March 26, 2026 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.

5 comments

Astronomers detect the first comet whose nucleus’ reversed its rotation

Astronomers using data collected by the orbiting Gehrels Swift and Hubble space telescopes now think the nucleus of a small comet reversed its rotation sometime in 2017, caused by the force of the material sublimated off its surface.

From the abstract of their paper [pdf]:

The rotations of cometary nuclei are known to change in response to outgassing torques. The nucleus of the Jupiter-family comet 41P/Tuttle–Giacobini–Kresak exhibited particularly dramatic rotational changes when near perihelion in 2017 April. Here, we use archival Hubble Space Telescope observations from 2017 December to study the postperihelion lightcurve of the nucleus and to assess the nucleus size.

From both Hubble photometry and nongravitational acceleration measurements, we find a diminutive nucleus with effective radius 500 ± 100 meters. Systematic optical variations are consistent with a two-peaked (i.e., rotationally symmetric) lightcurve with period 0.60 ± 0.01 days, substantially different from periods measured earlier in 2017. The spin of the nucleus likely reversed between perihelion in 2017 April and December as a result of the outgassing torque.

In plain English: the thrust of the material being thrown from the surface as the comet made its close approach to the Sun was sufficient to slow and then reverse the nucleus’s rotation. This process was helped by the relatively small size of the nucleus compared to the material being sublimated from it.

The data also suggests the nucleus was once much larger, and has been whittled down to its present small size as it made its multiple close fly-bys of the Sun during the past 1,500 years. Rather than break-up, as most comets do at some point as their nucleus gets smaller, this comet’s nucleus simply kept shrinking, to the point that the thrust of that material could change its rotation.

0 comments

Genesis cover

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 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

The space station part of Isaacman’s new program is facing push back, from industry and Congress

The American space stations under construction
Four of the American space stations under development.
The fifth, Max Space, is a late comer and not shown.

At a hearing yesterday before the space subcommittee of the House Science, Space, and Technology Committee, both the trade organization representing the five commercial space station projects as well as some members of Congress expressed strong reservations about NASA’s new plan to build a core module as a basis for helping these companies develop their space stations.

Dave Cavossa, President of the Commercial Space Federation (CSF) that represents these companies, outlined in his statement [pdf] to the committee the industry’s dissatisfaction, not so much because of the specifics of NASA’s plan but because it follows other sudden changes last year by the previous NASA administrator Sean Duffy, and is still uncertain in its outline.

Given the delays and possible shifts in strategy, industry has been left to continue spending resources to develop private space stations without a full understanding of what NASA will require from a private station, how the agency will structure the rest of the procurement and program, and when industry may see a return on investment. This uncertainty challenges the public-private partnership business model and puts the agency at risk of deorbiting ISS before private stations are operational.

The trade group proposed that NASA stick with its previous plan to fund two or more station projects, dropping Isaacman’s core module proposal. It also wanted Congress give the agency the funds to do so.

Cavossa also strongly disputed NASA’s claim that the market at present doesn’t support these commercial stations.
» Read more

18 comments

All space stocks soar in anticipation of SpaceX’s impending IPO

It appears SpaceX’s upcoming initial public offering (IPO) of publicly-traded stocks, now anticipated to raise as much as $75 billion for the company, has caused stock investors to also pour their money into a whole range of space stocks, causing them all to soar in value.

Initially, it was expected that the IPO could raise $50 billion for the company, but the latest report indicates it could raise as much as $75 billion, with a valuation as high as $1.75 trillion. The colossal figures being thrown around on Wednesday have garnered excitement among investors for other space stocks that are already publicly traded.

Here were the top gainers in the session:

  • Firefly Aerospace: +19%
  • Intuitive Machines: +11%
  • AST SpaceMobile: +9%
  • EchoStar Corporation: 9%
  • Rocket Lab Corporation: +8%

The most recent indications suggest SpaceX will file the offering’s prospectus in the next week or so. If the predictions about it are correct, and SpaceX does raise $75 billion, it would then have on hand more than three times the cash that Congress normally budgets annually to NASA, with an ability to use that money far more effectively.

