\endgroup$ Commented Jan 17, 2021 at 15:45

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