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NASA Astronaut Tracy C. Dyson’s Scientific Mission aboard Space Station
4 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater) NASA astronaut Tracy C. Dyson smiles for a portrait in the vestibule between the Kibo laboratory module and the Harmony module aboard space station.NASANASA astronaut Tracy C. Dyson is returning home after a six-month mission aboard the International Space Station. While on orbit, Dyson conducted an array of experiments and technology demonstrations that contribute to advancements for humanity on Earth and the agency’s trajectory to the Moon and Mars.
Here is a look at some of the science Dyson conducted during her mission:
Heart-Shaped Bioprints NASANASA astronaut Tracy C. Dyson operates the BioFabrication Facility for the Redwire Cardiac Bioprinting Investigation, which 3D prints cardiovascular tissue samples. In microgravity, bio inks used for 3D printing are less likely to settle and retain their shape better than on Earth. Cardiovascular disease is currently the number one cause of death in the United States, and findings from this space station investigation could one day lead to 3D-printed organs such as hearts for patients awaiting transplants.
Wicking in Weightlessness NASANASA astronaut Tracy C. Dyson handles hardware for the Wicking in Gel-Coated Tubes (Gaucho Lung) experiment. This study uses a tube lined with various gel thicknesses to simulate the human respiratory system. A fluid mass known as a liquid plug is then observed as it either blocks or flows through the tube. Data regarding the movement and trailing of the liquid plug allows researchers to design better drug delivery methods to address respiratory ailments.
Programming for Future Missions NASA NASANASA astronaut Tracy C. Dyson runs student-designed software on the free-flying Astrobee robot. This technology demonstration is part of Zero Robotics, a worldwide competition that engages middle school students in writing computer code to address unique specifications. Winning participants get to run their software on an actual Astrobee aboard the space station. This educational opportunity helps inspire the next generation of technology innovators.
Robo-Extensions NASAAs we venture to the Moon and Mars, astronauts may rely more on robots to ensure safety and preserve resources. Through the Surface Avatar study, NASA astronaut Tracy C. Dyson controls a robot on Earth’s surface from a computer aboard station. This technology demonstration aims to toggle between manipulating multiple robots and “diving inside” a specific bot to control as an avatar. This two-way demonstration also evaluates how robot operators respond their robotic counterparts’ efficiency and general output. Applications for Earth use include exploration of inhospitable zones and search and rescue missions after disasters.
Capturing Earth’s Essence NASAFor Crew Earth Observations, astronauts take pictures of Earth from space for research purposes. NASA astronauts Suni Williams (left) and Tracy C. Dyson (right) contribute by aiming handheld cameras from the space station’s cupola to photograph our planet. Images help inform climate and environmental trends worldwide and provide real-time natural disaster assessments. More than four million photographs have been taken of Earth by astronauts from space.
Multi-faceted Crystallization Processor NASANASA astronaut Tracy C. Dyson holds a cassette for Pharmaceutical In-Space Laboratory – 04 (ADSEP-PIL-04), an experiment to crystallize the model proteins lysozyme and insulin. Up to three cassettes with samples can be processed simultaneously in the Advanced Space Experiment Processor (ADSEP), each at an independent temperature. Because lysozyme and insulin have well-documented crystal structures, they can be used to evaluate the hardware’s performance in space. Successful crystallization with ADSEP could lead to production and manufacturing of versatile crystals with pharmaceutical applications.
Cryo Care NASANASA astronauts Tracy C. Dyson and Matthew Dominick preserve research samples in freezers aboard the space station. Cryopreservation is essential for maintaining the integrity of samples for a variety of experiments, especially within the field of biology. The orbiting laboratory has multiple freezer options with varying subzero temperatures. Upon return, frozen samples are delivered back to their research teams for further analysis.
