SpaceX and NASA could take a tentative step toward orbital refueling on the next test flight of Starship, but the US space agency says officials haven't made a final decision on when to begin demonstrating cryogenic propellant transfer capabilities that are necessary to return astronauts to the Moon.

NASA is keen on demonstrating orbital refueling technology, an advancement that could lead to propellant depots in space to feed rockets heading to distant destinations beyond Earth orbit. In 2020, NASA announced agreements with four companies—Lockheed Martin, United Launch Alliance, SpaceX, and a Florida-based startup named Eta Space—to prove capabilities in the area of refueling and propellant depots using cryogenic propellants.

These cryogenic fluids—liquid hydrogen, methane, and liquid oxygen—must be kept at temperatures of several hundred degrees below zero, or they turn into a gas and boil off. Russian supply freighters regularly refuel the International Space Station with hydrazine and nitrogen tetroxide, room-temperature rocket propellants that can be stored for years in orbit, but rockets using more efficient super-cold propellants have typically needed to complete their missions within hours.

NASA and industry engineers want to extend this lifetime to days, weeks, or months, but this requires new technologies to maintain the propellants at cryogenic temperature and, in some cases like Starship, to transfer the propellants from one vehicle to another.

NASA and several companies are funding efforts in this area, called cryogenic fluid management. NASA's agreements from 2020 committed more than $250 million in government funding for cryogenic fluid management tests in space. These funding agreements announced in October 2020, called "Tipping Point" awards, require substantial private funding from the companies participating in the demonstrations.

According to John Dankanich, who leads NASA's efforts in developing new capabilities for in-space transportation, there are "major technical obstacles" for cryogenic fluid management. The real challenge, he said, will be in validating things like automated couplers, flow meters, and advanced insulation all work together in microgravity. These, along with other technologies, are "highly interdependent" on one another to make cryogenic refueling a reality, he said.

Individual technologies necessary for in-orbit cryogenic refueling are at a stage of development where they are "ready now to go into flight systems," Dankanich said, either with a demonstration in space or on an operational spacecraft.

First, small steps

By the fourth anniversary of those awards, only SpaceX appears to have a chance to complete the tasks outlined in its "Tipping Point" award, valued at $53 million.

This test would involve transferring super-cold propellant from one tank to another inside a Starship spacecraft. It's a precursor to future, more complex demonstrations involving two giant Starships docked together in Earth orbit. Then SpaceX will be ready to send a Starship toward the Moon for a test landing without astronauts onboard. Once that is successful, NASA will clear Starship for a crew landing on the agency's Artemis III mission, marking the astronauts' return to the lunar surface for the first time since 1972.

That's easier said than done; all worthy projects require a first step. That could happen as soon as the next full-scale test flight of SpaceX's gigantic Super Heavy booster and Starship rocket, a stainless steel launcher that stands nearly 400 feet (121 meters) tall. SpaceX has flown the rocket twice, most recently on November 18, when the Starship upper stage reached space for the first time before self-destructing just short of orbital velocity. This test flight was largely successful, achieving several key milestones such as stage separation and demonstrating improved reliability of the rocket's methane-fueled Raptor engines.

SpaceX has a $2.9 billion contract with NASA to provide a commercial Human Landing System (HLS) derived from Starship for the Artemis III mission, the first human landing mission planned during NASA's Artemis program. The readiness of the Starship landing craft and new commercial spacesuits are widely seen as drivers of the schedule for Artemis III, which is at risk of a delay from late 2025.

Lakiesha Hawkins, deputy associate administrator for NASA's Moon to Mars program office, discussed the Artemis schedule Monday with a committee from the National Academies charged with reviewing the agency's workforce, infrastructure, and technology programs.

Hawkins did not verbally address SpaceX's plans for the next Starship test flight, but one of her slides noted SpaceX is "moving quickly" toward the third Super Heavy/Starship launch, and that this flight "will include a propellant transfer demonstration."

However, Jimi Russell, a NASA spokesperson, suggested to Ars this is still only a possibility. When it does happen, the tank-to-tank propellant transfer within Starship will demonstrate moving 10 metric tons of liquid oxygen, according to the 2020 Tipping Point award terms. SpaceX is collaborating with NASA's Glenn Research Center and Marshall Space Flight Center on the demonstration.

"NASA and SpaceX are reviewing options for the demonstration to take place during an integrated flight test of Starship and the Super Heavy rocket," Russell said in a  statement. "However, no final decisions on timing have been made."

Elon Musk, the company's founder and CEO, said on November 19 that hardware for the next Super Heavy/Starship test should be ready in three to four weeks. That projection seems dubious because SpaceX hasn't moved any pieces of the rocket to the launch pad for pre-flight testing, but a test flight early next year appears realistic.

Other factors that could play into the Starship launch schedule include tune-ups or fixes to resolve problems that occurred on the November 18 test flight and receiving a new launch license from the Federal Aviation Administration.

When SpaceX tries transferring 10 metric tons of propellant from tank to tank inside Starship, it will be at a scale never before attempted in space. But it's a small fraction of the amount of fuel and oxidizer needed to fill a Starship spacecraft in orbit. The ship's total propellant capacity is some 1,200 metric tons. After the tank-to-tank demonstration, SpaceX will attempt a ship-to-ship propellant transfer between two Starships linked together in Earth orbit.

"That’s really when we start maturing the systems, and when it really gets exciting for HLS, because those are the building blocks that we need and, frankly, it’s never been done successfully in orbit," said Lisa Watson-Morgan, NASA's HLS program manager, in an interview with Ars last month.

This discussion of propellant transfer leaves out critical work on Starship's life support system needed to accommodate crews on the lunar surface. SpaceX also needs to move forward with more Raptor engine testing, but the company recently completed a ground test to confirm it can reignite a Raptor engine in the extreme cold conditions resulting from extended time in space. SpaceX has also completed Raptor test-firings at different throttle settings to simulate how the engines must perform during a descent burn to reach the lunar surface.

Others in the running

The other companies working with NASA on cryogenic fluid management are still at least a couple of years away from any meaningful flight demonstrations.

Lockheed Martin's demo, expected to use liquid hydrogen, is scheduled for 2025 and will test 15 key cryo fluid management technologies. Eta Space is developing a small-scale fuel depot to demonstrate long-duration cryogenic storage of liquid oxygen for nine months. This mission, known as LOXSAT, is scheduled to launch with Rocket Lab in 2025, according to Dankanich.

Liquid hydrogen is the smallest molecule and needs to be stored at colder temperatures than methane or liquid oxygen. It is the most efficient rocket fuel in common use, but is prone to leaks.

United Launch Alliance is working on a liquid hydrogen/liquid oxygen "smart propulsion cryogenic system" on a Vulcan Centaur upper stage, testing precise tank pressure control, tank-to-tank transfer, and multi-week propellant storage, according to NASA. Dankanich said Monday ULA's flight demonstration is scheduled for 2026.

Like Starship, Blue Origin's human-rated lunar lander for Artemis will rely on orbital refueling but with liquid hydrogen. Blue Origin's approach to cryogenic fluid management involves actively controlling the temperature of liquid hydrogen using cryocoolers, while SpaceX is using passive thermal control on Starship.

Dankanich said Blue Origin plans "multiple interim demonstrations" with its cryogenic systems before its lander is certified to carry astronauts to the Moon's surface, but he didn't offer a schedule for those flight tests leading up to Blue Origin's first human landing mission, slated for no sooner than 2029.

