moon

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How the Moon got a makeover

moon, planetary science, Science, volcanism / /

Putting on a new face —

The Moon’s former surface sank to the depths, until volcanism brought it back.

–

Image of the moon.

Our Moon may appear to shine peacefully in the night sky, but billions of years ago, it was given a facial by volcanic turmoil.

One question that has gone unanswered for decades is why there are more titanium-rich volcanic rocks, such as ilmenite, on the near side as opposed to the far side. Now a team of researchers at Arizona Lunar and Planetary Laboratory are proposing a possible explanation for that.

The lunar surface was once flooded by a bubbling magma ocean, and after the magma ocean had hardened, there was an enormous impact on the far side. Heat from this impact spread to the near side and made the crust unstable, causing sheets of heavier and denser minerals on the surface to gradually sink deep into the mantle. These melted again and were belched out by volcanoes. Lava from these eruptions (more of which happened on the near side) ended up in what are now titanium-rich flows of volcanic rock. In other words, the Moon’s old face vanished, only to resurface.

What lies beneath

The region of the Moon in question is known as the Procellarum KREEP Terrane (PKT). KREEP signifies high concentrations of potassium (K), rare earth elements (REE), and phosphorus (P). This is also where ilmenite-rich basalts are found. Both KREEP and the basalts are thought to have first formed when the Moon was cooling from its magma ocean phase. But the region stayed hot, as KREEP also contains high levels of radioactive uranium and thorium.

“The PKT region… represents the most volcanically active region on the Moon as a natural result of the high abundances of heat-producing elements,” the researchers said in a study recently published in Nature Geoscience.

Why is this region located on the near side, while the far side is lacking in KREEP and ilmenite-rich basalts? There was one existing hypothesis that caught the researchers’ attention: it proposed that after the magma ocean hardened on the near side, sheets of these KREEP minerals were too heavy to stay on the surface. They began to sink into the mantle and down to the border between the mantle and core. As they sank, these mineral sheets were thought to have left behind trace amounts of material throughout the mantle.

If the hypothesis was accurate, this would mean there should be traces of minerals from the hardened KREEP magma crust in sheet-like configurations beneath the lunar surface, which could reach all the way down to the edge of the core-mantle boundary.

How could that be tested? Gravity data from the GRAIL (Gravity Recovery and Interior Laboratory) mission to the Moon possibly had the answer. It would allow them to detect gravitational anomalies caused by the higher density of the KREEP rock compared to surrounding materials.

Coming to the surface

GRAIL data had previously revealed that there was a pattern of subsurface gravitational anomalies in the PKT region. This appeared similar to the pattern that the sheets of volcanic rock were predicted to have made as they sank, which is why the research team decided to run a computer simulation of sinking KREEP to see how well the hypothesis matched up with the GRAIL findings.

Sure enough, the simulation ended up forming just about the same pattern as the anomalies GRAIL found. The polygonal pattern seen in both the simulations and GRAIL data most likely means that traces of heavier KREEP and ilmenite-rich basalt layers were left behind beneath the surface as those layers sank due to their density, and GRAIL detected their residue due to their greater gravitational pull. GRAIL also suggested there were many lesser anomalies in the PKT region, which makes sense considering that a large part of the crust is made of volcanic rocks thought to have sunk and left behind residue before they melted and surfaced again through eruptions.

We now also have an idea of when this phenomenon occurred. Because there are impact basins that dated to around 4.22 billion years ago (not to be confused with the earlier far-side impact), but the magma ocean is thought to have hardened before that, the researchers think that the crust also began to sink before that time.

“The PKT border anomalies provide the most direct physical evidence for the nature of the post-magma ocean… mantle overturn and sinking of ilmenite into the deep interior,” the team said in the same study.

This is just one more bit of information regarding how the Moon evolved and why it is so uneven. The near side once raged with lava that is now volcanic rock, much of which exists in flows called mare (which translates to “sea” in Latin). Most of this volcanic rock, especially in the PKT region, contains rare earth elements.

We can only confirm that there really are traces of ancient crust inside the Moon by the collection of actual lunar material far beneath the surface. When Artemis astronauts are finally able to gather samples of volcanic material from the Moon in situ, who knows what will come to the surface?

Nature Geoscience, 2024.  DOI: 10.1038/s41561-024-01408-2

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NASA still doesn’t understand root cause of Orion heat shield issue

artemis, artemis II, human spaceflight, Lockheed Martin, moon, NASA, orion, Space / /

Flight rationale —

“When we stitch it all together, we’ll either have flight rationale or we won’t.”

–

NASA's Orion spacecraft descends toward the Pacific Ocean on December 11, 2021, at the end of the Artemis I mission.

