Astronaut Walter Schirra's decision to bring a Swedish-made Hasselblad on his Mercury spaceflight set the course for NASA's choice of the camera for the Apollo lunar program. //

Schirra's was a much more sophisticated — and pricey — choice than the simple Ansco Autoset that John Glenn bought for $40 at a Cocoa Beach, Florida, drug store. Glenn used it to take pictures from orbit on Friendship 7 in February 1962. The Hasselblad retailed for about $500 and used a much larger negative than Glenn's 35 mm camera. It also sported interchangeable, Carl Zeiss lenses and removable film magazines. //

Schirra acknowledged that his six orbits in October 1962 didn't leave much time for photography, but that on the next flight the following spring, with 22 orbits, astronaut Gordon Cooper "got some absolutely gorgeous pictures," said Schirra.

Hasselblad's Chris Cooze says until then, the space agency was so focused on the technical side of spaceflight that photography was something of an afterthought.

He says it was in 1965, when NASA released stunning photos of Ed White's spacewalk on Gemini 4, that Hasselblad "put two and two together" and realized the pictures were taken with one of their cameras.

"Then they got in touch with NASA to see if there was anything that we could cooperate on," Cooze says. //

On July 20, 1969, the Apollo 11 Lunar Module landed with two cameras, but only one went outside — carried by Neil Armstrong. That explains why nearly every photograph of an astronaut on the surface during that first landing are of Armstrong crewmate Edwin "Buzz" Aldrin. Armstrong had the only camera for nearly the entire two-and-a-half hours the two walked around the Sea of Tranquility. //

"There were no directions to take photographs of each other, which I always find really interesting," she says. "You're going to travel all the way to the moon and nobody ever thought, 'Gee, we should take pictures of people.' " //

Moon rocks, it turns out, are more valuable than cameras. So, the astronauts were instructed to pack the exposed film but leave behind the Hasselblads.

And, that's where they remain today, untouched, at the six Apollo landing sites.

Apollo Guidance Computer software engineer, "invented" virtual machines for AGC (which explains how it was able to prioritize during the 12-02 alarms in Apollo 11 landing).

Join us for a once-in-a-lifetime celebration of the 50th anniversary of Apollo 11, featuring a 363-foot Saturn V rocket projected on the east face of the Washington Monument and a special "Apollo 50: Go for the Moon" show. This presentation was conceived and commissioned by the National Air and Space Museum, and is made possible through a partnership with the U.S. Department of the Interior and 59 Productions.

On July 16 through 20, the projection will be live from 9:30 pm to 11:30 pm.

It all builds up to July 19 and 20, when we will also present "Apollo 50: Go for the Moon," a 17-minute show that will combine full-motion projection mapping artwork and archival footage to recreate the launch of Apollo 11 and tell the story of the first Moon landing. The show will unfold on the face of the Washington Monument and supporting screens, including a 40-foot-wide recreation of the famous Kennedy Space Center countdown clock.

The free show will run at 9:30 pm, 10:30 pm, and 11:30 pm on Friday, July 19, and Saturday, July 20.

Despite what everyone says about the power of modern devices, they’re nowhere near as capable as the landmark early NASA system. //

How do you define power?” O’Brien asks. “It’s great to say, ‘This machine is so powerful.’ What do you mean by that?”

For him, it’s not about the raw number of transistors, but the machine fitting the mission. Capability, not power. “We had to get to the moon, get down, and get back, autonomously. They hit their targets of being accurate after a quarter million miles, hitting a target within 500 to 600 feet and one-tenth of a foot a second,” O’Brien said. “And you go, ‘My watch is more powerful.’ No, it is not.”

Religious faith always animated the American quest to explore the heavens.

Fifty years ago this Saturday, after Apollo 11’s Eagle lunar module had landed in the Sea of Tranquility, Buzz Aldrin took to the communication system and sent a message back to the ground crew on earth. “I would like to request a few moments of silence,” he asked. “I would like to invite each person listening in, wherever and whomever he may be, to contemplate for a moment the events of the past few hours and to give thanks in his own individual way.”

Then, NASA censored the most significant spiritual event in the history of space exploration.

