The James Webb Space Telescope (JWST or Webb) has detected carbon dioxide in the atmosphere of an exoplanet in a breakthrough discovery that will usher in a new era of research on worlds outside our solar system. The detection came during the James Webb Space Telescope's first campaign focusing on exoplanets, which are planets orbiting other stars. The observations targeted a hot gas giant called WASP-39 b located some 700 light-years away from Earth in the constellation Virgo. The planet, about as massive as Saturn but larger than Jupiter in size, had previously been observed by the Hubble Space Telescope in optical wavelengths and the now-retired Spitzer Space Telescope, which like Webb observed heat-carrying infrared wavelengths. The previous observations revealed the presence of water vapor, sodium and potassium in the planet's atmosphere, but it wasn't until Webb that scientists caught the signature of carbon dioxide. "As soon as the data appeared on my screen, the whopping carbon dioxide feature grabbed me," Zafar Rustamkulov, a graduate student at Johns Hopkins University in Baltimore, USA and a member of the transiting exoplanet team which undertook this investigation, said in a statement (opens in new tab). "It was a special moment, crossing an important threshold in exoplanet sciences." Carbon dioxide has never been detected on any exoplanet before. But astronomers hope that the compound can help them better understand the formation history and evolution of the planets where it's found, scientists said.
"This unequivocal detection of carbon dioxide is a major milestone for exoplanet atmosphere characterisation," Laura Kreidberg, director of the Max Planck Institute for Astronomy in Germany and co-author of a paper describing the discovery, said in a statement (opens in new tab). "Carbon dioxide helps us measure the complete carbon and oxygen inventory of the atmosphere, which is highly sensitive to the conditions in the disk where the planet formed."
Such measurements can help identify how far from its star the planet formed and determine how much solid and gaseous material it accumulated as it migrated to its current location.
The discovery was made using Webb's NIRSpec instrument, a highly sensitive spectrograph that splits incoming light into barcode-like spectra that reveal how the observed objects absorb light. Neither Webb nor any other existing telescope can capture direct images of the exoplanet or its atmosphere; instead, researchers compare observations of the star's typical light to light seen through the atmosphere as the planet passes in front of it.
The measurements of WASP-39 b were gathered on July 10, two days before the first official release of Webb images.
The researchers believe the telescope will be able to detect carbon dioxide in the atmospheres of other types of planets, including Earth-like rocky bodies scattered across the galaxy.
"The exoplanet community has been searching for the signature of carbon dioxide for decades," Kreidberg said. "With the extraordinary new capability of JWST, it will be possible to routinely detect carbon dioxide for hot Jupiters, as well as smaller, cooler planets more like our own Earth."
WASP-39 b orbits extremely close to its parent star, WASP-39, at less than 1/20th the distance between Earth and the sun), completing one orbit about every four Earth days. The planet was discovered in 2011 and can only be observed through the transits it makes around WASP-39, which cause brief dips in the star's brightness.
A paper describing the research has been accepted for publication by Nature; a preprint of the paper is available on arXiv.org(opens in new tab).
An uncrewed test of NASA’s Space Launch System and Orion spacecraft moved a step closer to launch with the completion of a flight readiness review Aug. 22. NASA officials said late Aug. 22 that the review confirmed plans for a launch of the Artemis 1 mission from Kennedy Space Center’s Launch Complex 39B as soon as 8:33 a.m. Eastern Aug. 29, at the beginning of a two-hour window. A second two-hour window is available Sept. 2, and a 90-minute window Sept. 5. “We had no exceptions today. We actually had no actions coming out of the review and we had no dissenting opinions,” Jim Free, NASA associate administrator for exploration systems development, said at a briefing after the review. There is still some “open work” to do on the SLS and Orion spacecraft before launch, said Mike Sarafin, Artemis mission manager at NASA. Some of that is planned work to prepare the vehicles for launch, “largely things that we have a path to close before we go fly.” One issue that won’t be checked until the final stages of the countdown is a step called the “hydrogen kickstart” to thermally condition the engines. That could not be tested during the series of wet dress rehearsals of the vehicle in April and June because a leak in a hydrogen bleed line detected in the final rehearsal in June. Sarafin and Charlie Blackwell-Thompson, Artemis launch director, said there is a plan to test that step during a “quiescent” phase in the countdown a few hours before launch once the core stage’s liquid hydrogen tank is filled. “We believe that we have taken all the actions to correct that problem,” Blackwell-Thompson said, but won’t know for certain until the test at the pad.