Welcoming New Science NASANASA astronaut Tracy C. Dyson is pictured between the Unity module and Northrop Grumman’s Cygnus spacecraft in preparation for depressurization and departure from the International Space Station. On long-duration missions, visiting vehicles provide necessities for crew daily living as well as new science experiments and supplies for ongoing research. This vehicle brought experiments to test water recovery technology, produce stem cells in microgravity, study the effects of spaceflight on microorganism DNA, and conduct science demonstrations for students.
Diana Garcia
International Space Station Research Communications Team
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Reinventing the Clock: NASA’s New Tech for Space Timekeeping
Here on Earth, it might not matter if your wristwatch runs a few seconds slow. But crucial spacecraft functions need accuracy down to one billionth of a second or less. Navigating with GPS, for example, relies on precise timing signals from satellites to pinpoint locations. Three teams at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, are at work to push timekeeping for space exploration to new levels of precision.
- One team develops highly precise quantum clock synchronization techniques to aid essential spacecraft communication and navigation.
- Another Goddard team is working to employ the technique of clock synchronization in space-based platforms to enable telescopes to function as one enormous observatory.
- The third team is developing an atomic clock for spacecraft based on strontium, a metallic chemical element, to enable scientific observations not possible with current technology.
The need for increasingly accurate timekeeping is why these teams at NASA Goddard, supported by the center’s Internal Research and Development program, hone clock precision and synchronization with innovative technologies like quantum and optical communications.
Syncing Up Across the Solar System“Society requires clock synchronization for many crucial functions like power grid management, stock market openings, financial transactions, and much more,” said Alejandro Rodriguez Perez, a NASA Goddard researcher. “NASA uses clock synchronization to determine the position of spacecraft and set navigation parameters.”
If you line up two clocks and sync them together, you might expect that they will tick at the same rate forever. In reality, the more time passes, the more out of sync the clocks become, especially if those clocks are on spacecraft traveling at tens of thousands of miles per hour. Rodriguez Perez seeks to develop a new way of precisely synchronizing such clocks and keeping them synced using quantum technology.
Work on the quantum clock synchronization protocol takes place in this lab at NASA’s Goddard Space Flight Center in Greenbelt, Md.NASA/Matthew KaufmanIn quantum physics, two particles are entangled when they behave like a single object and occupy two states at once. For clocks, applying quantum protocols to entangled photons could allow for a precise and secure way to sync clocks across long distances.
The heart of the synchronization protocol is called spontaneous parametric down conversion, which is when one photon breaks apart and two new photons form. Two detectors will each analyze when the new photons appear, and the devices will apply mathematical functions to determine the offset in time between the two photons, thus synchronizing the clocks.
While clock synchronization is currently done using GPS, this protocol could make it possible to precisely synchronize clocks in places where GPS access is limited, like the Moon or deep space.
Syncing Clocks, Linking Telescopes to See More than Ever BeforeWhen it comes to astronomy, the usual rule of thumb is the bigger the telescope, the better its imagery.
“If we could hypothetically have a telescope as big as Earth, we would have incredibly high-resolution images of space, but that’s obviously not practical,” said Guan Yang, an optical physicist at NASA Goddard. “What we can do, however, is have multiple telescopes in various locations and have each telescope record the signal with high time precision. Then we can stich their observations together and produce an ultra-high-res image.”
The idea of linking together the observations of a network of smaller telescopes to affect the power of a larger one is called very long baseline interferometry, or VLBI.
For VLBI to produce a whole greater than the sum of its parts, the telescopes need high-precision clocks. The telescopes record data alongside timestamps of when the data was recorded. High-powered computers assemble all the data together into one complete observation with greater detail than any one of the telescopes could achieve on its own. This technique is what allowed the Event Horizon Telescope’s network of observatories to produce the first image of a black hole at the center of our galaxy.
The Event Horizon Telescope (EHT) — a planet-scale array of eight ground-based radio telescopes forged through international collaboration — was designed to capture images of a black hole. Although the telescopes making up the EHT are not physically connected, they are able to synchronize their recorded data with atomic clocks.EHT CollaborationYang’s team is developing a clock technology that could be useful for missions looking to take the technique from Earth into space which could unlock many more discoveries.