After Aldrin ended the communication, he read a verse from the Gospel of John: “I am the vine, you are the branches. Whosoever abides in me will bring forth much fruit. Apart from me you can do nothing.” He then opened two small packages containing consecrated bread and wine from his church in Texas. Aldrin poured the wine into a chalice. “In the one-sixth gravity of the moon, the wine curled slowly and gracefully up the side of the cup,” he later recalled. As Neil Armstrong looked on in silence, Aldrin took communion. The first foods ever prepared or consumed on the moon were the Body and Blood of Christ. //

From the beginning, religious faith animated the American quest to explore the heavens. In 1962, President John F. Kennedy concluded his famous “we choose to go to the moon” speech by asking “God’s blessing on the most hazardous and dangerous and greatest adventure on which man has ever embarked.” Kennedy embarked on that journey to win a space race that pitted the God-fearing United States against godless Soviet communism.

Imagine this: It is July 16, 1969, and hundreds of thousands of people are camped out near the Kennedy Space Center overnight waiting for the launch of Apollo 11. Hundreds of millions more around the world are glued to their TVs and radios, awaiting the magical moment. It’s a bright sunny morning and Apollo 11 is gleaming on the launch pad as technicians check the | Read More »

The second day of Apollo 11 was a true journey into outer space. Having left behind the earth, gotten a ‘night’s’ sleep, and with the moon more than a day in the future, Neil Armstrong, Buzz Aldrin and Michael Collins were occupied with checklists and a great many adjustments, many of which were manually performed, as well as a mid-course correction burn of the engine. | Read More »

The landing sites that were planned for the lost Apollo missions are still waiting for the footsteps of human beings, //

However, three more missions to the moon - Apollos 18, 19 and 20 - could have been flown, but instead were canceled. All of the hardware for these missions had already been built, and trained astronauts were ready to fly. The savings of those cancellations amounted to only a few tens of millions of dollars.

An article in Seeker suggests that what was lost by this must be one of the most outrageous, bureaucratic decisions in space history.

"If the Apollo 18-20 flights were realized, school kids today could be looking at stunning photographs taken from the mountain-rimmed floors of the young impact craters Copernicus or Tycho, or the terrain on the far side of the moon, or the frozen volcanic lava flows from billions of years ago."

success of the Apollo missions to the moon would have inspired the United States to mount more voyages of discovery, not to be so anxious to bring the program to a close that it would cancel missions for which hardware had already been built.

However, the stress of the Vietnam War, racial tensions, and the efforts of some unscrupulous politicians to paint the space program as a drain of money that would better be spent on social programs contributed to Apollo's early close.

In the first of BBC Future’s stories recounting the Apollo program in 50 numbers, we look at the people who helped make the Moon missions reality.

Neil Armstrong was one of Nasa’s most accomplished pilots. As he descended towards the lunar surface on 20 July 1969, the success or failure of the first Moon landing depended on the skills, reactions and expertise of this one man. With a boulder field ahead of him, alarms sounding and fuel running low, he guided the spacecraft to the ground.

But in the few talks and interviews Armstrong gave about the landing, he was always modest about the achievement. He pointed instead to the thousands of people who had made the mission possible.

At its height, Nasa estimates that a total of 400,000 men and women across the United States were involved in the Apollo programme. The number includes everyone from astronauts to mission controllers, contractors to caterers, engineers, scientists, nurses, doctors, mathematicians and programmers.

To see how Nasa arrived at that figure, consider a single aspect of Apollo 11 – the lunar landing itself. Armstrong’s right hand man was Buzz Aldrin. On the ground, there was a room full of mission controllers. Behind this core team of 20-30 (per shift) were hundreds of engineers in Houston and a team at MIT in Boston advising on the computer alarms.

Mission Control was supported by communications ground stations around the world, the engineering team at the Grumman Corporation that built the lander, and all their subcontractors. Add in support staff – from senior managers to the people selling the coffee – and already there are thousands involved. Multiply that by all the different components of the endeavour – from rockets to spacesuits, communications to fuel, design to training, launch to splashdown…and 400,000 seems an almost modest figure.

Teasel Muir-Harmony, Apollo Spacecraft Curator at the Smithsonian National Air and Space Museum in Washington DC. “Each of the [Apollo 11] crew members was born in 1930, they all have military experience, they're all pilots and I believe they're all Christian – so they fit a very narrow set of criteria that was required at the time to be an astronaut.”

