Sens. Elizabeth Warren (D-Mass.) and Tammy Duckworth (D-Ill.), both members of the Senate Armed Services Committee, sent a letter to Meink seeking clarity on his relationship with SpaceX and its chief executive, Elon Musk
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While inspired by Israel's Iron Dome air-defense system, the American version is designed to operate on a much larger scale
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Skylo has raised $30 million to enable standard smartphones to connect to partner geostationary satellites in more areas worldwide.
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Layoffs of staff at NOAA have included its Office of Space Commerce, potentially affecting work on space traffic coordination and remote sensing licensing.
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The FCC formally kicked off a process to explore new uses for upper C-band satellite spectrum , potentially paving the way for another windfall for incumbent operators.
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Globular springtails (Dicyrtomina minuta) are small bugs about five millimetres long that can be seen crawling through leaf litter and garden soil. While they do not have wings and cannot fly, they more than make up for it with their ability to hop relatively large heights and distances.
This jumping feat is thanks to a tail-like appendage on their abdomen called a furcula, which is folded in beneath their body, held under tension.
When released, it snaps against the ground in as little as 20 milliseconds, flipping the springtail up to 6 cm into the air and 10 cm horizontally.
Researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences have now created a robot that mimics this jumping ability.
They modified a cockroach-inspired robot to include a latch-mediated spring actuator, in which potential energy is stored in an elastic element – essentially a robotic fork-like furcula.
Via computer simulations and experiments to control the length of the linkages in the furcula as well as the energy stored in them, the team found that the robot could jump some 1.4 m horizontally, or 23 times its body length – the longest of any existing robot relative to body length.
The work could help design robots that can traverse places that are hazardous to humans.
“Walking provides a precise and efficient locomotion mode but is limited in terms of obstacle traversal,” notes Harvard’s Robert Wood. “Jumping can get over obstacles but is less controlled. The combination of the two modes can be effective for navigating natural and unstructured environments.”
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HELSINKI — China and Pakistan have signed an astronaut training agreement that could see the first international astronaut arrive at the Tiangong space station. The China Manned Space Engineering Office […]
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The space industry thrives on precision, innovation and scientific rigor. But in today’s media landscape, facts often take a backseat to spectacle. Two of the loudest voices in the space […]
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On February 19, the Mitchell Institute published a report on the United States Space Force’s Theory of Competitive Endurance. The report assumes the Space Force’s core theoretical approach could undermine […]
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Two spacecraft, one from a startup and the other built by a major aerospace company, are experiencing problems after their launch as rideshares on a lunar lander mission.
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The internal temperature of a building is important – particularly in offices and work environments –for maximizing comfort and productivity. Managing the temperature is also essential for reducing the energy consumption of a building. In the US, buildings account for around 29% of total end-use energy consumption, with more than 40% of this energy dedicated to managing the internal temperature of a building via heating and cooling.
The human body is sensitive to both radiative and convective heat. The convective part revolves around humidity and air temperature, whereas radiative heat depends upon the surrounding surface temperatures inside the building. Understanding both thermal aspects is key for balancing energy consumption with occupant comfort. However, there are not many practical methods available for measuring the impact of radiative heat inside buildings. Researchers from the University of Minnesota Twin Cities have developed an optical sensor that could help solve this problem.
Room thermostats are used in almost every building today to regulate the internal temperature and improve the comfort levels for the occupants. However, modern thermostats only measure the local air temperature and don’t account for the effects of radiant heat exchange between surfaces and occupants, resulting in suboptimal comfort levels and inefficient energy use.
Finding a way to measure the mean radiant temperature in real time inside buildings could provide a more efficient way of heating the building – leading to more advanced and efficient thermostat controls. Currently, radiant temperature can be measured using either radiometers or black globe sensors. But radiometers are too expensive for commercial use and black globe sensors are slow, bulky and error strewn for many internal environments.
In search of a new approach, first author Fatih Evren (now at Pacific Northwest National Laboratory) and colleagues used low-resolution, low-cost infrared sensors to measure the longwave mean radiant temperature inside buildings. These sensors eliminate the pan/tilt mechanism (where sensors rotate periodically to measure the temperature at different points and an algorithm determines the surface temperature distribution) required by many other sensors used to measure radiative heat. The new optical sensor also requires 4.5 times less computation power than pan/tilt approaches with the same resolution.
The researchers tested infrared thermal array sensors with 32 x 32 pixels in four real-world environments (three living spaces and an office) with different room sizes and layouts. They examined three sensor configurations: one sensor on each of the room’s four walls; two sensors; and a single-sensor setup. The sensors measured the mean radiant temperature for 290 h at internal temperatures of between 18 and 26.8 °C.
The optical sensors capture raw 2D thermal data containing temperature information for adjacent walls, floor and ceiling. To determine surface temperature distributions from these raw data, the researchers used projective homographic transformations – a transformation between two different geometric planes. The surfaces of the room were segmented into a homography matrix by marking the corners of the room. Applying the transformations to this matrix provides the surface distribution temperature on each of the surfaces. The surface temperatures can then be used to calculate the mean radiant temperature.
