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      ESA has signed contracts with several European companies for an overall amount of € 233 million to develop Genesis and a LEO-PNT demonstrator, two new missions within the FutureNAV programme that will keep Europe at the forefront of satellite navigation worldwide.
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    • By NASA
      3 min read
      NASA Delivers Science Instrument to JAXA’s Martian Moons Mission
      On March 14, NASA delivered its gamma-ray and neutron spectrometer instrument to JAXA (Japan Aerospace Exploration Agency) for integration onto JAXA’s MMX (Martian Moons eXploration) mission spacecraft and final system-level testing.  
      U.S. and Japanese team members gather around and discuss the gamma-ray spectrometer portion of the MEGANE instrument during its development at Johns Hopkins APL. NASA/JAXA/Johns Hopkins APL/Ed Whitman NASA’s Mars-moon Exploration with Gamma Ray and Neutrons (MEGANE) instrument, developed by the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, in collaboration with colleagues from Lawrence Livermore National Laboratory (LLNL) in California, will play a major role in the MMX mission, which aims to characterize and determine the origin of Mars’ moons Phobos and Deimos and deliver a sample from Phobos to Earth. 
      Scientists suspect the asteroid-sized bodies either are remnants of an ancient collision between Mars and a large impactor or are themselves asteroids captured by Mars’ gravity. By measuring the energies of neutrons and gamma rays emitted from the surface of Phobos, MEGANE will let MMX “see” the elemental composition of the moon’s surface and help peg the likely origin of the moon. 
      “MEGANE will be a key instrument on MMX, making a big contribution toward the goal of understanding the origin of the Martian moons,” said Thomas Statler, MEGANE program scientist at NASA Headquarters in Washington. “NASA is glad to see MEGANE ready for integration, another step in NASA’s continuing collaboration with JAXA on this groundbreaking mission.”
      The instrument team received the green light last fall to ship MEGANE (pronounced meh-GAH-nay, the Japanese word for “eyeglasses”) after the project’s standing review board evaluated the device’s readiness. That milestone marked the end of a demanding 6-year design and development process, which met NASA’s cost and schedule constraints. 
      “Passing the pre-ship review and delivering the hardware are significant steps for all those working on MEGANE,” said APL’s David Lawrence, the instrument’s principal investigator. “Like all spaceflight builds, we have had challenges getting to this point, but we are excited to see how MEGANE works with all the other spacecraft components for this exciting MMX mission.”    
      With MEGANE now in Japan, the MMX team will begin integrating the scientific instruments, including MEGANE, with other spacecraft components, before putting the entire system through a series of tests in preparation for launch, which is scheduled for fiscal year 2026, aboard a JAXA H3 rocket. 
      “For me personally, I’m looking forward to all the integration and test operations that are to come,” said Sarah Bucior, a space systems engineer in SES and the MEGANE I&T Lead Engineer. “I love rockets, so I’m really interested to see how they build their spacecraft and then follow it along to launch operations and liftoff.”
      MEGANE was developed under NASA’s Discovery Program, which provides low-cost access to space. The Discovery Program is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama for the Science Mission Directorate at NASA Headquarters in Washington. The instrument science team includes investigators from APL, LLNL, Marietta College, NASA’s Ames Research Center in California’s Silicon Valley, and JAXA. 
      To learn more about MEGANE and the MMX mission, visit http://megane.jhuapl.edu.
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      4 Min Read Cheers! NASA’s Webb Finds Ethanol, Other Icy Ingredients for Worlds
      Webb MIRI image of a region near the protostar known as IRAS 23385. IRAS 23385 and IRAS 2a. Credits:
      NASA, ESA, CSA, W. Rocha (Leiden University) What do margaritas, vinegar, and ant stings have in common? They contain chemical ingredients that NASA’s James Webb Space Telescope has identified surrounding two young protostars known as IRAS 2A and IRAS 23385. Although planets are not yet forming around those stars, these and other molecules detected there by Webb represent key ingredients for making potentially habitable worlds.
      An international team of astronomers used Webb’s MIRI (Mid-Infrared Instrument) to identify a variety of icy compounds made up of complex organic molecules like ethanol (alcohol) and likely acetic acid (an ingredient in vinegar). This work builds on previous Webb detections of diverse ices in a cold, dark molecular cloud.
