NASA

reentry-of-nasa-satellite-will-exceed-the-agency’s-own-risk-guidelines

Reentry of NASA satellite will exceed the agency’s own risk guidelines

No one on the ground has ever been injured by falling space junk, but there are examples of space debris causing property damage.

NASA’s two Van Allen Probes launched into elliptical orbits ranging from a few hundred miles above Earth up to an apogee, or high point, of nearly 20,000 miles. The orbits are inclined 10 degrees to the equator, limiting the risk of injury or damage to a swath of the tropics. NASA ended the mission in 2019 when the satellites ran out of fuel.

At that time, NASA engineers expected the spacecraft to reenter the atmosphere in 2034. But higher-than-anticipated solar activity caused the atmosphere to swell outward, increasing atmospheric drag on the satellites beyond initial estimates, according to NASA. Van Allen Probe B is expected to reenter no earlier than 2030, with a similar risk to the public.

The two spacecraft were built by the Johns Hopkins University Applied Physics Lab. NASA said the mission made several major discoveries, including “the first data showing the existence of a transient third radiation belt, which can form during times of intense solar activity.”

Several NASA satellites have reentered the atmosphere without complying with the government’s risk standard. One of the satellites, the Rossi X-ray Timing Explorer, fell out of orbit in 2018 with a 1-in-1,000 chance of harming someone on the ground. No one was hurt. RXTE was launched in 1995, just four months before NASA issued its first standard on orbital debris mitigation and reentry risk management.

While NASA has exceeded its standards before, the US government is not a top offender when it comes to unmitigated reentry risks. China launched four heavy-lift Long March 5B rockets between 2020 and 2022, and left its massive core stages in orbit to fall back to Earth. The four abandoned rocket cores, each nearly 24 tons in mass, reentered the atmosphere uncontrolled. Two of them dropped wreckage on land—in the Ivory Coast and Borneo—but no injuries were reported.

Reentry of NASA satellite will exceed the agency’s own risk guidelines Read More »

nasa-and-spacex-disagree-about-manual-controls-for-lunar-lander

NASA and SpaceX disagree about manual controls for lunar lander

The report notes that during every one of the Apollo program’s crewed lunar landings, astronauts engaged the backup manual control method. (Of course, this occurred six decades ago, when flight software was considerably less sophisticated than today.)

As NASA and SpaceX near a key decision point, known as Critical Design Review, the issue remains unresolved. The new report suggests that this may result in automation being the only landing method.

A similar fight over Dragon

The space agency and SpaceX engaged in a similar back-and-forth during the design process for the Crew Dragon spacecraft a decade ago. SpaceX initially wanted touchscreens only, with limited flight commands available to astronauts. NASA pushed back and wanted what were essentially joysticks for astronauts to fly the vehicles like previous spacecraft. A former NASA astronaut then working at SpaceX, Garret Reisman, helped broker a compromise by which astronauts could manually fly the vehicles using controls on touchscreens.

However, the new report says the flight controls for Dragon were built on many successful missions by a cargo version of the vehicle that flew to the International Space Station.

“Starship will not have the same level of proven flight heritage in the actual operating environment for its crewed lunar missions,” the report states. “Incorporating this system capability is a key element of HLS’s human-rating certification and part of an essential crew survival strategy.”

A design for Blue Origin’s manual control has not yet been made, according to the inspector general.

There is other interesting information in the report, including details on the uncrewed demonstration flights that SpaceX and Blue Origin are both required to fly before human missions can take place. The inspector general notes that these flights will not require life support systems and airlocks, as human missions will. Nor will the tall Starship vehicle be required to test an elevator to bring crew down to the surface.

There will also be a limited ability to test the abrasive impact of lunar dust, expected to be returned inside the vehicles after Moonwalks, on life support equipment during these uncrewed demonstrations.

NASA and SpaceX disagree about manual controls for lunar lander Read More »

with-gateway-likely-gone,-where-will-lunar-landers-rendezvous-with-orion?

With Gateway likely gone, where will lunar landers rendezvous with Orion?


Drink up, astrodynamicists!

“We will challenge every requirement, clear every obstacle, delete every blocker.”

Artist’s illustration of Starship on the surface of the Moon. Credit: SpaceX

Last week, NASA Administrator Jared Isaacman unveiled a major shakeup in the Artemis Program, intended to put the nation on a better path back to the Moon. The changes focused largely on increasing the launch cadence of NASA’s large SLS rocket and putting a greater emphasis on lunar surface activities. Days later, the US Senate indicated that it broadly supported these plans.

This is all well and good, but it neglects a critical element of the Artemis program: a lander capable of taking astronauts down to the lunar surface from an orbit around the Moon and back up to rendezvous with Orion. NASA has contracted with SpaceX and Blue Origin to develop these landers, Starship and Blue Moon MK2, respectively.

As part of his announcement, Isaacman said a revamped Artemis III mission will now be used to test one or both of these landers near Earth before they are called upon to land humans on the Moon later this decade.

NASA will launch Artemis III next year, he said, to be followed by one or possibly even two lunar landings in 2028. A single landing before the end of 2028 seems like a stretch, even for glass-half-full optimists in the space community. And for there to be a chance of happening, SpaceX or Blue Origin, or both, need to get hustling quickly.

Can they?

“Challenge every requirement”

Isaacman is mindful of these challenges, and one of his first moves as administrator was meeting with engineers from SpaceX and Blue Origin to hear their ideas for accelerating NASA’s Artemis timeline.

After this meeting on January 13, Isaacman said NASA would do what it could to facilitate the faster development of a Human Landing System: “We will challenge every requirement, clear every obstacle, delete every blocker and empower the team to deliver… and we will do it with time to spare.”

What does this actually mean? It suggests that Isaacman has directed his teams to make working with NASA less cumbersome for SpaceX and Blue Origin.