Aside from technical hurdles, Dankanich said there's another potential barrier to widespread advancements in cryogenic refueling and propellant depots. For most of the tech demos, NASA is partnering with companies on a cost-sharing basis, reducing the cost to taxpayers. NASA would like to use data from the demonstrations to provide "ground truth" for models to predict the behavior of cryogenic fluids in space. Because NASA is a government agency, these models would be available to a broad cross-section of researchers and engineers.

Under the terms of these public-private partnerships, industry retains ownership, and these companies may consider details about their technology proprietary, limiting NASA's ability to share lessons learned with academic institutions or other outside groups.

“In some cases, we can't force them to even instrument the systems in the way that we need them instrumented in order to get the data that we would need to validate," Dankanich said. "If they're willing to provide the telemetry that we need, then we may, on the NASA side, be able to get some of that information. But we can't disclose the design details or the specifics to the community, which is necessary for model validation.

"Data right restrictions are a big challenge with the way that we're procuring all of our cryogenic fluid management systems," Dankanich said. "At the same time, the outlook is pretty good, right? We do have the SpaceX large-scale cryo settling propellant transfer planned for next year."

A little more than three months ago the Indian space agency, ISRO, achieved a major success by putting its Vikram lander safely down on the surface of the Moon. In doing so India became the fourth country to achieve a soft landing on the Moon, and this further ignited the country's interest in space exploration.

But it turns out that is not the end of the story for the Chandrayaan 3 mission. In a surprise announcement made Monday, ISRO announced that it has successfully returned the propulsion module used by the spacecraft into a high orbit around Earth. This experimental phase of the mission, the agency said in a statement, tested key capabilities needed for future lunar missions, including the potential for returning lunar rocks to Earth.

A capable module

The primary task of the propulsion module was to deliver the Vikram 3 lander into a low-lunar orbit, 100 km above the surface of the Moon. After doing this in August, the propulsion module moved to an orbit around the Moon at an altitude of 150 km. There, its remaining operational goal was to support a science experiment, known as SHAPE, to observe the Earth.

However, after a month of flying in this orbit, Indian mission operators found that the spacecraft still had a reserve of more than 100 kg of propellant. The propulsion module, which is powered by monomethylhydrazine and a nitric oxide-based oxidizer, had launched with 1,696 kg of fuel and oxidizer. This excess of propellant raised the possibility of additional maneuvers.

The engineers knew that the SHAPE mission could carry out its observations of Earth's atmosphere from a different orbit. By looking at Earth from a distance, this innovative science experiment seeks to set a benchmark for what to expect from the atmospheric signatures of exoplanets that may be capable of supporting life. So, the Indian engineers reasoned, it would be good to demonstrate the capability of their spacecraft to return to Earth orbit.

"It was decided to use the available fuel in the PM to derive additional information for future lunar missions and demonstrate the mission operation strategies for a sample return mission," the Indian space agency said Monday.

Back to Earth orbit

On October 9 the propulsion module raised its lunar orbit from 150 km to 5,112 km, and four days later it burned its engine again to begin exiting lunar orbit. In its new orbit around Earth, the propulsion module reached its first perigee on November 22, coming to within 154,000 km of the planet's surface. Over time the orbit will vary, with a minimum perigee of 115,000 km. Such a high orbit will not threaten any operational satellites around Earth, ISRO said. It is also a fine orbit from which the SHAPE payload can continue to carry out its observations of Earth's atmosphere.

So what's next?

India has not declared its future plans for the Moon beyond the Lunar Polar Exploration Mission, a joint operation with the Japanese space agency, JAXA. That mission is planned to carry a lunar lander and rover to the south pole of the Moon later this decade, but no earlier than 2026.

However, a lunar sample return mission would seem a good bet for the future. NASA, with the help of its astronauts, returned about 800 pounds of rocks during the Apollo missions. In the 1970s, the Soviet Union completed three robotic sample return missions, and China's Chang’e 5 lunar lander brought back samples three years ago.

Given the demise of the Soviet Union and Russia's lack of successful missions beyond low-Earth orbit, India now credibly has the third most advanced deep-space exploration program in the world. India placed a spacecraft into orbit around Mars in 2014, and its Vikram lander succeeded in December after Russia's Luna 25 spacecraft crashed into the Moon in August.

Good morning. It's December 5, and today's photo takes us very far from home to a dusty star factory of a galaxy that we need every bit of the James Webb Space Telescope's power to resolve.

This is the object AzTECC71, and astronomers say we are observing the galaxy as it existed just 900 million years after the Big Bang. And since the Universe is 13.7 billion years old, that is light from a long time ago in a galaxy far, far away.

What is special about this object is that we have not seen very many galaxies such as this one, shrouded as it is by dust. That precludes observation by optical instruments, including the Hubble Space Telescope. Whereas astronomers once thought this kind of dusty galaxy was rare, they now believe they are fairly common, and they just haven't been able to see them before.

This object first appeared as a blob in ground-based telescopes that can observe in the infrared portion of the spectrum. Due to light scattering by the dust, it was not visible when Hubble looked for it, however. But thanks to the Webb telescope, astronomers now have a better view of the distant, dusty galaxy.

"This thing is a real monster," said Jed McKinney, a postdoctoral researcher at The University of Texas at Austin involved in the observations. "Even though it looks like a little blob, it’s actually forming hundreds of new stars every year. And the fact that even something that extreme is barely visible in the most sensitive imaging from our newest telescope is so exciting to me. It’s potentially telling us there’s a whole population of galaxies that have been hiding from us."

See you tomorrow with a celestial treat closer to home. It almost has to be, right?

Source: J. McKinney/M. Franco/C. Casey/The University of Texas at Austin.

CRISPR—Clustered Regularly Interspaced Short Palindromic Repeats—is the microbial world’s answer to adaptive immunity. Bacteria don’t generate antibodies when they are invaded by a pathogen and then hold those antibodies in abeyance in case they encounter that same pathogen again, the way we do. Instead, they incorporate some of the pathogen’s DNA into their own genome and link it to an enzyme that can use it to recognize that pathogenic DNA sequence and cut it to pieces if the pathogen ever turns up again.

The enzyme that does the cutting is called Cas, for CRISPR associated. Although the CRISPR-Cas system evolved as a bacterial defense mechanism, it has been harnessed and adapted by researchers as a powerful tool for genetic manipulation in laboratory studies. It also has demonstrated agricultural uses, and the first CRISPR-based therapy was just approved in the UK to treat sickle-cell disease and transfusion-dependent beta-thalassemia.

Now, researchers have developed a new way to search genomes for CRISPR-Cas-like systems. And they’ve found that we may have a lot of additional tools to work with.

Modifying DNA

To date, six types of CRISPR-Cas systems have been identified in various microbes. Although they differ in detail, they all have the same appeal: They deliver proteins to a given sequence of genetic material with a degree of specificity that has heretofore been technically difficult, expensive, and time-consuming to achieve. Any DNA sequence of interest can be programmed into the system and targeted.

The native systems found in microbes usually bring a nuclease—a DNA-cleaving enzyme—to the sequence, to chop up the genetic material of a pathogen. This ability to cut any chosen DNA sequence can be used for gene editing; in tandem with other enzymes and/or DNA sequences, it can be used to insert or delete additional short sequences, correcting mutant genes. Some CRISPR-Cas systems cleave specific RNA molecules instead of DNA. These can be used to eliminate pathogenic RNA, like the genomes of some viruses, the way they are eliminated in their native bacteria. This can also be used to rescue defects in RNA processing.

