Category: Science

WASHINGTON — The Office of Space Commerce has selected three companies to participate in a pathfinder program that could lead to the incorporation of commercial data into its space traffic coordination system.

The office announced Jan. 19 that placed orders with COMSPOC, LeoLabs and Slingshot Aerospace for data and services related to objects in low Earth orbit. The orders are part of what the office calls a Consolidated Pathfinder project to test how the office can incorporate commercial space situational awareness (SSA) data.

The Office of Space Commerce is charged with establishing a civil space traffic coordination system, which it calls the Traffic Coordination System for Space or TraCSS. It is designed to take over from the Defense Department responsibilities for tracking space objects and providing warnings of potential conjunctions to government and commercial satellite operators.

“Through this pathfinder, and others to follow, we are working diligently toward incorporating commercial capabilities into TraCSS,” Rich DalBello, director of the Office of Space Commerce, said in a statement. “The Office of Space Commerce has always championed the government’s use of commercial space capabilities, and it is a core enabler of our own SSA program.”

Two of the companies will provide both catalogs of objects they track in low Earth orbit — LeoLabs using its network of radars and Slingshot with its group of optical telescopes — as well as related services. The third company, COMSPOC, will provide orbit determination services. A fourth company, yet to be selected, will provide data integrity services.

“We will be providing them the entire catalog, plus our expertise and insight, so they can then move to incorporate commercial data into the ultimate TraCSS system,” Kate Maliga, vice president of government affairs at LeoLabs, said in an interview. The company will also provide TraCSS with the conjunction data messages, or warnings of potential close approaches, it generates from its catalog.

Mike Wasson, vice president and general manager of COMSPOC, said his company will take the catalog data from LeoLabs and Slingshot and combine it. “We will fuse those different data sources through our orbit determination processes to create an accurate state of objects in low Earth orbit,” he said. While not a part of the current project, he said COMSPOC would be able to combine that data with additional sources using different phenomenologies, like passive radar or space-based sensors.

The Office of Space Commerce said last year it planned to conduct a series of pathfinders with industry to examine how to best incorporate commercial data into TraCSS. These tests will take place in a part of TraCSS called HORIZON, which officials described last year as a “sandbox” to do testing while not affecting operational systems.

The Consolidated Pathfinder project is slated to last about six months. The Office of Space Commerce said it is planning a separate pathfinder project, called Improved Satellite Owner/Operator Ephemeris, that will incorporate satellite position data provided directly by the operators of satellites.

The ultimate goal of TraCSS is to establish a system that takes in data from multiple sources, including commercial providers and the Defense Department as well as potentially other partners, to provide civil space traffic coordination services. The office has a mandate to provide a basic safety service free of charge to satellite operators, while companies are able to charge for more advanced services.

An ongoing challenge is determining what is included in a free basic service and what are more advanced services that companies can charge for. “We have been talking with them and to a lot of the stakeholders,” said Maliga, who noted that LeoLabs currently provides premium services to about 70% of LEO satellite operators.

“We’ll see when it becomes operational,” she said of the division of basic and advanced services, “but we definitely think it’s moving in the right direction.”

The Office of Space Commerce is taking an iterative approach to TraCSS, one that Sandra Magnus, chief engineer for the program, called “crawl, walk, run” in a presentation last July. An initial Phase 1.0 is set to be ready as soon as September, with updates on a quarterly basis through September 2025.

DalBello said at the AMOS Conference in Hawaii in September that his office got off to a slow start because of a lack of funding and personnel, which has improved after the office secured $70 million for fiscal year 2023, with $88 million requested for 2024. Much of that funding will go towards purchases of commercial infrastructure, data and services, he said then.

Wasson, though, said he thinks the Office of Space Commerce could move faster by making greater use of commercial capabilities. “They could turn the switch and we could be producing what they need for Space Policy Directive 3 in a matter of days,” he said. Space Policy Directive 3 instructed the Commerce Department in 2018 to establish a civil space traffic coordination system.