At 38, Armstrong was the joint youngest Apollo commander (with Tom Stafford and Gene Cernan). Charlie Duke, the 36-year-old Apollo 16 lunar lander pilot, was the youngest Moonwalker. The oldest man to walk on the Moon was America’s first astronaut, Alan Shepard. By the time of his Apollo 14 mission in 1971, he was 47.

The record for the oldest man in space is held by the same astronaut who was the first American to orbit the Earth. John Glenn was 77 when he took part in a nine-day mission on space shuttle Discovery in 1998.

Thirty three men flew 11 Apollo missions. Of these, 27 men reached the Moon, 24 orbited the Moon – but only 12 walked on the surface. They represented “mankind” and had the challenge of conveying the experience to a global audience.

No-one knew what Neil Armstrong was going to say when he stepped down onto the lunar surface. He’d not discussed it with anyone, although his words: “That’s one small step for [a] man, one giant leap for mankind” could not have been more poetic or appropriate if they had been conceived by a committee of speech writers.

But what do you say when you’re the second man on the Moon? Buzz Aldrin summed-up the view of the barren lunar landscape perfectly in just two words: “magnificent desolation.”
All eight astronauts – along with six Soviet cosmonauts – are commemorated with a plaque left on the Moon by the crew of Apollo 15.

Looking at the coverage of Apollo, you might be forgiven for thinking it was a solely (white) male endeavour. The astronauts were all men, the mission controllers were all men, even the TV anchors were male. The only women seen on TV were the astronauts’ wives.

However, as we now know, there were thousands of women behind the scenes supporting Apollo and essential to its success. There were secretaries and nurses, mathematicians and programmers; women sewed together the spacesuits and wound the wires for the Apollo guidance computers.

Even so, the space programme wasn’t geared-up for women.

“Even when they built new buildings they forgot there were going to be more and more women as workers,” says Morgan. “The first building I worked in only had one ladies room in the whole three-storey building - they had to convert a men's room on each floor to a ladies’ room…so we had ladies’ rooms with urinals.”

Some astronauts didn’t want to bring TV cameras on board – but the footage captured has gone down as some of the most memorable in human history.

Christmas Eve 1968, the crew of Apollo 8 – Frank Borman, Jim Lovell and Bill Anders – were about to get their first glimpse of the far side of the Moon.

“We fired the spacecraft engine something like four minutes to slow down enough to get into lunar orbit,” says Borman. “We’re about halfway through when we looked down and there was the Moon.”

“The lunar surface was terribly distressed with meteorites, holes, craters, volcanic residue,” he says. “But one of the things that struck me was there's absolutely no colour, it was either grey or black or white.”

“It was a very interesting first view
But the most captivating view came as they swung back around on the fourth orbit and Anders spotted the Earth in the command module window.

“Oh my God, look at that picture over there! There's the Earth coming up. Wow, is that pretty!” he exclaimed. “You got a colour film, Jim? Hand me a roll of colour, quick, would you?”

These cartridges containing reels of 70mm film could be easily swapped on the crew’s Hasselblad cameras.

“Take several, take several of them,” said Lovell. “Here, give it to me!”

Once the film was developed back on Earth several weeks later, Nasa image 2383 (and the frames either side) would become one of the most famous pictures of all time.

The picture, showing the Earth in the context of the barren Moon, was one of the unexpected achievements of the Apollo programme.
“I think it's probably one of the more significant pictures that humans have ever taken,” agrees Borman. “The Earth was the only thing in the entire universe that had any colour – a beautiful sight, we're very fortunate to live on this planet.”

In the run-up to the Apollo missions, there was tremendous resistance among many Nasa engineers and astronauts to the idea of carrying TV cameras for live broadcasts from space. It was frivolous and would interfere with the mission, they argued.

The formidable head of mission control, Chris Kraft, thought otherwise and insisted that TV was a way of showing American taxpayers how their money was being spent.

The first astronauts to carry a TV camera into orbit were the crew of Apollo 7 – Wally Schirra, Don Eisele and Walt Cunningham. After a shaky start, they soon got the hang of adding a little showbiz to the space programme.

Despite their shortcomings, these first TV broadcasts from space – a total of seven – nonetheless won an enthusiastic global following. They gave the missions an immediacy that wasn’t possible with film or photography.

When the Apollo 7 crew returned to Earth, they were rewarded with an Emmy Award from the National Academy of Television Arts and Sciences for their efforts.