For example, to reach the Moon during the initial Artemis missions, a lander must dock with the Orion spacecraft. That may sound routine, as spacecraft have been rendezvousing and docking in space for six decades.

However, Orion is saddled with thousands of requirements, and virtually every decision point regarding docking must be signed off on by the lander company—SpaceX or Blue Origin—as well as NASA, Orion’s contractor Lockheed Martin, and the European service module contractor Airbus. Additionally, Orion has a lot of sensitive elements to work around, such as the plumes of its thrusters, and engineers have spent a lot of time working on issues such as ensuring consistent cabin pressures between vehicles. In short, it gets complicated fast.

A carbonated orbit emerges

One way NASA is helping the lander companies is by no longer requiring them to dock with Orion in a near-rectilinear halo orbit, an elliptical orbit that comes as close as 3,000 km to the surface of the Moon and as far as 70,000 km. This is where NASA planned to construct the Lunar Gateway space station, which is now likely to be canceled. It’s a boon for lunar landers since it required more energy to first stop there before dropping down to the surface.

Why not simply have Orion meet the landers in a low-lunar orbit, similar to the Apollo Program? This would allow the landers to consume less propellant on the way down and back up from the Moon. The reason is that, due to a number of poor decisions over the last 15 years, the Orion spacecraft’s service module does not have the performance needed to reach low-lunar orbit and then return safely to Earth. Hence the use of a near-rectilinear halo orbit.

A comparison between the NRHO and EPO/CoLA orbits.

Credit: American Astronautical Society conference paper

A comparison between the NRHO and EPO/CoLA orbits. Credit: American Astronautical Society conference paper

However, a research paper published in July 2022 by NASA engineers at Johnson Space Center analyzes several other circular and elliptical orbits that Orion could reach with its present propulsive capabilities. Out of this analysis came another useful orbit with a name that just rolls off the tongue: Elliptical Polar Orbit with Coplanar Line of Apsides, or EPO/CoLA.

There are many details about the EPO/CoLA orbit in the research paper, but critically, its closest point to the Moon lies just 100 km above the Moon’s surface (the apolune distance is 6,500 km). For many landing sites, the paper notes, a Human Landing System vehicle can perform a single burn to reach a much lower orbit.

As part of his change in plans, Isaacman said the Space Launch System rocket’s upper stage would be “standardized” for Artemis IV and beyond. That means the first lunar landing mission will use a new upper stage, likely the Centaur V built by United Launch Alliance. This will have more propulsive capabilities than the current rocket, so it is possible that for Artemis IV, Orion could reach an even more favorable orbit (i.e., closer to the Moon, requiring less energy to reach the surface) than EPO/CoLA.

Can Starship be accelerated?

At the end of the day, it’s helpful to find new orbits and relax requirements where appropriate. But it will still be up to the lander contractors to deliver the goods, and for NASA, the sooner the better.

Last November, Ars looked at several ways Starship might be brought online faster as a lunar lander. Perhaps the biggest problem with using Starship as a lander is the need to fly multiple uncrewed tanker missions to refuel Starship in low-Earth orbit before it transits to the Moon and awaits a crew aboard Orion. This necessitates an estimated one- or two-dozen launches.

The best solution we could come up with was flying an optimized, expendable Starship tanker stage that would maximize propellant delivery per flight. When asked about this, though, SpaceX founder Elon Musk shot down the idea. Once Starship begins flying at rate, Musk believes, a dozen or more tanker missions per lunar flight will not pose a major impediment.

So it should come as no surprise that SpaceX has not proposed significant changes to its Human Landing System hardware. In response to NASA’s desire to accelerate the Artemis timeline, the company has indicated that it will prioritize the Human Landing System more as part of the Starship program. The company also suggested that eliminating the requirement to dock in near-rectilinear halo orbit could open up new mission plans, including potentially docking with Orion in orbit around Earth rather than the Moon.

What about Blue Origin?

Blue Origin, founded by Jeff Bezos, has been more responsive. Last October, Ars reported that the company had started working on a faster architecture that would not require orbital refueling. A month later, Blue Origin’s chief executive, Dave Limp, said the company “would move heaven and Earth” to help NASA reach the Moon sooner.

Based on recent documents reviewed by Ars, the company is continuing to refine its plan for a human lunar landing. Without a requirement to rendezvous in a near-rectilinear halo orbit, a lunar landing could potentially be accomplished with as few as three launches of Blue Origin’s New Glenn rocket. This would require the more powerful 9×4 variant of the New Glenn rocket now in development. The EPO/CoLA orbit described above enables such a mission profile.

One mission plan seen by Ars shows the launch of a simplified MK2 lander on one rocket, and two more launches of transfer stages, which subsequently dock in low-Earth orbit. The first transfer stage pushes this stack out of low-Earth orbit before separating. The second transfer stage pushes the lander into EPO/CoLA, where it docks with Orion and two astronauts move on board MK2. This second transfer stage then moves the lander to a 15 x 100 km lunar orbit before separating. MK2 then flies down to the Moon.

After a short stay on the Moon, the interim MK2 lander would ascend back to the EPO/CoLA, where it meets up with Orion.

There are plenty of questions about the readiness of the Blue Origin hardware, of course. And there are a lot of moving pieces now with the Moon landing moving to Artemis IV and the probable use of new orbits for a rendezvous with Orion near the Moon. So all of this remains very notional.

Neither NASA nor Blue Origin has spoken publicly about their accelerated landing plans. Hopefully, that will change soon, because it’s entirely possible that NASA’s best chance to reach the Moon before China will come down to the ability of a company that proudly sports a turtle as a mascot to move a little more quickly.

Note: This story was updated at 11: 30 am ET Friday with additional information.

Photo of Eric Berger

Eric Berger is the senior space editor at Ars Technica, covering everything from astronomy to private space to NASA policy, and author of two books: Liftoff, about the rise of SpaceX; and Reentry, on the development of the Falcon 9 rocket and Dragon. A certified meteorologist, Eric lives in Houston.

