NASA's proposal to build a small space station at the Earth Moon Lagrange Point-2, which is where the gravity of the Earth and moon cancel out 38,000 miles from the far side of the moon, is coming under some criticism.
The EMLP-2 station proposal
According to the Orlando Sentinel, NASA officials made a presentation to the White House for a space station to be built at the EMLP-2 point using left over International Space Station modules. The station would be serviced by the Orion Multi Purpose Crew Vehicle launched by the heavy lift Space Launch System. A near term purpose for the EMLP-2 station would be for astronauts to teleoperate robotic explorers on the lunar surface, with one mission mentioned a lunar sample return. Later the station could be used as a way station and refueling depot to support deep space missions, to the asteroids and eventually to Mars.
Problems with the EMLP-2 station
The Orlando Sentinel suggests that there are two problems with the NASA proposal. First, because of the great distance the station would be from Earth, problems of resupply and even rescue in case of disaster would be more difficult than with the ISS in low Earth orbit. Also, since the station would be beyond Earth's magnetic field, radiation shielding would be a major issue.
EMLP-2 station a make work project
Paul Spudis, a planetary geologist who writes frequently on space issues, offers a critique of the near term stated purpose of the EMLP-2 station. He suggests that positioning astronauts 38,000 miles from the moon would provide little if any advantage to controllers on Earth where it comes to teleoperating robots on the lunar surface. Spudis suggests that such a station would make sense if it were part of a larger cislunar transportation infrastructure that included a fuel depot supplied, by preference, by rocket fuel refined from lunar ice known to lay in the permanently shadowed craters at the moon's north and south poles.
EMLP-2 station a plot to justify Orion/SLS
John Strickland, a space advocate and a member of the National Space Society Board of Directors, suggests in the Space Review that building what is in effect a smaller version of the ISS at an Earth Moon Lagrange Point is a scheme by NASA to justify the expense of the Orion and Space Launch System. Currently Orion/SLS have a limited number of destinations. Without a lander, astronauts cannot access the lunar surface. Without a long duration habitation module, astronauts cannot visit Earth-approaching asteroids. A station in empty space in the cislunar system is about the only place that the Orion/SLS can go.
Strickland, like Spudis, favors a space station at one of the EMLPs if it could serve as a fuel depot. But he suggests that building such a space station is pointless until reusable launch vehicles and space craft are developed to service such a facility and take advantage of its capabilities to explore further into the solar system.
Mark R. Whittington is the author of Children of Apollo and The Last Moonwalker. He has written on space subjects for a variety of periodicals, including The Houston Chronicle, The Washington Post, USA Today, the L.A. Times, and The Weekly Standard.