But there are lots of additional ways to modify nucleic acids that might be useful. And it’s an open question as to whether enzymes that perform additional modifications have evolved. So, some researchers decided to search for them.

Researchers at MIT developed a new tool to detect variable CRISPR arrays and applied it to 8.8 tera (1012)-base pairs of prokaryotic genomic information. Many of the systems they found are rare and only appeared in the dataset in the past 10 years, highlighting how important it is to continue adding environmental samples that were previously hard to attain into these data repositories.

The new tool was required because databases of protein and nucleic acid sequences are expanding at a ridiculous rate, so the techniques for analyzing all of that data need to keep up. Some algorithms that are used to analyze them try to compare every sequence to every other one, which is obviously untenable when dealing with billions of genes. Others rely on clustering, but these find only genes that are highly similar so they can’t really shed light on the evolutionary relationships between distantly related proteins. But fast locality-sensitive hashtag-based clustering (“flash clust”) works by binning billions of proteins into fewer, larger clusters of sequences that differ slightly to identify new, rare relatives.

The search using FLSHclust successfully pulled out 188 new CRISPR-Cas systems.

Lots of CRISPyness

A few themes emerged from the work. One is that some of the newly identified CRISPR systems use Cas enzymes with never-before-seen domains, or appear to be fusions with known genes. The scientists further characterized some of these and found one to be more specific than the CRISPR enzymes currently in use, and another that cuts RNA that they propose is structurally distinct enough to comprise an entirely new seventh type of CRISPR-Cas system.

A corollary of this theme is the linkage of enzymes with different functionalities, not just nucleases (enzymes that cut DNA and RNA), with CRISPR arrays. Scientists have harnessed CRISPR’s remarkable gene-targeting ability by linking it to other kinds of enzymes and molecules, like fluorescent dyes. But evolution obviously got there first.

As one example, FLSHclust identified something called a transposase associated with two different types of CRISPR systems. A transposase is an enzyme that helps a particular stretch of DNA jump to another part of the genome. CRISPR RNA-guided transposition has been seen before, but this is another example of it. A whole host of proteins with varying functions, like proteins with transmembrane domains and signaling molecules, were found linked to CRISPR arrays, highlighting the mix-n-match nature of the evolution of these systems. They even found a protein expressed by a virus that binds to CRISPR arrays and renders them inactive—essentially, the virus inactivates the CRISPR system that evolved to protect against viruses.

Not only did the researchers find novel proteins associated with CRISPR arrays, but they also found other regularly interspaced repeat arrays that were not associated with any cas enzymes—similar to CRISPR but not CRISPR. They’re not sure what the functionality of these RNA guided systems might be but speculate that they are involved in defense just like CRISPR is.

The authors set out to find “a catalog of RNA-guided proteins that expand our understanding of the biology and evolution of these systems and provide a starting point for the development of new biotechnologies." It seems they achieved their goal: “The results of this work reveal unprecedented organizational and functional flexibility and modularity of CRISPR systems,” they write. They go on to conclude: “This represents only a small fraction of the discovered systems, but it illuminates the vastness and untapped potential of Earth’s biodiversity, and the remaining candidates will serve as a resource for future exploration.”

Article DOI: 10.1126/science.adi1910

Welcome to Edition 6.21 of the Rocket Report!

Someone is always watching, and it's more difficult than ever to hide bad news. This is one of my mantras as a reporter who will always come down on the side of transparency. We've seen space companies and government agencies in the United States try to downplay setbacks, which, let's face it, are inevitable in the space business. In China, it looks like a recent test-firing of a rocket motor didn't go well. Unsurprisingly, Chinese officials haven't said a thing.

As always, we welcome reader submissions, and if you don't want to miss an issue, please subscribe using the box below (the form will not appear on AMP-enabled versions of the site). Each report will include information on small-, medium-, and heavy-lift rockets, as well as a quick look ahead at the next three launches on the calendar.

Something exploded at a Chinese spaceport. A Chinese launch vehicle maker appears to have suffered an explosion at a test site at Jiuquan Satellite Launch Center, Space News reports. Satellite images show what are likely test stand facilities and the apparent aftermath of an exhaust plume from a hot fire test on the desert surface. Charred debris can be seen scattered across the surrounding area. The images were published on the social media platform X by Harry Stranger, who uses satellite imagery to track space industry developments. The facility is likely operated by the China Aerospace Science and Industry Corp. (CASIC), a state-owned enterprise that builds the solid-fueled Kuaizhou rocket.

Sleuthing for evidence ... Stranger posted about the explosion on X and used satellite images from several sources to pinpoint the time of the explosion to sometime on November 21 or 22. A similar explosion on the same test stand at Jiuquan occurred in October 2021. We can presume the explosion was likely related to a ground test of solid-fueled motors for the Kuaizhou 1A or Kuaizhou 11 rocket, which can haul payloads of several hundred kilograms to a metric ton into low-Earth orbit. The Kuaizhou rocket family is one of several small Chinese rockets in this lift class. Chinese officials haven't acknowledged the explosion. It goes to show that you can't hide an incident of this size. (submitted by Ken the Bin and martialartstechie)

The world's spaceports are busier than ever. Led by SpaceX and China, the world's launch providers have put more rockets and payloads into orbit so far in 2023 than in any prior year, continuing an upward trend in launch activity over the last five years, Ars reports. The flight of a SpaceX Falcon 9 rocket from Cape Canaveral, Florida, on November 22 was the 180th launch of 2023 to put its payload into orbit, eclipsing the mark of 179 successful orbital launches from last year. Global launch activity stagnated after the end of the Cold War, when Russia, and to a lesser extent the United States, cut back on their military space programs. For nearly 30 years, the record number of orbital launches in a calendar year stood at 129, a tally from 1984. In 2005, only 52 rockets made their way into orbit.

No turning back? ... SpaceX has launched 89 times so far this year, with 87 successful flights to reach orbit. Chinese rockets are 53-for-54. At this rate, SpaceX is on track for around 100 launches this year, with about 200 orbital missions worldwide. You can bet on more than 200 launches in 2024 if SpaceX achieves its goal of flying 12 times per month, which would give the company 144 launches during the course of the year. China's launch tally next year will likely be similar to this year's number.

New money for rocket propulsion startup Ursa Major. At a time when economic conditions are making it harder for startups to raise money, Ursa Major's announcement this week of $138 million in fundraising got our attention. Ars discussed the plans for this colourado-based company in last week's Rocket Report, when Ursa Major's CEO said the startup sees an opportunity to use 3D printing to disrupt the industry that produces solid rocket motors for military and spaceflight applications. Since then, Ursa Major revealed Series D and D-1 fundraising rounds that brought in $138 million from venture capital firms and institutional investors.

Funding Lynx ... Ursa Major says this new funding will go toward the company's Lynx solid rocket motor program, which will use advanced manufacturing techniques to produce rocket motors ranging in size from 2 inches to 22.5 inches in diameter. Rocket motors of this size can be used in a variety of military missiles, such as air defense units and Stingers, that currently face bottlenecks in production and struggle to meet demand from the US military and allies. Ursa Major is also working on the 50,000-pound-thrust Ripley engine for sale to developers of small commercial launch vehicles, and Draper, a storable liquid engine designed to defend against hypersonic weapons. (submitted by Ken the Bin)

Firefly's fourth launch scheduled for December. Firefly Aerospace is preparing to launch its fourth Alpha rocket in December from Vandenberg Space Force Base in California. This mission, which Firefly calls FLTA004, or "Fly the Lightning," will carry into orbit a small technology demonstration satellite for Lockheed Martin. The payload, named Tantrum and funded by Lockheed Martin, will test a new wideband Electronically Steerable Antenna design to demonstrate "faster on-orbit sensor calibration to deliver rapid capabilities" for the US military.

