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Latest Galileo satellites join constellation with enhanced, faster fix
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By NASA
BBEME Course Description:
An interactive learning series designed to highlight critical interactions and various engagements across all GSFC locations, Facilities, and Institutes that lead to mission success. Themes include: strategic goals, current developments, mission success critical topics
Instructional Strategy:
•Facilitated panel discussions
•Leadership engagements
•One-on-one interactions
•Facilitated case studies
BBEME Workshops have been previously offered at GISS, Katherine Johnson IV&V, and Goddard’s Earth Science Division. The workshop targets groups of around 30 participants for a 1-2 day session.
If your group is interested in hosting a workshop, contact alysha.bayens@nasa.gov
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By European Space Agency
In a landmark achievement, ESA successfully migrated Galileo’s Control Centres in a highly complex operation involving over 200 people from the Agency, industry and EUSPA. This milestone marked the beginning of a global operation to upgrade Galileo’s entire Ground Segment, a vast network of stations spread around the world.
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By European Space Agency
Last night a crucial step in the European Space Agency’s eclipse-making Proba-3 mission was completed: the two spacecraft, flying jointly since launch, have successfully separated. This leaves them ready to begin their cosmic dance in the world’s first-ever precision formation-flying mission.
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By NASA
Modular Assembled Radiators for Nuclear Electric Propulsion Vehicles, or MARVL, aims to take a critical element of nuclear electric propulsion, its heat dissipation system, and divide it into smaller components that can be assembled robotically and autonomously in space. This is an artist’s rendering of what the fully assembled system might look like.NASA The trip to Mars and back is not one for the faint of heart. We’re not talking days, weeks, or months. But there are technologies that could help transport a crew on that round-trip journey in a relatively quick two years.
One option NASA is exploring is nuclear electric propulsion, which employs a nuclear reactor to generate electricity that ionizes, or positively charges, and electrically accelerates gaseous propellants to provide thrust to a spacecraft.
Researchers at NASA’s Langley Research Center in Hampton, Virginia, are working on a system that could help bring nuclear electric propulsion one significant, technology-defining step closer to reality.
Modular Assembled Radiators for Nuclear Electric Propulsion Vehicles, or MARVL, aims to take a critical element of nuclear electric propulsion, its heat dissipation system, and divide it into smaller components that can be assembled robotically and autonomously in space.
“By doing that, we eliminate trying to fit the whole system into one rocket fairing,” said Amanda Stark, a heat transfer engineer at NASA Langley and the principal investigator for MARVL. “In turn, that allows us to loosen up the design a little bit and really optimize it.”
Loosening up the design is key, because as Stark mentioned, previous ideas called for fitting the entire nuclear electric radiator system under a rocket fairing, or nose cone, which covers and protects a payload. Fully deployed, the heat dissipating radiator array would be roughly the size of a football field. You can imagine the challenge engineers would face in getting such a massive system folded up neatly inside the tip of a rocket.
The MARVL technology opens a world of possibilities. Rather than cram the whole system into an existing rocket, this would allow researchers the flexibility to send pieces of the system to space in whatever way would make the most sense, then have it all assembled off the planet.
Once in space, robots would connect the nuclear electric propulsion system’s radiator panels, through which a liquid metal coolant, such as a sodium-potassium alloy, would flow.
While this is still an engineering challenge, it is exactly the kind of engineering challenge in-space-assembly experts at NASA Langley have been working on for decades. The MARVL technology could mark a significant first milestone. Rather than being an add-on to an existing technology, the in-space assembly component will benefit and influence the design of the very spacecraft it would serve.
“Existing vehicles have not previously considered in-space assembly during the design process, so we have the opportunity here to say, ‘We’re going to build this vehicle in space. How do we do it? And what does the vehicle look like if we do that?’ I think it’s going to expand what we think of when it comes to nuclear propulsion,” said Julia Cline, a mentor for the project in NASA Langley’s Research Directorate, who led the center’s participation in the Nuclear Electric Propulsion tech maturation plan development as a precursor to MARVL. That tech maturation plan was run out of the agency’s Space Nuclear Propulsion project at Marshall Space Flight Center in Huntsville, Alabama.
NASA’s Space Technology Mission Directorate awarded the MARVL project through the Early Career Initiative, giving the team two years to advance the concept. Stark and her teammates are working with an external partner, Boyd Lancaster, Inc., to develop the thermal management system. The team also includes radiator design engineers from NASA’s Glenn Research Center in Cleveland and fluid engineers from NASA’s Kennedy Space Center in Florida. After two years, the team hopes to move the MARVL design to a small-scale ground demonstration.
The idea of robotically building a nuclear propulsion system in space is sparking imaginations.
“One of our mentors remarked, ‘This is why I wanted to work at NASA, for projects like this,’” said Stark, “which is awesome because I am so happy to be involved with it, and I feel the same way.”
Additional support for MARVL comes from the agency’s Space Nuclear Propulsion project. The project’s ongoing effort is maturing technologies for operations around the Moon and near-Earth exploration, deep space science missions, and human exploration using nuclear electric propulsion and nuclear thermal propulsion.