The first launch of the Space Launch System remains on schedule for as soon as Aug. 29 after the Artemis 1 mission passed its flight readiness review Aug. 22. Credit: NASA/Joel Kowsky
“If we do not successfully demonstrate that,” Sarafin said, “we are not going to launch that day.”
A launch on Aug. 29 would start what is scheduled to be a 42-day mission for the Orion spacecraft. The SLS’s upper stage will place the spacecraft on a trajectory to the moon, called translunar injection (TLI), less than two hours after liftoff. Orion will fly by the moon five days later, maneuvering into a distant retrograde orbit around the moon. After spending two weeks in that orbit, the spacecraft will maneuver back to the moon, performing another powered flyby to bring it back to Earth, splashing down off coast of San Diego, California Oct. 10.
The six-week mission is a stress test of sorts of the spacecraft. Howard Hu, NASA Orion program manager, noted that Orion is designed to support a four-person crew for three weeks. “This mission allows us to push a lot of capability,” he said. “The long-class mission we’re talking about, 42 days, will allow us to stress a lot of systems.”
“Going 42 days puts a lot more stress on those systems, plus the environment it’s in — longer exposure to radiation, longer exposure to micrometeoroid hits — means we’re going to learn a lot from this test flight,” said Bob Cabana, NASA associate administrator. “We’re stressing it beyond what it is designed for and we’ll see what we learn.”
Cabana and others at the briefing emphasized that Artemis 1 was a test flight. “It’s not without risk,” he said. That includes scenarios, he said, where Orion is not able to complete the planned mission and returns early.
NASA, though, will push to at least send Orion towards the moon to enable the mission’s top objective, testing the spacecraft’s heat shield at lunar reentry velocities of about 40,000 kilometers per hour. That includes pressing ahead with TLI even if there are issues with the spacecraft, like a solar panel that doesn’t properly deploy immediately after launch.
“We have a lean-forward strategy to get our high-priority objective, which is to demonstrate the heat shield at lunar reentry conditions,” said Sarafin. “We’re going to press to the point of translunar injection unless we’re sure we’re going to lose the vehicle.”
“We would be go on this flight for conditions that we would normally be no-go for on a crewed flight in the interest of crew safety, because we want to buy down risk,” he added.
We now know where on the moon NASA astronauts will set foot after more than 50 years' absence. The agency announced 13 potential landing regions for its Artemis 3 mission during a news conference held on Friday (Aug. 19). All the candidates are clustered near the south pole of the moon, an area of key scientific and exploration interest alike. "They're of value to the scientific community and the technology community," Mark Kirasich, deputy associate administrator for the Artemis Campaign Development Division at NASA, said during the news conference. "People want and need to do things there." "We can do exciting science at all of them," said Sarah Noble, Artemis lunar science lead for NASA's Planetary Science Division. "Many of these are places that the science community has been talking about for years." The selected regions are: Faustini Rim A, Peak Near Shackleton, Connecting Ridge, Connecting Ridge Extension, two regions on the rim of de Gerlache Crater, de Gerlache-Kocher Massif, Haworth, Malapert Massif, Leibnitz Beta Plateau, two regions on the rim of Nobile Crater and Amundsen Rim. The agency has identified and will evaluate more than 10 specific landing sites within each region, all of which are within six degrees of latitude of the south pole of the moon.
A diagram shows the 13 candidate regions for the Artemis 3 moon landing. (Image credit: NASA)
The constraints NASA has focused on to date have been strictly logistical, including how the site is lit, how easily a team of astronauts can communicate with Earth from the site, and the terrain. And NASA isn't building the vehicle that will ferry astronauts from lunar orbit to the surface, SpaceX's Starship, so the discussions have been held with the company as well as government personnel.
"This will be the first time we will land a human lander at the south pole, it will be the first landing of the Starship, so we have to pay close attention to the engineering and safety constraints of the mission and the vehicle," Kirasich said.
Moreover, site selection is complicated because NASA can't simply choose a site and move on: None of the 13 regions are constantly accessible, so the mission's launch date will determine where the astronauts can touch down.
