Members Can Post Anonymously On This Site
-
Similar Topics
-
By NASA
7 min read
A New Alloy is Enabling Ultra-Stable Structures Needed for Exoplanet Discovery
A unique new material that shrinks when it is heated and expands when it is cooled could help enable the ultra-stable space telescopes that future NASA missions require to search for habitable worlds.
Advancements in material technologies are needed to meet the science needs of the next great observatories. These observatories will strive to find, identify, and study exoplanets and their ability to support life. Credit: NASA JPL One of the goals of NASA’s Astrophysics Division is to determine whether we are alone in the universe. NASA’s astrophysics missions seek to answer this question by identifying planets beyond our solar system (exoplanets) that could support life. Over the last two decades, scientists have developed ways to detect atmospheres on exoplanets by closely observing stars through advanced telescopes. As light passes through a planet’s atmosphere or is reflected or emitted from a planet’s surface, telescopes can measure the intensity and spectra (i.e., “color”) of the light, and can detect various shifts in the light caused by gases in the planetary atmosphere. By analyzing these patterns, scientists can determine the types of gasses in the exoplanet’s atmosphere.
Decoding these shifts is no easy task because the exoplanets appear very near their host stars when we observe them, and the starlight is one billion times brighter than the light from an Earth-size exoplanet. To successfully detect habitable exoplanets, NASA’s future Habitable Worlds Observatory will need a contrast ratio of one to one billion (1:1,000,000,000).
Achieving this extreme contrast ratio will require a telescope that is 1,000 times more stable than state-of-the-art space-based observatories like NASA’s James Webb Space Telescope and its forthcoming Nancy Grace Roman Space Telescope. New sensors, system architectures, and materials must be integrated and work in concert for future mission success. A team from the company ALLVAR is collaborating with NASA’s Marshall Space Flight Center and NASA’s Jet Propulsion Laboratory to demonstrate how integration of a new material with unique negative thermal expansion characteristics can help enable ultra-stable telescope structures.
Material stability has always been a limiting factor for observing celestial phenomena. For decades, scientists and engineers have been working to overcome challenges such as micro-creep, thermal expansion, and moisture expansion that detrimentally affect telescope stability. The materials currently used for telescope mirrors and struts have drastically improved the dimensional stability of the great observatories like Webb and Roman, but as indicated in the Decadal Survey on Astronomy and Astrophysics 2020 developed by the National Academies of Sciences, Engineering, and Medicine, they still fall short of the 10 picometer level stability over several hours that will be required for the Habitable Worlds Observatory. For perspective, 10 picometers is roughly 1/10th the diameter of an atom.
NASA’s Nancy Grace Roman Space Telescope sits atop the support structure and instrument payloads. The long black struts holding the telescope’s secondary mirror will contribute roughly 30% of the wave front error while the larger support structure underneath the primary mirror will contribute another 30%.
Credit: NASA/Chris Gunn
Funding from NASA and other sources has enabled this material to transition from the laboratory to the commercial scale. ALLVAR received NASA Small Business Innovative Research (SBIR) funding to scale and integrate a new alloy material into telescope structure demonstrations for potential use on future NASA missions like the Habitable Worlds Observatory. This alloy shrinks when heated and expands when cooled—a property known as negative thermal expansion (NTE). For example, ALLVAR Alloy 30 exhibits a -30 ppm/°C coefficient of thermal expansion (CTE) at room temperature. This means that a 1-meter long piece of this NTE alloy will shrink 0.003 mm for every 1 °C increase in temperature. For comparison, aluminum expands at +23 ppm/°C.
While other materials expand while heated and contract when cooled, ALLVAR Alloy 30 exhibits a negative thermal expansion, which can compensate for the thermal expansion mismatch of other materials. The thermal strain versus temperature is shown for 6061 Aluminum, A286 Stainless Steel, Titanium 6Al-4V, Invar 36, and ALLVAR Alloy 30.