He said he was concerned that the momentum built up developing TraCSS could be lost if there is a change in administrations after the 2024 elections, unless there was a system already in operation before then.

“What we’re going to be doing with our commercial partners is continuing to advocate that after this pathfinder that they don’t shut things down,” he said. “They can keep this as a funded effort and we start adding on additional features to make this a viable solution in 2024.”

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HELSINKI — The Tianzhou-7 cargo spacecraft docked at China’s Tiangong space station Wednesday to resupply the orbital outpost.

A Long March 7 rocket lifted off from Wenchang Satellite Launch Center on Hainan island at 9:27 a.m. Eastern (1427 UTC) Jan. 17. Tianzhou-7 separated from the launcher and entered its predetermined orbit 10 minutes later, the China Manned Space Engineering Office (CMSEO) announced.

Tianzhou-7 docked at Tiangong just over three hours later, at 12:46 (1746 UTC), according to CMSEO. The Shenzhou-17 crew aboard the space station will later enter the Tianzhou 7 cargo spacecraft and carry out cargo transfer and other related work. 

The launch was the first to Tiangong in 2024. China completed the space station in late 2022 and has been sending regular, three person crews to Tiangong for roughly six-month-long missions. Each mission includes a handover, during which time there are briefly six astronauts aboard.

China plans to launch three further missions to Tiangong in 2024. These will be the Shenzhou 18 and 19 crewed missions and the Tianzhou-8 mission. The latter will fly roughly eight months from now. 

Tianzhou-7 carries 260 items of cargo, with a total mass of around 5.6 tons. Of this around 2.4 tons are supplies for the astronauts, including fresh fruit and vegetable and gift packages related to the incoming Year of the Dragon.

60 science units include an experiment focused on human bone cells and another carrying anaerobic archaea which will look at viability and methane production of early terrestrial life in a simulated cosmic environment.

CMSEO plans to send a Tianzhou spacecraft to Tiangong once every eight months. This is up from the original plan of once every six months, thanks to improvements in the capacity of the Tianzhou spacecraft. 

The automated docking was not as fast as the two-hour launch-to-docking performed by Tianzhou-5 in 2022, but the three-hour Tianzhou-7 docking was fuel and technology intensive.

CMSEO is also fostering low-cost cargo alternatives to supply Tiangong. The agency issued a call for proposals in May 2023 and selected four proposals in September to advance to a detailed design study phase.

While all selected cargo spacecraft proposals came from state-owned entities, it is understood that commercial launch vehicles are involved in plans to launch these spacecraft, rather than relying solely on Long March rockets.

The Kinetica-2 launcher being developed by CAS Space is understood to be the launcher for a proposal from the Innovation Academy for Microsatellites (IAMCAS) under the Chinese Academy of Sciences (CAS). CAS Space is a CAS spinoff. 

Additionally, the Gravity-1 solid rocket launched by Orienspace from the Yellow Sea last week included a self-developed low-cost cargo spacecraft, according to the company. This was partly as a mass simulator to verify the rocket’s performance.

China aims to operate Tiangong for at least a decade. A co-orbiting space telescope with a roughly two-meter-diameter aperture is set to launch in 2025. “Xuntian” will be able to dock with Tiangong for maintenance, repairs and possibly upgrades.

The country is also planning to expand Tiangong with a multipurpose module. This will allow further full-sized modules to dock with the orbital outpost. The lifespan could also be extended, keeping it in orbit long after the International Space Station is expected to be deorbited.

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WASHINGTON — The U.S. Space Force last year launched a small satellite on a Firefly rocket in a demonstration of responsive launch, sending the payload to orbit just 27 hours after receiving launch orders.

That mission, named Victus Nox, was impressive, Gen. Michael Guetlein, vice chief of space operations of the U.S. Space Force, said Jan. 19. But he cautioned that responsive space should be about more than setting speed records.

If a U.S. satellite gets taken out by an adversary, the default response cannot just be to speedily launch a replacement, Guetlein said at the Center for Strategic and International Studies. He argued that the Space Force needs to think more unconventionally about backup solutions.