Later missions would push the boundaries of TV technology, with improved cameras, transmitters and content. Apollo 8 broadcast live from lunar orbit for the first time and, during Apollo 10, the crew produced the first colour TV shows from the Moon.

Broadcasting from the relatively bright and controlled conditions of the Apollo spacecraft was very different from transmitting the first images from the surface of another world. But Nasa realised it was essential to broadcast mankind’s first footsteps on the Moon.

Nasa wasn’t taking any risks with ensuring the live video reached the Earth and arranged for the transmissions to be received by 64-metre wide dishes in Goldstone, California and at Parkes in New South Wales, Australia.

Engineers at Parkes spent months working with Nasa to prepare the giant radio telescope to receive the first TV pictures from the lunar surface. On the 21 July 1969, everything was ready for the big event but then the weather suddenly changed.

“Just minutes before the Moonwalk was due to begin, a violent squall hit the telescope with winds that were over the safe operating speeds,” says Parkes operations scientist John Sarkissian. “The astronauts may have been on the Sea of Tranquility on the Moon,” says Sarkissian, “but it was the ocean of storms here.”

During the later Apollo missions, a TV camera was fixed to the lunar rover to give viewers a drivers-eye view of the Moon. The camera was remote-controlled from Earth, which also enabled operators to capture one of the coolest shots in TV history. As Apollo 17 blasts-off from the Moon, the camera tilts to follow its trajectory

Around 600 million people watched as Neil Armstrong took his first tentative small step on the lunar surface. At that time, it was the world’s largest-ever TV audience.

But by the time of Apollo 13, just nine months later, the world had already lost interest. As Jim Lovell, Jack Swigert and Fred Haise travelled to the Moon, none of the national US TV networks carried their broadcast.

28,000: Distance the Blue Marble image taken from, in miles

As the Apollo 17 crew headed to the Moon for the final time in 1972, they were instructed to take a picture looking back at the Earth. The image – known as the Blue Marble – gives a unique perspective of the whole Earth hanging in the blackness of space. Not only does it show the South Pole but it puts Africa – not the USA – at the centre.

Even when we return to the Moon, these first images – particularly those of Earth – will have a special place in the history of humankind.
In the words of Apollo 8 commander, Frank Borman: “I don't think any of us paid any attention to the fact that we would be going all the way to the Moon and be more interested in looking at the Earth.”

111: Height of Saturn V rocket in metresAt 36 storeys high, the Saturn V ranks as one of the greatest technical and engineering achievements of the 20th Century. Its development was led by Wernher von Braun who, even while building V2 rockets for Hitler, dreamed of building a rocket to carry men to the Moon. “Not only was he technically competent,” says Jay Honeycutt, a rocket engineer and later senior manager at Nasa, “but he had great leadership skills and a great ability to communicate with government officials who funded the projects.”

2: Maximum speed of the crawler transporters, in miles per hour

The Saturn Vs were put together in the Vehicle Assembly Building (VAB), a structure so large it even has its own weather system. Engineers then had the challenge of getting the rockets to the launch pad, some five or so kilometres away. After an initial suggestion to float the spacecraft on barges, it was decided to build giant tracked vehicles called crawler-transporters.

With eight giant tracks – driven by 16 electric motors, powered by two generators – the crawler-transporters are more like ships than vehicles. And, like ships, the drivers are part of a team of operators and engineers that keep the vehicles moving slowly to the launch pad. Very slowly.
“The crawler has the power to go two miles an hour,” says driver Sam Dove. “However, you really don’t want to get it up to two, especially with a load on it – the most we ever go is one.”During Apollo, it could take up to 16 hours to deliver the spacecraft the few kilometres from the VAB to the launchpad. The time from pad to orbit was just eight minutes.

5: Saturn V upper stages on the Moon

Just nine minutes after launch, the Saturn V had already shed its first and second stages, sending them tumbling away towards the Atlantic Ocean. The third stage (rather confusingly known as the S4B), with its single engine, gave the spacecraft enough speed to reach orbit before shutting down.

Then, after one and a half revolutions of the Earth, the crew relit the S4B’s engine. In a manoeuvre known as Trans Lunar Injection, the rocket thrust the spacecraft out of orbit on a trajectory towards the Moon.

After the astronauts shut the engine down for a second time, and with the lunar lander extracted from the casing at the top, the rocket was abandoned. But – because it was travelling at the same speed and in the same direction as the spacecraft – unless the crew changed trajectory, the spent rocket would follow them to the Moon.

