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.

Last week, NASA’s Curiosity rover detected a belch of natural gas on the red planet. The gas has since dissipated, leaving only a mystery.

Don't expect a huge structure like the International Space Station.

In a year when we’ll celebrate Apollo 11’s 50th anniversary, it’s worth remembering the pathfinders who completed the same mission with one critical order: don’t actually land on the moon. //

But Snoopy didn’t have enough fuel to land on the moon and then blast off again. According to Craig Nelson, author of the book “Rocket Men,” Cernan speculated that the lander’s ascent module had been short-fueled on purpose: “A lot of people thought about the kind of people we were: ‘Don’t give those guys an opportunity to land, ‘cause they might!’”

Mission control might never have witnessed Neil Armstrong take his first steps on the moon if it weren't for the vision of men like Eugene Shoemaker

On the Moon right now, there lies an aluminium sculpture of an astronaut with a beautiful message.

NASA and Lockheed Martin have now taken a step closer to a future with faster-than-sound air travel over land.

Lockheed Martin Aeronautics Company of Palmdale, California, recently began manufacturing the first part of NASA’s X-59 Quiet SuperSonic Technology (QueSST) aircraft. When completed, NASA will use the X-59 to study how reducing the sonic boom heard from traditional supersonic jets to a quiet sonic “thump” could lead to acceptance of supersonic flight over land.

Pictured, a Lockheed Martin technician at their Palmdale, California, facility prepares a machine to shave the first piece of NASA’s X-59 QueSST aircraft, which later will be integrated into the overall structure.

“We’ve reached an exciting milestone not only for NASA but for airliners and passengers wishing to arrive to their destination in half the time,” said Craig Nickol, the NASA project manager for the Low-Boom Flight Demonstrator project. “Manufacturing the first part of the X-59 is a step on a path that leads to the completion of an exciting research aircraft, quiet supersonic flight and new markets for faster air travel.”

When completed, the single-pilot experimental aircraft will go through a series of tests to prove its performance. Then the X-59 will fly over a number of U.S communities, collecting data on how the public responds to the quiet “sonic thump.” U.S. and international regulators will use the data to potentially change the rules that currently ban supersonic flight over land.

Lockheed Martin was selected by NASA to build, design and conduct initial flight tests of the X-59. Work under the contract began April 2 and runs through Dec. 31, 2021.

“We never dreamt that it would be this clear, this beautiful.”

Physical Scientist J.T. Heineck of NASA’s Ames Research Center in California’s Silicon Valley gets his first glimpse at a set of long-awaited images, and takes a moment to reflect on more than 10 years of technique development – an effort that has led to a milestone for NASA’s Aeronautics Research Mission Directorate.

NASA has successfully tested an advanced air-to-air photographic technology in flight, capturing the first-ever images of the interaction of shockwaves from two supersonic aircraft in flight.

“I am ecstatic about how these images turned out,” said Heineck. “With this upgraded system, we have, by an order of magnitude, improved both the speed and quality of our imagery from previous research.”

The images were captured during the fourth phase of Air-to-Air Background Oriented Schlieren flights, or AirBOS, which took place at NASA’s Armstrong Flight Research Center in Edwards, California. The flight series saw successful testing of an upgraded imaging system capable of capturing high-quality images of shockwaves, rapid pressure changes which are produced when an aircraft flies faster than the speed of sound, or supersonic. Shockwaves produced by aircraft merge together as they travel through the atmosphere and are responsible for what is heard on the ground as a sonic boom.

The system will be used to capture data crucial to confirming the design of the agency’s X-59 Quiet SuperSonic Technology X-plane, or X-59 QueSST, which will fly supersonic, but will produce shockwaves in such a way that, instead of a loud sonic boom, only a quiet rumble may be heard. The ability to fly supersonic without a sonic boom may one day result in lifting current restrictions on supersonic flight over land.
T-38 aircraft creating shockwaves during supersonic flight.
When aircraft fly faster than the speed of sound, shockwaves travel away from the vehicle, and are heard on the ground as a sonic boom. NASA researchers use this imagery to study these shockwaves as part of the effort to make sonic booms quieter, which may open the future to possible supersonic flight over land. The updated camera system used in the AirBOS flight series enabled the supersonic T-38 to be photographed from much closer, approximately 2,000 feet away, resulting in a much clearer image compared to previous flight series.
Credits: NASA Photo

The images feature a pair of T-38s from the U.S. Air Force Test Pilot School at Edwards Air Force Base, flying in formation at supersonic speeds. The T-38s are flying approximately 30 feet away from each other, with the trailing aircraft flying about 10 feet lower than the leading T-38. With exceptional clarity, the flow of the shock waves from both aircraft is seen, and for the first time, the interaction of the shocks can be seen in flight.

“We’re looking at a supersonic flow, which is why we’re getting these shockwaves,” said Neal Smith, a research engineer with AerospaceComputing Inc. at NASA Ames’ fluid mechanics laboratory. //

One of the greatest challenges of the flight series was timing. In order to acquire this image, originally monochromatic and shown here as a colorized composite image, NASA flew a B-200, outfitted with an updated imaging system, at around 30,000 feet while the pair of T-38s were required to not only remain in formation, but to fly at supersonic speeds at the precise moment they were directly beneath the B-200. The images were captured as a result of all three aircraft being in the exact right place at the exact right time designated by NASA’s operations team

Here are the times they could have died in space.

Hi! I'm Amy Shira Teitel! Spaceflight historian, author, and all-around space history nerd! With Vintage Space you'll get weekly videos about spaceflight history, things that I'm curious about, things you guys are curious about, and things no one knew they wanted to know about! I've also got a companion blog: vintagespace.wordpress.com (archive at: popsci.com/blog-network/vintage-space) a podcast: https://itunes.apple.com/gb/podcast/vintage-space-podcast-on-radio/id1166391203?mt=2 and a book: bit.ly/astbtcog ... just in case you guys need more space history!

It roved a staggering 45.16 kilometers across the red planet. //

Late Tuesday night, scientists at NASA's Jet Propulsion Laboratory sent their final data uplink to the Opportunity rover on Mars. Over this connection, via the Deep Space Network, the American jazz singer Billie Holiday crooned "I'll Be Seeing You," a song which closes with the lines:

I'll find you in the morning sun
And when the night is new
I'll be looking at the moon
But I'll be seeing you

Opportunity landed on Mars more than 15 Earth years ago, on January 25, 2004. So much time has passed since then. Facebook would not be created until a month later. YouTube would not get its first video upload for more than a year. George W. Bush was still in his first presidency. NASA's Cassini spacecraft had not yet even arrived in the Saturn system.

And yet from that moment on, Opportunity and its sister rover, Spirit, began plugging along the surface of Mars. Originally designed for 90-day lifetimes, the rovers persisted. Spirit lasted until 2010, when its batteries were unable to keep the spacecraft's critical components from freezing.