269 Results for OB-1 Lunar Simulant at 1/3-g  Side A simulant flow would randomly stop and require flow enhancing assistance but flowed well  during most tests without assistance and display ed an average 38 seconds to empty the hopper. Side  B simulant flow would occasionally stop flowing but flowed well for the majority of tests and displayed  an average time of 34 seconds to empty the hopper.   Results for OB-1 Lunar Simulant at 1-g  The hopper hourglass assembly has heat transmitting fins on Side A and no fins on Side B. This simulant would begin to flow but would stop and did not flow reliably flow at 1-g from side a without the use of flow enhancing techniques (Suspect the simu lant was wet because it flowed better at 1/3-g than  at 1-g, we should repeat the 1-g testing). The flow would stop normally after approximately 25 seconds and would not re-start without the use of a flow enhancement technique.   Results for OB-1 Lunar Simulant at 1-g Using the Hammer Technique  Hammering did help the flow characteristics allo wing the simulant to flow from the hopper in  approximately 41 seconds. Hammering would allow cons tant simulant flow but the flow would stop if  the hammering technique was not maintained. Side B wi thout the heat transfer fins did exhibit simulant  flow during most of the tests. The simulant flow would occasionally slow but did not stop allowing the hopper to empty its contents in approximately 25 seconds on average.   Results for OB-1 Lunar Simulant at 2-g  Both Side A and Side B flowed well during 2-g runs and did not require flow enhancement techniques. Side A would empty the hopper in approximately 24 seconds. Side B would empty the hopper in approximately 20 seconds.   Pneumatic Regolith Feed System 

Description

A typical pneumatic conveyor system consists of four  basic elements: (1) a source of compressed gas, (2)  a device for feeding granular material into the gas flow, (3) a conduit for the dusty gas flow, and (4) a gassolids separation device at the receiving end of the pipeline. An open-loop pneumatic conveyor system  does not attempt to recover the convey gas, whereas a closed-loop system does recover the gas.    Industrial types of pneumatic conv eyor systems on earth can be open-loop or closed-loop depending, for  example, on whether or not the co nvey gas is inherently valuable or is environmentally hazardous.  However, pneumatic conveyor syst ems that are developed for lunar applications must be closed-loop  systems in order to reuse the gas, which repres ents a scarce and valuable resource on the moon.  Although a pneumatic lunar regolith co nveyor system that is developed for field testing on earth may be  operated as an open-loop prototype, the technology must be developed eventually for a closed-loop system for the planetary exploration.  Consequently, the effect of the gr avitational environment must be  taken into account when developing a planetary regol ith pneumatic conveyor sy stem (Liu 1988, Sullivan  1992, Sullivan 1994, Schrunk 1999, Crosby 2008).  Experiments had been performed in earth’s gravity at NASA Kennedy Space Center, but results were not  known for the lunar gravity environment. A reduce d gravity flight (RGF) experiment was led by  researchers from NASA KSC and was bas ed on the previous terrestrial ex periments, but re configured to  a portable design. The RGF experiment was conducted over two flight days (13-14 August, 2009) onboard a Zero-G Corporation aircraft that was confi gured for reduced gravity testing and was prepared  for the flight test at the NASA JSC Reduced Gravity Office’s facility loca ted at Ellington Field in Houston,  Texas.    Pneumatic conveying will prove to  be viable for the moon if the trans ported dusty gas can be filtered  sufficiently at the delivery end to allow for recove ry of the transport gas for repeated use. Since  membrane filters are impractical on the moon due to  high maintenance costs, cyclones appear to be the  NASA/CP-2010-216272