In my view, the mission was much less a scientific one than a political one. The target was the lunar south pole, a previously unexplored area. The mission was scaled back from including a lunar rover because of Western sanctions after Putin's War in Ukraine began. It is speculated that it went ahead to prove to the world that sanctions would not affect Russia's ability to lead the world. The landing coinciding with BRICS would also be a political thumb in the eye of the West over the ICC kerfuffle, and it would bolster Russia's image in that group, particularly by one-upping India by two days. This is not just an egg in the face. This is Putin being held down and letting the henhouse drop their product on him.

I still expect to see the Russians taking a page of Irish history and using the Red Hand of the O'Neills rule to claim it arrived first at the south pole area of the moon.

In the 1950s, with the USSR seemingly sprinting ahead in the space race, US scientists hatched a bizarre plan – nuking the surface of the Moon to frighten the Soviets.

The current race to the Moon is opening up opportunities for lunar astronomy.

India took the first step toward its second attempt to land on the Moon on Friday with the launch of its Chandrayaan-3 mission from the Satish Dhawan Space Centre in the southeastern part of the country. //

To date, only the Soviet Union, the United States, and China have made soft landings on the Moon. India will attempt to become the fourth country to do so and is the first of as many as half a dozen missions that will attempt to land on the Moon during the next six months.

India has developed the Chandrayaan-3 mission on a shoestring budget, about $90 million. But it is important for the Indian space agency to demonstrate competence with this second attempt—especially as its neighbor China has flown a series of increasingly complex and successful lunar missions, including landing on the far side of the Moon and returning regolith samples to Earth. If successful, the Vikram lander would touch down further south than any previous lunar mission.

The descent from lunar orbit to landing was broken into three phases, and each of these phases had a specific computer program associated with it. Here’s the way it worked on all six lunar landings:

The descent began with the braking phase — the first and longest phase. It was flown entirely automatically by the computer (Program 63). Its goal was to slow the spacecraft from about 3,800 miles/hour to about 700 miles/hour, and to decrease the LM’s altitude from about 50,000 feet to 7,000 feet.
The approach phase began when the LM was about 7,000 feet in altitude and about 2 miles from the landing site. The computer was still doing all the flying (Program 64), but the crew could now see the landing site and offer adjustments to the computer.
The landing phase began around 500 - 700 feet in altitude. The Commander flipped a switch next to his left thumb, causing the computer to switch to Program 66. The computer was now in what was known as attitude hold. The Commander selected the spot where he wanted to land, and used his controls to tell the computer where to go. The computer was also responsible for keeping the LM upright. The landing phase ends with the LM on the lunar surface. //

Here are the times (in minutes and seconds) that each of the missions spent in the landing phase:

Apollo 11: 2:23

Apollo 12: 1:44

Apollo 14: 2:01

Apollo 15: 1:16

Apollo 16: 1:00

Apollo 17: 1:08

Apollo 11 had by far the longest landing phase — almost 2 and a half minutes. That’s how long it took Armstrong to find a suitable landing spot and guide the computer toward it.

At the other extreme was Apollo 16 — when it entered the landing phase, a suitable landing spot was right there and it took John Young only a minute to guide the computer through the last few hundred feet and onto the lunar surface.

All of these missions went through the same phases — they differed only in how long each phase lasted.

As far as Armstrong being the one to fly the LM, that was also the plan, and again, it was the Commander who guided the LM during the landing phase on all six lunar landing missions. The job of the LMP (Lunar Module Pilot) was to provide crucial support during the landing, monitoring systems and calling out numbers throughout the landing phase. If you listen to the audio of any of the lunar landings, the voice you hear calling out numbers is the LMP.

Andrew Swenson
MS in Space Systems Engineering, US Naval Postgraduate School (Graduated 1993)May 14

Why does NASA not allow anyone to inspect the lunar module (lunar excursion module) that traveled to the Moon during Apollo missions?

