The Lunar Gateway is expected to be positioned on-orbit around the Moon or in a Halo orbit at the L2 Lagrange point. The proposed Lunar Gateway is a game-changer for enabling new science utilizing CubeSats and presents a refreshing new opportunity for utilization of these small spacecraft as explorers. We propose to develop a Lunar CubeSat Lander that will be deployed from the Lunar Gateway Logistics Module (presumed to be at L2) to perform science and exploration of the lunar surface. The CubeSat lander will land near Mare Tranquilitatis to determine the extent of the void and identify the presence of volatile resources including water in its regolith. The CubeSat lander is a 27U with stowed dimensions of 34 cm×35 cm×36 cm and mass of 54 kg. It will be deployed from the Lunar Gateway and perform a lunar orbit insertion by using its onboard High-Performance Green Propulsion (HPGP) system followed by descent maneuver to get into a 25 km altitude from the lunar surface. From there, the lander will get into a powered descent maneuver over Mare Tranquilitatis taking 4-6 minutes. Onboard visual navigation will be used to land on the Mare Tranquilitatis Region by rapidly firing the descent thrusters. The lander is equipped with a Volatile Analysis by Pyrolysis of Regolith (VAPoR) instrument to perform pyrolysis and mass spectrometry of lunar regolith. Moreover, it will carry three spherical hopping robots (SphereX) that will hop inside the pit to perform mapping and electrical impedance spectroscopy of regolith inside the pit to determine the presence to water.