The Space Force, for example, could pursue agreements with allies around the world to use their space assets, leverage commercial satellite providers or explore other alternatives to assure capability, he said. Being responsive means fundamentally changing how the Space Force approaches problems and how “guardians should think about tactically relevant timelines.”

“It’s not just about building hardware,” he said. 

More Victus Nox-style missions are being planned in the coming years, including one co-sponsored by the Pentagon’s Defense Innovation Unit. But Guetlein insisted that the idea of responsive space is to consider all options to meet the mission. “We need to broaden our thought process,” he said. 

Guetlein noted that missions like Victus Nox also help to re-evaluate bureaucratic business processes and internal workflows within the Space Force. And they provide opportunities to learn how to use critical thinking, sometimes over established protocol. 

Jason Kim, chief executive officer of Millennium Space Systems, said he witnessed some novel ways of doing business during the planning for Victus Nox. Millennium Space, a spacecraft manufacturer owned by Boeing, supplied the satellite for the Victus Nox mission. 

“What I observed during mission operations was guardians using critical thought, as opposed to using checklists all the time,” Kim said at CSIS during a panel discussion. 

Kim said he saw a “warrior mindset” applied to responsive space. With much shortened timelines, it may not be realistic to check off every item on the traditional checklist, he added. The attitude was more along the lines that “we’ve done that analysis, we need to make this decision really quickly, we have the recommended plan, let’s go execute.”

What this means for the launch sector

The Space Force’s evolving view of responsive space does not necessarily translate into a booming new business for rocket companies.

Brett Alexander, chief revenue officer of Firefly Aerospace, said the company  believes the success of Victus Nox could lead to commercial opportunities to provide rapid-response launches. 

“There are other commercial customers now that do want that responsiveness,” Alexander said at the CSIS panel discussion. 

The success of the Victus Nox mission last September, he said, “has allowed us to diversify our offering to the private sector, to the benefit of our business as well.”

However, even if the military continues to perform occasional demonstrations like Victus Nox as test cases, for launch providers, responsive launch is unlikely to be more than a niche amidst the larger small satellite launch market. 

Given the limited commercial demand for these types of missions, military demonstrations are not enough to sustain multiple companies hoping to specialize in dedicated small satellite launches. 

A cautionary tale is the now-defunct launch startup Virgin Orbit, which had actively lobbied the Defense Department to fund more rapid-response launch contests. Its executives thought winning these could lead to stable revenue streams.  

“Virgin orbit was in business for responsive launch,” Kurt Eberly, director of space launch at Northrop Grumman, said at the panel. But the market fundamentals still do not support many companies pursuing these specialized services full-time, he added.

“They were hoping to see more of a commercial demand signal … but it didn’t happen,” Eberly noted. 

Many commercial customers launching small satellites would rather wait months to hitch a discounted ride on a SpaceX rocket than pay a premium for a dedicated launch on shorter notice, Eberly said. To these customers, it’s worth waiting to get on a Transporter rideshare “because the price is right.”

From demos to operations

Alexander said the Space Force has yet to develop an “acquisition strategy” for responsive launch. “I think the challenge for the Space Force now is to move from demos to operations.”

One approach could be to work with commercial rocket companies and satellite manufacturers so the military could access existing production lines — and suppliers would not have to build hardware specifically for responsive launch missions. “If we’re launching 12 times a year, instead of building a rocket for the tactically responsive space mission that sits around and waits, you take the rocket that’s already coming off the production line,” Alexander said.

The same could be done with the spacecraft, and suppliers would have to agree to allow DoD to preempt a commercial customer if there is a pressing national security mission, Alexander added. “Acquisition strategy is a boring term but it’s the coin of the realm.”

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TAMPA, Fla. — Viasat has successfully demonstrated a satellite navigation signal on an airplane that could help the United Kingdom replace capabilities lost after leaving the European Union, the operator announced Jan. 18. 

A Saab 340B turboprop plane used a positioning, navigation, and timing (PNT) overlay signal from I-3 F5, Viasat’s 24-year-old satellite, to improve GPS accuracy during an hour-long test flight late last year over Cranfield, England.

