The Lunar Transfer Vehicle (LTV) is a variant of the OTV. The spacecraft is essentially an OTV with lunar landing legs attached.
The Lunar Lander Kit consists of the landing legs and an Above Ground Level (AGL) radar. The legs would have a liquid springs and landing discs to absorb shock and to act as a leveling mechanism.
The rocket nozzle extension is not used to allow more clearance between the bottom of the nozzle and the lunar surface. Table 1 summarizes the LTV inert mass.
Payload Trays are used to store any additional payload that needs to be brought down from lunar orbit, which will obviously add more mass to the lander (Table 2).
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