Because it shrinks when other materials expand, ALLVAR Alloy 30 can be used to strategically compensate for the expansion and contraction of other materials. The alloy’s unique NTE property and lack of moisture expansion could enable optic designers to address the stability needs of future telescope structures. Calculations have indicated that integrating ALLVAR Alloy 30 into certain telescope designs could improve thermal stability up to 200 times compared to only using traditional materials like aluminum, titanium, Carbon Fiber Reinforced Polymers (CFRPs), and the nickel–iron alloy, Invar.
The hexapod assembly with six ALLVAR Alloy struts was measured for long-term stability. The stability of the individual struts and the hexapod assembly were measured using interferometry at the University of Florida’s Institute for High Energy Physics and Astrophysics. The struts were found to have a length noise well below the proposed target for the success criteria for the project. Credit: (left) ALLVAR and (right) Simon F. Barke, Ph.D. To demonstrate that negative thermal expansion alloys can enable ultra-stable structures, the ALLVAR team developed a hexapod structure to separate two mirrors made of a commercially available glass ceramic material with ultra-low thermal expansion properties. Invar was bonded to the mirrors and flexures made of Ti6Al4V—a titanium alloy commonly used in aerospace applications—were attached to the Invar. To compensate for the positive CTEs of the Invar and Ti6Al4V components, an NTE ALLVAR Alloy 30 tube was used between the Ti6Al4V flexures to create the struts separating the two mirrors. The natural positive thermal expansion of the Invar and Ti6Al4V components is offset by the negative thermal expansion of the NTE alloy struts, resulting in a structure with an effective zero thermal expansion.
The stability of the structure was evaluated at the University of Florida Institute for High Energy Physics and Astrophysics. The hexapod structure exhibited stability well below the 100 pm/√Hz target and achieved 11 pm/√Hz. This first iteration is close to the 10 pm stability required for the future Habitable Worlds Observatory. A paper and presentation made at the August 2021 Society of Photo-Optical Instrumentation Engineers conference provides details about this analysis.
Furthermore, a series of tests run by NASA Marshall showed that the ultra-stable struts were able to achieve a near-zero thermal expansion that matched the mirrors in the above analysis. This result translates into less than a 5 nm root mean square (rms) change in the mirror’s shape across a 28K temperature change.
The ALLVAR enabled Ultra-Stable Hexapod Assembly undergoing Interferometric Testing between 293K and 265K (right). On the left, the Root Mean Square (RMS) changes in the mirror’s surface shape are visually represented. The three roughly circular red areas are caused by the thermal expansion mismatch of the invar bonding pads with the ZERODUR mirror, while the blue and green sections show little to no changes caused by thermal expansion. The surface diagram shows a less than 5 nanometer RMS change in mirror figure. Credit: NASA’s X-Ray and Cryogenic Facility [XRCF] Beyond ultra-stable structures, the NTE alloy technology has enabled enhanced passive thermal switch performance and has been used to remove the detrimental effects of temperature changes on bolted joints and infrared optics. These applications could impact technologies used in other NASA missions. For example, these new alloys have been integrated into the cryogenic sub-assembly of Roman’s coronagraph technology demonstration. The addition of NTE washers enabled the use of pyrolytic graphite thermal straps for more efficient heat transfer. ALLVAR Alloy 30 is also being used in a high-performance passive thermal switch incorporated into the UC Berkeley Space Science Laboratory’s Lunar Surface Electromagnetics Experiment-Night (LuSEE Night) project aboard Firefly Aerospace’s Blue Ghost Mission 2, which will be delivered to the Moon through NASA’s CLPS (Commercial Lunar Payload Services) initiative. The NTE alloys enabled smaller thermal switch size and greater on-off heat conduction ratios for LuSEE Night.
