Future Mars missions may use lunar-derived oxygen as a propellant for interplanetary transit. A man-tended platform as a Node in low lunar orbit offers a site for storage and transfer of lunar oxygen to the transport vehicles as well as rendezvous and transfer for lunar-bound cargo and crews. In addition, it could provide an emergency safe-haven for a crew awaiting rescue. A conceptual design study yielded an approximate size for the platform needed to support typical oxygen transfer rates which were based upon NASA studies of Mars missions. The Node consists of a gravity gradient stabilized lunar orbiting tank-farm with a storage capacity of 100,000 kg of lunar oxygen, 3,300 kg of lunar cargo and 9,300 kg of Earth supplied hydrogen. An emergency habitat configuration accomodates 14 persons on-board for 110 days. The Node supports an annual lunar oxygen Ereduction of 106 kg with 220,000 kg of oxygen delivered to Earth orbit for an expenditure of 109,000 g of Earth supplied hydrogen
