TECHNOLOGY TRENDS:

• Either water or liquid nitrogen levels can be measured within 1-mm spatial resolution and 1°C up to a distance of 70 m from the optical interrogation unit. An innovative fiber-optic sensor has been developed for low-thrust-level settled mass gauging with measurement uncertainty <0.5 percent over cryogenic propellant tank fill levels from 2 to 98 percent. The proposed sensor uses a single optical fiber to measure liquid level and liquid distribution of cryogenic propellants. Every point of the sensing fiber is a “point sensor” that not only distinguishes liquid and vapor, but also measures temperature. This sensor is able to determine the physical location of each “point sensor” with 1-mm spatial resolution. Acting as a continuous array of numerous liquid/vapor point sensors, the truly distributed optical sensing fiber can be installed in a propellant tank in the same manner as silicon diode point sensor stripes using only a single feed-through to connect to an optical signal interrogation unit outside the tank. MORE
  
  
• Purge Monitoring Technology for Gaseous Helium (GHe) Conservation
  John C. Stennis Space Center provides rocket engine propulsion testing for the NASA space programs. Since the development of the Space Shuttle, every Space Shuttle Main Engine (SSME) has gone through acceptance testing before going to Kennedy Space Center for integration into the Space Shuttle. The SSME is a large cryogenic rocket engine that uses Liquid Oxygen (LO2) and Liquid Hydrogen (LH2) as propellants. Due to the extremely cold cryogenic conditions of this environment, an inert gas, helium, is used as a purge for the engine and propellant lines since it can be used without freezing in the cryogenic environment. MORE
  
  
• Storage, Distribution, and Conservation of Fluids (Cryogens, Liquids, Gases) Hydrogen is an inherently dangerous gas due to its combustibility and invisible flame. Area sensors only detect the presence, not the source of a hydrogen leak. This presents problems in high wind environments such as launch pads where a leak may not be detected at all. The Hydrogen Tape, developed in collaboration with the Florida Solar Energy Center, overcomes these limitations by providing users with an easily deployable visual indication system that can precisely pinpoint the leak. This tape can effectively identify leaks in pipe flanges and connections that area sensors and flame cameras may miss. Work is also underway at KSC to develop HyperTape, a tape that can visually detect the presence of hypergols, another dangerous but ubiquitous chemical. KSC researchers were able to achieve between 25-50 percent reductions in thermal heat transfer without greatly affecting the mechanical properties or processing conditions of Aerogel composite materials when compared to the base materials. This approach is important to reduce weight of lunar habitat systems, cryogenic storage tanks, and piping where weight and thermal conductivity are crucial to mission success. MORE