“The test met expectations and was successful,” Viasat vice president of strategic programs and partnerships Gary Lay told SpaceNews, and involved four separate runway approaches.

Lay declined to disclose specific performance details. The tests aimed to show how the signal from a repurposed I-3 F5 transponder could improve positioning accuracy to a few centimeters, compared with the few meters provided by standard GPS alone.

Greater accuracy enables aircraft to make more high-precision landing approaches with less costly navigation support from the ground, with important safety implications for pilots unable to see a runway or other obstacles in bad weather. 

The United Kingdom lost access to the European Geostationary Navigation Overlay Service (EGNOS) for safety-related applications in 2021 following Brexit. 

According to Viasat, 19 airports across the United Kingdom had EGNOS procedures in place before the country left the European Union, and nearly 40% of flights one regional operator canceled due to weather could have gone ahead if a sovereign alternative had been in place. 

The operator is leading a group of local companies to develop a UK Space-Based Augmentation System (UKSBAS) for replacing EGNOS, supported by funding from the British government.

With aviation tests wrapped up, the group plans to show how the system could also be used for rail, uncrewed aerial vehicles, and autonomous road vehicles.

Viasat has three small satellites on order, slated to launch in 2027, that will carry navigation transponders to support the service after I-3 F5 runs out of fuel.

One of these satellites will support a similar GPS overlay system for Australia and New Zealand, called the Southern Positioning Augmentation Network (SouthPAN), following a government contract worth roughly $123 million.

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Researchers have developed an algorithm to help public health agencies and others develop a fast and effective response to disasters, whether they’re dealing with a hurricane or anthrax attack.

In recent tests, they confirmed that the algorithm, called the receiving-staging-storing-distributing (RSSD) algorithm, was faster and, in many situations, more effective in helping responders get critical supplies where they’re most needed.

Armin Mikler has been interested in disaster and emergency response since Hurricane Katrina devastated the Gulf Coast in 2005, killing more than 1,800 people, causing more than $100 billion in damage, and exposing serious flaws in the nation’s ability to respond to disasters.

Mikler, chair of the computer sciences department at Georgia State University, began working with colleagues at the University of North Texas to develop tools to improve disaster planning and response.

In emergency situations, the population in the affected area needs to be essentially divided up so that medication and other resources can be distributed effectively. This requires the creation of “drop points,” places in the affected area where supplies are delivered from a central point, or depot, such as the Strategic National Stockpile. The number of vehicles needed to deliver supplies, as well as their carrying capacities, are also major factors. When given the capacity of the vehicles and a time limit, the RSSD algorithm can work out ideal routes to points of delivery.

“The question needs to be answered, how do we get from the central point where they drop off, how do we deliver it to all the points where it’s actually needed?” Mikler says.

“That depends on how many points we have. And that is a very fluid problem, in the case of such emergencies. For instance, we don’t know exactly how many points of dispensing would actually be opening.”

Because of the fluidity of these situations, the algorithm he developed needed to be fast to respond effectively to the rapidly changing situations. Usually, problems like this would be solved using an algorithm that provides the best possible and most efficient solution, known as an optimization algorithm. However, optimization algorithms take a long time to find an answer.

“This is time that we often do not have when we need to reconfigure our plans,” Mikler says.

In short, Mikler and his colleagues found that fast and “good enough” is better in an emergency than taking too long to find a “perfect” solution.

To see how this algorithm stacked up to the others in both speed and accuracy, Mikler and PhD student Emma McDaniel conducted benchmarking tests with the RSSD algorithm and others.

Mikler and McDaniel recently published the results of these experiments in an article in PeerJ Computer Science.

They found that even though the RSSD algorithm doesn’t find the optimal solution, it does find consistently good solutions that take a minimum amount of response time. So, not only is the algorithm itself fast, but it also finds some of the fastest routes for resource delivery.