Enlarge / NASA’s Orion spacecraft descends toward the Pacific Ocean on December 11, 2021, at the end of the Artemis I mission.

NASA

NASA officials declared the Artemis I mission successful in late 2021, and it’s hard to argue with that assessment. The Space Launch System rocket and Orion spacecraft performed nearly flawlessly on an unpiloted flight that took it around the Moon and back to Earth, setting the stage for the Artemis II, the program’s first crew mission.

But one of the things engineers saw on Artemis I that didn’t quite match expectations was an issue with the Orion spacecraft’s heat shield. As the capsule streaked back into Earth’s atmosphere at the end of the mission, the heat shield ablated, or burned off, in a different manner than predicted by computer models.

More of the charred material than expected came off the heat shield during the Artemis I reentry, and the way it came off was somewhat uneven, NASA officials said. Orion’s heat shield is made of a material called Avcoat, which is designed to burn off as the spacecraft plunges into the atmosphere at 25,000 mph (40,000 km per hour). Coming back from the Moon, Orion encountered temperatures up to 5,000° Fahrenheit (2,760° Celsius), hotter than a spacecraft sees when it reenters the atmosphere from low-Earth orbit.

Despite heat shield issue, the Orion spacecraft safely splashed down in the Pacific Ocean. Engineers discovered the uneven charring during post-flight inspections.

No answers yet

Amit Kshatriya, who oversees development for the Artemis missions in NASA’s exploration division, said Friday that the agency is still looking for the root cause of the heat shield issue. Managers want to be sure they understand the cause before proceeding with Artemis II, which will send astronauts Reid Wiseman, Victor Glover, Christina Koch, and Jeremy Hansen on a 10-day flight around the far side of the Moon.

This will be the first time humans fly near the Moon since the last Apollo mission in 1972. In January, NASA announced a delay in the launch of Artemis II from late 2024 until September 2025, largely due to the unresolved investigation into the heat shield issue.

“We are still in the middle of our investigation on the performance of the heat shield from Artemis I,” Kshatriya said Friday in a meeting with a committee of the NASA Advisory Council.

Engineers have performed sub-scale heat shield tests in wind tunnels and arc jet facilities to better understand what led to the uneven charring on Artemis I. “We’re getting close to the final answer in terms of that cause,” Kshatriya said.

NASA officials previously said it is unlikely they will need to make changes to the heat shield already installed on the Orion spacecraft for Artemis II, but haven’t ruled it out. A redesign or modifications to the Orion heat shield on Artemis II would probably delay the mission by at least a year.

Instead, engineers are analyzing all of the possible trajectories the Orion spacecraft could fly when it reenters the atmosphere at the end of the Artemis II mission. On Artemis I, Orion flew a skip reentry profile, where it dipped into the atmosphere, skipped back into space, and then made a final descent into the atmosphere, sort of like a rock skipping across a pond. This profile allows Orion to make more precise splashdowns near recovery teams in the Pacific Ocean and reduces g-forces on the spacecraft and the crew riding inside. It also splits up the heat load on the spacecraft into two phases.

The Apollo missions flew a direct reentry profile. There is also a reentry mode available called a ballistic entry, in which the spacecraft would fly through the atmosphere unguided.

Ground teams at NASA's Kennedy Space Center in Florida moved the Orion spacecraft for the Artemis II mission into an altitude chamber earlier this month.

Enlarge / Ground teams at NASA’s Kennedy Space Center in Florida moved the Orion spacecraft for the Artemis II mission into an altitude chamber earlier this month.

The charred material began flying off the heat shield in the first phase of the skip reentry. Engineers are looking at how the skip reentry profile affected the performance of the Orion heat shield. NASA wants to understand how the Orion heat shield would perform during each of the possible reentry trajectories for Artemis II.

“What we have the analysis teams off doing is saying, ‘OK, independent of what the constraints are going to be, what can we tolerate?” Kshatriya said.

Once officials understand the cause of the heat shield charring, engineers will determine what kind of trajectory Artemis II needs to fly on reentry to minimize risk to the crew. Then, managers will look at building what NASA calls flight rationale. Essentially, this is a process of convincing themselves the spacecraft is safe to fly.

“When we stitch it all together, we’ll either have flight rationale or we won’t,” Kshatriya said.

Assuming NASA approves the flight rationale for Artemis II, there will be additional discussions about how to ensure Orion heat shields are safe to fly on downstream Artemis missions, which will have higher-speed reentry profiles as astronauts return from landings on the Moon.