An Optical Atomic Clock Built for Space TravelSpacecraft navigation systems currently rely on onboard atomic clocks to obtain the most accurate time possible. Holly Leopardi, a physicist at NASA Goddard, is researching optical atomic clocks, a more precise type of atomic clock.
While optical atomic clocks exist in laboratory settings, Leopardi and her team seek to develop a spacecraft-ready version that will provide more precision.
The team works on OASIC, which stands for Optical Atomic Strontium Ion Clock. While current spacecraft utilize microwave frequencies, OASIC uses optical frequencies.
The Optical Atomic Strontium Ion Clock is a higher-precision atomic clock that is small enough to fit on a spacecraft.NASA/Matthew Kaufman“Optical frequencies oscillate much faster than microwave frequencies, so we can have a much finer resolution of counts and more precise timekeeping,” Leopardi said.
The OASIC technology is about 100 times more precise than the previous state-of-the-art in spacecraft atomic clocks. The enhanced accuracy could enable new types of science that were not previously possible.
“When you use these ultra-high precision clocks, you can start looking at the fundamental physics changes that occur in space,” Leopardi said, “and that can help us better understand the mechanisms of our universe.”
The timekeeping technologies unlocked by these teams, could enable new discoveries in our solar system and beyond.
More on cutting-edge technology development at NASA GoddardBy Matthew Kaufman, with additional contributions from Avery Truman
NASA’s Goddard Space Flight Center, Greenbelt, Md.
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Sentinel-2C to Vega and orbit – fit-check to liftoff timelapse
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Sentinel-2C will provide high-resolution data that is essential to Copernicus – the Earth observation component of the European Union’s Space programme. Developed, built and operated by ESA, the Copernicus Sentinel-2 mission provides high-resolution optical imagery for a wide range of applications including land, water and atmospheric monitoring.
The mission is based on a constellation of two identical satellites flying in the same orbit but 180° apart: Sentinel-2A and Sentinel-2B. Together, they cover all of Earth’s land and coastal waters every five days. Once Sentinel-2C is operational, it will replace its predecessor, Sentinel-2A, following a brief period of tandem observations. Sentinel-2D will eventually take over from Sentinel-2B.
Sentinel-2C was the last liftoff for the Vega rocket – after 12 years of service this was the final flight, the original Vega is being retired to make way for an upgraded Vega-C.
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Astronomers Have Found a Star with a Hot Jupiter and a Cold Super Jupiter in Orbit
Located in the constellation Ursa Major, roughly 300 light-years from Earth, is the Sun-like star HD 118203 (Liesma). In 2006, astronomers detected an exoplanet (HD 118203 b) similar in size and twice as massive as Jupiter that orbits very closely to Liesma (7% of the distance between Earth and the Sun), making it a “Hot Jupiter.” In a recent study, an international team of astronomers announced the detection of a second exoplanet in this system: a Super Jupiter with a wide orbit around its star. In short, they discovered a “Cold Super-Jupiter” in the outskirts of this system.
Gracjan Maciejewski – an Associate Professor with the Institute of Astronomy at Nicolaus Copernicus University (NCU) in Torun, Poland – led the study, which recently appeared in the journal Astronomy & Astrophysics. He was joined by researchers from the Department of Astronomy and Astrophysics and the Center for Exoplanets and Habitable Worlds at Pennsylvania State University (PSU), the Instituto de Astrofísica de Canarias, the Agencia Espacial Española (AEE), the Instituto de Astrofísica de Andalucía (IAA-CSIC), and the Center for Astrophysical Surveys at the National Center for Supercomputing Applications (NCSA).