To benchmark the results, Mikler and McDaniel used a database called the CVRPLIB (Capacitated Vehicle Routing Problem Library) as their baseline for best answers to emergency situations. The database contains optimal vehicle route distances for various combinations of depot locations and the number of people who need supplies. Using these datasets, Mikler and McDaniel compared the RSSD algorithm to three others that solve similar problems. In terms of consistency, RSSD came out on top.

The algorithm, first developed in 2014, has been improved over time and is now integrated into response planning software that is used by the Texas Department of State Health Services to assist in both emergency response planning as well as real-time emergency response. Sampson Akwafuo, an assistant professor at California State University, has also used the algorithm to help plan emergency resource delivery in resource-poor areas in some African countries.

“We’re really able to come up with workable, feasible solutions to problems in a much shorter time,” Mikler says.

And time is of the essence in disaster and emergency response.

Source: Katherine Duplessis for Georgia State University

WASHINGTON — Sierra Space has successfully tested a full-scale version of an inflatable module it is developing for commercial space stations.

The company announced Jan. 22 that it performed a burst test of a full-sized version of its Large Integrated Flexible Environment (LIFE) module on a test stand at NASA’s Marshall Space Flight Center, demonstrating that the module exceeds the agency’s safety requirements.

In what is known as an ultimate burst pressure test, the LIFE module was inflated and the pressure inside increased until it burst. The module burst at a pressure of 77 pounds per square inch (psi), nearly 27% above NASA’s recommended level of 60.8 psi, itself four times above the maximum operating pressure for the module.

The test of the full-sized LIFE module comes after Sierra Space performed a series of subscale tests of the technology. In one such test in September, a subscale version equipped with a metallic “blanking plate” intended to simulate a window achieved a 33% safety margin. At the time, the company said the next step was to perform burst tests on the full-scale LIFE module.

The main purpose of the burst tests was to demonstrate the performance of the restraint layer, or pressure shell, of the module. That layer is made of straps of Vectran, a high-strength fiber, along with other fabrics. Sierra Space developed the layer in partnership with ILC Dover.

LIFE is designed to fit within a five-meter payload fairing at launch and then inflate once in orbit. When fully expanded, the module will have a volume of 300 cubic meters, about one third the habitable volume of the International Space Station. Sierra Space has proposed a larger version of LIFE, designed to fit into a seven-meter payload fairing, with a volume of 1,400 cubic meters.

“Sierra Space’s inflatable space station technology offers the absolute largest in-space pressured volume, the best unit economics per on-orbit volume and lowest launch and total operating costs,” argued Tom Vice, chief executive of Sierra Space, in a statement about the test.

LIFE is intended to be one of Sierra Space’s contributions to Orbital Reef, the commercial space station being developed with Blue Origin and others. Sierra Space, though, has proposed launching a LIFE module as a “Pathfinder” space station before Orbital Reef. The company received an unfunded NASA Space Act Agreement in June to give it access to NASA expertise and data to support work on Pathfinder as well as the crewed version of its Dream Chaser spaceplane.

Sierra Space said more tests of LIFE technology are planned for this year, including work on the “atmospheric barrier” and micrometeoroid and orbital debris layers of the module. The company said in September is expected to start work on flight hardware for LIFE in 24 to 36 months.

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Researchers have taken the first steps toward finding liquid solvents that may someday help extract critical building materials from lunar and Martian rock dust.

Extracting these materials is an important piece in making long-term space travel possible.

Using machine learning and computational modeling, the researchers found about half a dozen good candidates for solvents that can extract materials on the moon and Mars usable in 3D printing. The powerful solvents, called ionic liquids, are salts that are in a liquid state.

“The machine learning work brought us down from the 20,000-foot to the 1,000-foot level,” says Soumik Banerjee, associate professor in the School of Mechanical and Materials Engineering at Washington State University.

“We were able to down select a lot of ionic liquids very quickly, and then we could also scientifically understand the most important factors that determine whether a solvent is able to dissolve the material or not.”

