Re-Learning How To Run

As I write this, four astronauts are on their way around the moon for the first time in 50 years. A lot us have asked ourselves just exactly why you’d send people out that far when the environment is so hostile and we have increasingly competent robots that could do the jobs in their place. If anything, that’s even more true now than it was back in the day of the Apollo program, when the remote operations capability was a lot more constrained. But having people, potentially in the near future, on the lunar surface remains qualitatively different.

I was recently re-watching some of the footage from Apollo 16 when the astronauts were driving around in the Lunar Roving Vehicle, and the discussions that they’re having about the lunar geology that they can see for the first time with their own eyes is very convincing. Having people in situ tightens the loop of “hey, that’s interesting”, “let’s take a closer look”, and “I wonder what that means” in a way that minutes or hours of transmission time, and sterile observation of photos on a computer monitor just break. In comparison, our Mars rovers move excruciatingly slowly, the data comes back through a very thin pipe, and it takes months or years to analyze.

Of course, there is danger to human life; it’s a lot more expensive to get people safely to, and importantly back from, the moon than it would be with a disposable robot. Comparison with the Mars rovers is also unfair because travel to Mars is another scale entirely. Even if it does make sense to send humans for exploration on the moon, it may not make sense to do the same on the red planet, in the near future or ever. Given all that, I’m stoked that we can see through the robots eyes, but if all else were equal, I’m sure that we’d learn more from human explorers.

While in a lot of ways the Artemis I and now the Artemis II missions are underwhelming in comparison to the many “firsts” of Apollo, I absolutely appreciate them for what they are: a shakedown trial of a set of technologies and practices that we used to grasp, but which have atrophied over the last five decades. If a new generation of scientists is to put feet onto regolith, we need to learn to walk before they can run, or rover. In that spirit, I’ll be crossing my fingers for the future of manned spaceflight over the next week and a half.

A Nebula Straight From The Stars To Your Table

Space may truly be the final frontier, but maybe that frontier can be closer than you thought. Pictures of nebulae and planets bring the colorful sights of deep space right to your screen. You may even have models of some of the rockets used for those missions on a shelf. However, did you know that you could even have a model of those nebulae or planetary surfaces from [NASA]?

While we have covered some distributed models from [NASA] here before, the catalog has expanded far past what 2016 had in store. Additionally, the catalog has been sorted into a more user-friendly, filterable interface than a simple GitHub repository. Most models even have a description attached, giving some basic background information on what the Crab Nebula is, for example.

There could always be more; there don’t appear to be many models of the space shuttle or some other expected files, but what is there is incredible. Some non-3D model files can also be found from star maps to full planetary maps.

While this file repository is cool and all, it’s not all [NASA] does. When not sending rockets deep into space for cool pictures, [NASA] has to make sure the Moon doesn’t explode. Was that a possibility at some point? Of course it has been!

A Univac 1219 cabinet

See The Computers That Powered The Voyager Space Program

Have you ever wanted to see the computers behind the first (and for now only) man-made objects to leave the heliosphere? [Gary Friedman] shows us, with an archived tour of JPL building 230 in the ’80s.

A NASA employee picks up a camcorder and decides to record a tour of the place “before they replace it all with mainframes”. They show us computers that would seem prehistoric compared to anything modern; early Univac and IBM machines whose power is outmatched today by even an ESP32, yet made the Voyager program possible all the way back in 1977. There are countless peripherals to see, from punch card writers to Univac debug panels where you can see the registers, and from impressive cabinets full of computing hardware to the zip-tied hacks “attaching” a small box they call the “NIU”, dangling off the inner wall of the cabinet. And don’t forget the tape drives that are as tall as a refrigerator!

We could go on ad nauseum, nerding out about the computing history, but why don’t you see it for yourself in the video after the break?

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Laser Ranging Makes GPS Satellites More Accurate

Although GNSS systems like GPS have made pin-pointing locations on Earth’s sphere-approximating surface significantly easier and more precise, it’s always possible to go a bit further. The latest innovation involves strapping laser retroreflector arrays (LRAs) to newly launched GPS satellites, enabling ground-based lasers to accurately determine the distance to these satellites.

Similar to the retroreflector array that was left on the Moon during the Apollo missions, these LRAs will be most helpful with scientific pursuits, such as geodesy. This is the science of studying Earth’s shape, gravity and rotation over time, which is information that is also incredibly useful for Earth-observing satellites.

Laser ranging is also essential for determining the geocentric orbit of a satellite, which enables precise calibration of altimeters and increasing the accuracy of long-term measurements. Now that the newly launched GPS III SV-09 satellite is operational this means more information for NASA’s geodesy project, and increased accuracy for GPS measurements as more of its still to be launched satellites are equipped with LRAs.

Self-healing CMOS Imager To Withstand Jupiter’s Radiation Belt

Ionizing radiation damage from electrons, protons and gamma rays will over time damage a CMOS circuit, through e.g. degrading the oxide layer and damaging the lattice structure. For a space-based camera that’s inside a probe orbiting a planet like Jupiter it’s thus a bit of a bummer if this will massively shorted useful observation time before the sensor has been fully degraded. A potential workaround here is by using thermal energy to anneal the damaged part of a CMOS imager.

The first step is to detect damaged pixels by performing a read-out while the sensor is not exposed to light. If a pixel still carries significant current it’s marked as damaged and a high current is passed through it to significantly raise its temperature. For the digital logic part of the circuit a similar approach is used, where the detection of logic errors is cause for a high voltage pulse that should also result in annealing of any damage.

During testing the chip was exposed to the same level of radiation to what it would experience during thirty days in orbit around Jupiter, which rendered the sensor basically unusable with a massive increase in leakage current. After four rounds of annealing the image was almost restored to full health, showing that it is a viable approach.

Naturally, this self-healing method is only intended as another line of defense against ionizing radiation, with radiation shielding and radiation-resistant semiconductor technologies serving as the primary defenses.

Artemis II Agenda Keeps Moon-Bound Crew Busy

With the launch of Artemis II from Cape Canaveral potentially just weeks away, NASA has been releasing a steady stream of information about the mission through their official site and social media channels to get the public excited about the agency’s long-awaited return to the Moon. While the slickly produced videos and artist renderings might get the most attention, even the most mundane details about a flight that will put humans on the far side of our nearest celestial neighbor for the first time since 1972 can be fascinating.

The Artemis II Moon Mission Daily Agenda is a perfect example. Released earlier this week via the NASA blog, the document seems to have been all but ignored by the mainstream media. But the day-by-day breakdown of the Artemis II mission contains several interesting entries about what the four crew members will be working on during the ten day flight.

Of course, the exact details of the agenda are subject to change once the mission is underway. Some tasks could run longer than anticipated, experiments may not go as planned, and there’s no way to predict technical issues that may arise.

Conversely, the crew could end up breezing through some of the planned activities, freeing up time in the schedule. There’s simply no way of telling until it’s actually happening.

With the understanding that it’s all somewhat tentative, a look through the plan as it stands right now can give us an idea of the sort of highlights we can expect as we follow this historic mission down here on Earth.

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