In the meantime, preparations on the Orion spacecraft for Artemis II continue at NASA’s Kennedy Space Center. The crew and service modules for Artemis II were mated together earlier this year, and the entire Orion spacecraft is now inside a vacuum chamber for environmental testing.

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Rocket Report: Starship could fly again in May; Ariane 6 coming together

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Eating their lunch —

“I think we’re really going to focus on getting reentry right.”

–

Nine kerosene-fueled Rutherford engines power Rocket Lab's Electron launch vehicle off the pad at Wallops Island, Virginia, early Thursday.

Enlarge / Nine kerosene-fueled Rutherford engines power Rocket Lab’s Electron launch vehicle off the pad at Wallops Island, Virginia, early Thursday.

Welcome to Edition 6.36 of the Rocket Report! SpaceX wants to launch the next Starship test flight as soon as early May, the company’s president and chief operating officer said this week. The third Starship test flight last week went well enough that the Federal Aviation Administration—yes, the FAA, the target of many SpaceX fans’ frustrations—anticipates a simpler investigation and launch licensing process than SpaceX went through before its previous Starship flights. However, it looks like we’ll have to wait a little longer for Starship to start launching real satellites.

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.

Starship could threaten small launch providers. Officials from several companies operating or developing small satellite launch vehicles are worried that SpaceX’s giant Starship rocket could have a big impact on their marketability, Space News reports. Starship’s ability to haul more than 100 metric tons of payload mass into low-Earth orbit will be attractive not just for customers with heavy satellites but also for those with smaller spacecraft. Aggregating numerous smallsats on Starship will mean lower prices than dedicated small satellite launch companies can offer and could encourage customers to build larger satellites with cheaper parts, further eroding business opportunities for small launch providers.

Well, yeah … SpaceX’s dedicated rideshare missions are already reshaping the small satellite launch market. The price per kilogram of payload on a Falcon 9 rocket launching a Transporter mission is less than the price per unit on a smaller rocket, like Rocket Lab’s Electron, Firefly’s Alpha, or Europe’s Vega. Companies operating only in the smallsat launch market tout the benefits of their services, often pointing to their ability to deliver payloads into bespoke orbits, rather than dropping off bunches of satellites into more standardized orbits. But the introduction of Orbital Transfer Vehicles for last-mile delivery services has made SpaceX’s Transporter missions, and potentially Starship rideshares, more attractive. “With Starship, OTVs can become the best option for smallsats,” said Marino Fragnito, senior vice president and head of the Vega business unit at Arianespace. If Starship is able to achieve the very low per-kilogram launch prices proposed for it, “then it will be difficult for small launch vehicles,” Fragnito said.

Rocket Lab launches again from Virginia. Rocket Lab’s fourth launch from Wallops Island, Virginia, and the company’s first there in nine months, took off early Thursday with a classified payload for the National Reconnaissance Office, the US government’s spy satellite agency, Space News reports. A two-stage Electron rocket placed the NRO’s payload into low-Earth orbit, and officials declared it a successful mission. The NRO did not disclose any details about the payload, but in a post-launch statement, the agency suggested the mission was conducting technology demonstrations of some kind. “The knowledge gained from this research will advance innovation and enable the development of critical new technology,” said Chris Scolose, director of the NRO.

A steady customer for Rocket Lab … The National Reconnaissance Office has become a regular customer of Rocket Lab. The NRO has historically launched larger spacecraft, such as massive bus-sized spy satellites, but like the Space Force, is beginning to launch larger numbers of small satellites. This mission, designated NROL-123 by the NRO, was the fifth and last mission under a Rapid Acquisition of a Small Rocket (RASR) contract between NRO and Rocket Lab, dating back to 2020. It was also Rocket Lab’s second launch in nine days, following an Electron flight last week from its primary base in New Zealand. Overall, it was the 46th launch of a light-class Electron rocket since it debuted in 2017. Rocket Lab is building a launch pad for its next-generation Neutron rocket at Wallops. (submitted by EllPeaTea)

The easiest way to keep up with Eric Berger’s space reporting is to sign up for his newsletter, we’ll collect his stories in your inbox.

Night flight for Astrobotic’s Xodiac. The Xodiac rocket, a small terrestrial vertical takeoff and vertical landing technology testbed, made its first night flight, Astrobotic says in a statement. The liquid-fueled Xodiac is designed for vertical hops and can host prototype sensors and other payloads, particularly instruments in development to assist in precision landings on other worlds. This first tethered night flight of Xodiac in Mojave, California, was in preparation for upcoming flight testing with the NASA TechLeap Prize’s Nighttime Precision Landing Challenge. These flights will begin in April, allowing NASA to test the ability of sensors to map a landing field designed to simulate the Moon’s surface in near-total darkness.