As part of its Artemis mission, NASA, which funded Banerjee’s work, wants to send humans back to the moon and then to deeper space to Mars and beyond. But to make such long-term missions possible, astronauts will have to use the materials and resources in those extraterrestrial environments, using 3D printing to make structures, tools, or parts from essential elements extracted from lunar or Martian soil.

“In situ resource utilization is a big deal over the next couple of decades for NASA,” says Banerjee. “Otherwise, we would need a terribly high payload of materials to carry from Earth.”

Acquiring those building materials must be done in an environmentally friendly and energy efficient way. The method to mine the elements also can’t use water, which isn’t available on the moon.

Ionic liquids, which Banerjee’s group has been studying for more than a decade for use in batteries, could be the answer.

Testing each ionic liquid candidate in a lab is expensive and time consuming, however, so the researchers used machine learning and modeling at the level of atoms to narrow down from hundreds of thousands of candidates. They looked for those that might digest lunar and Martian materials, extract important elements such as aluminum, magnesium, and iron, regenerate themselves, and perhaps produce oxygen or water as a byproduct to help provide life-support.

Identifying superior qualities that the solvents will need, the researchers were able to find about half a dozen very strong candidates. Important factors for success included the size of the molecular ions that make up the salts, its surface charge density, which is the charge per unit area of the ions, and the mobility of the ions in the liquids.

Working with researchers at the University of Colorado in a separate study, the researchers tested a few ionic liquids in the lab for their ability to dissolve compounds. They hope to eventually build a lab-scale or pilot-scale reactor and test good candidate solvents with lunar regolith-type materials.

The new study appears in the Journal of Physical Chemistry B.

Source: Washington State

WASHINGTON — Astrobotic confirmed Jan. 17 that its Peregrine lunar lander will reenter over the South Pacific on Jan. 18, concluding a 10-day mission that failed to land on the moon because of a propellant leak.

In a statement, the company said it had adjusted the spacecraft’s trajectory to ensure it would safely reenter at about 4 p.m. Eastern Jan. 18. The reentry location in an ellipse several hundred kilometers long with its center a little more than 500 kilometers south-southwest of Fiji.

The company said it had to perform a two-step process to put the spacecraft on that reentry trajectory. One involved a series of 23 short burns by the spacecraft’s main engines. Astrobotic first tested those main engines Jan. 13, confirming they worked. However, the company said at the time that, because of the oxidizer leak, the fuel-to-oxidizer ratio “is well outside of the normal operating range of the main engines making long controlled burns impossible.”

Astrobotic said it also oriented the spacecraft so that the force from the leaking propellant would push the spacecraft towards the desired reentry zone over the South Pacific, ensuring that any debris that survives reentry will fall outside of populated regions.

The company announced Jan. 13 that the spacecraft appeared to be on a trajectory that would lead to reentry, and the next day said that, after discussions with NASA and others, it would allow the spacecraft to reenter rather than attempt a maneuver to miss the Earth. There had been speculation since then, though, that perturbations in the orbit caused by leaking fuel or other factors would require a maneuver to confirm a safe spacecraft reentry.

Peregrine launched Jan. 8 on the first United Launch Alliance Vulcan Centaur, but suffered a propellant leak hours later. The company said it believed a valve in a helium pressurization system failed to close, overpressurizing an oxidizer tank and rupturing it, creating the propellant leak.

The company was able to stabilize the spacecraft and turn on many of its payloads, even as it ruled out any attempt at a lunar landing because of the propellant leak. The launch placed Peregrine onto a highly elliptical orbit that took it out beyond the moon’s orbit. It was to swing back around the Earth before going into orbit around the moon to prepare for a Feb. 23 landing.

Peregrine carried 20 payloads, including five for its biggest customer, NASA’s Commercial Lunar Payload Services (CLPS) program. NASA said it backed Astrobotic’s decision to reenter the lander to safely conclude the mission.

“While it’s too soon to understand the root cause of the propulsion incident, NASA continues to support Astrobotic, and will assist in reviewing flight data, identifying the cause, and developing a plan forward for the company’s future CLPS and commercial flights,” Nicola Fox, NASA associate administrator for science, said in a Jan. 14 statement.