Which one would you like to inspect and how would you get there? Here are the locations of each one….good luck with your inspection:

Apollo 5- Destroyed in Earth's Atmosphere.
Apollo 9- Destroyed in Earth's Atmosphere.
Apollo 10- Heliocentric orbit
Apollo 11- released in lunar orbit, location unknown.
Apollo 12- Impacted Moon 20 November 1969 at 22:17:17.7 UT (5:17 PM EST) 3.94 S, 21.20 W
Apollo 13- Burned up in Earth's atmosphere.
Apollo 14- Impacted Moon 07 February 1971 at 00:45:25.7 UT (06 February, 7:45 PM EST) 3.42 S, 19.67 W
Apollo 15- Impacted Moon 03 August 1971 at 03:03:37.0 UT (02 August, 11:03 PM EDT) 26.36 N, 0.25 E
Apollo 16- Released around moon, impact site unknown. Orbited for about a year.
Apollo 17- Impacted Moon 15 December 1972 at 06:50:20.8 UT (1:50 AM EST) 19.96 N, 30.50 E

Wickwick Ars Legatus Legionis
13y
30,072
Terakh said:

let's see the promises actually get delivered on "near" agreed upon time and cost given that some of the stuff don't even exist.

As long as Congress funds the programs on the agreed-upon schedules, I think both landers will be ready before their respective Artemis missions are flown.

Unfortunately, Congress has a history of reducing funding levels below what the delivery time requires then complaining that the programs are delayed. But those sorts of shenanigans only seem to happen to fixed-price contracts where they have no control over where and how the money is spent. The cost-plus rocket contracts seem immune to any sorts of cuts. //

EricBerger Ars Scholae Palatinae
7y
1,067
ARS STAFF
pipe13 said:

...and a large source of energy. You know, to mine the water, collect the CO2, and put the proverbial toothpaste back in the tube.

The numbers are pretty sobering: Approximately 750 kilowatts of continuous energy, for two years, to produce 1,000 tons of liquid oxygen and methane. //

RichyRoo Wise, Aged Ars Veteran
5y
113
Subscriptor
Hopefully Smarter said:

I love seeing the enthusiasm about spreading the toxic virus of humanity throughout the universe.

without us there is no point to the rest of the universe //

abie Ars Scholae Palatinae
5y
719
Hopefully Smarter said:

I love seeing the enthusiasm about spreading the toxic virus of humanity throughout the universe.

What you call a toxic virus, I call the light of consciousness. We've found no signs of life anywhere in the universe. Life might be incredibly rare, intelligent life rarer still. Taking the first hesitant steps to establishing life off Earth should be a cause for celebration, not miserable cynicism such as yours.

Last Friday, NASA awarded a $3.4 billion contract to a team led by Blue Origin for the design and construction of a second Human Landing System to fly astronauts down to the Moon.

The announcement capped a furious two-year lobbying campaign by Blue Origin owner Jeff Bezos to obtain a coveted piece of NASA's Artemis program. NASA also notched a big win, gaining the competition with SpaceX it sought for landing services. But there is a more profound takeaway from this.

After losing the initial lander contract to SpaceX two years ago, Blue Origin did not just bid a lower price this time around. Instead, it radically transformed the means by which it would put humans on the Moon. The Blue Moon lander is now completely reusable; it will remain in lunar orbit, going up and down to the surface. It will be serviced by a transport vehicle that will be fueled in low-Earth orbit and then deliver propellant to the Moon. This transporter, in turn, will be refilled by multiple launches of the reusable New Glenn rocket.

To be sure, that is a lot of hardware that has yet to be built and tested. But when we step back, there is one inescapable fact. With SpaceX's fully reusable Starship, and now Blue Moon, NASA has selected two vehicles based around the concept of many launches and the capability to store and transfer propellant in space.

This is a remarkable transformation in the way humans will explore outer space—potentially the biggest change in spaceflight since the Soviet Union launched the Sputnik satellite in 1957. It has been a long time coming. //

The German physicist Max Planck is credited with the notion that science advances only when older practitioners die off, leaving room for new ideas. The philosopher of science Thomas Kuhn more pithily summarized the sentiment by writing, "Science advances one funeral at a time."

Goff offered a variation on this idea for spaceflight: "Space policy seems to progress one congressional retirement at a time," he said.

Like Sowers, he welcomed NASA's entry into an era of reusable spaceflight. But Goff noted that it is really only happening because two billionaires, Elon Musk and Jeff Bezos, are aggressively pushing the idea forward.

NASA has spent so much over the last decade on the development of the SLS rocket—north of $40 billion, including ground systems—that there has been little money left over for exploration payloads to fly on them. Therefore, when it came time to fund the lunar landers, NASA had to go with the least expensive options. Both Starship and Blue Moon are, roughly, at least $10 billion development programs. But because it can purchase them with fixed-price contracts, NASA is only paying about a third of the overall cost for both, $6.3 billion.