Another responsive launch ... Firefly and Lockheed Martin announced the launch contract for the Tantrum mission in June, about six months before the scheduled launch. Firefly's previous Alpha launch in September was part of a US Space Force responsive launch demonstration, in which the company proved it could integrate a small satellite payload with its Alpha rocket and launch it within 27 hours of receiving launch orders. Firefly says a secondary objective for the next Alpha launch will be to reduce the "total working hours" required from payload arrival at the launch site until launch readiness. "During the final launch operations, the mission team will encapsulate and mate the payload to Firefly’s Alpha rocket using a similar responsive timeline," Firefly said. This matches what Firefly's CEO, Bill Weber, said following the launch in September. At that time, Weber said Firefly would make its responsive launch capability a standard offering for future missions. (submitted by Ken the Bin)

Astra stays alive with $2.7 million in fundraising. Amid its struggle to stay afloat facing dwindling cash reserves and an unfriendly public market, Astra secured an additional $2.7 million from investors, Payload reports. The company will still need to secure long-term financing. This is the latest saga for Astra, which has seen its fundraising spigot dry up after its first orbital-class launcher, Rocket 3, failed to become a viable vehicle. Astra has pivoted to focus on producing small electric engines for satellites and announced mass layoffs earlier this year in a bid to right the ship. Most recently, the company's cofounders, Chris Kemp and Adam London, offered to take the company private. Astra went public
during the SPAC boom of 2021, when the company boasted a valuation of more than $2 billion.

Separating the wheat from the chaff ... Astra is fighting to avoid going the way of Virgin Orbit, which went bankrupt in May. Work on Astra's new launch vehicle, Rocket 4, has slowed to a crawl. Astra's spacecraft engines business, which it acquired when it bought Apollo Fusion in 2021, appears to be on more solid footing with demand from satellite constellation manufacturers. More news on Astra is sure to come soon because the company just doesn't have much financial runway in front of it. (submitted by Ken the Bin)

Ariane 6 finally has a launch schedule. One of the most common questions for European Space Agency officials this year has been "when will Europe's new Ariane 6 rocket launch for the first time?" It's running four years late, and its long-term future is up in the air after ESA recently announced the agency will open some of its launches to other rockets developed by European startups. Josef Aschbacher, ESA's director general, was unwavering in his refusal to be more specific than "2024" each time a reporter asked about the Ariane 6 launch schedule. Now, with a recent Ariane 6 hot fire test successfully complete, ESA announced Thursday that the first Ariane 6 rocket is on track for launch between June 15 and July 31 of next year.

A seven-minute engine test cleared the way ... The seven-minute test-firing on November 23 of an Ariane 6 rocket on its launch pad in French Guiana was the most significant test remaining on the rocket's road to liftoff, Ars reports. The test lasted 426 seconds while a full-size test model of the Ariane 6 rocket remained on its launch pad. For the rocket to actually take off, it would need to light its four strap-on solid-fueled boosters. That was not part of the plan for last week's test. The hot fire test lasted about a minute less than its planned duration, which officials from ESA and ArianeGroup blamed on a bad sensor and not a problem with the rocket or its main engine.

Firefly's Miranda engine ignites for the first time. For the first time, Firefly Aerospace has hot-fired the new Miranda engine it is developing to power two new medium-lift rockets being co-developed with Northrop Grumman. The Miranda engine burns kerosene and liquid oxygen but is significantly more powerful than the Reaver engine that Firefly uses on its smaller Alpha rocket. "The turbopump-fed engine test further validates the design of Miranda’s startup sequence, transient conditions, and tap-off engine architecture at a larger scale," Firefly said in a statement. Working at Firefly's test site in Central Texas, engineers will build up to a full-duration, 206-second Miranda hot fire test to fully qualify the Miranda engine for flight.

The power source for two new rockets ... Seven of these 230,000-pound-thrust engines will power the first stage of the Antares 330 rocket Firefly and Northrop Grumman are developing to replace the Antares 230, which launched for the final time in August. The Antares rocket family has exclusively been used to launch Northrop Grumman's Cygnus cargo ships on resupply flights to the International Space Station. The Antares 230 used Russian engines on its first stage, and Northrop Grumman no longer has access to these engines after Russia's invasion of Ukraine. The next three Cygnus cargo ships will launch on SpaceX Falcon 9 rockets, and the Antares 330 is due to resume launching Cygnus missions in 2025. After the Antares 330, Northrop Grumman and Firefly are partnering on a Medium Launch Vehicle (MLV) to compete for a broader range of launch contracts with NASA, the US military, and commercial customers. Seven Miranda engines will also power the first stage of the MLV, along with a vacuum variant of Miranda on the second stage. (submitted by Ken the Bin)

A Chinese company is developing a stainless steel rocket. Chinese launch startup LandSpace has unveiled plans to develop a reusable stainless steel rocket, Space News reports. The Zhuque-3 (Vermillion Bird 3) rocket will use stainless propellant tanks and clusters of Tianque methane-liquid oxygen propellant rocket engines, according to a presentation by LandSpace's CEO last week. The two-stage launcher will have a payload capacity of 20 metric tons to low-Earth orbit (LEO) when expendable. Recovery of the first stage downrange will allow 16.5 tons to LEO, while a landing back at the launch site will offer a capacity of 11 tons to LEO. A render of the rocket shows grid fins and deployable landing legs on the first stage.

Following the lead ... Talk of a reusable stainless steel rocket with methane-fueled engines immediately makes one think of SpaceX's Starship. LandSpace seems to be a leader among the crop of Chinese commercial startups that are developing rockets outside the bounds of the country's traditional roster of state-owned enterprises. In July, LandSpace launched its expendable Zhuque 2 rocket, which became the first methane-fueled launcher to successfully achieve orbit, beating a bevy of US rockets to the milestone. Methane is favored for reusable rockets because it leaves less residue inside engines than kerosene fuel. Another Chinese launch company, Space Pioneer, is developing a Falcon 9-class medium to heavy lift kerosene-fueled rocket that could fly next year. LandSpace has not disclosed a tentative test launch date and the dimensions of its planned Zhuque 3 rocket, suggesting the plan is at a very early stage, according to Space News. (submitted by Ken the Bin and EllPeaTea)

China is making progress on a Raptor-like engine. China is progressing with a program to develop full-flow staged-combustion-cycle methane engines to power its reusable Long March 9 super heavy-lift launcher, Space News reports. These engines are similar in design to SpaceX's Raptor, which powers the Super Heavy booster and Starship rocket. The Long March 9 itself appears similar in design and capability to Starship, and China says it will eventually have reusable boosters and upper stages. There are 33 Raptors on SpaceX's Super Heavy, and the Long March 9, planned for a debut in 2033, will have 26 of China's new methalox engines.