The team compared the temperatures measured by their sensors against ground truth measurements obtained via the net-radiometer method. The optical sensor was found to be repeatable and reliable for different room sizes, layouts and temperature sensing scenarios, with most approaches agreeing within ±0.5 °C of the ground truth measurement, and a maximum error (arising from a single-sensor configuration) of only ±0.96 °C. The optical sensors were also more accurate than the black globe sensor method, which tends to have higher errors due to under/overestimating solar effects.
The researchers conclude that the sensors are repeatable, scalable and predictable, and that they could be integrated into room thermostats to improve human comfort and energy efficiency – especially for controlling the radiant heating and cooling systems now commonly used in high-performance buildings. They also note that a future direction could be to integrate machine learning and other advanced algorithms to improve the calibration of the sensors.
This research was published in Nature Communications.
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Rocket Lab says the first launch of its Neutron rocket remains planned for 2025 after a recent research report concluded it could slip to as late as 2027.
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HELSINKI — South Korea has approved new space strategies, including plans for reusable launch vehicles, as it seeks to become one of the world’s top five space powers. The Korea […]
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New statistical analyses of the supermassive black hole M87* may explain changes observed since it was first imaged. The findings, from the same Event Horizon Telescope (EHT) that produced the iconic first image of a black hole’s shadow, confirm that M87*’s rotational axis points away from Earth. The analyses also indicate that turbulence within the rotating envelope of gas that surrounds the black hole – the accretion disc – plays a role in changing its appearance.
The first image of M87*’s shadow was based on observations made in 2017, though the image itself was not released until 2019. It resembles a fiery doughnut, with the shadow appearing as a dark region around three times the diameter of the black hole’s event horizon (the point beyond which even light cannot escape its gravitational pull) and the accretion disc forming a bright ring around it.
Because the shadow is caused by the gravitational bending and capture of light at the event horizon, its size and shape can be used to infer the black hole’s mass. The larger the shadow, the higher the mass. In 2019, the EHT team calculated that M87* has a mass of about 6.5 billion times that of our Sun, in line with previous theoretical predictions. Team members also determined that the radius of the event horizon is 3.8 micro-arcseconds; that the black hole is rotating in a clockwise direction; and that its spin points away from us.
The latest analysis focuses less on the shadow and more on the bright ring outside it. As matter accelerates, it produces huge amounts of light. In the vicinity of the black hole, this acceleration occurs as matter is sucked into the black hole, but it also arises when matter is blasted out in jets. The way these jets form is still not fully understood, but some astrophysicists think magnetic fields could be responsible. Indeed, in 2021, when researchers working on the EHT analysed the polarization of light emitted from the bright region, they concluded that only the presence of a strongly magnetized gas could explain their observations.
The team has now combined an analysis of ETH observations made in 2018 with a re-analysis of the 2017 results using a Bayesian approach. This statistical technique, applied for the first time in this context, treats the two sets of observations as independent experiments. This is possible because the event horizon of M87* is about a light-day across, so the accretion disc should present a new version of itself every few days, explains team member Avery Broderick from the Perimeter Institute and the University of Waterloo, both in Canada. In more technical language, the gap between observations exceeds the correlation timescale of the turbulent environment surrounding the black hole.
The part of the ring that appears brightest to us stems from the relativistic movement of material in a clockwise direction as seen from Earth. In the original 2017 observations, this bright region was further “south” on the image than the EHT team expected. However, when members of the team compared these observations with those from 2018, they found that the region reverted to its mean position. This result corroborated computer simulations of the general relativistic magnetohydrodynamics of the turbulent environment surrounding the black hole.
Even in the 2018 observations, though, the ring remains brightest at the bottom of the image. According to team member Bidisha Bandyopadhyay, a postdoctoral researcher at the Universidad de Concepción in Chile, this finding provides substantial information about the black hole’s spin and reinforces the EHT team’s previous interpretation of its orientation: the black hole’s rotational axis is pointing away from Earth. The analyses also reveal that the turbulence within the accretion disc can help explain the differences observed in the bright region from one year to the next.
To observe M87* in detail, the EHT team needed an instrument with an angular resolution comparable to the black hole’s event horizon, which is around tens of micro-arcseconds across. Achieving this resolution with an ordinary telescope would require a dish the size of the Earth, which is clearly not possible. Instead, the EHT uses very long baseline interferometry, which involves detecting radio signals from an astronomical source using a network of individual radio telescopes and telescopic arrays spread across the globe.
The facilities contributing to this work were the Atacama Large Millimeter Array (ALMA) and the Atacama Pathfinder Experiment, both in Chile; the South Pole Telescope (SPT) in Antarctica; the IRAM 30-metre telescope and NOEMA Observatory in Spain; the James Clerk Maxwell Telescope (JCMT) and the Submillimeter Array (SMA) on Mauna Kea, Hawai’I, US; the Large Millimeter Telescope (LMT) in Mexico; the Kitt Peak Telescope in Arizona, US; and the Greenland Telescope (GLT). The distance between these telescopes – the baseline – ranges from 160 m to 10 700 km. Data were correlated at the Max-Planck-Institut für Radioastronomie (MPIfR) in Germany and the MIT Haystack Observatory in the US.