"The only way NASA could really afford to do this was by not doing business as usual," Goff said.

An independent report published Thursday had troubling findings about the money spent by the agency on propulsion for the Space Launch System rocket. Moreover, the report by NASA Inspector General Paul Martin warns that if these costs are not controlled, it could jeopardize plans to return to the Moon. //

"The agency’s reliance on cost-plus awards increases its financial risk," Martin wrote. "In our judgment, NASA has used cost-plus contracting structures for its SLS booster and engine contracts to a greater extent than warranted. Although the SLS is a new vehicle, its heritage boosters and RS-25 engines are well-established."

Cost-plus contracts pay the recipient the total amount of their costs plus a fee. This is in contrast to the fixed-price contracts NASA has given SpaceX and Blue Origin for landers, the design of which is much more experimental and cutting-edge in nature than repurposing space shuttle hardware. //

For example, the current cost of manufacturing a new RS-25 main engine—which will be used for the Artemis V mission and onward—is about $100 million. NASA and Aerojet are trying to achieve a 30 percent cost savings by the end of this decade, bringing the cost down to $70.5 million. //

Compared to the private sector, even getting the cost of an RS-25 engine down to $70.5 million is a preposterously high price. Blue Origin manufactures engines of comparable power and size, the BE-4, for less than $20 million. And SpaceX is seeking to push the similarly powerful Raptor rocket engine costs even lower, to less than $1 million per engine.

Based on all of the new data in his latest report, Martin said his office has had to revise its estimate of the total cost of a Space System Launch, inclusive of ground systems and the Orion spacecraft. It is now $4.2 billion.

Q:

I am curious what aspects of the Apollo program were impressive/advanced from an engineering perspective, in the 1960s and 1970s. That is, what would have made an educated engineer say, “Wow, they solved that problem?”

I ask the question because I know that as an engineering layperson I know I have very poor intuitions about what is technically difficult in spaceflight. For instance, I only learned from this website that maintaining 1 atm of pressure in a spacecraft isn't very difficult. Also, some technologies like pressure suits and rocket engines had already been developed. So it is not obvious (to me) what the actual innovations and engineering achievements of the program were.

A:

There was no one breakthrough that made it possible. The "big deal", in the mind of the world, was just that an obviously very hard thing was accomplished. And, if you doubted how hard it was, people can point out that no one has done it again in more than fifty years.

However, there are some good examples of challenging problems that had to be solved.

Problem 1: Rocket Size. Before Apollo, everyone thought we would send the top of a multi-stage rocket to the moon, it would land on its tail and launch again to return to earth. When you run the numbers on that, you end up with a pretty big lander requiring a lot of fuel, and a huge launcher to send it on its way; much larger than Saturn. The trick ended up being to only send down a little bug, and even leave part of that behind on the moon. If we had stuck with the giant lander we would never have been ready in time.

Problem 2: Rendezvous. The new method required being good at approaching and docking with another spacecraft. That's a hard enough problem that, even though the physics was well understood, they didn't really see the issues until they actually tried it. (I always get annoyed when characters in science fiction stories fail to foresee problems that the science should have told them beforehand, but sometimes that's how it works.) Wisely they tried it in Gemini in low earth orbit and had the hang of it by Apollo.

Problem 3: Rocket Size (Again). Even with the trick (called Lunar Orbit Rendezvous) used to solve Problem 1, they needed a much bigger rocket than anyone had built before. And so they built it. To get it to the launch pad, they built the crawler transporters, some of the largest land vehicles built up to that time, and to have a protected place to stack the stages, they built the Vehicle Assembly Building, one of the largest buildings by open volume in the world. I think seeing a tower the size of a 36-story skyscraper rise into the sky made a lot of people say, "Wow, they solved that problem?" I was too young at the time, but it was the initial uncrewed Apollo 4 launch of the Saturn V that made my dad think, "Huh, they might actually pull this off!"