Through another recent NASA SBIR effort, the ALLVAR team worked with NASA’s Jet Propulsion Laboratory to develop detailed datasets of ALLVAR Alloy 30 material properties. These large datasets include statistically significant material properties such as strength, elastic modulus, fatigue, and thermal conductivity. The team also collected information about less common properties like micro-creep and micro-yield. With these properties characterized, ALLVAR Alloy 30 has cleared a major hurdle towards space-material qualification.
As a spinoff of this NASA-funded work, the team is developing a new alloy with tunable thermal expansion properties that can match other materials or even achieve zero CTE. Thermal expansion mismatch causes dimensional stability and force-load issues that can impact fields such as nuclear engineering, quantum computing, aerospace and defense, optics, fundamental physics, and medical imaging. The potential uses for this new material will likely extend far beyond astronomy. For example, ALLVAR developed washers and spacers, are now commercially available to maintain consistent preloads across extreme temperature ranges in both space and terrestrial environments. These washers and spacers excel at counteracting the thermal expansion and contraction of other materials, ensuring stability for demanding applications.
For additional details, see the entry for this project on NASA TechPort.
Project Lead: Dr. James A. Monroe, ALLVAR
The following NASA organizations sponsored this effort: NASA Astrophysics Division, NASA SBIR Program funded by the Space Technology Mission Directorate (STMD).
Share
Details
Last Updated Jul 01, 2025 Related Terms
Technology Highlights Astrophysics Astrophysics Division Science-enabling Technology Explore More
7 min read NASA Webb ‘Pierces’ Bullet Cluster, Refines Its Mass
Article
1 day ago
2 min read Hubble Captures an Active Galactic Center
Article
4 days ago
2 min read NASA Citizen Scientists Find New Eclipsing Binary Stars
Article
5 days ago
View the full article
-
By NASA
Explore This Section Exoplanets Home Exoplanets Overview Exoplanets Facts Types of Exoplanets Stars What is the Universe Search for Life The Big Questions Are We Alone? Can We Find Life? The Habitable Zone Why We Search Target Star Catalog Discoveries Discoveries Dashboard How We Find and Characterize Missions People Exoplanet Catalog Immersive The Exoplaneteers Exoplanet Travel Bureau 5 Ways to Find a Planet Strange New Worlds Universe of Monsters Galaxy of Horrors News Stories Blog Resources Get Involved Glossary Eyes on Exoplanets Exoplanet Watch More Multimedia ExEP Artist’s concept of a planet orbiting two brown dwarfs. The planet is in a polar orbit (red), perpendicular to the mutual orbit of the two brown dwarfs (blue). ESO/L. Calçada The Discovery
A newly discovered planetary system, informally known as 2M1510, is among the strangest ever found. An apparent planet traces out an orbit that carries it far over the poles of two brown dwarfs. This pair of mysterious objects – too massive to be planets, not massive enough to be stars – also orbit each other. Yet a third brown dwarf orbits the other two at an extreme distance.
Key Facts
In a typical arrangement, as in our solar system, families of planets orbit their parent stars in more-or-less a flat plane – the orbital plane – that matches the star’s equator. The rotation of the star, too, aligns with this plane. Everyone is “coplanar:” flat, placid, stately.
Not so for possible planet 2M1510 b (considered a “candidate planet” pending further measurements). If confirmed, the planet would be in a “polar orbit” around the two central brown dwarfs – in other words, its orbital plane would be perpendicular to the plane in which the two brown dwarfs orbit each other. Take two flat disks, merge them together at an angle in the shape of an X, and you have the essence of this orbital configuration.
“Circumbinary” planets, those orbiting two stars at once, are rare enough. A circumbinary orbiting at a 90-degree tilt was, until now, unheard of. But new measurements of this system, using the ESO (European Southern Observatory) Very Large Telescope in Chile, appear to reveal what scientists previously only imagined.
Details
The method by which the study’s science team teased out the planet’s vertiginous existence is itself a bit of a wild ride. The candidate planet cannot be detected the way most exoplanets – planets around other stars – are found today: the “transit” method, a kind of mini-eclipse, a tiny dip in starlight when the planet crosses the face of its star.