With Gateway likely gone, where will lunar landers rendezvous with Orion? Read More »

ding-dong!-the-exploration-upper-stage-is-dead

Ding-dong! The Exploration Upper Stage is dead

Now, you might think NASA would ask industry for solutions to this problem. After all, United Launch Alliance was developing a more powerful upper stage for its Vulcan rocket, the Centaur V, that used the same propellant as the core stage of the SLS rocket. And Blue Origin was also developing a powerful upper stage engine, the BE-3U, powered by hydrogen. These options were cheaper, available, and … summarily ignored.

10 years, billions of dollars, and not much to show for it

Congress, smelling jobs, wanted NASA to develop a brand new upper stage. So in 2016, lawmakers allocated $85 million for preliminary work on the upper stage, and have since awarded more than $3.5 billion.

For the development of a rocket’s second stage.

With engines (RL-10s) that have been flying in space for six decades.

And after all of this, a decade later, the upper stage remains years from being ready to fly.

In some ways, the Exploration Upper Stage was the perfect vehicle for pork. It not only spread largesse among Boeing and Aerojet Rocketdyne (for the engines), but it also necessitated a massive new launch tower in Florida. That was good for the Exploration Ground Systems program at Kennedy Space Center.

The original cost estimates of these projects are always instructive to look back on. Boeing’s initial contract to build the Exploration Upper Stage started at $962 million, and NASA planned to launch the rocket on the second flight of the SLS in 2021. Oops. As for the launch tower, the initial estimate for its cost was $383 million, but as of late, it was heading north of $2 billion. So we are talking billions and billions and billions of dollars for a relatively straightforward upper stage, using off-the-shelf engines and a large launch tower.

Ding-dong! The Exploration Upper Stage is dead Read More »

asteroid-defense-mission-shifted-the-orbit-of-more-than-its-target

Asteroid defense mission shifted the orbit of more than its target


The binary asteroid’s orbit around the Sun was affected by the impact.

Italy’s LICIACube spacecraft snapped this image of asteroids Didymos (lower left) and Dimorphos (upper right) a few minutes after the impact of DART on September 26, 2022. Credit: ASI/NASA

On September 26, 2022, NASA’s Double Asteroid Redirection Test (DART) spacecraft crashed into a binary asteroid system. By intentionally ramming a probe into the 160-meter-wide moonlet named Dimorphos, the smaller of the two asteroids, humanity demonstrated that the kinetic impact method of planetary defense actually works. The immediate result was that Dimorphos’ orbital period around Didymos, its larger parent body, was slashed by 33 minutes.

Of course, altering a moonlet’s local orbit doesn’t seem like enough to safeguard Earth from civilization-ending impacts. But now, as long-term observational data has come in, it seems we accomplished more than that. DART actually changed the trajectory of the entire Didymos binary system, altering its orbit around the Sun.

Tracking space rocks

Measuring the orbital shift of a 780-meter-wide primary asteroid and its moonlet from millions of miles away isn’t trivial. When DART slammed into Dimorphos, it didn’t knock the binary system wildly off its trajectory around the Sun. The change in the system’s heliocentric trajectory was expected to be small, a minuscule nudge that would become apparent only after months or years of continuous observation. By analyzing enough painstakingly gathered data, a global team of researchers led by Rahil Makadia at the University of Illinois Urbana-Champaign has now determined the consequences of the DART impact.

To find the infinitesimal deviation DART created, Makadia’s team relied mostly on a technique called stellar occultation. When an asteroid passes in front of a distant star from the perspective of an observer on Earth, the star briefly blinks out. By precisely timing these blinks as they sweep across the globe, astronomers can pinpoint an asteroid’s position with astonishing accuracy.

Between October 2022 and March 2025, we captured 22 such stellar occultations of the Didymos system. Combined with a huge dataset publicly available at the Minor Planet Data Center that included nearly 6,000 ground-based astrometric measurements taken over 29 years, optical navigation data from the DART probe’s approach, and ground-based radar measurements, researchers finally had all they needed.

“Once we had enough measurements before and after the DART impact, we could discern how Didymos’ orbit has changed,” Makadia said.

When the vending-machine-sized DART probe crashed into Dimorphos at over 22,000 kilometers per hour, it decreased the along-track velocity of the entire Didymos system by roughly 11.7 micrometers per second. But the team thinks it’s still significant. “When you do it early enough, even a small impulse can accumulate over years and cause a meaningful shift,” Makadia explained.

Also, the DART impact itself was not the only force that changed Didymos’ orbit.

The ejecta engine

The pure kinetic energy of a 500-kilogram spacecraft hitting at hypersonic speeds is impressive, but on its own, it would not slow a huge asteroid that much. When DART struck Dimorphos, it blasted pulverized rock and dust out into the void. “The material kicked up off an asteroid surface acts like an extra rocket plume,” Makadia said.

Scientists call this effect the momentum enhancement factor, denoted by the Greek letter beta. If the spacecraft impact transferred exactly its own momentum and no debris was kicked up, beta would be exactly one.

Because Dimorphos orbits Didymos, some of the ejecta remained trapped in the system, where it altered the mutual orbit between the two rocks. But a crucial fraction of the ejecta achieved escape velocity from the entire binary system. The momentum carried away by the system-escaping debris is what ultimately contributed to shoving the center of mass of the whole Didymos-Dimorphos pair. “In our case, we found that the beta parameter due to DART impact was around two,” Makadia explained.

The debris blasted completely out of the Didymos system gave the asteroids a push roughly equal to the initial impact of the spacecraft itself.

To calculate how momentum was transferred, Makadia and his colleagues had to determine precisely how massive Didymos and Dimorphos are. By linking the heliocentric deflection to the previously known changes in Dimorphos’ local orbit, the researchers were able to perform a neat mathematical trick to uncover the bulk densities of both asteroids. And this revealed something a bit unexpected about the Didymos system.