An artist’s rendering that shows the different components of a fully assembled nuclear electric propulsion system.NASAView the full article
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By NASA
On Jan. 7, 1610, Italian astronomer Galileo Galilei peered through his newly improved 20-power homemade telescope at the planet Jupiter. He noticed three other points of light near the planet, at first believing them to be distant stars. Observing them over several nights, he noted that they appeared to move in the wrong direction with regard to the background stars and they remained in Jupiter’s proximity but changed their positions relative to one another. Four days later, he observed a fourth point of light near the planet with the same unusual behavior. By Jan. 15, Galileo correctly concluded that he had discovered four moons orbiting around Jupiter, providing strong evidence for the Copernican theory that most celestial objects did not revolve around the Earth.
Two of Galileo’s telescopes.National Geographic. Painting by Giuseppe Bertini (1858) of Galileo demonstrating his telescope to the Doge of Venice.gabrielevanin.it Page from Galileo’s notebook about his observations of Jupiter’s satellites.University of Michigan Special Collections Library. In March 1610, Galileo published his discoveries of Jupiter’s satellites and other celestial observations in a book titled Siderius Nuncius (The Starry Messenger). As their discoverer, Galileo had naming rights to Jupiter’s satellites. He proposed to name them after his patrons the Medicis and astronomers called them the Medicean Stars through much of the seventeenth century, although in his own notes Galileo referred to them by the Roman numerals I, II, III, and IV, in order of their distance from Jupiter. Astronomers still refer to the four moons as the Galilean satellites in honor of their discoverer.
In 1614, the German astronomer Johannes Kepler suggested naming the satellites after mythological figures associated with Jupiter, namely Io, Europa, Ganymede, and Callisto, but his idea didn’t catch on for more than 200 years. Scientists didn’t discover any more satellites around Jupiter until 1892 when American astronomer E.E. Barnard found Jupiter’s fifth moon Amalthea, much smaller than the Galilean moons and orbiting closer to the planet than Io. It was the last satellite in the solar system found by visual observation – all subsequent discoveries occurred via photography or digital imaging. As of today, astronomers have identified 95 moons orbiting Jupiter.
Image of Jupiter and three of its four Galilean satellites through an amateur telescope, similar to what Galileo might have seen. Hubble Space Telescope image of Jupiter and three of its four Galilean satellites during a rare triple transit. Although each of the Galilean satellites has unique features, such as the volcanoes of Io, the heavily cratered surface of Callisto, and the magnetic field of Ganymede, scientists have focused more attention on Europa due to the tantalizing possibility that it might be hospitable to life. In the 1970s, NASA’s Pioneer 10 and 11 and Voyager 1 and 2 spacecraft took ever increasingly detailed images of the large satellites including Europa during their flybys of Jupiter. The photographs revealed Europa to have the smoothest surface of any object in the solar system, indicating a relatively young crust, and also one of the brightest of any satellite indicating a highly reflective surface. These features led scientists to hypothesize that Europa is covered by an icy crust floating on a subsurface salty ocean. They further postulated that tidal heating caused by Jupiter’s gravity reforms the surface ice layer in cycles of melting and freezing.
Image of Europa taken by Pioneer 10 during its flyby of Jupiter in 1973. Image of Europa taken by Voyager 1 during its 1979 flyby of Jupiter. Image of Europa taken by Voyager 2 during its 1979 flyby of Jupiter. More detailed observations from NASA’s Galileo spacecraft that orbited Jupiter between 1995 and 2003 and completed 11 close encounters with Europa revealed that long linear features on its surface may indicate tidal or tectonic activity. Reddish-brown material along the fissures and in splotches elsewhere on the surface may contain salts and sulfur compounds transported from below the crust and modified by radiation. Observations from the Hubble Space Telescope and re-analysis of images from Galileo revealed possible plumes emanating from beneath Europa’s crust, lending credence to that hypothesis. While the exact composition of this material is not known, it likely holds clues to whether Europa may be hospitable to life.
Global view of Europa from the Galileo spacecraft. More detailed views of varied terrain on Europa from Galileo. Cutaway illustration of Europa’s icy crust, subsurface ocean and possible vents that transport material to the surface. Future robotic explorers of Europa may answer some of the outstanding questions about this unique satellite of Jupiter. NASA’s Europa Clipper set off in October 2024 on a 5.5-year journey to Jupiter. After its arrival in 2030, the spacecraft will enter orbit around the giant planet and conduct 49 flybys of Europa during its four-year mission. Managed by the Jet Propulsion Laboratory in Pasadena, California, and the Applied Physics Laboratory at Johns Hopkins University in Baltimore, Maryland, Europa Clipper will carry nine instruments including imaging systems and a radar to better understand the structure of the icy crust. Data from Europa Clipper will complement information returned by the European Space Agency’s JUICE (Jupiter Icy Moon Explorer) spacecraft. Launched in April 2023, JUICE will first enter orbit around Jupiter in 2031 and then enter orbit around Ganymede in 2034. The spacecraft also plans to conduct studies of Europa complementary with Europa Clipper’s. The two spacecraft should greatly increase our understanding of Europa and perhaps uncover new mysteries.
Illustration of the Europa Clipper spacecraft investigating Europa. Illustration of the JUICE spacecraft exploring Europa.European Space Agency. View the full article
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