      Image A: Parallel Field to Protostar IRAS 23385 (MIRI Image)
      This image at a wavelength of 15 microns was taken by MIRI (the Mid-Infrared Instrument) on NASA’s James Webb Space Telescope, of a region near the protostar known as IRAS 23385. IRAS 23385 and IRAS 2A (not visible in this image) were targets for a recent research effort by an international team of astronomers that used Webb to discover that the key ingredients for making potentially habitable worlds are present in early-stage protostars, where planets have not yet formed. NASA, ESA, CSA, W. Rocha (Leiden University) What is the origin of complex organic molecules (COMs) ?
      “This finding contributes to one of the long-standing questions in astrochemistry,” said team leader Will Rocha of Leiden University in the Netherlands. “What is the origin of complex organic molecules, or COMs, in space? Are they made in the gas phase or in ices? The detection of COMs in ices suggests that solid-phase chemical reactions on the surfaces of cold dust grains can build complex kinds of molecules.”
      As several COMs, including those detected in the solid phase in this research, were previously detected in the warm gas phase, it is now believed that they originate from the sublimation of ices. Sublimation is to change directly from a solid to a gas without becoming a liquid. Therefore, detecting COMs in ices makes astronomers hopeful about improved understanding of the origins of other, even larger molecules in space.
      Scientists are also keen to explore to what extent these COMs are transported to planets at much later stages of protostellar evolution. COMs in cold ices are thought to be easier to transport from molecular clouds to planet-forming disks than warm, gaseous molecules. These icy COMs can therefore be incorporated into comets and asteroids, which in turn may collide with forming planets, delivering the ingredients for life to possibly flourish.
      The science team also detected simpler molecules, including formic acid (which causes the burning sensation of an ant sting), methane, formaldehyde, and sulfur dioxide. Research suggests that sulfur-containing compounds like sulfur dioxide played an important role in driving metabolic reactions on the primitive Earth.
      Image B: Complex Organic Molecules in IRAS 2A
      NASA’s James Webb Space Telescope’s MIRI (Mid-Infrared Instrument) has identified a variety of complex organic molecules that are present in interstellar ices surrounding two protostars. These molecules, which are key ingredients for making potentially habitable worlds, include ethanol, formic acid, methane, and likely acetic acid, in the solid phase. The finding came from the study of two protostars, IRAS 2A and IRAS 23385, both of which are so young that they are not yet forming planets. Illustration: NASA, ESA, CSA, L. Hustak (STScI). Science: W. Rocha (Leiden University). Similar to the early stages of our own solar system?
      Of particular interest is that one of the sources investigated, IRAS 2A, is characterized as a low-mass protostar. IRAS 2A may therefore be similar to the early stages of our own solar system. As such, the chemicals identified around this protostar were likely present in the first stages of development of our solar system and later delivered to the primitive Earth.
      “All of these molecules can become part of comets and asteroids and eventually new planetary systems when the icy material is transported inward to the planet-forming disk as the protostellar system evolves,” said Ewine van Dishoeck of Leiden University, one of the coordinators of the science program. “We look forward to following this astrochemical trail step-by-step with more Webb data in the coming years.”
      These observations were made for the JOYS+ (James Webb Observations of Young ProtoStars) program. The team dedicated these results to team member Harold Linnartz, who unexpectedly passed away in December 2023, shortly after the acceptance of this paper.
      This research has been accepted for publication in the journal Astronomy & Astrophysics.
      The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.
      Downloads
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      Download full resolution images for this article from the Space Telescope Science Institute.
      This research has been accepted for publication in the journal Astronomy & Astrophysics.
      Media Contacts
      Laura Betz – laura.e.betz@nasa.gov, Rob Gutro – rob.gutro@nasa.gov
      NASA’s Goddard Space Flight Center, Greenbelt, Md.
      Christine Pulliam – cpulliam@stsci.edu
      Space Telescope Science Institute, Baltimore, Md.
