Direct ascent

Direct ascent is a method of landing a spacecraft on the Moon or another planetary surface directly, without first assembling the vehicle in Earth orbit, or carrying a separate landing vehicle into orbit around the target body.

It was proposed as the first method to achieve a crewed lunar landing in the United States Apollo program, but was rejected because it would have required developing a prohibitively large launch vehicle.

[1] The Soviet Union also considered several direct ascent strategies, though in the end they settled on an approach similar to NASA's: two men in a Soyuz spacecraft with a one-man LK lander.

The Soviet engineering firm OKB-52 continued to develop the UR-700 modular booster for the direct ascent LK-700 ship.

Science fiction movies such as Rocketship X-M and Destination Moon have frequently depicted direct ascent missions, although the first was a two-stage vehicle which accidentally, and successfully landed on Mars, but failed to successfully return to Earth (crashed in Nova Scotia), and the second was a single-stage vehicle which successfully landed on the Moon, and speculatively returned to Earth (return not shown).