Building on the legacy of Masten … Xodiac has completed more than 160 successful flights, dating back to the vehicle’s original owner, Masten Space Systems. Masten filed for bankruptcy in 2022, and the company was acquired by Astrobotic a couple of months later. Astrobotic’s primary business area is in developing and flying robotic Moon landers, so it has a keen interest in mastering automated landing and navigation technologies like those it is testing with NASA on Xodiac. David Masten, founder of Masten Space Systems, is now chief engineer for Astrobotic’s propulsion and test department. “The teams will demonstrate their systems over the LSPG (Lunar Surface Proving Ground) at night to simulate landing on the Moon during the lunar night or in shadowed craters.” (submitted by Ken the Bin)

Rocket Report: Starship could fly again in May; Ariane 6 coming together Read More »

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A Japanese spacecraft faceplanted on the Moon and lived to tell the tale

Japan, JAXA, moon, slim, Space / /
Japan's SLIM spacecraft is seen nose down on the surface of the Moon.

Japan’s SLIM spacecraft is seen nose down on the surface of the Moon.

Japan’s first lunar lander made an unsteady touchdown on the Moon last week, moments after one of its two main engines inexplicably lost power and apparently fell off the spacecraft, officials said Thursday.

About the size of a small car, the Small Lander for Investigating Moon (SLIM) landed on Friday, making Japan the fifth country to achieve a soft landing on the lunar surface. Shortly after landing, ground teams in Japan realized the spacecraft was not recharging its battery with its solar panels. The evidence at the time suggested that SLIM likely ended up in an unexpected orientation on the Moon, with its solar cells facing away from the Sun.

With the benefit of six days of data crunching and analysis, officials from the Japan Aerospace Exploration Agency (JAXA) briefed reporters Thursday on what they have learned about SLIM’s landing. Indeed, the spacecraft toppled over after touching down, with its nose planted into the lunar regolith and its rear propulsion section pointed toward space.

It turns out that SLIM overcame a lot to get to that point. In the final minute of Friday’s descent, one of SLIM’s two engines failed, leaving the craft’s sole remaining engine to bring the spacecraft in for an off-balance landing. Still, JAXA officials said the spacecraft achieved nearly all of its primary objectives. The roughly $120 million robotic mission made the most pinpoint landing on the Moon in history, just as it set out to do.

“From the spacecraft, we were able to acquire all the technical data related to navigation guidance leading to landing, which will be necessary for future pinpoint landing technology, as well as navigation camera image data during descent and on the lunar surface,” JAXA said in a statement.

One of two tiny robots released by SLIM just before landing relayed a remarkable image of the lander standing upside down a short distance away. This might be the first close-up view of a crash landing, however gentle, on another world.

One plucky bird

Based on the update JAXA released Thursday, it’s extraordinary that SLIM made it to the surface in one piece.

After launching in September and arriving at the Moon in December, SLIM lined up for a final descent to the lunar surface on Friday. Around 20 minutes before landing, the spacecraft ignited its two hydrazine-fueled rocket engines for a braking maneuver to drop out of lunar orbit.

JAXA officials said everything went according to plan in the initial phases of the descent. The spacecraft pitched over from a horizontal orientation to begin a final vertical descent to the surface. SLIM’s guidance computer was preloaded with a map of the landing zone, and an onboard navigation camera took pictures of the Moon’s surface throughout the landing sequence. The spacecraft’s computer used these images to compare to the map, allowing SLIM to autonomously correct its course along the way.

The SLIM spacecraft was built by Mitsubishi Electric under contract with JAXA.

Enlarge / The SLIM spacecraft was built by Mitsubishi Electric under contract with JAXA.

JAXA

But at an altitude of around 160 feet (50 meters), something went wrong with the spacecraft’s propulsion system. Less than a minute before touchdown, one of the engines suddenly lost thrust, and moments later, a down-facing navigation camera caught a glimpse of what appeared to be one of the engine nozzles falling away from the spacecraft. JAXA said engineers believe the engine failure was likely caused by “some external factor other than the main engine itself.” Officials are still investigating to determine the root cause.

The spacecraft continued descending on the power of its remaining engine, but it became more difficult to control the lander. The thrust from the single engine imparted a sideways motion to the spacecraft. Normally, SLIM would have used thrusters to tilt itself from the vertical orientation necessary for the final descent and into a position to plop itself on the lunar surface along the spacecraft’s long axis. SLIM had five crushable landing legs to absorb the force of the gentle impact.

While this two-stage landing sequence was the plan, JAXA said Thursday that the spacecraft “touched the ground in an almost straight standing position with lateral velocity.” The vertical speed at touchdown was about 3.1 mph (1.4 meters per second), slightly slower than the expected descent rate.