“Most studies were going under the assumption that both asteroids have equal density—turns out that assumption was not correct,” Makadia said.

A rubble pile

Based on Makadia’s calculations, Didymos, the primary body, is relatively solid. It has a bulk density of around 2.6 tons per cubic meter, which aligns with standard estimates for siliceous asteroids. Dimorphos, however, is a different story. Its density is a surprisingly low 1.51 tons per cubic meter. This implies that the smaller asteroid targeted by DART is essentially a fluffy, loosely bound agglomeration of boulders, rocks, and dust, with empty voids between the rubble.

“This was a real surprise,” Makadia said. “We previously didn’t know anything about the density of Dimorphos.” The contrast in density tells the story of how this binary system formed.

Billions of years of uneven heating and radiation from the Sun can cause an irregularly shaped asteroid like Didymos to gradually spin faster, a phenomenon known as the YORP (Yarkovsky, O’Keefe, Radzievskii, Paddack) effect. Eventually, Didymos spun so fast that the centrifugal force overcame its gravity, and it began shedding loose material from its equator. That shed material eventually coalesced in orbit, gently clumping together to form the porous, fragile moonlet we now know as Dimorphos.

Overall, Didymos is nearly 200 times more massive than its smaller companion, which explains why shifting the larger asteroid system takes such an enormous amount of force. The sheer inertia of Didymos means that the barycenter deflection of its entire system was just a tiny fraction of the deflection felt locally by Dimorphos.

Planetary defense

Makadia’s findings confirm the models we used to estimate the consequences of the DART impact: The Didymos system still poses zero threat to us, at least for the next 100 years or so. “The pre-DART condition was that the closest the Didymos system can get to Earth was around 15 lunar distances, and this has not changed appreciably,” Makadia explained.

The goal of DART was primarily to take our planetary defense out of the realm of computer models and get us some hands-on, practical experience, and Makadia thinks we succeeded in doing that. “Our work proves that hitting the secondary asteroid is a viable path for deflecting a binary system away as long as the push is large enough,” he said. “This wasn’t the goal of DART, but we can always design a bigger spacecraft.”

This experience applies both to deflecting binary asteroid systems like Didymos and singular objects. “Our results definitely help us in all sorts of future kinetic impact endeavors,” Makadia added.

The final verification of the DART mission’s consequences, though, will come in late 2026, when the European Space Agency’s Hera spacecraft will arrive at the Didymos system.

By performing independent, in-situ measurements of things like the density of Didymos and Dimorphos, Hera will provide a lot of precise gravitational and physical data that Makadia hopes to use to refine his calculations.

“It’s a high-fidelity instrument that hopefully will give us confirmation of what we believe,” Makadia said. “Plus, there are always new things to be found out when we visit an asteroid. I’m very excited about when Hera gets there.”

Science Advances, 2026.  DOI: 10.1126/sciadv.aea4259

Photo of Jacek Krywko

Jacek Krywko is a freelance science and technology writer who covers space exploration, artificial intelligence research, computer science, and all sorts of engineering wizardry.

Asteroid defense mission shifted the orbit of more than its target Read More »

congress-extends-iss-and-tells-nasa-to-get-moving-on-private-space-stations

Congress extends ISS and tells NASA to get moving on private space stations

Nominally, NASA plans to have one or more of these companies operating a commercial space station in low-Earth orbit by 2030. This is the date at which the US space agency has stated it will retire the aging laboratory, some elements of which are now nearly three decades old. However, some space policy officials have questioned whether any of the companies might be ready by then.

Cruz and other senators on the committee appear to share those concerns, as their legislation extends the International Space Station’s lifespan from 2030 to 2032 (an extension must still be approved by international partners, including Russia). Moreover, the authorization bill states, “The Administrator shall not initiate the de-orbit of the ISS until the date on which a commercial low-Earth orbit destination has reached an initial operational capability.”

With this legislation, the US Senate is making clear that it views a permanent human presence in low-Earth orbit as a high priority. This version of the authorization legislation must still be passed by the full Senate and work its way through the House of Representatives.

Reaction from the companies

After the legislation passed the Commerce committee, Axiom Space said on social media that it welcomes the changes: “Axiom Space is proud to support the NASA Authorization Act of 2026. The bill is a clear indicator that Chairman @SenTedCruz and the Senate Commerce Committee are determined to ensure the success of the entire human spaceflight enterprise.”

In an interview, the chief executive of Vast, Max Haot, said his company also welcomed the clarifying legislation—both for its language on commercial space stations as well as its reflection of the fact that NASA Administrator Jared Isaacman has been working overtime to set the Artemis lunar program on a better path for success.

“We are really impressed by what Jared has been able to do with the American space program and aligning all of the stakeholders,” he said. “As it relates to commercial space stations, we were happy to see the renewed commitment to transition from the ISS to commercial alternatives.”

Haot said there should not be a hard date for de-orbiting the International Space Station but that it should depend on the readiness of the commercial providers. He said Vast is confident that, should NASA issue an RFP and awards for private providers this year, Vast will be ready to support a continuous human presence in low-Earth orbit by the end of 2030.

Congress extends ISS and tells NASA to get moving on private space stations Read More »

the-us-senate-empowers-nasa-to-fully-engage-in-lunar-space-race

The US Senate empowers NASA to fully engage in lunar space race

During a brief hearing on Wednesday morning, the Senate Committee on Commerce, Science, and Transportation spent only a few minutes “marking up” new legislation that provides guidance to NASA for its various initiatives, including the Artemis program to land humans on the Moon.

“Our bill authorizes critical funding for, and gives strategic direction to, the agency in line with the priorities of administrator Isaacman and the Trump administration,” said the committee’s chairman, Sen. Ted Cruz, (R-Texas).