Instead they used the next most prolific method, “radial velocity” measurements. Orbiting planets cause their stars to rock back and forth ever so slightly, as the planets’ gravity pulls the stars one way and another; that pull causes subtle, but measurable, shifts in the star’s light spectrum. Add one more twist to the detection in this case: the push-me-pull-you effect of the planet on the two brown dwarfs’ orbit around each other. The path of the brown dwarf pair’s 21-day mutual orbit is being subtly altered in a way that can only be explained, the study’s authors conclude, by a polar-orbiting planet.
Fun Facts
Only 16 circumbinary planets – out of more than 5,800 confirmed exoplanets – have been found by scientists so far, most by the transit method. Twelve of those were found using NASA’s now-retired Kepler Space Telescope, the mission that takes the prize for the most transit detections (nearly 2,800). Scientists have observed a small number of debris disks and “protoplanetary” disks in polar orbits, and suspected that polar-orbiting planets might be out there as well. They seem at last to have turned one up.
The Discoverers
An international science team led by Thomas A. Baycroft, a Ph.D. student in astronomy and astrophysics at the University of Birmingham, U.K., published a paper describing their discovery in the journal “Science Advances” in April 2025. The planet was entered into NASA’s Exoplanet Archive on May 1, 2025. The system’s full name is 2MASS J15104786-281874 (2M1510 for short).
Share
Details
Last Updated May 21, 2025 Related Terms
Exoplanets Astrophysics Binary Stars Brown Dwarfs Science & Research The Universe Keep Exploring Discover More Topics From NASA
Search for Life
Stars
Galaxies
Black Holes
View the full article
-
By NASA
The space shuttle Discovery launches from NASA’s Kennedy Space Center in Florida, heading through Atlantic skies toward its 51-D mission. The seven-member crew lifted off at 8:59 a.m. ET, April 12, 1985.NASA The launch of space shuttle Discovery is captured in this April 12, 1985, photo. This mission, STS-51D, was the 16th flight of NASA’s Space Shuttle program, and Discovery’s fourth flight.
Discovery carried out 39 missions, more than any other space shuttle. Its missions included deploying and repairing the Hubble Space Telescope and 13 flights to the International Space Station – including the very first docking in 1999. The retired shuttle now resides at the National Air and Space Museum’s Steven F. Udvar-Hazy Center in Virginia.
Learn more about NASA’s Space Shuttle Program.
Image credit: NASA
View the full article
-
By NASA
Explore This Section Exoplanets Home Exoplanets Overview Exoplanets Facts Types of Exoplanets Stars What is the Universe Search for Life The Big Questions Are We Alone? Can We Find Life? The Habitable Zone Why We Search Target Star Catalog Discoveries Discoveries Dashboard How We Find and Characterize Missions People Exoplanet Catalog Immersive The Exoplaneteers Exoplanet Travel Bureau 5 Ways to Find a Planet Strange New Worlds Universe of Monsters Galaxy of Horrors News Stories Blog Resources Get Involved Glossary Eyes on Exoplanets Exoplanet Watch More Multimedia ExEP This artist’s concept pictures the planets orbiting Barnard’s Star, as seen from close to the surface of one of them. Image credit: International Gemini Observatory/NOIRLab/NSF/AURA/P. Marenfeld The Discovery
Four rocky planets much smaller than Earth orbit Barnard’s Star, the next closest to ours after the three-star Alpha Centauri system. Barnard’s is the nearest single star.
Key Facts
Barnard’s Star, six light-years away, is notorious among astronomers for a history of false planet detections. But with the help of high-precision technology, the latest discovery — a family of four — appears to be solidly confirmed. The tiny size of the planets is also remarkable: Capturing evidence of small worlds at great distance is a tall order, even using state-of-the-art instruments and observational techniques.