For the first few Apollo missions, Nasa’s solution was to send the S4B into orbit around the Sun. And, today, the S4B stages for Apollos 8, 9, 10 and 11 are still orbiting the Sun. Apollo 12’s upper stage, however, has been recaptured by the Earth’s gravity.
For the remaining missions, Nasa came up with a more imaginative plan.

The Apollo Lunar Surface Experiment Package (Alsep), left by the moonwalkers of Apollo 12 onwards, included a seismometer which relayed data to Earth. By smashing the S4B stages into the Moon, geologists could trace the resulting tremors through the lunar rock to help determine its geological composition.

As the missions progressed, and the more stages they crashed, the more data they got back. The Alseps continued to return data until 1977, when Nasa shut the programme down.

The Apollo programme pushed space and computing technology to its limit. Cutting edge at the time, some of the tech used seems alarmingly simple today.

74: Memory (ROM) of Apollo guidance computer, in kilobytes

Computer technology was one of the greatest – and long lasting – achievements of Apollo. From the solid-state microcomputer fitted to the lunar lander, to mighty IBM mainframes, with their flashing lights and banks of magnetic tape.

Although the 74 KB ROM and 4 KB RAM memory of the AGC sounds puny today – the equivalent of a 1980s home computer such as the Sinclair ZX Spectrum or Commodore 64 – it was an impressive machine. Designed for the rigours of spaceflight, its software was hard-wired into coils and, crucially, it was set up so it couldn’t crash.

22: Diameter of Saturn V computer, in feet

If the Apollo Guidance Computer was impressive for its miniaturisation, then the computer controlling the Saturn V Moon rocket must rank as the largest ever launched.

Fitted within a ring above the top of the upper (third) stage of the rocket, the Saturn V instrument unit was massive. As well as digital and analogue computers, the unit contained all the electronics to control and monitor the rocket that would get men to the Moon.

Designed by Wernher von Braun’s rocketry team in Huntsville, Alabama, the computer was built by IBM. It was practically the equivalent of flying a mainframe computer into space and then abandoning it.

When Apollo 12 was struck by lightning during launch, knocking out power in the command module, mission controllers believe the circular design of the rocket’s computer saved it from the power surge.

The Apollo astronauts might have been in peak physical condition, but that doesn’t mean they didn’t suffer all sorts of health complaints. In space, no-one can hear your sneeze.24: Number of decongestant tablets taken by the Apollo 7 crew

Apollo 7 was commanded by one of Nasa’s most experienced astronauts, Wally Schirra - a veteran of both Mercury and Gemini missions. Alongside him in the capsule, rookie astronauts Don Eisele and Walt Cunningham. Commentators predicted this would be the crew to make the first attempt to land on the Moon.

Within hours of launch, however, Schirra came down with a cold.

It's nearly 50 years since the US became the first country to land men on the Moon.

The Apollo 11 mission was a huge moment in US and world history, but what exactly happened and why does it matter?

Nasa has released new images of the Apollo landing sites on the Moon, taken from an orbiting spacecraft.

They show scientific equipment, the lunar rovers and a trail of footprints left by astronauts 40 years ago.

Director Tom Jennings and engineer Poppy Northcutt reflect on seminal era in space flight

A set of original videotape recordings of the Apollo 11 Moon landing that were bought for $217.77 at a government surplus auction by a former NASA intern in the 1970s could raise up to $2 million when they are auctioned this month. //

Viewed only three times since they were bought directly from NASA at the auction in 1976, the tapes are the only surviving first-generation recordings of Neil Armstrong’s first steps on the Moon, according to Sotheby’s. In a statement, Sotheby’s explains that the tapes are “sharper and more distinct” than the few tapes that survive from network television broadcasts of the Moon landing.

The videotapes are from the collection of Gary George, who purchased them while serving an intern at NASA. In June 1976, George attended an auction at Houston’s Ellington Air Force Base where he bought a single lot of some 1,150 reels of magnetic tape whose “Owning Agency Or Reporting Office,” was listed as NASA.

“Among the reels were about sixty-five boxes of 2-inch, reel-to-reel videotapes of the type used by television stations,” explains Sotheby’s in a statement, noting that George planned to sell the used tapes, which could be re-recorded, to local TV stations.

