December 18, 2025 Quick space links
Courtesy of BtB’s stringer Jay. This post is also an open thread. I welcome my readers to post any comments or additional links relating to any space issues, even if unrelated to the links below.
- Saturn’s biggest moon might not have an ocean after all
Or it may. Lots of uncertainties based on the limited available data.
- Graphic showing the nine small commercial launchers being developed in India
The tweet also notes it left out two more because they are in very early stages of development.
- Movie created from Perseverance’s navigation cameras, showing what it saw during its June 20, 2025 longest record drive, 1,350.7 feet
The drive was so long because the rover was returning across ground it had already traveled, and so it knew exactly what to expect.
- Interstellar Comet 3I/ATLAS makes its closest approach to Earth this week
You will still need a telescope to see it.
- On this day in 1903 the Wright Brothers achieved the first powered, heavier-than-air, manned airplane flight
And the rest is history, as nicely illustrated by the next link.
- On this day in 1972 Apollo 17 astronaut Ron Evans did a spacewalk on the way back from the Moon
The tweet shows some beautiful enhanced 16mm film of that spacewalk, done to retrieve film canisters from the outside of the Apollo service module.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Courtesy of BtB’s stringer Jay. This post is also an open thread. I welcome my readers to post any comments or additional links relating to any space issues, even if unrelated to the links below.
- Saturn’s biggest moon might not have an ocean after all
Or it may. Lots of uncertainties based on the limited available data.
- Graphic showing the nine small commercial launchers being developed in India
The tweet also notes it left out two more because they are in very early stages of development.
- Movie created from Perseverance’s navigation cameras, showing what it saw during its June 20, 2025 longest record drive, 1,350.7 feet
The drive was so long because the rover was returning across ground it had already traveled, and so it knew exactly what to expect.
- Interstellar Comet 3I/ATLAS makes its closest approach to Earth this week
You will still need a telescope to see it.
- On this day in 1903 the Wright Brothers achieved the first powered, heavier-than-air, manned airplane flight
And the rest is history, as nicely illustrated by the next link.
- On this day in 1972 Apollo 17 astronaut Ron Evans did a spacewalk on the way back from the Moon
The tweet shows some beautiful enhanced 16mm film of that spacewalk, done to retrieve film canisters from the outside of the Apollo service module.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
More on tough aluminum
https://techxplore.com/news/2025-12-optimal-cooling-aging-stronger-lightweight.html
“This framework both improves our understanding of high-strength aluminum alloys and opens the door to modeling complex behaviors in many advanced alloys used for lightweight and sustainable manufacturing,” said Liang Qi, an associate professor of materials science and engineering and U-M and corresponding author of the study published in npj Computational Materials.
The research team focused on 7000-series aluminum-magnesium-zinc (Al-Mg-Zn) alloys originally developed for aerospace applications. Tiny particles of magnesium and zinc, which substitute into the aluminum matrix, form precipitates that reinforce the aluminum to create exceptional strength at low weights.
However, the alloy has been limited to aerospace applications because its strengthening process—especially the natural aging step that occurs at room temperature—is highly unpredictable. Aerospace manufacturers avoid natural aging using costly, specialized processing steps like high-temperature deformation or low-temperature storage. While an effective workaround, these methods are unfavorable for large-scale vehicle manufacturing.
To reduce these costs and expand the material’s integration in autobody structures, the research team aims to understand the hardening processes on the microscale during natural aging—when the metal sits at room temperature over a period of time.
“Our work helps engineers better understand how tiny defects and atomic movements affect the strengthening of advanced aluminum alloys, especially natural aging of Al-Mg-Zn alloys. The results of the research provide a pathway to understanding how to improve the formability of these alloys for automotive applications,” said Louis G. Hector Jr., a senior technical fellow at General Motors Research & Development and co-author of the study.”
Add iron for toughness
https://www.nature.com/articles/s41467-025-67281-8
The White House just dropped a new executive order, entitled: “Ensuring American Space Superiority.” I think this is an important development. (I will leave it to our wise host to offer specific commentary on it.)
https://www.whitehouse.gov/presidential-actions/2025/12/ensuring-american-space-superiority/
Wondering how much input Jared had into this. Is it a coincidence that it happens on the day he is sworn in?
“Saturn’s biggest moon might not have an ocean after all.”
This is interesting, but yeah, right now the magic ball says “answer hazy ask again later.” Like, in 2034 when Dragonfly arrives. Or maybe even later.
Richard M: I am reviewing that order now. Most interesting. Expect a post later today.
Hi Bob,
Yeah, for starters, some worthy people are noting with interest what it says about NASA procurement . . . but I am sure you’ve picked up on that by now.
Looking forward to it.
It’s customary when one of these Apollo 17 milestones comes up that so many of us chime in about how sad it is that no humans have been out that far since December 1972. Indeed, our new NASA Administrator and his Polaris Dawn crew hold the record for any flight since then, and obviously, they did not have anything like the view Ron Evans did.
And I am still one of those people. I wish we had a regular ongoing presence on the Moon. But I have certainly come to change how I think that should or should not have happened, as I learned more about how NASA operated back then, and in the years since then. “We should have kept Apollo going!” Or, even: “We had an entire set of hardware built for one more mission, and it’s all in rocket gardens and museums now!”
I grok fully now why Apollo had to end, and it wasn’t just the collapse in public support, not least because it just wasn’t sustainable at those costs — inevitable in a purely government operation — but also *safety*. Yeah, I’d have chosen to fly Apollo 18 if it had been up to me, but I’d have been biting my nails, because every Apollo mission was a high risk mission, probably Russian Roulette-level risky….and oh my, think of the second guessing if you got a James Michener ending out of *that* decision.
But what’s really been lacking until now is the lack of commercial capabilities to provide that sustainability. And now, finally, we’re on the cusp of having that.
It was kinda-sorta controversial, but to me, the song for the “Star Trek: Enterprise” series was a perfect choice.
“It’s been a long road, gettin’ from there to here . . .”
Taking to the air, and eventually to outer space, has meant a long series of baby steps, and occasional missteps.
Richard M,
That Titan study seems to pretty clearly establish that there is not a unitary subsurface water ocean there, but what is now murky is exactly what is there instead. A final answer to that question may not be in-hand even after the Dragonfly mission. It may well require landing a drilling rig on Titan to settle the issue with any finality.
Re: the Trump EO about space, a lot of good stuff there and nothing bad that I can see. Highlights are:
1. US back to the Moon by 2028.
2. US permanent lunar base begun by 2030.
3. Underlining the importance of Golden Dome deployment commencing by 2028.
4. Prioritizing detection of nuclear weapons placed, covertly, in space.
5. Prioritizing nuclear power for lunar application by 2030.
6. Enabling increased launch and re-entry cadence.
7. Reforming, simplifying and speeding up space-related acquisitions.
Musk’s recent declarations about a space-based AI data center effort to be led by SpaceX will dovetail nicely with much that is in this EO.
Dick Eagleson: Refresh your browser and read my analysis of Trump’s executive order. I think you have missed its biggest goal.
The rover drove a little more than one lap around a standard track (400 meters). It took one solar day. I can run that in about 1 minute 30 seconds. I am in decent shape, but not great. Olympians can do it between 40 and 50 secs. Average humans can walk it in about 5 mins.
My point is this: robotic exploration is good. We should continue, but it cannot replace humans actually being there exploring making decisions and acting in real time.