Details
Watching for wobbles in the light from a star is one of the leading methods for detecting exoplanets — planets orbiting other stars. This “radial velocity” technique tracks subtle shifts in the spectrum of starlight caused by the gravity of a planet pulling its star back and forth as the planet orbits. But tiny planets pose a major challenge: the smaller the planet, the smaller the pull. These four are each between about a fifth and a third as massive as Earth. Stars also are known to jitter and quake, creating background “noise” that potentially could swamp the comparatively quiet signals from smaller, orbiting worlds.
Astronomers measure the back-and-forth shifting of starlight in meters per second; in this case the radial velocity signals from all four planets amount to faint whispers — from 0.2 to 0.5 meters per second (a person walks at about 1 meter per second). But the noise from stellar activity is nearly 10 times larger at roughly 2 meters per second.
How to separate planet signals from stellar noise? The astronomers made detailed mathematical models of Barnard’s Star’s quakes and jitters, allowing them to recognize and remove those signals from the data collected from the star.
The new paper confirming the four tiny worlds — labeled b, c, d, and e — relies on data from MAROON-X, an “extreme precision” radial velocity instrument attached to the Gemini Telescope on the Maunakea mountaintop in Hawaii. It confirms the detection of the “b” planet, made with previous data from ESPRESSO, a radial velocity instrument attached to the Very Large Telescope in Chile. And the new work reveals three new sibling planets in the same system.
Fun Facts
These planets orbit their red-dwarf star much too closely to be habitable. The closest planet’s “year” lasts a little more than two days; for the farthest planet, it’s is just shy of seven days. That likely makes them too hot to support life. Yet their detection bodes well in the search for life beyond Earth. Scientists say small, rocky planets like ours are probably the best places to look for evidence of life as we know it. But so far they’ve been the most difficult to detect and characterize. High-precision radial velocity measurements, combined with more sharply focused techniques for extracting data, could open new windows into habitable, potentially life-bearing worlds.
Barnard’s star was discovered in 1916 by Edward Emerson Barnard, a pioneering astrophotographer.
The Discoverers
An international team of scientists led by Ritvik Basant of the University of Chicago published their paper on the discovery, “Four Sub-Earth Planets Orbiting Barnard’s Star from MAROON-X and ESPRESSO,” in the science journal, “The Astrophysical Journal Letters,” in March 2025. The planets were entered into the NASA Exoplanet Archive on March 13, 2025.
Share
Details
Last Updated Apr 01, 2025 Related Terms
Exoplanets Radial Velocity Terrestrial Exoplanets Keep Exploring Discover More Topics From NASA
Universe
Exoplanets
Search for Life
Exoplanet Catalog
This exoplanet encyclopedia — continuously updated, with more than 5,600 entries — combines interactive 3D models and detailed data on…
View the full article
-
By NASA
4 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
A NASA researcher and innovation architect from the Convergent Aeronautics Solutions project Discovery team collaborating at a whiteboard during a visit to Chapel Hill, N.C. on Aug. 13, 2024.NASA / Ariella Knight Convergent Aeronautics Solutions (CAS) Discovery identifies problems worth solving for the benefit of all.
We formulate “convergent” problems—across multiple disciplines and sectors—and build footholds toward potentially transformative opportunities in aeronautics. As aeronautics rapidly advances, it is increasingly intersecting with other sectors like energy, healthcare, emergency response, economic resilience, the space economy, and more.
CAS Discovery builds new innovation tools and methods, a workforce adept at innovation methods, and transdisciplinary teams of researchers within and beyond NASA that conduct regular “Discovery sprints”—expeditions into cross-sector topic areas that could beneficially transform aeronautics and humanity.
WHAT is Discovery?
Participatory
It is difficult to understand and effectively address stakeholders’ needs & capabilities without engaging them. Discovery, in consultation with key NASA offices and other government agencies, has honed mechanisms to lawfully and respectfully engage and invite participation from stakeholders, communities, industry, NGOs and government to collaboratively formulate complex societal challenges tied to aviation.