"We will have to have, likely even for a given launch date perhaps, one or two sites, but we will have a collection of sites that we can use along a launch period," Kirasich said. "Exactly how many, we don't know yet; we have a lot to learn between now and then."
But NASA won't be relying on any scouts for additional information. The agency's venerable Lunar Reconnaissance Orbiter (LRO) has already provided the data that mission personnel need, according to Jacob Bleacher, chief exploration scientist at NASA. In fact, he said that at this point in LRO's mission, the spacecraft is in an orbit from which it can't observe these regions at all.
"But part of what went into some of our considerations for sites was the basis of availability of data," Bleacher said. "We can't target these locations again with the Lunar Reconnaissance Orbiter, but we have targeted them specifically in the past."
Whichever site Artemis 3 astronauts explore, their experience will be very different from that of the 12 men who have walked on the moon to date.
"This is a new part of the moon, it's a place that we've never explored," Noble said. "All six Apollo sites were in sort of the central part of the near side, and now we're going someplace completely different, with different and ancient geologic terrains."
And the south pole is a tantalizing destination because orbital observations show that frozen water is locked beneath the lunar surface in the stark cold of what scientists refer to as permanently shadowed regions.
Scientists hope that studying water and other "volatile" compounds that easily evaporate away will teach them about the moon's history and relationship with Earth. Meanwhile, the exploration-minded are interested in the ice because they hope it can support future humans on the moon or be made into rocket fuel.
Today's announcement comes just over a week before the targeted launch of Artemis 1, an uncrewed test flight for NASA's lunar exploration program. That mission's rocket stack is now on the launch pad at NASA's Kennedy Space Center in Florida, counting down to liftoff on Aug. 29.
Artemis 1 is meant to test the two key systems the moon exploration program will rely on: the Space Launch System (SLS) megarocket and the Orion crew capsule. If all goes well, NASA will send astronauts to lunar orbit on Artemis 2, targeting launch in 2024, before the new moon landing, which could occur in 2025 or 2026 if all goes well.
"I feel like we're on a roller coaster that's about to pass the top of the largest hill," Bleacher said. "Buckle up, everyone, we're going on a ride to the moon here."
Students at the Delft University of Technology (TU Delft) in the Netherlands are developing the world's smallest and lightest moon rover, called Lunar Zebro. Named after the Dutch phrase for "six-legged," Lunar Zebro will indeed have six legs instead of wheels, allowing it to climb taller obstacles on the moon than its wheeled counterparts can overcome. The rover will be the size of a standard sheet of paper and weigh about 5.5 pounds (2.5 kilograms). "The most unique feature of the Zebro is its locomotion, of course, which is done using C-shaped legs based on the RHex project from the University of Pennsylvania," Simon J. Stenger, the project's chief engineer, said in a video about the project. "This enables the rover to traverse difficult terrains without getting stuck." The project has been in the work for the better part of a decade, although it started with Earthbound implications. The Zebro Group was founded in 2013 with the goal of developing a "flexible and inexpensive alternative to the big and complex rover platforms we normally see around the world," according to Maneesh Kr. Verma, Zebro Group head of operations. But the group didn't set its lunar ambitions until 2017.
A still from a video shows a prototype of the Lunar Zebro moon rover. (Image credit: ESA - European Space Agency)
Now, the team hopes to send one rover to the moon in the coming years for a technical demonstration lasting one lunar day, or 14 Earth days. That mission would also include a science payload: a sensor to measure radiation on the moon.
Ultimately, the team hopes that Lunar Zebro would be able to operate in insect-like swarms. "With a swarm like this, we could explore caves and other risky terrains where a conventional rover might not dare to go," Verma said. "Also, searching for specific features or things becomes easier since a swarm can cover a much larger area at once."
Size, method of movement and swarm capabilities aside, Lunar Zebro also stands out because it is an all-student project. "Since the inception of the project in 2017, almost 120 students have now been a part of the project, and this is their legacy," said Prachi Sachdeva, Lunar Zebro head of partner relations.
And of course, the rover would join the select ranks of successful missions to the lunar surface. To date, only the U.S., Soviet Union and China have executed soft landings on the moon, although a host of nations is looking to notch the milestone in coming years. "The Lunar Zebro will be not only the first Dutch mission to land on the moon, but also the first European."
