Landers were built under the guise of a supply vehicle for a future mission to Mars, but secretly intended for the Endurance mission. They appear attached to the Endurance on opposite sides of the central docking hub, (Lander 1 on starboard with Lander 2 on the port side). Landers can be piloted by either humans or robots, and are used to transport supply pods to a planetary surface from the Endurance.
CASE pilots Lander 2 down to Dr. Mann's planet, delivering two cargo pods to its icy surface. Brand uses the same Lander to rescue Cooper after Dr. Mann left him to suffocate from ammonia. While Dr Mann stole Ranger 1 after Romilly's death, Cooper and Brand picked up TARS and followed Dr. Mann to orbit, where he docked to the Endurance first, but imperfectly. This causes rapid decompression that destroys Ranger 1 and sets the Endurance on a deadly spin, falling out of orbit. Cooper, with the help of TARS, manage to use Lander 2 to dock with the ship, stop its spin, and boost it out of orbit.
Lander 1 is used as an expendable rocket booster when performing a powered sling-shot around Gargantua. It is probable that Lander 1's supplies were transferred to the Endurance before being ejected with TARS when it ran out of fuel. It is presumed that the craft was destroyed when entering Gargantua. However, unlike the Ranger, the Lander was well armored, enabling TARS to travel through accretion disk debris, study the singularity, and enter the Tesseract. The craft could potentially have survived with TARS, later found in orbit around Saturn.
Lander 2 was later flown by Brand and CASE to reach the surface of Edmunds' planet. With the amount of fuel available after delivering supplies to Mann's planet and pushing the Endurance out of orbit, only two cargo pods were delivered to the surface of Edmunds. It remains capable of atmospheric flight, but has insufficient fuel to return to orbit.
Unlike the Ranger's sleek, aerodynamic design, Landers appear as faceted, boxy spacecraft, loosely resembling the Apollo Lunar Module. In the official novelization, Cooper compared the Ranger and the Lander with a racehorse versus a draft horse. The Lander's design was not optimized for fast and efficient atmospheric flight like the Ranger, but instead for effective and reliable atmospheric deceleration while carrying a heavy payload to a planetary surface. The high drag design removes the need for parachutes, spoilers, and other potentially failure prone drag devices.
The Lander's heat shield is located on its upper surface, thus performs atmospheric entry inverted, protecting the belly-mounted payload. The seats can rotate around the craft's forward axis. This maintains a comfortable upright position for its passengers and pilots while rotating and listing. To maintain visibility in any orientation, the lander has windows both top and bottom. The windows on its upper surface are made of sapphire to withstand the heat of reentry. The windows on the nose and sides of the Lander are protected by thermal insulation tiles that slide on top of the windows like a closet door. Flanking its fuselage are four faceted fuel pods, each tipped with electric air jet nozzles for atmospheric flight and reaction control system (RCS) thrusters for maneuvers in space. The RCS thrusters are fueled by hydrazine and nitrogen tetroxide.
The Lander is equipped with six bell-shaped chemical/plasma rocket engines divided into two separate housings. These engines generate the far greater thrust required to propel the heavier craft into orbit. In fact, the Lander is powerful enough to propel the Endurance from a decaying orbit into escape velocity.
During atmospheric flight, the Lander uses electric air jets to maneuver to a chosen location on the surface before landing. The same air jets are used to rise from the surface before firing its main engines. The Lander is also heavily armored, enabling it to survive very hostile environments. The Lander carries a crew of four people and one robot, though there is space in the central compartment for additional passengers. It also contains four hypersleep pods and survival gear for long duration missions.