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      Details
      Last Updated Mar 13, 2024 Editor Stephen Sabia Contact Laura Betz laura.e.betz@nasa.gov Related Terms
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    • By NASA
      10 Min Read Zero-Boil-Off Tank Experiments to Enable Long-Duration Space Exploration
      Figure 1. The Gateway space station—humanity’s first space station around the Moon—will be capable of being refueled in space. Credits:
      NASA Do we have enough fuel to get to our destination? This is probably one of the first questions that comes to mind whenever your family gets ready to embark on a road trip. If the trip is long, you will need to visit gas stations along your route to refuel during your travel. NASA is grappling with similar issues as it gets ready to embark on a sustainable mission back to the Moon and plans future missions to Mars. But while your car’s fuel is gasoline, which can be safely and indefinitely stored as a liquid in the car’s gas tank, spacecraft fuels are volatile cryogenic liquid propellants that must be maintained at extremely low temperatures and guarded from environmental heat leaks into the spacecraft’s propellant tank. And while there is already an established network of commercial gas stations in place to make refueling your car a cinch, there are no cryogenic refueling stations or depots at the Moon or on the way to Mars. Furthermore, storing volatile propellant for a long time and transferring it from an in-space depot tank to a spacecraft’s fuel tank under microgravity conditions will not be easy since the underlying microgravity fluid physics affecting such operations is not well understood. Even with today’s technology, preserving cryogenic fuels in space beyond several days is not possible and tank-to-tank fuel transfer has never been previously performed or tested in space.
      Heat conducted through support structures or from the radiative space environment can penetrate even the formidable Multi-Layer Insulation (MLI) systems of in-space propellant tanks, leading to boil-off or vaporization of the propellant and causing tank self-pressurization. The current practice is to guard against over-pressurizing the tank and endangering its structural integrity by venting the boil-off vapor into space. Onboard propellants are also used to cool down the hot transfer lines and the walls of an empty spacecraft tank before a fuel transfer and filling operation can take place.  Thus, precious fuel is continuously wasted during both storage and transfer operations, rendering long-duration expeditions—especially a human Mars mission—infeasible using current passive propellant tank pressure control methods.
      Zero-Boil-Off (ZBO) or Reduced Boil-Off (RBO) technologies provide an innovative and effective means to replace the current passive tank pressure control design. This method relies on a complex combination of active, gravity-dependent mixing and energy removal processes that allow maintenance of safe tank pressure with zero or significantly reduced fuel loss.
      Zero Boil-off Storage and Transfer: A Transformative Space Technology
      At the heart of the ZBO pressure control system are two proposed active mixing and cooling mechanisms to counter tank self-pressurization.  The first is based on intermittent, forced, subcooled jet mixing of the propellantand involves complex, dynamic, gravity-dependent interaction between the jet and the ullage (vapor volume) to control the condensation and evaporation phase change at the liquid-vapor interface. The second mechanism uses subcooled droplet injection via a spraybar in the ullage to control tank pressure and temperature. While the latter option is promising and gaining prominence, it is more complex and has never been tested in microgravity where the phase change and transport behavior of droplet populations can be very different and nonintuitive compared to those on Earth.
      Although the dynamic ZBO approach is technologically complex, it promises an impressive advantage over the currently used passive methods. An assessment of one nuclear propulsion concept for Mars transport estimated that the passive boil-off losses for a large liquid hydrogen tank carrying 38 tons of fuel for a three-year mission to Mars would be approximately 16 tons/year. The proposed ZBO system would provide a 42% saving of propellant mass per year. These numbers also imply that with a passive system, all the fuel carried for a three-year Mars mission would be lost to boil-off, rendering such a mission infeasible without resorting to the transformative ZBO technology.
      The ZBO approach provides a promising method, but before such a complex technological and operational transformation can be fully developed, implemented, and demonstrated in space, important and decisive scientific questions that impact its engineering implementation and microgravity performance must be clarified and resolved.
      The Zero-Boil-Off Tank (ZBOT) Microgravity Science Experiments
      The Zero Boil-off Tank (ZBOT) Experiments are being undertaken to form a scientific foundation for the development of the transformative ZBO propellant preservation method. Following the recommendation of a ZBOT science review panel comprised of members from aerospace industries, academia, and NASA, it was decided to perform the proposed investigation as a series of three small-scale science experiments to be conducted onboard the International Space Station. The three experiments outlined below build upon each other to address key science questions related to ZBO cryogenic fluid management of propellants in space.