Design and test ... The most recent update on the development of China's new methalox engine comes from a paper published by authors from the Xi’an Aerospace Propulsion Institute, a liquid propulsion design unit of the China Aerospace Science and Technology Corp., China's largest government-owned aerospace contractor. The authors said China's foundations for developing a full-flow staged-combustion-cycle methalox engine are relatively weak, but this is a focus area for China's space program. Chinese rocket designers unveiled the new architecture for the Long March 9 in 2022 and 2023, after previously planning an expendable super heavy lift rocket based on kerosene/liquid oxygen engines. (submitted by Ken the Bin and Tfargo04)

Starship V2 in the works. With just two Starship integrated test flights under its belt, SpaceX announced last week that it is already working on a major overhaul of its second-stage Starship vehicle, Payload reports. The design changes will be significant enough to speciate the ship, giving it the title of Version 2. SpaceX plans to finish and launch four or five additional Starship V1 prototypes before transitioning to its V2 product line, Elon Musk said on X. Insights gained from the upcoming flights will be integrated into the next-gen rocket.

What will be on V2?… Musk didn't detail what would be incorporated on Starship V2, but we can expect it will fly with upgraded versions of SpaceX's Raptor engines, called Raptor 3. It may also include nine Raptor engines rather than the six flying on the current iteration of Starship. Musk has previously discussed the possibility of enlarging the propellant tanks on future Starships, increasing the rocket's payload lift capability. These stretched tanks would allow more methane and liquid oxygen to fit onto the rocket. (submitted by Ken the Bin)

Next three launches

December 1: Falcon 9 | 425 Project & Rideshares | Vandenberg Space Force Base, California | 18:19 UTC

December 2: Falcon 9 | Starlink 6-31 | Cape Canaveral Space Force Station, Florida | 04:01 UTC

December 4: Long March 2C | Unknown Payload | Jiuquan, China | 04:10 UTC

Dec. 1, 2023: This story was updated after the liftoff of the Progress MS-25 mission to update the list of upcoming launches, and to correct the name of Firefly's next launch.

Widely accepted wisdom has it that electric vehicles are easier to maintain than those with internal combustion powertrains. It seems intuitive—EVs have many fewer moving parts than cars that have to detonate small quantities of hydrocarbon fuel thousands of times a minute. But the data don't really bear out the idea. In fact, according to data collected by Consumer Reports, EVs are significantly less reliable than conventionally powered cars.

CR is known for buying cars for its own test fleet, but for its annual auto reliability survey, the organization cast a wider net. Specifically, it gathered data from 330,000 owners of vehicles from model year 2000 onwards, and it uses that survey data to generate reliability scores for each vehicle and model year.

The results are a little inconvenient for the EV evangelist. EVs had 79 percent more reliability problems than a gasoline- or diesel-powered vehicle, on average. Plug-in hybrids fared even worse; these had 146 percent more issues on average than the conventional alternative. But simpler not-plug-in hybrids bucked this trend, with 26 percent fewer reliability problems than conventionally powered vehicles.

PHEVs also had the greatest number of potential trouble areas. A conventionally powered car, truck, or SUV has 17 main problem areas, according to CR, including minor stuff like trim rattling and more significant areas like the engine or transmission. PHEVs have all these plus electric motors, a high-voltage traction battery, and charging to contend with.

Hybrids have 19 potential trouble areas—all the above minus the charging problem—and EVs have just 12, since they go without things like internal combustion engines, fueling systems, or transmissions. (Yes, if you want to be very pedantic you could point out the Porsche Taycan and Audi e-Tron GT have two-speed transmissions, but no one will be impressed.)

Electric motors, charging, and battery problems make up most of the EV reliability complaints (and those are charging problems with the car, not with home or public charging hardware). The relative rawness of most EVs on sale is a big factor in this, and CR has some good advice for potential EV buyers: Do not get seduced by that launch edition vehicle.

"EVs are still in their relative infancy as mainstream vehicles, so it’s really not surprising that manufacturers, by and large, are still working out the kinks. That said, we are seeing signs of movement in the right direction. And as our data has consistently shown, reliability-minded consumers would be best served by forgoing brand new vehicles in their first model year," said Jake Fisher, senior director of auto testing at CR.

"Hybrids continue to surpass EVs and ICE vehicles for reliability even though hybrids are more complex with gas-powered engines supplemented by an electric drive system. This is because hybrid technology is now over 25 years old and is offered mainly from the most reliable automakers."

At first, CR's data looks like it's in conflict with one of its earlier reports; in 2020, its data showed that EVs and PHEVs had lifetime maintenance costs that were about twice as cheap as for an internal combustion-powered vehicle. But Fisher noted that the earlier study was looking at cost rather than reliability. Since the EVs and PHEVs were mostly under warranty (and EV powertrain warranties are typically much longer than regular powertrain warranties), many repairs did not cost the owners.

Who did well?

Different brands are having different reliability issues. Tesla, despite a legion of horror stories, finds itself very middle of the pack in terms of overall reliability, and in general it builds dependable EV powertrains—less so bodywork, paint/trim, and climate systems. It's the second-highest ranked domestic automaker in CR's list, and its two volume offerings, the Models 3 and Y, have average reliability, according to CR's data and predictions.

EVs from other automakers mostly tell the opposite story. These brands know how to assemble and paint cars, and they can build climate control systems that don't cause too many headaches. But there are many more complaints about their electric powertrains. CR says that the Ford Mustang Mach-E is a notable bright spot, "which has shown enough improvement in its EV battery and charging system to now be rated average for predicted reliability and is eligible for CR’s recommendation."

Meanwhile, PHEVs are the worst of both worlds. As an example, the conventionally powered Chrysler Pacifica minivan is one of CR's recommended picks this year, based on its reliability. But the plug-in hybrid Pacifica is well below average, thanks to plenty of problems with its hybrid drivetrain and charging system.

Those reliability problems affect different manufacturers differently, though. By contrast, Toyota's RAV4 Prime was one of the most reliable vehicles in the entire survey, despite being a PHEV.

In general, the Asian OEMs dominate the upper end of the reliability chart, although Mini, Porsche, and BMW also made the top 10. As noted, Tesla placed pretty solidly mid-pack, along with other domestic brands like Buick, Ram, Cadillac, Chevrolet, and Dodge.

From there, things got progressively worse. Ford is in 22nd place overall, and many of its best-sellers like the F-150 and Bronco suffer from below-average reliability, as does the F-150 Lightning and the F-150 hybrid. (The Ford Maverick and Edge stick out from the rest of the range with above-average reliability ratings.)

But bottom of the heap came Chrysler, which also took the honor for the least reliable vehicle overall, the aforementioned Pacifica Hybrid.

Earlier this month, one corner of the Internet got a little bit greener, thanks to a first-of-its-kind geothermal operation in the northern Nevada desert. Project Red, developed by a geothermal startup called Fervo, began pushing electrons onto a local grid that includes data centers operated by Google. The search company invested in the project two years ago as part of its efforts to make all of its data centers run on green energy 24/7.

Project Red is small—producing between 2 and 3 megawatts of power, or enough to power a few thousand homes—but it is a crucial demonstration of a new approach to geothermal power that could make it possible to harness the Earth’s natural heat anywhere in the world.

Hot rock is everywhere, with temperatures rising hundreds of degrees Fahrenheit within the first few miles of the surface, but geothermal plants provide just a small fraction of the global electricity supply. That’s largely because they are mostly built where naturally heated water can be easily tapped, like hot springs and geysers. Hot water is pumped to the surface, where it produces steam that powers turbines.

The Nevada site, an “enhanced” geothermal system, or EGS, works differently. Instead of drilling into a natural hydrothermal system, Fervo dug into rock that is completely dry and effectively created an artificial hot spring by pumping down water that returns to the surface much hotter.