There are many many more, but it was really the cumulative effect of solving thousands of hard problems that was the big deal. //

Number 2 is a small example of the large original research involved. A guy, later known as "Doctor Rendezvous", did his Ph.D. thesis at MIT on it in 1963. His next job was to fly it! Here's Buzz Aldrin's thesis: dspace.mit.edu/handle/1721.1/12652 –
Adam
May 19 at 1:38

The "slow down to catch up, speed up to slow down" stuff of orbital rendezvous was reportedly very confusing to the non-engineer test pilots and required someone like Buzz Aldrin to truly figure out. It's one thing to draw the equations out on paper but a whole other thing to actually do it in the cockpit. –
Jörg W Mittag
May 17 at 19:48

@JörgWMittag I think its still confusing to a lot of people today, mainly because of the terms "slow down" and "speed up" in that phrase are ... wrong, but appropriate? –
Moo
May 17 at 21:32

@Moo - If you go faster, you also go higher. Now that you're higher, you've got farther to go, so you're actually going slower –
Richard
May 18 at 18:36 //

A:

what has ALWAYS impressed the heck out of me is the sheer magnitude of scale involved... not physical size (although its size was truly impressive) but rather the huge number of complex problems that needed to be all solved in a complex optimization matrix to arrive at a suitable overall solution. This was the largest systems integration project ever to date and on a tight timeline. Project management on an unheard of scale and scope. That to me was the "Wow... they solved THAT problem" thing.

Yes. Apollo was a triumph of project management as much as, or maybe even more than, it was a technological feat. –
Wayne Conrad
May 18 at 2:40

I would argue that project management was born within the Apollo program. I don't think it even had a name beforehand. –
Vladimir Cravero
May 18 at 8:18 //

A:

It was fractally hard.

Everything they did was Voltroning hard problems together to solve other hard problems. And this was all done in a coordinated way on an incredibly tight timescale.

The long answer would fill a series of books. E.g. for a high level overview of the effort involved in the LEM alone, you can look at Tom Kelly's Moon Lander (and you should; it's great).

But to put a quick gloss on top of it, Apollo was not an aerospace engineering triumph, Apollo was a systems engineering triumph. Everyone solved hard problems in every field, but the real accomplishment was orchestrating those solutions in a way that led a seven-year program from zero to the moon.

Apollo systems engineering built upon Polaris (see en.wikipedia.org/wiki/UGM-27_Polaris). –
Jon Custer
May 18 at 20:42

@JonCuster Sort of, but it's more complicated than that. I'm not putting a history of SE in this answer though. Recommend Morris' "Management of Projects" from 1990 or so if you want an overview of the most relevant thread for Apollo/ –
fectin
May 19 at 0:55

Thought Icelandic glacier water was rare? How about chugging down some Moon water. //

Scientists in China have found glass beads contained in lunar soil might hold enough water to provide a resource for future lunar missions.

The results, published in Nature Geoscience this week, stem from data collected by China's Chang'e-5 mission, and suggest the Moon's surface holds much more trapped water than previously thought and the liquid compound vital to continuing life could be relatively easy to extract.

Small glass beads created when meteorites smash into the lunar surface have long been considered a candidate for water storage. Using samples from the Apollo 11 mission, a US study published in 2012 found between 200 and 300 parts per million of water and hydroxyl (OH) in the glass beads they contained. //

Water made it into the beads via the solar winds, the reasoning goes. Solar winds are a plasma emitted from the sun containing hydrogen ions. On earth, they cause the aurora borealis and aurora australis, owing to an interaction with the Earth's magnetic field in the upper atmosphere. As the Moon has no magnetic field, the solar winds can reach its surface and interact with minerals in the soils containing oxygen. Because the solar wind is always, erm, blowing, the water in the beads is replenished.

Hasselblad and NASA’s journey together began in 1962 during the Mercury program. Prospective NASA astronaut and photography enthusiast Walter Schirra had his own Hasselblad 500C with a Planar f/2.8, 80mm lens. Knowing the high quality of the Hasselblad camera, Schirra suggested to NASA that they use a Hasselblad to document space since the previous camera model utilised delivered disappointing results. After buying a few 500Cs, a weight-loss program followed including removal of its leather covering, auxiliary shutter, reflex mirror, and viewfinder. A new film magazine was constructed in order to allow for 70 exposures instead of the usual 12. Finally, a matte black outer paint job minimized reflections in the window of the orbiter. The streamlined Hasselblad would find itself in the payload for Mercury 8 (MA-8) in October 1962. The successful, high quality images that Schirra captured across his six orbits of the Earth would spark a new chapter in the history of Hasselblad and a long, close and mutually beneficial cooperation between the American space agency and the Swedish camera manufacturer.

