Primary network (PN) structure to supply martian base. LDO, low Deimos orbit; LMO, low Mars orbit; DTO, low Phobos orbit; LPO, low Phobos orbit; GEO, geostationary orbit ; LTO, lunar transfer orbit. (IMAGE) Beijing Institute of Technology Press Co., Ltd Caption Primary network (PN) structure to supply martian base. LDO, low Deimos orbit; LMO, low Mars orbit; DTO, low Phobos orbit; LPO, low Phobos orbit; GEO, geostationary orbit ; LTO, lunar transfer orbit. Credit Space: Science & Technology Usage Restrictions News organizations may use or redistribute this image, with proper attribution, as part of news coverage of this paper only License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.