“Because the ground contact conditions such as lateral speed and attitude exceeded the specification range, a large attitude change occurred after touchdown, and the aircraft settled in a different attitude than expected,” JAXA said.

In other words, the squirrelly landing caused the spacecraft to tip over. SLIM settled in a bottoms-up position on a shallow slope rather than on its side. Its solar panel wasn’t facing up but was instead pointed toward the west, away from the Sun’s position in the eastern morning sky at the landing site.

A Japanese spacecraft faceplanted on the Moon and lived to tell the tale Read More »

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NASA urged Astrobotic not to send its hamstrung spacecraft toward the Moon

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A camera on Astrobotic's Peregrine spacecraft captured this view of a crescent Earth during its mission.

Enlarge / A camera on Astrobotic’s Peregrine spacecraft captured this view of a crescent Earth during its mission.

Astrobotic knew its first space mission would be rife with risks. After all, the company’s Peregrine spacecraft would attempt something never done before—landing a commercial spacecraft on the surface of the Moon.

The most hazardous part of the mission, actually landing on the Moon, would happen more than a month after Peregrine’s launch. But the robotic spacecraft never made it that far. During Peregrine’s startup sequence after separation from its United Launch Alliance Vulcan rocket, one of the spacecraft’s propellant tanks ruptured, spewing precious nitrogen tetroxide into space. The incident left Peregrine unable to land on the Moon, and it threatened to kill the spacecraft within hours of liftoff.

“What a wild adventure we were just on, not the outcome we were hoping for,” said John Thornton, CEO of Astrobotic.

Astrobotic’s control team, working out of the company’s headquarters in Pittsburgh, swung into action to save the spacecraft. The propellant leak abated, and engineers wrestled control of the spacecraft to point its solar arrays toward the Sun, allowing its battery to recharge. Over time, Peregrine’s situation stabilized, although it didn’t have enough propellant remaining to attempt a descent to the lunar surface.

Peregrine continued on a trajectory out to 250,000 miles (400,000 kilometers) from Earth, about the same distance as the Moon’s orbit. Astrobotic’s original flight plan would have taken Peregrine on one long elliptical loop around Earth, then the spacecraft would have reached the Moon during its second orbit.

On its way back toward Earth, Peregrine was on a flight path that would bring it back into the atmosphere, where it would burn up on reentry. That meant Astrobotic had a decision to make. With Peregrine stabilized, should they attempt an engine burn to divert the spacecraft away from Earth onto a trajectory that could bring it to the vicinity of the Moon? Or should Astrobotic keep Peregrine in line to reenter Earth’s atmosphere and avoid the risk of sending a crippled spacecraft out to the Moon?

Making lemonade out of lemons

This was the first time Astrobotic had flown a space mission, and its control team had much to learn. The malfunction that caused the propellant leak appears to have been with a valve that did not properly reseat during the propulsion system’s initialization sequence. This valve activated to pressurize the fuel and oxidizer tanks with helium.

When the valve didn’t reseat, it sent a “rush of helium” into the oxidizer system, Thornton said. “I describe it as a rush because it was very, very fast. “Within a little over a minute, the pressure had risen to the point in the oxidizer side that it was well beyond the proof limit of the propulsion tank. We believe at that point the tank ruptured and led to, unfortunately, a catastrophic loss of propellant … for the primary mission.”

Thornton described the glum mood of Astrobotic’s team after the propellant leak.

“We were coming from the highest high of a perfect launch and came down to the lowest low, when we found out that the spacecraft no longer had the helium and no longer had the propulsion needed to attempt the Moon landing,” he said. “What happened next, I think, was pretty remarkable and inspiring.”

In a press briefing Friday, Thornton outlined the obstacles Astrobotic’s controllers overcame to keep Peregrine alive. Without a healthy propulsion system, the spacecraft’s solar panels were not pointed at the Sun. With a few minutes to spare, one of Astrobotic’s engineers, John Shaffer, devised a solution to reorient the spacecraft to start recharging its battery.

As Peregrine’s oxidizer tank lost pressure, the leak rate slowed. At first, it looked like the spacecraft might have only hours of propellant remaining. Then, Astrobotic reported on January 15 that the leak had “practically stopped.” Mission controllers powered up the science payloads aboard the Peregrine lander, proving the instruments worked and demonstrating the spacecraft could have returned data from the lunar surface if it landed.

The small propulsive impulse from the leaking oxidizer drove Peregrine slightly off course, putting it on a course to bring it back into Earth’s atmosphere. This set up Astrobotic for a “very difficult decision,” Thornton said.