On Friday, in a blog post not even promoted by the company's Twitter account or a news release, Blue Origin quietly said its "Blue Alchemist" program has been working on this very topic for the last two years. The company, founded by Jeff Bezos, has made both solar cells and electricity transmission wires from simulated lunar soil—a material that is chemically and mineralogically equivalent to lunar regolith.

The engineering work is based on a process known as "molten regolith electrolysis," and Blue Origin has advanced the state of the art for solar cell manufacturing. In this process, a direct electric current is applied to the simulated regolith at a high temperature, above 1,600° Celsius. Through this electrolysis process, iron, silicon, and aluminum can be extracted from the lunar regolith. Blue Origin says it has produced silicon to more than 99.999 percent purity through molten regolith electrolysis.

The key advance made by Blue Alchemist is that its engineers and scientists have taken the byproducts of this reaction—and these materials alone—to fabricate solar cells as well as the protective glass cover that would allow them to survive a decade or longer on the lunar surface. //

For decades scientists and engineers have talked about using the dusty lunar surface to manufacture solar panels. All of the key ingredients for solar cells are present in this rocky and dusty regolith on the surface of the Moon—silicon, iron, magnesium, aluminum, and more.

The abundance of these ingredients has led to hundreds of research papers exploring this idea since lunar soil was returned to Earth during the Apollo program but relatively little engineering development. In other words, we don't know whether covering the Moon with solar panels is simply a great science fiction idea, or if it would actually work. //

Although our vision is technically ambitious, our technology is real now," the company said in its blog post. "Blue Origin’s goal of producing solar power using only lunar resources is aligned with NASA’s highest priority Moon-to-Mars infrastructure development objective."

This is a notable research breakthrough, as the same electrolysis process could also be used to produce metals for building habitats and other structures, as well as oxygen. These are all important for "living off the land" if humans are to avoid the expense of needing to bring everything from Earth to live and work in space. While it is a long way from lab experiments to manufacturing on the Moon, these experiments are a critical first step.

Using film from U.S. spy balloons to take pictures of the Moon

"THERE WILL BE LAUGHTER IF THIS PIECE WORKS ...".

Article from the newspaper "St. Petersburg Vedomosti" of April 10, 1993. by Igor Borisovich Lisochkin.

Russian text reference provided by Alexander Dzhuly. Subsection headers inserted by Sven Grahn //

And the fact that we "photographed" the opposite side of the Moon with an American film that was sent to our country with purely spying goals, I told my closest associates only many years later, long after the untimely death of Sergei Pavlovich Korolev. In fifteen years. The abbreviation “AB”, I think, is not necessary to decipher. Of course, this is the "American Balloons". Odessites never lose their sense of humor. Starting with "Vostok" I acted as the chief designer of space television systems. Of course, I perfectly remember the immortal flight of Yuri Alekseevich Gagarin, and everything that followed. But this is another story and completely different adventures.”

After launching on a Falcon 9 rocket in August 2022, the Korean Pathfinder Lunar Orbiter slid into orbit around the Moon last month. This was South Korea's first lunar probe, and among its chief objectives was surveying the polar regions of the Moon for resources such as water ice.

One of the six instruments carried by the half-ton satellite was a hyper-sensitive camera built by NASA called ShadowCam. The camera was designed with maximum sensitivity to light, such that it could provide images of permanently shadowed regions of the poles—which is to say, capture images of things that are inherently very dark.

Earlier this week, the ShadowCam team released its first image, which reveals a wall and the floor of Shackleton Crater near the south pole of the Moon. At first glance, there's nothing remarkable about the photo. It looks a lot like... the Moon.

However, what you're actually looking at is an area of the Moon that lies in total darkness. Here is a photograph taken by NASA's Lunar Reconnaissance Orbiter in 2009, shortly after it reached the Moon. That black area on the left of the photo? That's the region of Shackleton Crater imaged by ShadowCam. Yeah, it's pretty phenomenal. //

According to the imaging team, the camera's ability to capture clear images at high sensitivity is the equivalent of increasing from ISO 100 to greater than 12,800 without increasing grain.

There are also valid concerns about the safety of the SLS and Orion hardware. These vehicles are large, complex machines that will only fly infrequently, at most once a year. At such a flight rate, this launch system will always be experimental.