NASA and Peregrine plan to discuss the mission in a media briefing Jan. 19, hours after Japan’s SLIM spacecraft attempts its own landing on the moon.

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Supernovae are the predominant contributors to forming sources that eventually produce fast radio bursts, new research suggests.

Fast radio bursts (FRBs), fleeting blasts of energy from space, are a cosmic enigma.

“Fast radio bursts are one of astronomy’s greatest mysteries,” says lead author Mohit Bhardwaj, a member of the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst (CHIME/FRB) collaboration and a postdoctoral fellow at Carnegie Mellon University.

“These extremely powerful radio blasts can travel cosmological distances and emit more energy than the sun does in a thousand years, despite lasting only a few thousandths of a second. Even more intriguing is that, though they hit the Earth roughly every minute from all over the sky, their origin is still unknown.”

The researchers examined 18 nearby FRB hosts, all of which were spiral or late-type galaxies. The prevalence of late-type galaxies suggests that FRB sources predominantly occur in relatively young galaxies, with the sources possibly produced by supernovae that involve the core collapse of a massive star.

“This work identifies an intriguing trend that suggests most local FRBs likely come from core-collapse supernovae,” says Bridget Andersen, a coauthor of the paper and current PhD student at McGill University working under the supervision of Professor Victoria Kaspi. “In future studies, it will be particularly interesting to see if this trend persists with a larger number of localized host galaxies.”

The work holds particular significance because, a year ago, following the detection of an FRB source in a globular cluster of the Messier 81 galaxy—housing an extremely old stellar population—there was speculation that such sources might dominate the FRB population.

Bhardwaj says that the team’s findings disfavor such a scenario and instead support the hypothesis that the majority of FRB sources originate from the demise of massive stars, often resulting in the formation of either black holes or neutron stars.

“Looking ahead, as we amass larger samples of more precisely observed FRBs, we can further scrutinize these distinctions for both nearby and distant FRBs,” he says.

“By conducting more in-depth analyses, we hope to refine our understanding of the diverse origins of FRBs and potentially unveil the underlying mechanisms that drive these cosmic phenomena, shedding light on the intricacies of the universe’s radio signal bursts.”

The CHIME/FRB team recently doubled the catalog of known repeating FRBs and has continued to make progress in the field. The collaboration’s most recent paper, which appears Astrophysical Journal Letters, is significant because it pinpoints the host galaxies of the new nearby FRBs, which are promising candidates for identifying the proposed prompt or afterglow counterparts beyond radio wavelengths.

Understanding the origins of FRBs is a pivotal challenge in contemporary astronomy, and, so far, extragalactic FRBs have exclusively manifested as radio phenomena. By identifying their sources, cosmologists can gain new insights into the extreme astrophysical environments that give rise to these signals, and the physical mechanisms responsible for them.

“The ability to pinpoint the galaxy from which the FRB originated was key to this study. But with CHIME, we can only identify the host galaxies of the closest FRBs,” says coauthor Daniele Michilli, now a postdoctoral scholar at the MIT Kavli Institute for Astrophysics and Space Research. “We are building new CHIME ‘Outrigger’ telescopes in Canada and the US to enable precise sky localizations for all FRBs detected by CHIME. This will revolutionize the field and enable us to test the ideas put forth here.”

One prevailing hypothesis connecting these intense bursts of radio waves to astrophysical processes involves neutron stars, Bhardwaj says. He adds that the prominence of this hypothesis increased in 2020 when CHIME/FRB observed FRB-like bursts from a known highly magnetized neutron star (SGR 1935+2154) in our own galaxy, leading to the identification of magnetars—young, highly magnetized neutron stars—as a likely source.

“Regardless of their origin, these short bursts hold great promise for cosmological studies,” Bhardwaj says. “For each FRB, we can estimate the amount of ionized matter the FRB signal traveled through on the way to Earth. This unequivocally positions FRBs as a very promising probe for studying the distribution of ionized gas in the cosmic web.”

Source: McGill University