Spaceflight shipped its Sherpa-LTC2 orbital transfer vehicle (OTV) Aug. 10 to Cape Canaveral in Florida, where it will make a second attempt to debut the chemically powered space tug on a SpaceX launch. The Seattle-based company’s first Sherpa-LTC, which has more powerful thrusters for dropping satellites off in specific orbits post-launch faster than the other tugs it has deployed, leaked propellant in December after integrating with SpaceX equipment at Cape Canaveral. That led to SpaceX dropping the OTV from a Falcon 9 rideshare mission in January, forcing Spaceflight to find alternative launches for 10 cubesats set to hitch a ride on it. Benchmark Space Systems provided the non-toxic propulsion subsystems for both OTVs. The upcoming SpaceX launch will be the first time Benchmark’s Halcyon Avant bi-propellant thrusters have flown in space. Spaceflight CEO Curt Blake said Sherpa-LTC2 has “gone through all kinds of checks to get things right” ahead of its launch in September. Ahead of its four-to-five-day journey via truck from Seattle to Cape Canaveral, the OTV was integrated with a payload for Boeing’s Varuna Technology Demonstration Mission (Varuna-TDM). The demonstrator aims to test V-band communications for a proposed constellation of 147 non-geostationary broadband satellites.
“Potential customers and industry partners will have the opportunity to participate in preliminary evaluations of this service, which is intended to provide unprecedented levels of connectivity across the globe to government and commercial customers,” a Boeing spokesperson said.
California-based Astro Digital designed and built the payload, and booked the launch from Spaceflight on behalf of Boeing for what will be a dedicated mission. Astro Digital also provided the command and control system for Spaceflight’s Sherpa-LTC2.
SpaceX is slated to launch the OTV as part of a mission to deploy a batch of Starlink broadband satellites that Spaceflight expects will launch to low Earth orbit this fall.
If the mission goes according to plan, the Sherpa-LTC2 will deploy from Falcon 9 around 310 kilometers above the Earth, from where the OTV will ignite and transport its customer payload to a 1,000-kilometer low Earth orbit.
Frayed SpaceX relationship
Spaceflight has relied on SpaceX launches to deploy its expanding line of next-generation space tugs.
The first of these was a Sherpa-FX, which has no propulsion, that made its debut as part of SpaceX’s Transporter-1’s rideshare mission in January 2021
SpaceX’s Transporter-2 mission then deployed a Sherpa-FX2 and a Sherpa-LTE — Spaceflight’s first OTV with electric propulsion — later that year in June.
After the Sherpa-LTC was removed from SpaceX’s Transporter 3 flight in January 2022, Spaceflight had planned to launch a Sherpa-FX on its next rideshare flight in April.
However, SpaceX decided to remove the tug from its Transporter 4 mission following concerns about environmental factors affecting the satellites installed on the OTV.
About a week later, SpaceX said it would no longer work with Spaceflight after currently manifested missions.
Blake declined to discuss Spaceflight’s relationship with SpaceX, or what would be its last OTV to fly with the company.
To broaden its options, Spaceflight announced Aug. 8 an agreement to launch future space tugs on Arianespace’s Vega launch vehicles, including its next-generation Vega C rocket. Spaceflight said it signed a deal to access Vega with Italy’s SAB Launch Services — which also provides launch services on other European launchers — to cover launches starting as soon as next year.
Blake said Spaceflight is “very close to identifying specifics” for the customers and Vega missions that would use Sherpa, with the first launch likely around the end of 2023 or early 2024.
Spaceflight and SAB are also partnering to offer customers access to shared integration and storage facilities across Europe and the United States.
Blake said Spaceflight is talking to “a number of” other launch providers, and “getting close to finalizing deals to launch OTVs on various launch vehicles.”
Growing space tug family
Meanwhile, Spaceflight has been working through its remaining manifest with SpaceX to develop its space tug product line.
In May 2022, the company debuted Sherpa-AC (attitude control), a version for hosting payloads, on SpaceX’s Transporter 5 mission.
SpaceX is slated to launch a Spaceflight space tug in mid-2023 when it is set to deploy a Sherpa EScape (Sherpa-ES), which is designed to swing around the moon to deliver payloads in geostationary orbit.
According to Blake, its next OTV to fly could be the initial Sherpa-LTC that is under refurbishment.
“It’s a possibility,” he said, “we’ve got some customers that want to go, and we’re trying to find the capacity right now.”
A large portion of those are new vehicles, he added.