Astrobotic's first lunar lander, named Peregrine, at the company's Pittsburgh headquarters.

Enlarge / Astrobotic’s first lunar lander, named Peregrine, at the company’s Pittsburgh headquarters.

Nudging Peregrine off its collision course with Earth would have required the spacecraft to fire its main engines, and even if that worked, the lander would have needed to perform more maneuvers to get close to the Moon. A landing was still out of the question, but Thornton said there was a small chance Astrobotic could have guided Peregrine toward a flyby or impact with the Moon.

“The thing we were weighing was, ‘Should we send this back to Earth, or should we take the risk to operate it in cislunar space and see if we can send this out farther?'” Thornton said.

NASA urged Astrobotic not to send its hamstrung spacecraft toward the Moon Read More »

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Japan becomes the fifth nation to land a spacecraft on the Moon

Japan, JAXA, lunar exploration, moon, slim, Space / /
Artist's illustration of the SLIM spacecraft on final descent to the Moon.

Enlarge / Artist’s illustration of the SLIM spacecraft on final descent to the Moon.

The Japanese space agency’s first lunar lander arrived on the the Moon’s surface Friday, but a power system problem threatens to cut short its mission.

Japan’s robotic Smart Lander for Investigating Moon (SLIM) mission began a 20-minute final descent using two hydrazine-fueled engines to drop out of orbit. After holding to hover at 500 meters and then 50 meters altitude, SLIM pulsed its engines to fine-tune its vertical descent before touching down at 10: 20 am EST (15: 20 UTC).

The Japan Aerospace Exploration Agency (JAXA), which manages the SLIM mission, streamed the landing live on YouTube. About two hours after the touchdown, JAXA officials held a press conference to confirm the spacecraft made a successful landing, apparently quite close to its target. SLIM aimed to settle onto the lunar surface adjacent to a nearly 900-foot (270-meter) crater named Shioli, located in a region called the Sea of Nectar on the near side of the Moon.

But ground controllers at JAXA’s Sagamihara Campus in the western suburbs of Tokyo soon discovered the lander was in trouble. Its solar array was not generating electricity after landing, and without power, officials expected SLIM to drain its battery within a few hours.

In what could be the mission’s final hours, engineers prioritized downloading data from SLIM, including imagery taken during its descent, and potentially new pictures captured from the lunar surface. Official reported good communications links between SLIM and ground stations on Earth.

“Minimum success”

Even if SLIM falls silent, the mission has achieved its minimum success criteria, JAXA said. The SLIM mission is a technology demonstrator developed to verify the performance of a new vision-based navigation system needed for precision Moon landings.

“First and foremost, landing was made and communication was established,” said Hiroshi Yamakawa, JAXA’s president. “So a minimum success was made in my view.”

One of the core goals of the SLIM mission was to land within 100 meters (about 330 feet) of its bullseye. This accomplishment would be a remarkable improvement in lunar landing precision, which typically is measured in miles or kilometers. It would also be an enabling capability for future Moon missions because it lays the foundation for future spacecraft to land closer to lunar resources, such as water ice.

Hitoshi Kuninaka, director general of JAXA’s Institute of Space and Astronautical Science, said it will take about a month for engineers to fully analyze data from SLIM and determine the precision of the landing.

“But as you saw on the real-time data livestream, SLIM did trace the expected course, so my personal impression is that we probably have been able to more or less achieve a high precision landing within 100-meter accuracy,” Kuninaka said. “So the solar cell state is unlikely to impact the full success criteria.”

Kuninaka said ground teams have seen no evidence of any damage to the solar array on SLIM. It’s possible the lander is sitting in an orientation with its solar cells facing away from the Sun. All other components of SLIM, including its propulsion, thermal, and communication systems, all appear to be functioning well.

SLIM launched September 6 on top of a Japanese H-IIA rocket, riding to orbit alongside an X-ray astronomy telescope. The spacecraft took a long route to get to the Moon, trading time for fuel to preserve propellant for Friday’s landing attempt. SLIM entered orbit around the Moon on December 25, then completed several maneuvers to settle into a low-altitude orbit in preparation for the descent to the surface.

A milestone moment for Japan

The landing of SLIM made Japan the fifth country to soft-land a spacecraft on the Moon, following the Soviet Union, the United States, China, and India. But landing on the Moon is a hazardous thing to do. Three commercial landers similar in scale to SLIM failed to safely reach the lunar surface over the last five years.

One of those was developed by a Japanese company called ispace. Most recently, the US company Astrobotic attempted to send its Peregrine lander to the Moon, but a propellant leak cut short the mission. After looping more than 200,000 miles into space, Peregrine reentered Earth’s atmosphere Wednesday, where it was expected to burn up 10 days after its launch.