According to their study, the planet (HD 118203 c) is up to eleven times the mass of Jupiter and orbits its parent star at a distance of 6 AU (six times the distance between Earth and the Sun) with a period of 14 years. Astronomers discovered the parent star in 1891 using the Draper telescope, now located in the NCU Institute of Astronomy in Piwnice, near Torun. Liesma is a G-type yellow dwarf (like our Sun), but 20% more massive and twice as large. Astronomers estimate that the star and its entire planetary system are slightly older than the Sun (an estimated 5 billion years).
Henry Draper’s Astrograph (1891), donated by Harvard College Observatory in 1947. Credit: Andrzej RomanskiWhile astronomers have known that a fairly massive planet orbits HD 118203 for nearly twenty years, it was only in 2006 that it was confirmed using Radial Velocity (Doppler Spectroscopy) measurements. However, these measurements indicated a linear trend that indicated there may be a companion planet with a wider orbit. The presence of another planet would indicate that the system has a hierarchical orbital architecture, which could help astronomers learn more about the origins of hot Jupiters. As Prof. Andrzej Niedzielski, a co-author of the study, explained in an NCU news story:
“Doppler observations, however, indicated that this was not the end of the story, that there might be another planet out there. Therefore, we immediately included this system in our observational programs. At first, as part of the Torun-Pennsylvania exoplanet research program, conducted in collaboration with Professor Aleksander Wolszczan, we tracked the object with one of the largest optical instruments on Earth, the nine-metre Hobby-Eberly Telescope in Texas.”
The results were so promising that the international team continued observing the star using the Telescopio Nazionale Galileo (TNG) at the Roque de los Muchachos Observatory. But first, it was necessary to rule out the possibility that more planets were hiding in the system. “I analyzed photometric observations obtained with the Transiting Exoplanet Survey Satellite space telescope, showing that there were no other planets around HD 118203 larger than twice the size of Earth, and therefore not massive enough to be relevant for studying the dynamics of the system,” said Julia Sierzputowska – an astronomy student and co-author of the study.
By 2023, the team obtained solid data of a Super Jupiter with a wide orbit, demonstrating that HD 118203 was a hierarchical planetary system. Said Prof. Maciejewski:
“Patience pays off. The new observations collected in March 2023 proved crucial in determining the planet’s orbital parameters. Moreover, because it takes a planet several years to orbit its star, we were able to combine our Doppler observations with available astrometric measurements to unambiguously determine its mass. This allowed us to build a complete model of this planetary system and study its dynamical behaviour.”
Astronomers from the NCU have discovered a new planet in the constellation Ursa Major. Credit: Andrzej RomanskiThe configuration is peculiar, where one planet orbits closely with its star (forming a pair) while a second orbits them wide enough to form another pair with the first one. While both planets are massive and have rather elongated orbits, their mutual gravitational influence does not destabilize the system over the course of eons. According to their study, this is due to the effects of General Relativity, which prevents the planets from constantly changing the shape of their orbits and orientation in space.
This makes HD 118203 one of only a handful of hierarchical systems known to astronomers, which will help address theories of how massive planets form. This will, in turn, allow astronomers to learn more about the formation and evolution of the gas giants in our Solar System – Jupiter, Saturn, Uranus, and Neptune. The international team also plans to keep gathering data on this system in the hopes of finding additional exoplanets.
Further Reading: NCU News, Astronomy & Astrophysics
The post Astronomers Have Found a Star with a Hot Jupiter and a Cold Super Jupiter in Orbit appeared first on Universe Today.
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Future Gravitational Wave Observatories Could See the Earliest Black Hole Mergers in the Universe
In February 2016, scientists at the Laser Interferometer Gravitational-wave Observatory (LIGO) confirmed they made the first-ever detection of gravitational waves (GWs). These events occur when massive objects like neutron stars and black holes merge, sending ripples through spacetime that can be detected millions (and even billions) of light-years away. Since the first event, more than 100 GW events have been confirmed by LIGO, the Advanced VIRGO collaboration, and the Kamioka Gravitational Wave Detector (KAGRA).