The duration of the hearing, however, seems to be the inverse of its significance.

Elements of the legislation, now branded as The NASA Authorization Act of 2026 (see full text), have undergone significant revisions since just last week. The sweeping changes follow NASA Administrator Jared Isaacman’s announcement on Friday that he was shuffling the Artemis program to ensure that the US space agency would beat China back to the Moon and establish a long-term presence at the lunar south pole. In large part, the Senate’s bill endorses Isaacman’s plan of action.

“NASA faces a series of challenges,” Cruz said Wednesday. “Those challenges culminated in an announcement last Friday that NASA was making major changes to the Artemis missions and our eventual return to the lunar surface. Today, the Commerce committee will help guide those changes.”

Major changes to Artemis approved

With the revised legislation, Cruz and the Senate committee have empowered Isaacman and NASA to make significant changes to the Artemis Program. The revised plan for the space agency will likely lead to more launches and a much greater emphasis on the lunar surface.

The US Senate empowers NASA to fully engage in lunar space race Read More »

no-fooling:-nasa-targets-april-1-for-artemis-ii-launch-to-the-moon

No fooling: NASA targets April 1 for Artemis II launch to the Moon

NASA has fixed the problem that forced the removal of the rocket for the Artemis II mission from its launch pad last month, but it will be a couple of weeks before officials are ready to move the vehicle back into the starting blocks at Kennedy Space Center in Florida.

The 322-foot-tall (98-meter) rocket could have launched as soon as this week after it passed a key fueling test on February 21. During that test, NASA loaded the Space Launch System rocket with super-cold propellants without any major problems, apparently overcoming a persistent hydrogen leak that prevented the mission from launching in early February.

However, another problem cropped up just one day after the successful fueling demo. Ground teams were unable to flow helium into the rocket’s upper stage. Unlike the connections to the core stage, which workers can repair at the launch pad, the umbilical lines leading to the upper stage higher up the rocket are only accessible inside the cavernous Vehicle Assembly Building (VAB) at Kennedy.

Mission managers quickly decided to roll the rocket back to the assembly building for troubleshooting. The rocket returned to the VAB on February 25, and within a week, engineers found the source of the helium flow issue. Inspections revealed that a seal in the quick disconnect, through which helium flows from ground systems into the rocket, was obstructing the pathway, according to NASA.

Sealing the deal

“The team removed the quick disconnect, reassembled the system, and began validating the repairs to the upper stage by running a reduced flow rate of helium through the mechanism to ensure the issue was resolved,” NASA said in an update posted Tuesday. “Engineers are assessing what allowed the seal to become dislodged to prevent the issue from recurring.”

No fooling: NASA targets April 1 for Artemis II launch to the Moon Read More »

former-nasa-chief-turned-ula-lobbyist-seeks-law-to-limit-spacex-funding

Former NASA chief turned ULA lobbyist seeks law to limit SpaceX funding

A highly regarded administrator

A former Republican House member from Oklahoma, Bridenstine served a generally well-regarded term as NASA administrator from April 2018 to January 2021 during President Trump’s first term.

The high point of his tenure in office came in May 2020, thanks to SpaceX. That summer, with the Crew Dragon vehicle, SpaceX and NASA successfully flew two astronauts to the International Space Station, breaking America’s dependence on Russia for low-Earth orbit transportation. Bridenstine relished this with an oft-repeated mantra of launching American astronauts on American rockets from American soil.

However, after leaving NASA, Bridenstine has appeared to become hostile to the dominant company founded by Elon Musk. He joined the board of a competitor, Viasat. Later, Bridenstine became the executive of Government Operations for United Launch Alliance, while his firm also collected a hefty lobbying fee.

All of this is not particularly abnormal for the revolving door in Washington, DC, where senior officials go between government positions and industry. Nevertheless, some observers were surprised by the striking nature of Bridenstine’s attack on NASA for the decision to award a Human Landing System contract to SpaceX in April 2021, three months after he left office. A new administrator had not yet been confirmed at NASA at the time, so a senior NASA engineer, Steve Jurczyk, served as acting administrator for the space agency.

Attacking his own process

Bridenstine sharply criticized this lander decision during testimony before Cruz’s committee last September.

“There was a moment in time when we had no NASA administrator,” he said at 42 minutes into the hearing. “It was after I was gone, and before Senator Nelson became the NASA administrator. An architecture was selected. And I don’t know how this happens, but the biggest decision in the history of NASA, at least since I’ve been paying attention, the biggest decision happened in the absence of a NASA administrator. And that decision was, instead of buying a Moon lander, we’re gonna buy a big rocket.”

Former NASA chief turned ULA lobbyist seeks law to limit SpaceX funding Read More »

nasa-shakes-up-its-artemis-program-to-speed-up-lunar-return

NASA shakes up its Artemis program to speed up lunar return


“Launching SLS every three and a half years or so is not a recipe for success.”

Artist’s illustration of the Boeing-developed Exploration Upper Stage, with four hydrogen-fueled RL10 engines. Credit: NASA

NASA Administrator Jared Isaacman announced sweeping changes to the Artemis program on Friday morning, including an increased cadence of missions and cancellation of an expensive rocket stage.

The upheaval comes as NASA has struggled to fuel the massive Space Launch System rocket for the upcoming Artemis II lunar mission, and Isaacman has sought to revitalize an agency that has moved at a glacial pace on its deep space programs. There is ever-increasing concern that, absent a shake-up, China’s rising space program will land humans on the Moon before NASA can return there this decade with Artemis.

“NASA must standardize its approach, increase flight rate safely, and execute on the president’s national space policy,” Isaacman said. “With credible competition from our greatest geopolitical adversary increasing by the day, we need to move faster, eliminate delays, and achieve our objectives.”