A Russian lander crashed into the Moon in August, and India’s first lunar lander failed in 2019. India tried again last year and made history when Chandrayaan 3 safely landed.

This artist's illustration shows the SLIM spacecraft descending toward the Moon and ejecting two deployable robots onto the lunar surface.

Enlarge / This artist’s illustration shows the SLIM spacecraft descending toward the Moon and ejecting two deployable robots onto the lunar surface.

Japan’s SLIM mission was primarily designed to test out new guidance algorithms and sensors, rather than pursuing scientific objectives. The technologies riding to the Moon on SLIM could be used on future spacecraft bound for the Moon. SLIM cost the Japanese government approximately 18 billion yen ($121 million) to design, develop, and build, according to JAXA.

The spacecraft is modest in size, measuring nearly 8 feet (2.4 meters) tall and nearly 9 feet (2.7 meters) across. Without propellant in its tanks, SLIM has a mass of roughly 660 pounds (200 kilograms).

“The start of the deceleration to the landing on the Moon’s surface is expected to be a breathless, numbing 20 minutes of terror!” said Kushiki Kenji, sub-project manager for the SLIM mission, before the landing.

Japan becomes the fifth nation to land a spacecraft on the Moon Read More »

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ULA’s Vulcan rocket shot for the Moon on debut launch—and hit a bullseye

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The first Vulcan rocket fires off its launch pad in Florida.

Enlarge / The first Vulcan rocket fires off its launch pad in Florida.

United Launch Alliance

CAPE CANAVERAL, Florida—Right out of the gate, United Launch Alliance’s new Vulcan rocket chased perfection.

The Vulcan launcher hit its marks after lifting off from Florida’s Space Coast for the first time early Monday, successfully deploying a commercial robotic lander on a journey to the Moon and keeping ULA’s unblemished success record intact.

“Yeehaw! I am so thrilled, I can’t tell you how much!” exclaimed Tory Bruno, ULA’s president and CEO, shortly after Vulcan’s departure from Cape Canaveral. “I am so proud of this team. Oh my gosh, this has been years of hard work. So far, this has been an absolutely beautiful mission.”

This was a pivotal moment for ULA, a 50-50 joint venture between Boeing and Lockheed Martin. The Vulcan rocket will replace ULA’s mainstay rockets, the Atlas V and Delta IV, with lineages dating back to the dawn of the Space Age. ULA has contracts for more than 70 Vulcan missions in its backlog, primarily for the US military and Amazon’s Project Kuiper broadband network.

The Vulcan rocket lived up to the moment Monday. It took nearly a decade for ULA to develop it, some four years longer than anticipated, but the first flight took off at the opening of the launch window on the first launch attempt.

Standing 202 feet (61.6 meters) tall, the Vulcan rocket ignited its two BE-4 main engines in the final seconds of a smooth countdown. A few moments later, two strap-on solid rocket boosters flashed to life to propel the Vulcan rocket off its launch pad at 2: 18 am EST (07: 18 UTC).

On the money

The BE-4 engines and solid-fueled boosters combined to generate more than 2 million pounds of thrust, vaulting Vulcan off the launch pad and through a thin cloud layer. A little over a minute after launch, Vulcan accelerated faster than the speed of sound, then jettisoned its strap-on boosters to fall into the Atlantic Ocean.

Then it was all BE-4. Each of these engines can produce more than a half-million pounds of thrust, consuming a mixture of liquified natural gas—essentially methane—and liquid oxygen. They are built by Blue Origin, the space company founded by billionaire Jeff Bezos. This was the first time BE-4s have flown on a rocket.

Rob Gagnon, ULA’s telemetry commentator, calmly called out mission milestones. “BE-4s continue to operate nominally… Vehicle is continuing to fly down the center of the range track, everything looking good… Nice and smooth operation of the booster.”

The BE-4s fired for five minutes, then shut down to allow Vulcan’s first stage booster to fall away from the rocket’s hydrogen-fueled Centaur upper stage. Two RL10 engines ignited to continue the push into orbit, then switched off as the upper stage coasted over the Atlantic and Africa. A restart of the Centaur upper stage 43 minutes into the flight gave the rocket enough velocity to send Astrobotic’s Peregrine lunar lander toward the Moon.

The nearly 1.5-ton spacecraft separated from Vulcan’s Centaur upper stage around 50 minutes after liftoff. “We have spacecraft separation, right on time,” Gagnon announced.

