Lagrange points are stable orbital positions in specific spatial relation to two massive orbital bodies, such as the Earth and Sol. These points were discovered by Joseph Louis Lagrange in 1772 while working on the “3 body problem.”
Nextsteps, a fascinating report on the best near term plan for space exploration, discusses the placing of a permanent human base located at Earth-Sol L2.
Final Report July 9, 2004
While the early astronomy missions to SEL2 have not been designed for human servicing and repair, this situation will surely change as the telescopes become more complex and expensive. Thus the construction and maintenance of large astronomical facilities at SEL2 may provide a compelling rationale for the initial step in a program of human exploration beyond low Earth orbit. The capabilities developed to enable construction and servicing of these large facilities will be an important step toward the overall set of capabilities required to provide human access to the Moon, near-Earth asteroids, Mars, and beyond.
The table below lists some of the possible investigations and the human-assembled or serviced telescope systems they will require.
- Investigation Candidate System
- X-ray studies of high-energy objects (quasars, black holes)
- Interferometric constellation of 10-meter class grazing-incidence telescopes
- Optical and infrared studies of the deep universe and extra-solar planetary systems
- 20-meter class cooled aperture telescope, expandable to 100-meter class with upgrades
- including a coronagraph
- Optical and infrared imaging of extra-solar planets
- Multiple 20-meter class cooled apertures, expandable to 100-meters, coherently linked
- optically over a baseline of 1000 -10000 kilometers
- Far infrared and sub-millimeter imaging of proto-stellar gas, dust, disks, and young
- planetary systems
- Dual 30 meter or larger cooled (~10K or less) apertures over a 10 km interferometric
- baseline, with narrow-band Terahertz receivers (500-1500 Ghz)
SEL2 also represents a relatively benign and low-risk destination for human space flight
development and staging. Its unique location at the edge of Earth’s gravitational influence
makes it an energy-efficient starting point for missions to deep space. Having developed the
capability to travel to SEL2 for telescope construction and servicing, astronauts at SEL2 may
also help to develop and test systems that will be used for journeys to more distant destinations. Preparing, servicing, and fueling interplanetary vehicles at SEL2 prior to their departure for NEO’s or Mars will allow us to minimize the program’s dependence on expensive new propulsion technologies and will help to reduce the total flight time an interplanetary crew must spend The value of human space flight as an enabler of
science was amply demonstrated by astronaut deployment and maintenance of the Hubble Space Telescope.
Hat tip, Brian Wang’s Nanotechnology Blog.