      Figure 3. Astronaut Joseph M. Acaba installing ZBOT Hardware in the Microgravity Science Glovebox aboard the International Space Station. Credit: NASA The ZBOT-1 Experiment: Self-Pressurization & Jet Mixing
      The first experiment in the series was carried out on the station in the 2017-2018 timeframe. Figure 3 shows the ZBOT-1 hardware in the Microgravity Science Glovebox (MSG) unit of the station. The main focus of this experiment was to investigate the self-pressurization and boiling that occurs in a sealed tank due to local and global heating, and the feasibility of tank pressure control via subcooled axial jet mixing. In this experiment, the complicated interaction of the jet flow with the ullage (vapor volume) in microgravity was carefully studied. Microgravity jet mixing data was also collected across a wide range of scaled flow and heat transfer parameters to characterize the time constants for tank pressure reduction, and the thresholds for geyser (liquid fountain) formation, including its stability, and penetration depth through the ullage volume. Along with very accurate pressure and local temperature sensor measurements, Particle Image Velocimetry (PIV) was performed to obtain whole-field flow velocity measurements to validate a Computational Fluid Dynamics (CFD) model.
      Figure 4. Validation of ZBOT CFD Model Predictions for fluid flow and deformation of a spherical ullage in microgravity by a subcooled liquid jet mixing against ZBOT experimental results: (a) Model prediction of ullage position and deformation and flow vortex structures during subcooled jet mixing; (b) PIV image capture of flow vortex structures during jet mixing; (c) Ullage deformation captured by white light imaging; and (d) CFD model depiction of temperature contours during subcooled jet mixing. (ZBOT-1 Experiment, 2018) Credit: Dr. Mohammad Kassemi, Case Western Reserve University Some of the interesting findings of the ZBOT-1experiment are as follows:
      Provided the first tank self-pressurization rate data in microgravity under controlled conditions that can be used for estimating the tank insulation requirements. Results also showed that classical self-pressurization is quite fragile in microgravity and nucleate boiling can occur at hotspots on the tank wall even at moderate heat fluxes that do not induce boiling on Earth.  Proved that ZBO pressure control is feasible and effective in microgravity using subcooled jet mixing, but also demonstrated that microgravity ullage-jet interaction does not follow the expected classical regime patterns (see Figure 4). Enabled observation of unexpected cavitation during subcooled jet mixing, leading to massive phase change at both sides of the screened Liquid Acquisition Device (LAD) (see Figure 5). If this type of phase change occurs in a propellant tank, it can lead to vapor ingestion through the LAD and disruption of liquid flow in the transfer line, potentially leading to engine failure. Developed a state-of-the-art two-phase CFD model validated by over 30 microgravity case studies (an example of which is shown in Figure 4). ZBOT CFD models are currently used as an effective tool for propellant tank scaleup design by several aerospace companies participating in the NASA tipping point opportunity and the NASA Human Landing System (HLS) program. Figure 5. White light image captures of the intact single hemispherical ullage in ZBOT tank before depressurization by the subcooled jet (left) and after subcooled jet mixing pressure collapse that led to massive phase change bubble generation due to cavitation at the LAD (right). (ZBOT-1 Experiment, 2018). Credit: Dr. Mohammad Kassemi, Case Western Reserve University The ZBOT-NC Experiment: Non-Condensable Gas Effects
      Non-condensable gases (NCGs) are used as pressurants to extract liquid for engine operations and tank-to-tank transfer. The second experiment, ZBOT-NC will investigate the effect of NCGs on the sealed tank self-pressurization and on pressure control by axial jet mixing. Two inert gases with quite different molecular sizes, Xenon, and Neon, will be used as the non-condensable pressurants. To achieve pressure control or reduction, vapor molecules must reach the liquid-vapor interface that is being cooled by the mixing jet and then cross the interface to the liquid side to condense.