Moreover, scientists have found numerous applications for GW astronomy, from probing the interiors of supernovae and neutron stars to measuring the expansion rate of the Universe and learning what it looked like one minute after the Big Bang. In a recent study, an international team of astronomers proposed another application for binary black hole (BBH) mergers: using the earliest mergers in the Universe to probe the first generation of stars (Population III) in the Universe. By modeling how the events evolved, they determined what kind of GW signals the proposed Einstein Telescope (ET) could observe in the coming years.
The study was led by Boyuan Liu, a postdoctoral researcher at the Center for Astronomy of Heidelberg University (ZAH) and a member of the Excellence Cluster STRUCTURES program. He was joined by colleagues from the ZAH and the Institut für Theoretische Astrophysik at Heidelberg University, the Cambridge Institute of Astronomy, the Institute for Physics of Intelligence, the Institut d’Astrophysique de Paris, the Centre de Recherche Astrophysique de Lyon, the Gran Sasso Science Institute (GSSI), the Kavli Institute for Cosmology, the Weinberg Institute for Theoretical Physics, and multiple universities.
From Cosmic Dark to DawnPopulation III stars are the first to have formed in the Universe, roughly 100 to 500 million years after the Big Bang. At the time, hydrogen and helium were the most plentiful forms of matter in the Universe, leading to stars that were very massive and had virtually no metals (low metallicity). These stars were also short-lived, lasting only 2 to 5 million years before they exhausted their hydrogen fuel and went supernova. At this point, the heavier elements created in their cores (lithium, carbon, oxygen, iron, etc.) dispersed throughout the cosmos, leading to Population II and I stars with higher metallicity content.
Astronomers and cosmologists refer to this period as “Cosmic Dawn” since these first stars and galaxies ended the “Cosmic Dark Ages” that preceded it. As Liu explained to Universe Today via email, the properties of Pop III stars were sensitive to the peculiar conditions of the Universe during Cosmic Dawn, which were very different from the present-day conditions. This includes the presence of Dark Matter Haloes, which scientists believe were vital to the formation of the first galaxies:
“The timing of Pop III star formation reflects the pace of early structure formation, which can teach us about the nature of dark matter and gravity. In the standard cosmology model, cosmic structure formation is bottom-up, starting from small halos, which then grow by accretion and mergers to become larger halos. Pop III stars are expected to be massive (> 10 solar masses, reaching up to 1 million solar masses, while present-day stars have an average mass of ~ 0.5 solar masses). So, many of them will explode as supernovae or become massive black holes (BHs) when they run out of fuel for nuclear fusion.”
These Pop III black holes are further believed to be where the first supermassive black holes (SMBHs) in the Universe came from. As astronomers have demonstrated, SMBHs play an important role in the evolution of galaxies. In addition to assisting in the formation of new stars and encouraging galaxy formation in the early Universe, they are also responsible for shutting down star formation in galaxies ca. 2 to 4 billion years after the Big Bang, during the epoch known as “Cosmic Noon.” The growth of these black holes and the UV radiation emitted by Pop III stars reionized the neutral hydrogen and helium that permeated the early Universe.
This led to the major phase transition that ended the Cosmic Dark Ages (ca. 1 billion years after the Big Bang), allowing the Universe to become “transparent” as it is today. However, as Liu stated, how this process started remains unclear:
“Generally speaking, Pop III stars mark the onset of cosmic evolution from a starless (boring) state to the current state with rich phenomena (reionization, diverse populations of galaxies with different masses, morphologies, and compositions, andquasars powered by accreting supermassive BHs). To understand this complex evolution, it isessential to characterize its initial phase dominated by Pop III stars.”