Shaking things up

The announced changes to the Artemis program include:

  • Cancellation of the Exploration Upper Stage and Block IB upgrade for SLS rocket
  • Artemis II and Artemis III missions will use the SLS rocket with existing upper stage
  • Artemis IV, V (and any additional missions, should there be) will use a “standardized” upper stage
  • Artemis III will no longer land on the Moon; rather Orion will launch on SLS and dock with Starship and/or Blue Moon landers in low-Earth orbit
  • Artemis IV is now the first lunar landing mission
  • NASA will seek to fly Artemis missions annually, starting with Artemis III in “mid” 2027, followed by at least one lunar landing in 2028
  • NASA is working with SpaceX and Blue Origin to accelerate their development of commercial lunar landers for Artemis IV and beyond

At the core of Isaacman’s concerns is the low flight rate of the SLS rocket and Artemis missions. During past exploration missions, from Mercury through Gemini, Apollo, and the Space Shuttle program, NASA has launched humans on average about once every three months. It has been nearly 3.5 years since Artemis I launched.

“This is just not the right pathway forward,” Isaacman said.

A senior NASA official, speaking on background to Ars, noted that the space agency has experienced hydrogen and helium leaks during both the Artemis I and Artemis II pre-launch preparations, and these problems have led to monthslong delays in launch.

“If I recall, the timing between Apollo 7 and 8 was nine weeks,” the official said. “Launching SLS every three and a half years or so is not a recipe for success. Certainly, making each one of them a work of art with some major configuration change is also not helpful in the process, and we’re clearly seeing the results of it, right?”

The goal, therefore, is to standardize the SLS rocket into a single configuration to make it as reliable as possible and to launch it as frequently as every 10 months. NASA will fly the SLS vehicle until there are commercial alternatives to launch crew to the Moon, perhaps through Artemis V as Congress has mandated, or perhaps even a little longer.

Is everyone on board?

The NASA official said all of the agency’s key contractors are on board with the change, and senior leaders in Congress have been briefed on the proposed changes.

The biggest opposition to these proposals would seemingly come from Boeing, which is the prime contractor for the Exploration Upper Stage, a contract worth billions of dollars to develop a more powerful rocket that was due to launch for the first time later this decade. However, in a NASA news release, Boeing appeared to offer at least some support for the revised plans.

“Boeing is a proud partner to the Artemis mission and our team is honored to contribute to NASA’s vision for American space leadership,” said Steve Parker, Boeing Defense, Space & Security president and CEO, in the news release. “The SLS core stage remains the world’s most powerful rocket stage, and the only one that can carry American astronauts directly to the moon and beyond in a single launch. As NASA lays out an accelerated launch schedule, our workforce and supply chain are prepared to meet the increased production needs.”

Solid reasons for changing Artemis III

NASA’s new approach to Artemis reflects a return to the philosophy of the Apollo program. During the late 1960s, the space agency flew a series of preparatory crewed missions before the Apollo 11 lunar landing. These included Apollo 7 (a low-Earth orbit test of the Apollo spacecraft), Apollo 8 (a lunar orbiting mission), Apollo 9 (a low-Earth orbit rendezvous with the lunar lander), and Apollo 10 (a test of the lunar lander descending to the Moon, without touching down).

With its previous Artemis template, NASA skipped the steps taken by Apollo 7, 9, and 10. In the view of many industry officials, this leap from Artemis II—a crewed lunar flyby of the Moon testing only the SLS rocket and Orion spacecraft—to Artemis III and a full-on lunar landing was enormous and risky.

The new approach will, in NASA parlance, “buy down” some of the risk for a 21st-century lunar landing, including performance and handling of a lunar lander, rendezvous and docking, communications, spacesuit performance, and more.

It will also increase the challenges for NASA. In particular, the timeline to bring the Orion spacecraft to readiness for a mid-2027 launch will need to be accelerated, and efforts to integrate that vehicle with one or both lander providers will need serious attention.

For the Artemis IV lunar landing mission, NASA will also need to human-rate a new upper stage for the SLS rocket. The vehicle currently uses a modified Delta IV upper stage manufactured by United Launch Alliance. But that rocket production line is closed, and NASA only has two more of these stages. With the cancellation of the Exploration Upper Stage, NASA will now procure a new stage commercially. NASA officials only said they will seek a “standardized” upper stage. As Ars has previously reported, the most likely replacement would be the Centaur V upper stage currently flying on Vulcan rockets.

What of the Lunar Gateway?

Friday’s announcement—which, for the space community, is the equivalent of a major earthquake—left some key details unaddressed. For example, NASA has been developing a larger launch tower to support the Block 1B version of the SLS rocket, with its more powerful upper stage. Development of this tower, finally underway, has been a clown show, with project costs ballooning from an initial estimate of $383 million to $1.8 billion, and delays stacked on delays. Will this tower be scrapped or repurposed?

Isaacman and other NASA officials were also mum on the Lunar Gateway, a proposed space station in a high orbit around the Moon. Key elements of this space station are under construction. However, cancellation of the Exploration Upper Stage raises questions about its future. The main purpose of the Block 1B version of SLS was to launch heavier payloads, most notably elements of the Gateway along with Orion.

“The whole Gateway-Moon base conversation is not for today,” the senior NASA official said. “We, I can assure you, will talk about the Moon base in the weeks ahead. I would just not overly read into this, because we had manifested some Gateway modules on Falcon Heavy already. The implications of standardizing SLS and increasing launch rate are about the ability to return to the Moon. I don’t think we necessarily have to speculate too much on what the other downstream implications are.”

The Gateway program office is based at Johnson Space Center in Houston, where the lunar station is viewed as a successor to the International Space Station in terms of flight operations.