As I have been saying now for more than a year, the real space program for the United States is being run by SpaceX, not NASA. Expect SpaceX to outpace NASA in their parallel and complementary efforts to build a moonbase.

7 comments

Conscious Choice cover

Now available in hardback and paperback as well as ebook!

From the press release: In this ground-breaking new history of early America, historian Robert Zimmerman not only exposes the lie behind The New York Times 1619 Project that falsely claims slavery is central to the history of the United States, he also provides profound lessons about the nature of human societies, lessons important for Americans today as well as for all future settlers on Mars and elsewhere in space.

 
Conscious Choice: The origins of slavery in America and why it matters today and for our future in outer space, is a riveting page-turning story that documents how slavery slowly became pervasive in the southern British colonies of North America, colonies founded by a people and culture that not only did not allow slavery but in every way were hostile to the practice.  
Conscious Choice does more however. In telling the tragic history of the Virginia colony and the rise of slavery there, Zimmerman lays out the proper path for creating healthy societies in places like the Moon and Mars.

 

“Zimmerman’s ground-breaking history provides every future generation the basic framework for establishing new societies on other worlds. We would be wise to heed what he says.” —Robert Zubrin, founder of the Mars Society.

 

All editions are available at Amazon, Barnes & Noble, and all book vendors, with the ebook priced at $5.99 before discount. All editions can also be purchased direct from the ebook publisher, ebookit, in which case you don't support the big tech companies and the author gets a bigger cut much sooner.

 

Autographed printed copies are also available at discount directly from the author (hardback $29.95; paperback $14.95; Shipping cost for either: $6.00). Just send an email to zimmerman @ nasw dot org.

Webb and Hubble take a look at Saturn

Saturn seen by Webb and Hubble

Astronomers using both the Hubble Space Telescope and the Webb Space Telescope have produced new complementary views of the ringed planet Saturn.

Those photographs are shown above, with Webb’s false-color infrared image to the left and Hubble’s optical image to the right. From the press release:

In the Webb image, a long-lived jet stream known as the “ribbon wave” meanders across the northern mid-latitudes, influenced by otherwise undetectable atmospheric waves. Just below that, a small spot represents a lingering remnant from the “Great Springtime Storm” of 2010 to 2012. Several other storms dotting the southern hemisphere of Saturn are visible in Webb’s image, as well. All these features are shaped by powerful winds and waves beneath the visible cloud deck, making Saturn a natural laboratory for studying fluid dynamics under extreme conditions.

…In Webb’s infrared image, the rings are extremely bright because they are made of highly reflective water ice. In both images, we’re seeing the sunlit face of the rings, a little less so in the Hubble image, hence the shadows visible underneath on the planet.

There are also subtle ring features such as spokes and structure in the B ring (the thick central region of the rings) that appear differently between the two observatories. The F ring, the outermost ring, looks thin and crisp in the Webb image, while it only slightly glows in the Hubble image.

The press release says little about the Hubble image, mostly because it shows little new by itself. It however is part of an on-going decade-long survey using Hubble to track Saturn’s changing weather patterns.

While both images are valuable, they also highlight our present limits in observing Saturn. Views from Earth can only see so much. It is like trying to watch a football game from ten miles away, with binoculars. And sadly, no mission is presently planned to return to Saturn.

1 comment

China launches two radar satellites

China today successfully placed two radar satellites into orbit, its Long March 2D rocket lifting off from its Taiyuan spaceport in north China.

China’s state-run press provided no information about where the rocket’s lower stages, using very toxic hypergolic fuels, crashed inside China.

The leaders in the 2026 launch race:

37 SpaceX
14 China
4 Rocket Lab
4 Russia

SpaceX continues to lead the entire world combined in total launches, as it did in both ’24 and ’25.

0 comments

Leaving Earth cover

Leaving Earth: Space Stations, Rival Superpowers, and the Quest for Interplanetary Travel, can be purchased as an ebook everywhere for only $3.99 (before discount) at amazon, Barnes & Noble, all ebook vendors, or direct from my ebook publisher, ebookit.

If you buy it from ebookit you don't support the big oppressive tech companies and I get a bigger cut much sooner.

 

Winner of the 2003 Eugene M. Emme Award of the American Astronautical Society.

