There is a largely unexplored alien country that is so close to Earth it would take a beam of light less than two seconds to get there.
This is the farside of on moon, often misrepresented and the “dark side” (with apologies to Pink Floyd). Because the moon keeps one hemisphere gravitationally locked on Earth, only the eyes of a handful of astronauts have directly seen the lunar farside.
The glorious NASA Apollo missions only explored half of the moon, the Earth-facing side dominated by frozen lava oceans — the mare. The farside bears unique invaluable secrets to 4 billion years of solar system evolution.
The farside is dramatically different from the nearside. It has the largest and deepest basin on the moon, and possibly the oldest impact site in the inner solar system. It offers fossil evidence for a tremendous lunar cataclysm and lunar magma ocean that once existed.
An eventual human return to the moon –- call it Apollo 2.0 — should be targeted for the farside. But it is very costly to conduct astronaut landings. If flown today, the Apollo missions would cost a staggering $18 billion per flight.
But this is not your father’s space race. NASA could take a cue from oceanographers and forge an even closer human/robot symbiosis in planetary exploration. Manned submersible vehicles and numerous teleoperated robots jointly conduct deep ocean exploration on Earth, why not do the equivalent in space?
The same could be done for Apollo 2.0, reports Jack Burns of the University of Colorado and co-investigators. He says that the return to the moon could be accomplished more quickly and affordably than full-blown Apollo-style manned sorties.
The centerpiece would be NASA’s new Orion space capsule. This Apollo-on-steroids vehicle would be lofted into a halo orbit about the Earth-moon Lagrange point L2. This is a gravitationally stable parking lot for spacecraft of all types to stage lunar sorties. The Orion would travel 15 percent farther from Earth than did the Apollo astronauts and spend almost three times longer in deep space.
Such an orbit would place a three-person Orion crew in a prime location to get a bird’s eye view of the lunar farside and have direct line-of-sight communications with Earth. For one lunar day — two weeks on Earth — The crew would teleoperate any number of small rover vehicles dispatched to the farside. The moon rovers would be “joysticked” by the Orion crew. The light delay travel time for commands would be only 0.4 second — shorter than if sent from ground controllers on Earth. Studies show that the so-called “cognitive horizon” for real-time telepresence is no more than 0.5 second.
Points of interest would include Schrödinger basin, one of the youngest impact sites on the moon. However, the basin walls and uplifted peak ring contain rocks from older episodes in lunar history. What’s more, a couple billion years after its formation there were small eruptions of volcanic material scattering young rocks across the surface. The rovers would have a smorgasbord of rocks to select over broad fraction of the moon’s history. It would be the geological equivalent of the rich record of the stratified Grand Canyon.
The Schrödinger basin is embedded within the gaping South Pole-Aitkin basin that formed much earlier and contains some of the very oldest rocks in the solar system. This kind of geologic survey would help scientists deduce the kinds of objects that bombarded the moon 4 billion years ago and at what rate. And, this might be forensic evidence for dramatic shifts in the orbits of the giant planets during that early epoch.
The lunar rock record could also tell when organic compounds were delivered to the inner solar system.
The mission would be a proof-of-concept for flights to asteroids and to the Mars system. It would be the first to demonstrate teleoperation of rovers by orbiting astronauts to undertake geological exploration and samples collection.
But would this “virtual presence” on the surface of a moon or planet be satisfying enough to budding astronauts? Would they want to stay cooped-up in a capsule rather than bounding along an alien terrain? Imagine Columbus’ crew staring at the shoreline on the New World, but not taking a longboat ashore.
Publication: “A Lunar L2-Farside Exploration and Science Mission Concept with the Orion Multi-Purpose Crew Vehicle and a Teleoperated Lander/Rover,” arXiv:1211.3462v1 [astro-ph.IM]
Image credits: Lockheed-Martin, NASA