WHY Return to the Moon? - Page 2

PRIMARY OBJECTIVES

New technology for radiation mitigation. 

We know much about radiation - yet protection against it is still in its infancy.  Nuclear accidents such as SL-1, Detroit, Three Mile Island, Chernobyl, Fukushima and many others show we are seriously lacking in countermeasures and protection.  Increased shielding in materials or liquid is expensive and moreso when you consider launching them from the Earth's surface.  Radiation has an immediate impact on biologics, electronics, material integrity and can make all of them radioactive. 

In respect to the Moon one suggestion has been to bury manned habitats under the regolith.  Studies such as this one with lunar simulates indicate a level of protection.  However lunar "dust" is comprised of very fine rock, silica and metals giving them grinding attributes and would require a mechanism to dig and safely adhere it to the exposed surfaces of any structure.  Any landing or impact near a habitat would stir the environment up.  It would be more practical to put a habitat into a crater and scoop regolith over it. Regolith and dust would be found on asteroids. 

Our standard radiation shielding is based on absorption and not redirection .   Absorption is required in nuclear reactors to slow down the nuclear process.  Redirection can be compared to the Earth's magnetic field redirecting the streaming from the Sun in the form of solar flares or Coronal Mass Ejections. Managing space radiation can be applied to terrestrial protections.  Current terrestrial nuclear power generation is a threat to survival.

One possible mitigation is the creation of strong magnetic fields.  Creating a sufficient field for human (and electronics) survival will require a lot of energy and protection of biologics and electronics within the field.

Electrostatic and regolith mitigation.   

Electrostatic charging/discharging can impact biologic, mechanical and electronic systems.  Electronic components coatings and other measures can minimize electrostatic impact. Structures such as manned spacecraft and the ISS can be electrostatically charged. Asteroids, the lunar surface and Mars can have surface charging.  The cause of this charging is from solar activity and space radiation.  Reviewing the following links show the dangers with electrostatic  charging/discharging and rigolith - they must be mitigated. 

                                     Electrostatic Discharge Issues in ISS Program EVAs       
                                          Rover wheel; charging on the lunar surface
                                         Electrical Phenomena on the Moon  and Mars                
                   Measurements of Charging of Apollo 17 Lunar Dust Grains by Electron Impact
                                       Electrostatic Environments of Mars and the Moon            
                                                Electrostatic Environment at the ISS
                          Dust Particle Removal by Electrostatic and Dielectrophoretic Forces  
                               ( with Applications to NASA Exploration Missions)

Electrostatic charging on the Moon increases when it enters the magnetotail.

On September 6, 2013 NASA launched the LADEE spacecraft "...to gather detailed information about the lunar atmosphere, conditions near the surface and environmental influences on lunar dust." LADEE science results and implications for exporation. LADEE Science Results and Implications for Exploration slideshow.

Quoting from Harrison Schmitts book Return to the Moon: page 123 "With over half the mass of the regolith made up of abrasive particles less than 100 um (micrometer) in diameter, this dust will penetrate into any space, fabric, bearing or moving parts not specifically sealed against it."; on page 124 "Dust also prevented the knife-edge indium seals of any of the sample return containers (rock boxes) from maintaining a vacuum during storage in the spacecraft and during transit to the Lunar Receiving Laboratory." This has been the case for every Apollo mission - making any bio-containment measures questionable.

Each Apollo astronaut on the moon showed "dust" collection on their spacesuits. Photographs of Apollo 17 astronauts Cernan and Schmitt around the Taurus-Littrow landing site showed considerable discoloration by lunar dust due to  electrostatic charging.

Electrostatic charging and dust are going to be a serious issue. Any manned habitat is going to require a "clean room" for collection and removal of particles.

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