摘要: The Crew Exploration Vehicle (CEV) Program has become the future centerpiece for NASA's access to space for human spaceflight. The program is initially being built on the Orbital Spaceplane program to provide crew transportation c... 展开 The Crew Exploration Vehicle (CEV) Program has become the future centerpiece for NASA's access to space for human spaceflight. The program is initially being built on the Orbital Spaceplane program to provide crew transportation capability to the International Space Station (ISS). However, the ISS is not the final human destination for NASA. On Jan 14, President Bush declared the goal of going to the Moon by 2020 and Mars sometime after 2030. However, cost of the program has become the central debate, and success may very well hinge on NASA not having to pay for the development of a new heavy lift vehicle. If NASA can use the already existing Evolved Expendable Launch Vehicle (EELV) system for Lunar and Mars missions, it will not only make them affordable, but also ensure commonality with commercial and military lift requirements. Having the military and NASA using both versions of the EELV will result in lower launch costs for the entire nation. This paper will analyze different CEV AND EELV architectures to transport humans to the entire Near Earth Environment (including lunar orbit and any of the Earth Moon Lagrangian Points). While the advantage of lunar orbit is obvious, it is just as important to reach a Lagrangian point since it would be the key staging point for a cost effective Mars transportation system. To use the EELV for a moon or Lagrangian mission will probably require 2-boosters orbital rendezvous. But what is the best orbit to rendezvous at before setting off for the Moon or Mars. What is the effect of using hydrogen and oxygen propellants mined on the moon. Can a single EELV launch both a landing craft in addition to an orbital transfer vehicle if lunar oxygen is used. This paper will answer some of these questions by looking at the mass returned to earth for the different architectures. 收起