“This work demonstrates the power of multi-epoch analysis at horizon scale, providing a new statistical approach to studying the dynamical behaviour of black hole systems,” says EHT team member Hung-Yi Pu from National Taiwan Normal University. “The methodology we employed opens the door to deeper investigations of black hole accretion and variability, offering a more systematic way to characterize their physical properties over time.”
Looking ahead, the ETH astronomers plan to continue analysing observations made in 2021 and 2022. With these results, they aim to place even tighter constraints on models of black hole accretion environments. “Extending multi-epoch analysis to the polarization properties of M87* will also provide deeper insights into the astrophysics of strong gravity and magnetized plasma near the event horizon,” EHT Management team member Rocco Lico, tells Physics World.
The analyses are detailed in Astronomy and Astrophysics.
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The congressional watchdog raised concerns about the agency's rush to deploy hundreds of military satellites before fully proving that they can establish laser communications in orbit
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A shareholder with more than 7% of SES’ economic interests is calling for reduced state control over the Luxembourg-based satellite operator, arguing that greater independence is needed to tackle mounting challenges.
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Swissto12 announced Feb. 27 its first major contract for electronically steered antennas, securing a deal to supply SES with ground terminals for the Luxembourg-based operator’s O3b mPower medium Earth orbit network.
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A new technique for using frequency combs to measure trace concentrations of gas molecules has been developed by researchers in the US. The team reports single-digit parts-per-trillion detection sensitivity, and extreme broadband coverage over 1000 cm-1 wavenumbers. This record-level sensing performance could open up a variety of hitherto inaccessible applications in fields such as medicine, environmental chemistry and chemical kinetics.
Each molecular species will absorb light at a specific set of frequencies. So, shining light through a sample of gas and measuring this absorption can reveal the molecular composition of the gas.
Cavity ringdown spectroscopy is an established way to increase the sensitivity of absorption spectroscopy and needs no calibration. A laser is injected between two mirrors, creating an optical standing wave. A sample of gas is then injected into the cavity, so the laser beam passes through it, normally many thousands of times. The absorption of light by the gas is then determined by the rate at which the intracavity light intensity “rings down” – in other words, the rate at which the standing wave decays away.
Researchers have used this method with frequency comb lasers to probe the absorption of gas samples at a range of different light frequencies. A frequency comb produces light at a series of very sharp intensity peaks that are equidistant in frequency – resembling the teeth of a comb.
However, the more reflective the mirrors become (the higher the cavity finesse), the narrower each cavity resonance becomes. Due to the fact that their frequencies are not evenly spaced and can be heavily altered by the loaded gas, normally one relies on creating oscillations in the length of the cavity. This creates shifts in all the cavity resonance frequencies to modulate around the comb lines. Multiple resonances are sequentially excited and the transient comb intensity dynamics are captured by a camera, following spatial separation by an optical grating.
“That experimental scheme works in the near-infrared, but not in the mid-infrared,” says Qizhong Liang. “Mid-infrared cameras are not fast enough to capture those dynamics yet.” This is a problem because the mid-infrared is where many molecules can be identified by their unique absorption spectra.
Liang is a member of Jun Ye’s group in JILA in Colorado, which has shown that it is possible to measure transient comb dynamics simply with a Michelson interferometer. The spectrometer entails only beam splitters, a delay stage, and photodetectors. The researchers worked out that, the periodically generated intensity dynamics arising from each tooth of the frequency comb can be detected as a set of Fourier components offset by Doppler frequency shifts. Absorption from the loaded gas can thus be determined.
This process of reading out transient dynamics from “dithering” the cavity by a passive Michelson interferometer is much simpler than previous setups and thus can be used by people with little experience with combs, says Liang. It also places no restrictions on the finesse of the cavity, spectral resolution, or spectral coverage. “If you’re dithering the cavity resonances, then no matter how narrow the cavity resonance is, it’s guaranteed that the comb lines can be deterministically coupled to the cavity resonance twice per cavity round trip modulation,” he explains.
The researchers reported detections of various molecules at concentrations as low as parts-per-billion with parts-per-trillion uncertainty in exhaled air from volunteers. This included biomedically relevant molecules such as acetone, which is a sign of diabetes, and formaldehyde, which is diagnostic of lung cancer. “Detection of molecules in exhaled breath in medicine has been done in the past,” explains Liang. “The more important point here is that, even if you have no prior knowledge about what the gas sample composition is, be it in industrial applications, environmental science applications or whatever you can still use it.”
Konstantin Vodopyanov of the University of Central Florida in Orlando comments: “This achievement is remarkable, as it integrates two cutting-edge techniques: cavity ringdown spectroscopy, where a high-finesse optical cavity dramatically extends the laser beam’s path to enhance sensitivity in detecting weak molecular resonances, and frequency combs, which serve as a precise frequency ruler composed of ultra-sharp spectral lines. By further refining the spectral resolution to the Doppler broadening limit of less than 100 MHz and referencing the absolute frequency scale to a reliable frequency standard, this technology holds great promise for applications such as trace gas detection and medical breath analysis.”
The spectrometer is described in Nature.
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