Key politicians, such as Sen. Ted Cruz, R-Texas, have been supportive of this new station. But during some recent congressional hearings, Cruz has indicated he is open to a lunar space station or an outpost on the lunar surface. He just wants to be sure NASA has an enduring presence on or near the Moon. One industry source said Isaacman could be laying the groundwork to replace the Gateway Program with a Moon Base program office in Houston. It is unclear how much of a political battle this would ultimately be.

Some of this has been well-predicted

Although the changes outlined by NASA on Friday are sweeping, they are not completely out of the blue.

In April 2024, Ars reported that some senior NASA officials were considering an Earth-orbit rendezvous between Orion and Starship as a means to buy down risk for a lunar landing. NASA ultimately punted on the idea before it was revived by Isaacman this month.

Additionally, in October 2024, Ars offered a guide to saving the “floundering” Artemis program by canceling the Block 1B upgrade for the SLS rocket, replacing its upper stage with a Centaur V, and canceling the Lunar Gateway. This would free up an estimated $2 billion annually to focus on accelerating a lunar landing, the publication estimated.

That may be the very course the space agency has embarked upon today.

Photo of Eric Berger

Eric Berger is the senior space editor at Ars Technica, covering everything from astronomy to private space to NASA policy, and author of two books: Liftoff, about the rise of SpaceX; and Reentry, on the development of the Falcon 9 rocket and Dragon. A certified meteorologist, Eric lives in Houston.

NASA shakes up its Artemis program to speed up lunar return Read More »

nasa-shakes-up-its-artemis-program-to-speed-up-lunar-return

NASA shakes up its Artemis program to speed up lunar return


“Launching SLS every three and a half years or so is not a recipe for success.”

Artist’s illustration of the Boeing-developed Exploration Upper Stage, with four hydrogen-fueled RL10 engines. Credit: NASA

NASA Administrator Jared Isaacman announced sweeping changes to the Artemis program on Friday morning, including an increased cadence of missions and cancellation of an expensive rocket stage.

The upheaval comes as NASA has struggled to fuel the massive Space Launch System rocket for the upcoming Artemis II lunar mission, and Isaacman has sought to revitalize an agency that has moved at a glacial pace on its deep space programs. There is ever-increasing concern that, absent a shake-up, China’s rising space program will land humans on the Moon before NASA can return there this decade with Artemis.

“NASA must standardize its approach, increase flight rate safely, and execute on the president’s national space policy,” Isaacman said. “With credible competition from our greatest geopolitical adversary increasing by the day, we need to move faster, eliminate delays, and achieve our objectives.”

Shaking things up

The announced changes to the Artemis program include:

  • Cancellation of the Exploration Upper Stage and Block IB upgrade for SLS rocket
  • Artemis II and Artemis III missions will use the SLS rocket with existing upper stage
  • Artemis IV, V (and any additional missions, should there be) will use a “standardized” upper stage
  • Artemis III will no longer land on the Moon; rather Orion will launch on SLS and dock with Starship and/or Blue Moon landers in low-Earth orbit
  • Artemis IV is now the first lunar landing mission
  • NASA will seek to fly Artemis missions annually, starting with Artemis III in “mid” 2027, followed by at least one lunar landing in 2028
  • NASA is working with SpaceX and Blue Origin to accelerate their development of commercial lunar landers for Artemis IV and beyond

At the core of Isaacman’s concerns is the low flight rate of the SLS rocket and Artemis missions. During past exploration missions, from Mercury through Gemini, Apollo, and the Space Shuttle program, NASA has launched humans on average about once every three months. It has been nearly 3.5 years since Artemis I launched.

“This is just not the right pathway forward,” Isaacman said.

A senior NASA official, speaking on background to Ars, noted that the space agency has experienced hydrogen and helium leaks during both the Artemis I and Artemis II pre-launch preparations, and these problems have led to monthslong delays in launch.

“If I recall, the timing between Apollo 7 and 8 was nine weeks,” the official said. “Launching SLS every three and a half years or so is not a recipe for success. Certainly, making each one of them a work of art with some major configuration change is also not helpful in the process, and we’re clearly seeing the results of it, right?”

The goal, therefore, is to standardize the SLS rocket into a single configuration to make it as reliable as possible and to launch it as frequently as every 10 months. NASA will fly the SLS vehicle until there are commercial alternatives to launch crew to the Moon, perhaps through Artemis V as Congress has mandated, or perhaps even a little longer.

Is everyone on board?

The NASA official said all of the agency’s key contractors are on board with the change, and senior leaders in Congress have been briefed on the proposed changes.

The biggest opposition to these proposals would seemingly come from Boeing, which is the prime contractor for the Exploration Upper Stage, a contract worth billions of dollars to develop a more powerful rocket that was due to launch for the first time later this decade. However, in a NASA news release, Boeing appeared to offer at least some support for the revised plans.

“Boeing is a proud partner to the Artemis mission and our team is honored to contribute to NASA’s vision for American space leadership,” said Steve Parker, Boeing Defense, Space & Security president and CEO, in the news release. “The SLS core stage remains the world’s most powerful rocket stage, and the only one that can carry American astronauts directly to the moon and beyond in a single launch. As NASA lays out an accelerated launch schedule, our workforce and supply chain are prepared to meet the increased production needs.”

Solid reasons for changing Artemis III

NASA’s new approach to Artemis reflects a return to the philosophy of the Apollo program. During the late 1960s, the space agency flew a series of preparatory crewed missions before the Apollo 11 lunar landing. These included Apollo 7 (a low-Earth orbit test of the Apollo spacecraft), Apollo 8 (a lunar orbiting mission), Apollo 9 (a low-Earth orbit rendezvous with the lunar lander), and Apollo 10 (a test of the lunar lander descending to the Moon, without touching down).

With its previous Artemis template, NASA skipped the steps taken by Apollo 7, 9, and 10. In the view of many industry officials, this leap from Artemis II—a crewed lunar flyby of the Moon testing only the SLS rocket and Orion spacecraft—to Artemis III and a full-on lunar landing was enormous and risky.