 
"Leaving Earth is one of the best and certainly the most comprehensive summary of our drive into space that I have ever read. It will be invaluable to future scholars because it will tell them how the next chapter of human history opened." -- Arthur C. Clarke

March 25, 2026 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.

5 comments

Isar’s second launch attempt scrubbed due to abort at T-0 seconds

Proposed or active spaceports in North Europe
Proposed or active spaceports in North Europe

The German rocket startup Isar Aerospace was today forced to scrub its second attempt to launch its Spectrum rocket from Norway’s Andoya spaceport when the rocket aborted the launch at T-0 seconds.

The launch was then scrubbed for the day because the launch window was only 15 minutes long. An earlier hold due to a boat violating the range had used up most of the window, leaving no time to recycle the rocket to try again.

No word yet on when the company will try again. At the moment Isar is in the lead to be the first new European startup to get off the ground, though Rocket Factory Augsburg from Germany and PLD from Spain are not far behind. Isar’s first launch attempt in March 2025 had failed seconds after lift-off due to a loss of attitude control.

Andoya is also in the lead to be the first European spaceport to complete an orbital launch, though SaxaVord on the Shetland Islands hopes to see that Rocket Factory launch in the coming months.

3 comments

Triton: Neptune’s largest moon

The southern mid-latitudes of Neptune's moon Trident
Click for original image.

Triton

Today’s cool image begins a new tour I plan on doing over the next week or so of the few close-up photographs we have of Neptune and its moons, sent back by Voyager-2 when it did its close fly-by of this distant planet on August 25, 1989. That fly-by was almost 37 years ago, and it remains our only close look. While at the time it shined a quick flashlight of new knowledge on Neptune, its moons, and its ring system, we remain generally in the dark about what’s there, despite some good imagery produced in subsequent years by Hubble and some ground-based telescopes.

The image above, cropped and enhanced to post here, shows a portion of the southern mid-latitudes of Triton, Neptune’s largest moon, as Voyager-2 made its closest pass at a distance of about 25,000 miles. The photo to the right, cropped and reduced, shows a more global view to provide some context, with the box indicating the approximate area covered by the upper image. It was taken when Voyager-2 was on approach, at a distance of about 330,000 miles. The top picture captures several dozen black plumes that appear to vent material from below. From the caption:

The plumes originate at very dark spots generally a few miles in diameter and some are more than 100 miles long. The spots which clearly mark the source of the dark material may be vents where gas has erupted from beneath the surface and carried dark particles into Triton’s nitrogen atmosphere. Southwesterly winds then transported the erupted particles, which formed gradually thinning deposits to the northeast of most vents.

It is possible that the eruptions have been driven by seasonal heating of very shallow subsurface deposits of volatiles, and the winds transporting particles similarly may be seasonal winds. The polar terrain, upon which the dark streaks have been deposited, is a region of bright materials mottled with irregular, somewhat dark patches. The pattern of irregular patches suggests that they may correspond to lag deposits of moderately dark material that cap the bright ice over the polar terrain.

As we only have a few images of this planet, and those provided views of only about 40% of its surface, any theory that tries to explain the weird geology here is certain to be wrong to some degree.

More to come in the next few days. As much as we think we know, these pictures are going instead highlight how sparse that knowledge really is.

13 comments

Swiss orbital tug startup Pave Space raises $40 million

A new orbital tug startup from Switzerland, Pave Space, has now successfully raised $40 million in private investment capital that it will use to develop a new kickstage engine and fly it on a demo mission.

The funding round was led by Visionaries Club and Creandum, with participation from Lombard Odier Investment Managers, Atlantic Labs, Sistafund, b2venture, ACE Investment Partners, Ilavaska Vuillermoz Capital, Pareto & Motier Ventures.

Pave had its start as a student project that built a reusable small hopper to test vertical take-off and landing. The company now joins about a dozen other orbital tug companies, offering a range of serves from moving satellites to removing space junk to doing satellite repair. Based on the amount of money that all of these companies are raising, both in the U.S. and Europe, it appears the investment community sees a strong demand for these services down the road, especially with the many gigantic constellations being proposed.

0 comments
1 29 30 31 32 33 2,927