That strategy piggybacks on hydraulic fracturing techniques developed by the oil and gas industry. Fervo drilled two wells that each extended more than 7,000 feet down before turning fully horizontal. It then connected them by fracking, producing cracks in the rock that connected the two boreholes. Water enters one borehole cold and exits the other at a temperature high enough to drive turbines and generate power.

Fervo announced that its experiment had been a success this summer after a monthlong testing period that saw temperatures at the bottom of the boreholes reach 375 degrees Fahrenheit (191 C) and enough water torrenting through the system to produce an estimated 3.5 megawatts of electricity. Those operational figures have held relatively steady since then, according to Fervo CEO Tim Latimer, suggesting the project was ready to be plugged into the grid for the long haul. The Nevada wells were drilled close enough to a traditional geothermal power plant that the project can use existing turbines and power lines to deliver electricity to the grid.

While output is short of the company’s initial 5-megawatt estimate when it announced with Google, Latimer says further tweaks should eke out more electricity in the future. As it stands, the project is the first to achieve such a high level of performance, he notes. While two plants in northeastern France currently produce electricity from dry rocks, they operate at substantially cooler temperatures and rely on exploiting natural fault systems in the rock. Latimer says that Fervo’s results point to a strategy that can be scaled up.

Greening the Internet

Geothermal energy could help Google with a challenge faced by all tech companies trying to reduce the impact of power-hungry data centers. Wind and solar now power vast swathes of the cloud computing behind Internet services and apps, but because wind and sun aren’t always available, the flow of energy derived from them isn’t either.

Google has in recent years purchased enough renewable power to cover its data operations’ annual energy use—but at any given hour of the day, on any particular grid, the electricity that flows into a data center may have to come from a dirtier source. The company is now working on a more ambitious 2030 goal to secure 24/7 clean energy on the local grids where its data centers are located. Geothermal is a leading candidate for making it possible. “There's a very small group of options there for technologies that we could scale,” says Michael Terrell, senior director for climate and energy at Google.

The company has explored other options, like new types of small-scale nuclear reactors or hydrogen fuel produced with renewable electricity, but they will likely take more time to develop. “Out of the next set of technologies after wind, solar, and lithium-ion storage, this is the first one that's actually out there now delivering electrons,” Terrell says of the new Nevada geothermal plant. With an output of just a few megawatts of power, it’s a long way from providing the hundreds of megawatts a typical data center might need, but he considers the concept proven out.

Although it’s now up and running, EGS still has risks. The initial costs of any project are high, simply because reaching rocks that are hot enough requires drilling thousands of feet beneath the surface. The granite beneath places like the western US is considered ideal for EGS, because it provides relatively shallow heat and lacks natural fissures, meaning the only cracks into which the water will flow are those that engineers create. But the hard, tombstone-like rock is especially difficult to drill through.

Once the hard work of drilling the wells is over, there’s still a chance that an EGS project will never tap enough heat or pump enough water to power a plant. Sometimes it’s just not possible to properly read out what conditions will be like down there in advance. And some past EGS projects have accidentally triggered destructive earthquakes by disturbing natural faults.

Those challenges can dissuade investors, says Latimer, who are more interested in doling out small sums to exciting new lab technologies or more significant investments to more proven technologies, like solar. He describes technologies like EGS—theoretically feasible, but not yet proven at large scale—as the “missing middle” for energy investment.

Latimer says that Fervo has focused on reducing up-front drilling costs and mitigating the risk that a project will fail, primarily through modeling based on geological data to build an accurate picture of how the geothermal system it is creating will function. That work has been aided by the US government, which has funded a project called FORGE in Utah aimed at “derisking” EGS technology, primarily by testing out pricey tools and techniques like drill bits and seismic monitoring to see what works. The lessons are passed along to startups like Fervo.

Fervo’s next EGS project, in Beaver County, Utah, is scheduled to be operational in 2026 and will be far bigger than Project Red, at 400 megawatts. The location, visible from the FORGE site, was chosen for its well-understood geology and proximity to existing transmission lines. Latimer declined to give specific cost estimates for the electricity produced from the project, but he said the project is on track to match the costs of a traditional geothermal project, and all of its future energy production is already spoken for by utilities and other electricity customers. “We’re sold out!” he says—for now, at least. Latimer says the company is in the early stages of additional projects throughout the western US.

This story originally appeared on wired.com.

Anybody who has pulled weeds in a garden knows that it's a tedious task. Scale it up to farm-sized jobs, and it becomes a nightmare. The most efficient industrial alternative, herbicides, have potentially devastating side effects for people, animals, and the environment. So a Swedish company named Ekobot AB has introduced a wheeled robot that can autonomously recognize and pluck weeds from the ground rapidly using metal fingers.

The four-wheeled Ekobot WEAI robot is battery-powered and can operate 10–12 hours a day on one charge. It weighs 600 kg (about 1322 pounds) and has a top speed of 5 km/h (2.5 mph). It's tuned for weeding fields full of onions, beetroots, carrots, or similar vegetables, and it can cover about 10 hectares (about 24.7 acres) in a day. It navigates using GPS RTK and contains safety sensors and vision systems to prevent it from unintentionally bumping into objects or people.

To pinpoint plants it needs to pluck, the Ekobot uses an AI-powered machine vision system trained to identify weeds as it rolls above the farm field. Once the weeds are within its sights, the robot uses a series of metal fingers to quickly dig up and push weeds out of the dirt. Ekobot claims that in trials, its weed-plucking robot allowed farmers to grow onions with 70 percent fewer pesticides. The weed recognition system is key because it keeps the robot from accidentally digging up crops by mistake.

Two years ago, Ekobot announced a collaboration with Swedish telecom company Telia that led to the integration of 5G mobile technology into the robot, which lets it communicate remotely with a central server to share collected learning data from anywhere in a farm field. This development was part of a pilot project for onion cultivation, and just recently, the company announced that the first "5G onions" grown using this weeding method are now available.

"The 5G onion has proven to have an extended shelf life, something that contributes to a reduction in wastage," reads a press release from Telia. "The 5G onion is not only more sustainable—it also tastes better. This is because efficient weeding and reduced use of pesticides enables onion shoots to grow more freely and for longer, enabling the onions to receive more sunlight and nutrients, making them more hardy and tasty."

Telia says that a limited number of 5G onions are available in Telia stores now (grab us one if you go) and that Ekobot's weeding technology will soon be used on carrots and beets.

Aside from Sweden, the tech is available in the Netherlands and is about to come to Denmark and Norway. Telia expects that the Ekobot system will become available "in 9 EU countries, the United Kingdom, and the United States" by 2030. When coupled with research on lasers that zap pests in flight, AI may help pave the way for a more sustainable and environmentally friendly farming system if widely adopted.

Where do planets come from? The entire process can get complicated. Planetary embryos sometimes run into obstacles to growth that leave them as asteroids or naked planetary cores. But at least one question about planetary formation has finally been answered—how they get their water.

For decades, planetary formation theories kept suggesting that planets receive water from ice-covered fragments of rock that form in the frigid outer reaches of protoplanetary disks, where light and heat from the emerging system’s star lacks the intensity to melt the ice. As friction from the gas and dust of the disk moves these pebbles inward toward the star, they bring water and other ices to planets after crossing the snow line, where things warm up enough that the ice sublimates and releases huge amounts of water vapor. This was all hypothesized until now.