The new approach will, in NASA parlance, “buy down” some of the risk for a 21st-century lunar landing, including performance and handling of a lunar lander, rendezvous and docking, communications, spacesuit performance, and more.

It will also increase the challenges for NASA. In particular, the timeline to bring the Orion spacecraft to readiness for a mid-2027 launch will need to be accelerated, and efforts to integrate that vehicle with one or both lander providers will need serious attention.

For the Artemis IV lunar landing mission, NASA will also need to human-rate a new upper stage for the SLS rocket. The vehicle currently uses a modified Delta IV upper stage manufactured by United Launch Alliance. But that rocket production line is closed, and NASA only has two more of these stages. With the cancellation of the Exploration Upper Stage, NASA will now procure a new stage commercially. NASA officials only said they will seek a “standardized” upper stage. As Ars has previously reported, the most likely replacement would be the Centaur V upper stage currently flying on Vulcan rockets.

What of the Lunar Gateway?

Friday’s announcement—which, for the space community, is the equivalent of a major earthquake—left some key details unaddressed. For example, NASA has been developing a larger launch tower to support the Block 1B version of the SLS rocket, with its more powerful upper stage. Development of this tower, finally underway, has been a clown show, with project costs ballooning from an initial estimate of $383 million to $1.8 billion, and delays stacked on delays. Will this tower be scrapped or repurposed?

Isaacman and other NASA officials were also mum on the Lunar Gateway, a proposed space station in a high orbit around the Moon. Key elements of this space station are under construction. However, cancellation of the Exploration Upper Stage raises questions about its future. The main purpose of the Block 1B version of SLS was to launch heavier payloads, most notably elements of the Gateway along with Orion.

“The whole Gateway-Moon base conversation is not for today,” the senior NASA official said. “We, I can assure you, will talk about the Moon base in the weeks ahead. I would just not overly read into this, because we had manifested some Gateway modules on Falcon Heavy already. The implications of standardizing SLS and increasing launch rate are about the ability to return to the Moon. I don’t think we necessarily have to speculate too much on what the other downstream implications are.”

The Gateway program office is based at Johnson Space Center in Houston, where the lunar station is viewed as a successor to the International Space Station in terms of flight operations.

Key politicians, such as Sen. Ted Cruz, R-Texas, have been supportive of this new station. But during some recent congressional hearings, Cruz has indicated he is open to a lunar space station or an outpost on the lunar surface. He just wants to be sure NASA has an enduring presence on or near the Moon. One industry source said Isaacman could be laying the groundwork to replace the Gateway Program with a Moon Base program office in Houston. It is unclear how much of a political battle this would ultimately be.

Some of this has been well-predicted

Although the changes outlined by NASA on Friday are sweeping, they are not completely out of the blue.

In April 2024, Ars reported that some senior NASA officials were considering an Earth-orbit rendezvous between Orion and Starship as a means to buy down risk for a lunar landing. NASA ultimately punted on the idea before it was revived by Isaacman this month.

Additionally, in October 2024, Ars offered a guide to saving the “floundering” Artemis program by canceling the Block 1B upgrade for the SLS rocket, replacing its upper stage with a Centaur V, and canceling the Lunar Gateway. This would free up an estimated $2 billion annually to focus on accelerating a lunar landing, the publication estimated.

That may be the very course the space agency has embarked upon today.

Photo of Eric Berger

Eric Berger is the senior space editor at Ars Technica, covering everything from astronomy to private space to NASA policy, and author of two books: Liftoff, about the rise of SpaceX; and Reentry, on the development of the Falcon 9 rocket and Dragon. A certified meteorologist, Eric lives in Houston.

NASA shakes up its Artemis program to speed up lunar return Read More »

nasa-reports-no-significant-leaks-in-artemis-ii-fueling-test,-eyes-march-6-launch

NASA reports no significant leaks in Artemis II fueling test, eyes March 6 launch

A second fueling test on NASA’s Space Launch System rocket ended Thursday night, giving senior managers enough confidence to move forward with plans to launch four astronauts around the Moon as soon as March 6.

Unlike the first attempt to load propellants into the SLS rocket on February 2, there were no major leaks during Thursday’s practice countdown at Kennedy Space Center in Florida. Technicians swapped seals at the launch pad after hydrogen gas leaked from the rocket’s main fueling line earlier this month. This time, the seals held.

“For the most part, those fixes all performed pretty well yesterday,” said Lori Glaze, acting associate administrator for NASA’s exploration programs. “We were able to fully fuel the SLS rocket within the planned timeline.”

The results keep the Artemis II mission on track for liftoff as soon as next month. NASA gave up on a series of February launch opportunities after encountering a persistent hydrogen leak during the first Wet Dress Rehearsal (WDR).

“We’re now targeting March 6 as our earliest launch attempt,” Glaze said. “I am going to caveat that. I want to be open, transparent with all of you that there is still pending work. There’s work, a lot of forward work, that remains.”

If teams complete all of that work, liftoff of the Artemis II mission could occur within a two-hour window opening at 8: 29 pm EST on March 6 (01: 29 UTC on March 7). NASA has other launch dates available on March 7, 8, 9, and 11, but the mission may have to wait until April. There are approximately five days per month that the mission can depart the Earth after accounting for the position of the Moon in its orbit, the flight’s trajectory, and thermal and lighting constraints.

The Artemis II mission will last between nine and 10 days, taking NASA’s Orion spacecraft with commander Reid Wiseman, pilot Victor Glover, and mission specialists Christina Koch and Jeremy Hansen around the far side of the Moon before returning to Earth for splashdown in the Pacific Ocean. Wiseman’s crew will set the record for the farthest humans have ever traveled from Earth, and will become the first people to fly to the vicinity of the Moon since 1972.

NASA reports no significant leaks in Artemis II fueling test, eyes March 6 launch Read More »