Convergent
Typical organizational structures limit convergence across knowledge boundaries. CAS Discovery is intentionally cross-sector and transdisciplinary because the most impactful ideas often lie at the intersection of boundaries, the borderlands where multiple disciplines and communities come together. We work to emerge multi-sector, system-of-systems challenges that integrate political, economic, social, technological, environmental, legal and ethical trends, needs, and capabilities.
Future-Focused
Organizations have a tendency of being driven by short-term thinking and relatively short time horizons. CAS Discovery uses strategic foresight methods to examine 20 to 50-year time horizons, systematically ingesting and synthesizing signals and trends from aero and non-aero sources to envision a variety of scenarios to uncover opportunities for the future of aeronautics.
Ecosystemic
We study the ecosystems that are part of aeronautics and aerospace. This helps in broadening consideration of impacts while practicing foresight. It enhances our awareness of the environment and gives stakeholders the ability to see ripple effects across technologies, economies, communities, etc. We seek to benefit the wellness of the entire ecosystem while also benefiting the constituents.
A group of NASA researchers and leaders from the Convergent Aeronautics Solutions project Discovery team at the agency’s Glenn Research Center in Cleveland, on April 30, 2024.NASA / Ricaurte Chock WHO is Discovery?
NASA Researchers
They are the engine that propels CAS Discovery. Our cross-center Discovery sprint and foresight teams are composed of researchers from NASA’s Ames Research Center and Armstrong Flight Research Center in California, Glenn Research Center in Cleveland, and Langley Research Center in Virginia.
Researchers from Outside of NASA
They collaborate with us as subject matter experts or Discovery sprint team members to contribute their backgrounds in fields less common within NASA, such as energy, economics, anthropology, and other areas. This collaboration happens through many mechanisms, such as freelancing, crowdsourcing, interviews, webinars, and podcasts.
Stakeholders
They are engaged in various ways and to different degrees, often co-envisioning potential futures, co-formulating problems, and co-designing solutions.
Innovation Architects
They are the glue that holds CAS Discovery together and the anti-glue that keeps our teams from getting stuck. They come from a wide range of experience, each bringing deep expertise in leading transdisciplinary teams and stakeholders through processes and methods from strategic foresight, complex systems design, human-centered design, and more.
CAS Center Integration Leads (CILs)
They work with NASA line management at each Aeronautics center to bring NASA researchers and potential new PIs into CAS. CILs also host annual Wicked Wild idea pitch events to bring new problem areas and solution ideas into CAS Discovery and early Execution phases.
Ames Research Center CIL: Ty Huang Armstrong Flight Research Center CIL: Matt Kearns Glenn Research Center CIL: Jeffrey Chin Langley Research Center CIL: Devin Pugh-Thomas CAS Discovery Leads
They oversee Discovery sprint and strategic foresight teams, topics, and processes; new tools and continuous improvement experiments; and the overall health of the CAS innovation front-end pipeline and related strategic outputs.
Discovery Lead: Eric Reynolds Brubaker, Langley Research Center Foresight Lead: Vikram Shyam, Glenn Research Center Sample Discovery Publications
COMING SOON: Links to Technical Memorandums and conference papers.
Facebook logo @NASA@NASAaero@NASA_es @NASA@NASAaero@NASA_es Instagram logo @NASA@NASAaero@NASA_es Linkedin logo @NASA Explore More
2 min read NASA Concludes Wind Study
Article 2 years ago 3 min read NASA Armstrong Supports Wind Study
Article 2 years ago 4 min read NASA Interns Help Identify Aviation Solutions to Health Care Challenges
Article 2 years ago Keep Exploring Discover More Topics From NASA
Convergent Aeronautics Solutions
Science Missions
Aeronautics STEM
Explore NASA’s History
Share
Details
Last Updated Mar 21, 2025 EditorJim BankeContactDiana Fitzgeralddiana.r.fitzgerald@nasa.gov Related Terms
Convergent Aeronautics Solutions View the full article
-
-
Check out these Videos
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.