NASA’s James Webb Telescope has now observed groundbreaking evidence of these ideas as it imaged four young protoplanetary disks.The telescope used its Medium-Resolution Spectrometer (MRS) of Webb’s Mid-Infrared Instrument (MIRI) to gather this data, because it is especially sensitive to water vapor. Webb found that in two of these disks, massive amounts of cold water vapor appeared past the snow line, confirming that ice sublimating from frozen pebbles can indeed deliver water to planets like ours.

On the edge

Webb had its proverbial eye on four protoplanetary disks that were only around 2 or 3 million years old and forming around Sun-like stars. Out of these disks, two were compact, while the other two were larger, and had multiple gaps interrupting the disk. The research team behind this investigation wanted to see whether water was brought to the inner disk through the sublimation of ice on pebbles that drifted inward from the edges of a disk. They were also trying to make out whether this happened more efficiently in compact or larger disks.

Past studies done with NASA’s Spitzer Space Telescope and ALMA had found some data suggesting that pebble drift from the outer to the inner parts of a disk, along with subsequent vaporization of ice, was possible. Unfortunately, the data was unclear because of its low resolution; spectral lines that identified the presence of water were blurred. Webb’s higher resolution was able to separate these lines so they were much more distinct and showed the spectra of warm and cool water.

The Webb researchers were looking for cool water, which would indicate sublimated ice that confirmed previous ideas of frozen pebble drift. Warm water in a disk could only go so far as evidence, as it would probably mean that drift and sublimation had already happened, and the water vapor that resulted had now been heated by the nascent planetary system’s star.

From pebble to planet

In the two larger disks, it was found that frozen pebbles in larger systems have a hard time getting through the gaps. They are often caught up with other materials floating around in a gap and remain stuck there instead of continuing to drift inward. They also tend to encounter pressure traps, or regions of increased pressure that cause them to accumulate, which does not completely prevent them from drifting but acts as a cosmic speed bump. While there was some cool water vapor detected in these disks, there was not the large amount of vapor at the snow line that the team was looking for.

Observations of the compact disks were a breakthrough. The data Webb beamed back showed that, while there were spectra suggesting the presence of warmer water vapor emissions far inside the disk, there was also an excess of cold water vapor emissions just on the outside of the snow line. It is from here that the water vapor will travel to the inner parts of the disk.

“Pebble drift and trapping provide a fundamental, natural process for a large-scale link between inner and outer disk regions that may explain the cool water excess revealed by MIRI in the compact disks analyzed in this work,” the researchers said in a study recently published in The Astrophysical Journal Letters.

So what happens from there? Eventually, drifting pebbles that lack ice will collide with each other until they begin to accrete into what might eventually become a planet. That hypothetical planet may later be supplied with water vapor, and billions of years from now, it could even become another Earth. Maybe analogs to our planet really are out there. They just might not have formed yet.

Astrophysical Journal Letters, 2023.  DOI: 10.3847/2041-8213/acf5ec

The European Space Agency (ESA) declared success after an Ariane 6 rocket fired its core-stage engine in French Guiana for seven minutes on Thursday, clearing one of a handful of remaining hurdles before the new launcher can lift off on its first test flight.

The Ariane 6's inaugural launch, now scheduled for next year, has been delayed repeatedly since ESA approved the new rocket for development in 2014. The test-firing of the Ariane 6 main engine on a launch pad at the Guiana Space Center in South America last week was the most significant test not yet accomplished on the rocket's preflight checklist.

The test lasted 426 seconds—a little more than seven minutes—while a full-size test model of the Ariane 6 rocket remained on its launch pad. In order for the rocket to actually take off, it would need to light its four strap-on solid-fueled boosters. That was not part of the plan for Thursday's test.

After loading super-cold liquid hydrogen and liquid oxygen propellants into the Ariane 6 rocket, the launch team in French Guiana gave a "go" for ignition of the rocket's Vulcain 2.1 main engine. The engine lit at 3:44 pm EST (20:44 UTC) and throttled up to full power, producing more than 200,000 pounds of thrust.

Thursday's test was nearly a minute shy of the 470-second duration that ESA publicized ahead of time, but officials were satisfied with the result. Several times during the test, the nozzle of the Vulcain 2.1 engine swiveled to exercise the rocket's thrust vector control steering system.

“Ariane 6 now has a core stage and an upper stage which have undergone all testing necessary to be ready for the inaugural flight," said Martin Sion, CEO of ArianeGroup, the joint venture between Airbus and Safran that is responsible for developing the Ariane 6 rocket.

Josef Aschbacher, ESA's director general, said in a statement that engineers "have now run through every step of the rocket's flight without it leaving Earth... We are back on track towards re-securing Europe’s autonomous access to space."

A long road to get here

The Ariane 6 rocket was originally supposed to launch for the first time in 2020, but it's now running four years late. The rocket it will replace, the Ariane 5, made its final flight in July, leaving Europe without a rocket to launch its own space missions. That has prompted ESA and the European Union to look abroad to get spacecraft into orbit. SpaceX, a rival of the European launch service provider Arianespace, has won contracts to launch several ESA missions due to the Ariane 6 delays.

Engineers designed the Ariane 6 as an expendable rocket, with no near-term roadmap to introduce reusable technology into the vehicle. And officials from ESA, which funded the lion's share of the rocket's development, have acknowledged the Ariane 6 will cost more per launch than originally expected.

So there are concerns about the Ariane 6's competitiveness with SpaceX on the commercial launch market. Earlier this month, ESA's member states agreed to change the way the agency develops new rockets. Rather than continuing to follow the top-down, government-managed approach ESA has used to develop European rockets over the last five decades, the agency plans to shift to a more commercial model to make European companies developing new rockets eligible to compete for ESA launch contracts.

In advance of the long-duration engine test last week, the Ariane 6 launch team in French Guiana completed a four-second test firing of the Ariane 6 main engine in September. Last month, teams completed a complex 36-hour countdown rehearsal test that involved the loading and unloading of cryogenic propellants from the rocket's tanks.

Engineers finished qualification testing of the Ariane 6's Vinci upper-stage engine earlier this year on a test stand in Germany. One more test of the Vinci engine is planned for December at the German facility, which will involve checks of the engine's response to simulated in-flight anomalies. That test doesn't need to be completed before the Ariane 6's first test flight, officials said.

The hydrogen-fueled Vinci engine on the Ariane 6's upper stage is one of the rocket's major new elements. It is designed to restart in space, replacing the Ariane 5's upper-stage engine that was only capable of a single burn on each mission.

In the coming weeks, ground crews in French Guiana will lower the Ariane 6 rocket used during this year's tests off its launch pad and roll it back to a nearby hangar. The core stage and upper stage assigned to the first Ariane 6 launch will ship to French Guiana from factories in France and Germany for final flight preparations.

"On this final stretch towards the first flight, we still have to carry out a few additional tests to demonstrate fault tolerance, deliver the first launcher to Kourou, and perform the launch system qualification review,” Sion said.

Later this week, officials from ESA and ArianeGroup plan to brief the media on the full results from the Ariane 6 test campaign and announce a schedule for the rocket's first flight.

Last week, news stories and a posting on an infectious disease surveillance system raised fears that another novel respiratory pathogen with pandemic potential was mushrooming in northern areas of China—namely Beijing and Liaoning province. The reports referenced "undiagnosed pneumonia" in "clusters" of children, hospitals that were "overwhelmed," and parents who were questioning whether "authorities were covering up the epidemic."

