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Long, David A.

Publications and source records attributed to Long, David A..

7 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2016

Long Duration Sorbent Testbed

The Long Duration Sorbent Testbed (LDST) is a flight experiment demonstration designed to expose current and future candidate carbon dioxide removal system sorbents to an actual crewed space cabin environment to assess and compare sorption working capacity degradation resulting from long term operation. An analysis of sorbent materials returned to Earth after approximately one year of operation in the International Space Station's (ISS) Carbon Dioxide Removal Assembly (CDRA) indicated as much as a 70% loss of working capacity of the silica gel desiccant material at the extreme system inlet location, with a gradient of capacity loss down the bed. The primary science objective is to assess the degradation of potential sorbents for exploration class missions and ISS upgrades when operated in a true crewed space cabin environment. A secondary objective is to compare degradation of flight test to a ground test unit with contaminant dosing to determine applicability of ground testing.

Howard, David F.↗
NASA NTRS2010

Results and Interpretation of the WFRD ELS Distillation Down-Select Test Data

Testing of the Wiped-film Rotating-disk (WFRD) evaporator was conducted in support of the Exploration Life Support Distillation Down-Select Test. The WFRD was constructed at NASA Ames Research Center (ARC) and tested at NASA Marshall Space Flight Center (MSFC). The WFRD was delivered to MSFC in September 2009, and testing of solution #1 and solution #2 immediately following. Solution #1 was composed of humidity condensate and urine, including flush water and pretreatment chemicals. Solution #2 was composed of hygiene water, humidity condensate, and urine, including flush water and pretreatment chemicals. During the testing, the operational parameters of the WFRD were recorded and samples of the feed, brine, and product were collected and analyzed. The steady-state results of processing 414L of feed solution #1 and 1283L of feed solution #2 demonstrated that running the WFRD at a brine temperature of 50 C gave an average production rate of 16.7 L/hr. The specific energy consumption was 80.5W-hr/L. Data Analysis shows that the water recovery rates were 94% and 91%, respectively. The total mass of the WFRD as delivered to MSFC was 300 Kg. The volume of the tests stand rack was 1m width x 0.7m depth x 1.9m height or 1.5 cu m of which about half of the total volume is occupied by equipment. Chemical analysis of the distillate showed an average TOC of 20ppm, a pH of 3.5, and a conductivity of 98 mho/cm. The conductivity of the distillate, compared to the feed, decreased by 98.9%., the total ion concentration decreased by 99.6%, the total organics decreased 98.6%, and the metals were at or below detection limits

Delzeit, Lance Dean↗
NASA NTRS1999

Vapor Compression Distillation Urine Processor Lessons Learned from Development and Life Testing

Vapor Compression Distillation (VCD) is the chosen technology for urine processing aboard the International Space Station (155). Development and life testing over the past several years have brought to the forefront problems and solutions for the VCD technology. Testing between 1992 and 1998 has been instrumental in developing estimates of hardware life and reliability. It has also helped improve the hardware design in ways that either correct existing problems or enhance the existing design of the hardware. The testing has increased the confidence in the VCD technology and reduced technical and programmatic risks. This paper summarizes the test results and changes that have been made to the VCD design.

Hutchens, Cindy F.↗
NASA NTRS1990

Test bed design for evaluating the Space Station ECLSS Water Recovery System

The design of the Phase III Environmental Control and Life Support System (ECLSS) Water Recovery System (WRS) test bed is in progress at the Marshall Space Flight Center (MSFC), building 4755, in Huntsville, Alabama. The overall design for the ECLSS WRS test bed will be discussed. Described within this paper are the design, fabrication, placement, and testing of the supporting facility which will provide the test bed for the ECLSS subsystems. Topics to be included are sterilization system design, component selection, microbial design considerations, and verification of test bed design prior to initiating WRS testing.

Ezell, Timothy G.↗