It can reasonably be argued that Starship is also not safe to launch on and land back on Earth. It, too, is a large and complex vehicle that will come back through Earth's atmosphere, dissipate heat, and perform delicate maneuvers before landing under the power of its own engines. Even though Starship will launch at least dozens of times per year, the vehicle is unlikely to meet NASA's safety requirements for humans for a long, long time. So Starship-only missions to the Moon are not a near-term solution.

Something even the prophet cannot predict
However, there is an alternative, the source suggested. NASA presently has a vehicle it has deemed safe enough to launch humans into space and back. That's SpaceX's Crew Dragon spacecraft, which launches on the rocket that owns the world record for the longest streak of successful launches—the Falcon 9. By the mid-2020s, Crew Dragon will already have launched humans into space dozens of times.

The safest and lowest-cost means of completing an Artemis mission to the Moon, therefore, may involve four astronauts launching to a fairly high altitude in low-Earth orbit on Crew Dragon and rendezvousing with a fully fueled Starship. The astronauts would then fly to the Moon, land, and come back to rendezvous with Crew Dragon in Earth orbit. They would then splash down on Earth inside Dragon.

This architecture is less risky because it doesn't involve launching on SLS, nor does it require two rendezvous and dockings in lunar orbit, far from Earth. The crew would only spend a couple of more days aboard Starship than they would during the existing Artemis III plan, so Starship life support should be up to the task. If you care about costs, this plan also excludes the $4.1 billion launch cost of Orion and the SLS rocket and substitutes Crew Dragon, which would be on the order of one-twentieth of the cost.

In addition to flying, landing, and returning from the moon in 1969 — NASA's Apollo 11 crew helped with a series of scientific experiments. One of them was to leave a special instrument with lots of little reflectors on the surface of the moon. The goal of that experiment was to beam a laser at the moon. Today on the show, Scientist-In-Residence Regina G. Barber talks to host Aaron Scott about the lunar laser ranging experiment — and how shooting that laser helped us better understand one of Einstein's theories.

Fifty years ago Friday, on Dec. 21, 1968, Apollo 8 lifted off, marking the first time humans left low Earth orbit and flew to the moon.

This was the second manned spaceflight of the Apollo program, and it was a nerve-wracking and remarkable flight that captured the world's attention. The mission capped a difficult and conflict-filled year in the U.S., offering a rare moment when people could feel good about their planet.

Any trip to space is risky. But a mission to the moon, nearly a quarter-million miles from Earth, was something else. There were many things that could go wrong and many unknowns about this first trip. But on Christmas Eve 1968, the capsule made it to lunar orbit. //

There was also an unexpected moment during the 20 hours they circled the moon. As they focused on the lunar surface below, something else caught the crew's attention.

"Oh my God, look at that picture over there! It's the Earth coming up. Wow, is that pretty!" exclaimed Anders.

Anders rushed to snap a picture of the Earth, rising above the barren lunar landscape. The "Earthrise" image remains one of the most famous ever taken in space, and Anders says it forever changed the way people think about where we live.

"The only color that we could see and contrasted by this really unfriendly, stark lunar horizon, made me think, 'You know, we really live on a beautiful little planet,' " he says. //

In an interview with NPR earlier this year, Borman, the mission commander, noticed the same thing. "The only telegram I remember out of all the thousands we got after Apollo 8 said, 'Thank you Apollo 8 you saved 1968,' " he said.

It's probable that the impact object comes from a Chinese rocket launched in 2014. //

It was engineer Jon Giorgini at NASA's Jet Propulsion Laboratory who realized this object was not, in fact, the upper stage of a Falcon 9 rocket. He wrote to Gray on Saturday morning explaining that the DSCOVR spacecraft's trajectory did not go particularly close to the Moon. The second stage would, therefore, be extremely unlikely to strike the Moon. This prompted Gray to dig back into his data and identify other potential candidates.

He soon found one: the Chinese Chang'e 5-T1 mission launched in October 2014 on a Long March 3C rocket. This lunar mission sent a small spacecraft to the Moon as a precursor test for an eventual lunar-sample return mission. The launch time and lunar trajectory are almost an exact match for the orbit of the object that will hit the Moon in March.

"In a sense, this remains 'circumstantial' evidence," Gray wrote. "But I would regard it as fairly convincing evidence. So I am persuaded that the object about to hit the moon on 2022 Mar 4 at 12:25 UTC is actually the Chang'e 5-T1 rocket stage."