But, rather than a sequel to the COVID-19 pandemic, the situation appears to be merely a side effect of it. According to independent experts and the World Health Organization, it's most likely that China is now experiencing a roaring comeback of a mix of common respiratory infections that were muted during the global health crisis. Many other countries experienced the same surges in the past year or two, including the US. As with the other countries, the wave of infection in China is mostly affecting children, who were less exposed to all sorts of pathogens amid the health restrictions, leaving them more vulnerable to infections now.

The global explosion of COVID-19 transmission and subsequent pandemic health measures severely disrupted common cycles of many infectious diseases worldwide, knocking seasonal respiratory infections like adenoviruses and RSV (respiratory syncytial virus) off their annual cycles. In the US, the 2020-2021 flu season was virtually nonexistent, for instance. But, as the novel coronavirus abated and restrictions lifted, those pathogens vigorously returned. (The US also experienced early and intense peaks of RSV and flu last year.)

China only lifted its strict zero-COVID policy at the end of 2022. Thus, this is the first year the country is heading into a respiratory transmission season without widespread restrictions.

"This phenomenon of 'lockdown exit' waves of respiratory infections is sometimes referred to as 'immunity debt,'" Francois Balloux, director of the University College London’s Genetics Institute, said in a media statement. He noted that the UK and other countries also saw such waves. But, he continued, "Since China experienced a far longer and harsher lockdown than essentially any other country on Earth, it was anticipated that those 'lockdown exit' waves could be substantial in China. Unless new evidence emerged, there is no reason to suspect the emergence of a novel pathogen."

A wave, not clusters

Last week, the WHO—which faced severe criticism for its early handling of the COVID-19 pandemic and its relationship with China—requested more information on China's surge in respiratory infections in children. On November 23, the United Nations agency held a teleconference with various Chinese health authorities to go through the requested data and ask questions. In a report of the meeting, the WHO said that the data indicated "an increase in outpatient consultations and hospital admissions of children due to Mycoplasma pneumoniae pneumonia [aka "walking pneumonia"] since May, and RSV, adenovirus and influenza virus since October."

Chinese officials told the WHO that while there were no detections of unusual or novel pathogens, there was a general increase of infections from multiple known pathogens. They also acknowledged that hospitals and clinics are busier than normal, but that hospital bed capacity and intensive care units are below capacity.

In an interview with Stat News, Maria Van Kerkhove, acting director of the WHO’s department of epidemic and pandemic preparedness and prevention, said the agency found China's data and explanations reasonable. The officials presented data from multiple pathogen surveillance systems that include age-specific data. The WHO also reviewed data from its own Global Influenza Surveillance and Response System and public databases.

"We specifically asked about clustering: Are you seeing a clustering of undiagnosed pneumonias? And they said no. They gave us the percentages of what is due to influenza, rhinovirus, adenovirus, mycoplasma pneumoniae," she said. "We asked about comparisons prior to the pandemic. And the waves that they’re seeing now, the peak is not as high as what they saw in 2018-2019….We asked some key questions like, are there any patients that were not diagnosable? No, they were infected by known pathogens. We asked if anything new was detected, any new variants, any new subtypes? And the answer was no. We asked if [they] have seen any unusual disease presentations for these pathogens. And they said no."

"[T]his is an overall increased wave, not discrete clusters," she concluded. "Basically, that signal that we were trying to verify was, in fact, not really a signal. It was just an indication of an overall transmission increase across the country."

For now. the WHO noted limited detailed information about the cases, but found overall that "the increasing trend in respiratory illnesses is expected."  The WHO advised people in China to take standard respiratory season precautions, such as getting COVID-19 and flu shots, staying home when sick, wearing masks, washing hands, and ensuring good ventilation. The agency did not recommend any specific measures for travelers to China.

What is hundreds of billions of times more powerful than the Sun, flashes on repeat with intense bursts of light, and verges on defying the laws of physics? No, it’s not your neighbors’ holiday lights glitching again. It’s an LFBOT in the depths of space.

LFBOTs (Luminous Fast Blue Optical Transients) are already quite bizarre. They erupt with blue light, radio, X-ray, and optical emissions, making them some of the brightest explosions ever seen in space, as luminous as supernovae. It is no exaggeration that they give off more energy than hundreds of billions of stars like our own. They also tend to live fast, blazing for only minutes before they burn themselves out and fade into darkness.

LFBOTs are quite rare, and in many cases their sources are unidentified. But we’ve never seen anything with the intensity of an LFBOT named AT2022tsd—aka the “Tasmanian Devil.” Its strange behavior was caught by 15 telescopes and observatories, including the W.M. Keck Observatory and NASA’s Chandra Space Telescope. Like other phenomena of its kind, it initially emitted incredible amounts of energy and then dimmed. Unlike any other LFBOT observed before, however, this one seemed to come back from the dead. It flared again—and again and again.

That’s no supernova

The most common extragalactic transient luminous events, meaning flashes of light that evolve and vanish rapidly, are supernovae. The lifespan of their initial explosion is typically mere weeks. The “Tasmanian Devil” not only evolved faster than a supernova, but 14 individual flares were observed, lighting up over a stretch of several months, or about a hundred days. Even toward the end of the event, one flare was almost as bright as the original outburst of the transient. Scientists who investigated AT2022tsd still aren’t completely sure if they have accounted for every single flare. It is even more intense than another similar LFBOT that made headlines when it was discovered: AT2018cow aka “The Cow.”

“The multiwavelength properties of AT2022tsd are most similar to those of AT2018cow-like transients… suggesting a common origin,” an international team of researchers said in a study recently published in Nature.

AT2018cow displayed emissions comparable to (though not nearly as powerful as) those of AT2022tsd. “The Cow” could also be a hint to where these events get so much energy, since other similar transients are now thought to possibly be powered by a long-lasting energy source, though no such source has actually been found for either “The Cow” or the “Tasmanian Devil” yet. This hypothetical source could be a compact object that keeps releasing enormous amounts of energy through a jet or outflow. Some transients like AT2018cow have been traced to magnetars or black holes that keep accreting material and therefore are provided with a constant stream of energy.

Out of nowhere?

The outbursts of  AT2022tsd had to have come from something, and researchers are still trying to figure out what. Supermassive black holes are a tempting option because of their massive amount of energy output. However, supermassive black holes also lurk at the centers of their galaxies. A closer look at “Tasmanian Devil” and where it was positioned in its galaxy determined it was not close enough to the galactic core to be fed by a supermassive black hole. Though that hypothesis is considered unlikely, scientists think there are still other possibilities.

“The possible power sources for the outflow are… a newborn neutron star or accretion onto a stellar-mass or intermediate-mass compact object,” they said in the same study. “In the latter case, the compact object could be a newly formed stellar-mass black hole.”

It is most likely that either a stellar-mass black hole, intermediate-mass black hole, or neutron star blasted out a phenomenon wild enough to be called the “Tasmanian Devil.” The LFBOT’s formation would probably have to have involved tidal disruption, which occurs when a star ventures too close to a black hole and is shredded by the black hole’s tidal forces. The tidal forces of neutron stars are also capable of disrupting stars. Devouring a star results in a huge input and output of energy for the black hole or neutron star, and that may explain what gave the “Tasmanian Devil” its wrath.

Could At2022tsd change our understanding of physics? Maybe. Both the extreme amount of energy it put out and the shorter bursts that continued for so long are testing the limits of physics because so many bursts of light being emitted during a short stretch of time would probably need to come from a relatively small source. But it’s not clear how we’re going to figure out what that source is.

Nature, 2023. DOI: 10.1038/s41586-023-06673-6