However, after selling some of the tapes and donating others to Lamar University and a local church, George’s father noticed that three of the boxes were labeled: “APOLLO 11 EVA | July 20, 1969 REEL 1 [–3]” and “VR2000 525 Hi Band 15 ips.”

Thinking that these particular tapes may be worth hanging on to, George saved the three boxes, giving them little thought until early 2008 when he learned that NASA was attempting to locate its original slow scan videotapes of the Apollo 11 EVA (Extravehicular Activity) in anticipation of the 40th anniversary of the first manned moon landing,” explains Sotheby’s.

It took two years and cost $5 million—but the results are absolutely spectacular.

HOUSTON—Following the completion of a multi-year, multi-million-dollar restoration, NASA's historic Apollo Mission Operations Control Room 2 ("MOCR 2") is set to reopen to the public next week. The $5 million in funding for the restoration was partially provided by Space Center Houston, but the majority of the money was donated by the city of Webster, the Houston suburb where the Johnson Space Center is located. Another half-million in funding came from the general public via a Kickstarter campaign (disclosure: your humble author was a backer).For the past two years, historians and engineers from the Kansas Cosmosphere's Spaceworks team have been lovingly restoring and detailing the 1,200-pound (544kg) historic sage green Ford-Philco consoles that populated the control room—repairing damage from decades of casual neglect and also adding in the correct control panels so that each console now correctly mirrors how it would have been configured for an Apollo flight.

Ars was invited to view the restored MOCR 2 last week as the final finishing restoration touches were still being applied. We conducted some interviews and shot some photos while technicians and construction workers bustled around us, hammering and screwing the last bits and bobs into place. The room's lighting system was in the process of being worked on, and the room flickered several times between fully illuminated daytime lighting and dim twilight—providing an even more accurate glimpse of what it might have looked like during an actual mission.

The Lunar Ascent Engine was used during the Apollo missions to ascent from the lunar surface back to the Command and Service Module. There was one risky aspect of that engine: it was not possible to fire it repeatedly. Each ascent engine used on the Apollo missions was fired for the first time on the Moon. //

Why was the engine manufactured like that? //

According to a Boeing document titled "Apollo Spacecraft Engine Specific Impulse Part II dated October 1968 (bold mine):

the injector and valve assembly are first calibrated and then acceptance test fired in a water cooled steel chamber with an ablative liner. A single compatibility test of 460 second duration is then carried out. Finally, the injector and valve assembly are then assembled with their flight chamber and the complete engine is acceptance tested...

The description of the acceptance tests for the complete engine includes:

The engine and its thrust measuring rig are mounted horizontally in a capsule. Altitude pressure is obtained by a steam ejector and maintained during engine firing by an exhaust driven diffuser. Propellant tanks are pressurized with helium. There is provision for both temperature conditioning and helium saturating the propellants. A minimum of two satisfactory engine acceptance tests of 15 second duration have to be carried out. ... Throat and exit area measurements are taken prior to the first test and after the last in each test series.

The Insider.com article 'We could have lost the Apollo 11 crew:' A once-classified anomaly nearly killed NASA's first moon astronauts, a new book reveals describes a problem during reentry of several Apollo missions where the Service Module jettison did not execute properly and so it remained dangerously close to the Command Module.

There is a lot of technical information in the NASA links. There seems to have been some sort of problem with sloshing that prevented the Service Module from continuing to move away from the Command Module, and this was addressed by a Service Module modification implemented for Apollo 14.

Question: How did sloshing prevent the Apollo Service Module from moving safely away from the Command Module and how was this fixed? //

...the service module, upon being jettisoned on a lunar return flight, should have entered the earth's atmosphere, then skipped out into a highly elliptical earth orbit. Thus, the risk of recontact with the command module during entry would have been eliminated. However, on Apollo 8, 10 and 11, the service module did not skip out as expected. //

they reduced the roll burn time to get the proper roll rate and simply commanded the -X thrusters to burn for only 25 seconds instead of burning to propellant depletion. The service module would still tumble due to the sloshing, but without the thrusters firing, it wouldn't accelerate back toward the command module. The shorter separation burn would not be enough to prevent prompt reentry of the service module, but apparently that wasn't a necessary feature of the operation.

I think the article greatly overstates the seriousness of the anomaly, by the way; it didn't "nearly kill" the crew of Apollo 11.