      This study will focus on how in microgravity the non-condensable gases can slow down or resist the transport of vapor molecules to the liquid-vapor interface (transport resistance) and will clarify to what extent they may form a barrier at the interface and impede the passage of the vapor molecules across the interface to the liquid side (kinetic resistance). By affecting the interface conditions, the NCGs can also change the flow and thermal structures in the liquid.
      ZBOT-NC will use both local temperature sensor data and uniquely developed Quantum Dot Thermometry (QDT) diagnostics to collect nonintrusive whole-field temperature measurements to assess the effect of the non-condensable gases during both self-pressurization heating and jet mixing/cooling of the tank under weightlessness conditions. This experiment is scheduled to fly to the International Space Station in early 2025, and more than 300 different microgravity tests are planned. Results from these tests will also enable the ZBOT CFD model to be further developed and validated to include the non-condensable gas effects with physical and numerical fidelity.
      The ZBOT-DP Experiment: Droplet Phase Change Effects
      ZBO active pressure control can also be accomplished via injection of subcooled liquid droplets through an axial spray-bar directly into the ullage or vapor volume. This mechanism is very promising, but its performance has not yet been tested in microgravity. Evaporation of droplets consumes heat that is supplied by the hot vapor surrounding the droplets and produces vapor that is at a much lower saturation temperature. As a result, both the temperature and the pressure of the ullage vapor volume are reduced. Droplet injection can also be used to cool down the hot walls of an empty propellant tank before a tank-to-tank transfer or filling operation. Furthermore, droplets can be created during the propellant sloshing caused by acceleration of the spacecraft, and these droplets then undergo phase change and heat transfer. This heat transfer can cause a pressure collapse that may lead to cavitation or a massive liquid-to-vapor phase change. The behavior of droplet populations in microgravity will be drastically different compared to that on Earth.
      The ZBOT-DP experiment will investigate the disintegration, coalescence (droplets merging together), phase change, and transport and trajectory characteristics of droplet populations and their effects on the tank pressure in microgravity. Particular attention will also be devoted to the interaction of the droplets with a heated tank wall, which can lead to flash evaporation subject to complications caused by the Liedenfrost effect (when liquid droplets propel away from a heated surface and thus cannot cool the tank wall). These complicated phenomena have not been scientifically examined in microgravity and must be resolved to assess the feasibility and performance of droplet injection as a pressure and temperature control mechanism in microgravity.
      Back to Planet Earth
      This NASA-sponsored fundamental research is now helping commercial providers of future landing systems for human explorers. Blue Origin and Lockheed Martin, participants in NASA’s Human Landing Systems program, are using data from the ZBOT experiments to inform future spacecraft designs.
      Cryogenic fluid management and use of hydrogen as a fuel are not limited to space applications. Clean green energy provided by hydrogen may one day fuel airplanes, ships, and trucks on Earth, yielding enormous climate and economic benefits. By forming the scientific foundation of ZBO cryogenic fluid management for space exploration, the ZBOT science experiments and CFD model development will also help to reap the benefits of hydrogen as a fuel here on Earth. 
      PROJECT LEAD
      Dr. Mohammad Kassemi (Dept Mechanical & Aerospace Engineering, Case Western Reserve University)
      SPONSORING ORGANIZATION
      Biological and Physical Sciences (BPS) Division, NASA Science Mission Directorate (SMD)
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      “We were actually collecting samples for them to look at these phytoplankton communities and how they are changing over time,” said Dr. Wiederwohl, an oceanographer at Texas A&M University.  “Phytoplankton are these tiny microscopic plants in the ocean that photosynthesize and produce about half of our oxygen worldwide. So every other breath we take is actually oxygen coming from the ocean.”
      Korina Zhang and Adam Neuville collecting data for NASA’s FjordPhyto project. They are students with Texas A&M’s American Universities International Program in Antarctica. Credit: Dr Chrissy Wiederwhol, Texas A&M FjordPhyto has also recently involved students from Penn State University and Virginia Tech.
      The students spent sixty days in a research vessel through the American Universities International Program (AUIP) limited study abroad program. The effort was coordinated with the FjordPhyto team at Scripps Institution of Oceaongraphy and Isidro Bosch of State University of New York in Geneseo, New York.
      Going to Antarctica? You can join the FjordPhyto project, too.
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