Probing the Early UniverseThe confirmation of gravitational waves (GW) was revolutionary for astronomers, and many applications have since been proposed. In particular, scientists are eager to study the primordial GWs created by the Big Bang, which will be possible with next-generation GW detectors like the Laser Interferometer Space Antenna (LISA). As Liu explained, existing GW detectors are mostly dedicated to studying binary black hole (BBH) mergers. The same is true of detectors expected to be built in the near future. Said Liu:
“The GW emission from a BH binary is stronger when they are closer. The GW emission carries away energy and angular momentum from the system such that the two BHs will get closer over time and eventually merge. We can only detect the GW signal at the final stage when they are about to merge. The time taken to reach the final stage is highly sensitive to the initial separation of the BHs. Basically, they have to start close (e.g., less than ~ 10% of the earth-sun distance for BHs below 10 solar masses) to merge within the current age of the Universe to be seen by us.”
The question is, how do two black holes get so close to each other that they will eventually merge? Astronomers currently rely on two evolutionary “channels” (sets of physical processes working together) to model this process: isolated binary stellar evolution (IBSE) and nuclear star cluster-dynamical hardening (NSC-DH). As Liu indicated, the resulting BBH mergers have distinct features in their merger rate and properties, depending on the channel they follow. They contain valuable information about the underlying physical processes.
“Knowledge of evolution channels is necessary to extract such information to fully utilize GWs as a probe for astrophysics and cosmology,” he added.
Modeling BBH EvolutionTo determine how black holes come to form binaries that will eventually merge, the team combined both channels into a single theoretical framework based on the semianalytical model Ancient Stars and Local Observables by Tracing Halos (A-SLOTH). This model is the first publicly available code that connects the formation of the first stars and galaxies to observations. “In general, A-SLOTH follows the thermal and chemical evolution of gas along the formation, growth, and mergers of dark matter halos, including star formation and the impact of stars on gas (stellar feedback) at the intermediate scale of individual galaxies/halos,” said Liu.
Current operating facilities in the global network and their planned expansion. Credit: Caltech/MIT/LIGO LabThey also used the Stellar EVolution for N-body (SEVN) code to predict how stellar binaries evolve into BBHs. They then modeled the orbit of each BBH in their respective dark matter halos and during halo mergers, which allowed them to predict when some BBHs will merge. In other cases, BBHs travel to the center of their galaxies and become part of a nuclear star cluster (NSC), where they are subject to disruptions, ejections, and hardening by gravitational scattering. From this, they followed the evolution of internal binary orbits to the moment of merger or disruption.
Next-Generation ObservatoriesAs Lui explained, their results had significant theoretical and observational implications:
“On the theory side, my work showed that the isolated binary evolution channel dominates at high redshifts (less than 600 million years after the Big Bang) and the merger rate is sensitive to the formation rate and initial statistics of Pop III binary stars. In fact, the majority (> 84%) of BH binaries, especially the most massive ones, are initially too wide to merge within the age of the Universe if they evolve in isolation. But a significant fraction (~ 45 – 64%) of them can merge by dynamical hardening if they fall into NSCs. These predictions are useful for the identification and interpretation of merger origins in observations.”
In terms of observational results, they found that the predicted detection of Pop III BBH mergers is not likely to be discernible by current instruments like LIGO, Advance Virgo, and KAGRA, which generally observe BBH mergers closer to Earth. “[A]ltough Pop III mergers can potentially account for a significant fraction of the most massive BH mergers detected so far (with BHs above 50 solar masses),” said Liu. “It is difficult to learn much about Pop III stars and galaxies in the early Universe from the existing data because the sample size of detected massive mergers is too small.”
However, next-generation detectors like the Einstein Telescope will be more efficient in detecting these distant sources of GWs. Once completed, the ET will allow astronomers to explore the Universe through GWs back to the Cosmic Dark Ages, providing information on the earliest BBH mergers, Pop III stars, and the first SMBHs. “My model predicts that the Einstein Telescope can detect up to 1400 Pop III mergers per year, offering us much better statistics to constrain the relevant physics.”
The paper that describes their findings recently appeared online and is being reviewed for publication in the Monthly Notices of the Royal Astronomical Society.
Further Reading: arXiv
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