Inside an 80-foot-tall chamber on Lockheed Martin’s Denver-area campus, backgrounded by red-rock ridges, stands a hulking spacecraft. You have to crane your neck to see the top of the apparatus. At the bottom, wires spew from a porthole to snake up and down and away. The cylindrical structure flows into a duller, funnel-like cone, which tapers into a tower with rocket nozzles. Next to it, the blue scaffolds of an indoor crane resemble a launchpad gantry.