With Astrobotic’s lander deployed, a third engine firing on the Centaur upper stage moved the rocket off its Moon-bound trajectory and onto a course into heliocentric orbit. “We have now achieved Earth escape,” Gagnon said.

The spent rocket stage will become a human-made artificial satellite of the Sun. A plate on the side of the Centaur upper stage contains small capsules holding the cremated remains of more than 200 people, a “memorial spaceflight” arranged by a Houston-based private company named Celestis.

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Navajo objection to flying human ashes to the Moon won’t delay launch

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The Moon sets over sandstone formations on the Navajo Nation.

Enlarge / The Moon sets over sandstone formations on the Navajo Nation.

Science instruments aren’t the only things hitching a ride to the Moon on a commercial lunar lander ready for launch Monday. Two companies specializing in “space burials” are sending cremated human remains to the Moon, and this doesn’t sit well with the Navajo Nation.

The Navajo people, one of the nation’s largest Indigenous groups, hold the Moon sacred, and putting human remains on the lunar surface amounts to desecration, according to Navajo Nation President Buu Nygren.

“The sacredness of the Moon is deeply embedded in the spirituality and heritage of many Indigenous cultures, including our own,” Nygren said in a statement. “The placement of human remains on the Moon is a profound desecration of this celestial body revered by our people.”

Last month, Nygren wrote a letter to NASA and the Department of Transportation, which licenses commercial space launches, requesting a postponement of the flight to the Moon. The human remains in question are mounted to the robotic Peregrine lander, built and owned by a Pittsburgh-based company named Astrobotic, poised for liftoff from Cape Canaveral Space Force Station in Florida on top of United Launch Alliance’s Vulcan rocket.

This is the second time a US spacecraft has gone to the Moon with human remains aboard. In 1998, NASA’s Lunar Prospector mission launched with a small capsule containing the ashes of Eugene Shoemaker, a pioneer in planetary geology. NASA intentionally crashed spacecraft into the Moon in 1999, leaving Shoemaker’s ashes permanently on the surface.

At that time, officials from the Navajo Nation objected to the scattering of Shoemaker’s ashes on the Moon. NASA promised to consult with tribal officials before another spacecraft flew to the Moon with human remains. A big part of Nygren’s recent complaint was the lack of dialogue on the matter before this mission.

“This act disregards past agreements and promises of respect and consultation between NASA and the Navajo Nation, notably following the Lunar Prospector mission in 1998,” Nygren said in a statement. He added that the request for consultation is “rooted in a desire to ensure that our cultural practices, especially those related to the Moon and the treatment of the deceased, are respected.”

An oversight

Officials from the White House and NASA met with Nygren on Friday to discuss his concerns. Speaking with reporters after the meeting, Nygren said he believes it was an oversight that federal officials didn’t meet with the Navajo Nation at an earlier stage.

“I think being able to consult into the future is one of the things that they’re going to try to work on,” he told reporters Friday. While Nygren said that was good to hear, “we were given no reassurance that the human remains were not going to be transported to the Moon on Monday.”

Removing the human remains would delay the launch at least several weeks. It would require removing Astrobotic’s lunar lander from the top of the Vulcan rocket, taking it back to a clean room facility, and opening the payload fairing to provide access to the spacecraft.

“They’re not going to remove the human remains and keep them here on Earth where they were created, but instead, we were just told that a mistake has happened, we’re sorry, into the future we’re going to try to consult with you,” Nygren said.

“We take concerns expressed from the Navajo Nation very, very seriously,” said Joel Kearns, deputy associate administrator for exploration in NASA’s science directorate. “And we think we’re going to be continuing this conversation.”

Buu Nygren, president of the Navajo Nation.

Enlarge / Buu Nygren, president of the Navajo Nation.

Astrobotic’s mission is different from Lunar Prospector in one important sense. The Peregrine lander is privately owned, while Lunar Prospector was a government spacecraft. NASA has a $108 million contract with Astrobotic to deliver the agency’s science payloads to the Moon as a commercial service. Astrobotic’s mission is the first time a US company will attempt to land a commercial spacecraft on the Moon.

While Nygren argues that NASA’s role as Astrobotic’s anchor customer should give the agency some influence over decision-making, the government’s only legal authority in overseeing the mission is through the Federal Aviation Administration.

The FAA is responsible for ensuring commercial launches, like the Vulcan rocket flight Monday, don’t put public safety at risk. The launch licensing process also includes an FAA review to ensure a launch would not jeopardize US national security, foreign policy interests, or international obligations.

“For our own missions … NASA works to be very mindful of potential concerns for any work that we’ll do on the Moon,” Kearns said. “In this particular case … NASA really doesn’t have involvement or oversight.”

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