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Readers! A November fund-raising drive!

 

It is unfortunately time for another November fund-raising campaign to support my work here at Behind the Black. I really dislike doing these, but 2025 is so far turning out to be a very poor year for donations and subscriptions, the worst since 2020. I very much need your support for this webpage to survive.

 

And I think I provide real value. Fifteen years ago I said SLS was garbage and should be cancelled. Almost a decade ago I said Orion was a lie and a bad idea. As early as 1998, long before almost anyone else, I predicted in my first book, Genesis: The Story of Apollo 8, that private enterprise and freedom would conquer the solar system, not government. Very early in the COVID panic and continuing throughout I noted that every policy put forth by the government (masks, social distancing, lockdowns, jab mandates) was wrong, misguided, and did more harm than good. In planetary science, while everyone else in the media still thinks Mars has no water, I have been reporting the real results from the orbiters now for more than five years, that Mars is in fact a planet largely covered with ice.

 

I could continue with numerous other examples. If you want to know what others will discover a decade hence, read what I write here at Behind the Black. And if you read my most recent book, Conscious Choice, you will find out what is going to happen in space in the next century.

 

 

This last claim might sound like hubris on my part, but I base it on my overall track record.

 

So please consider donating or subscribing to Behind the Black, either by giving a one-time contribution or a regular subscription. I could really use the support at this time. There are five ways of doing so:

 

1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.

 

2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation. Takes about a 10% cut.
 

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You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.


European engineers develop a tumbling rover design moved by the Martian wind

Tumbleweed being tested on sandy ground
Tumbleweed being tested on sandy ground. Click for video.

European engineers at Aarhus University in Denmark have now developed and tested a tumbling rover design that is propelled solely by the Martian wind. You can read their most recent paper here.

Not surprisingly, they call it “Tumbleweed.” The screen capture to the right comes from a video of a wind tunnel test proving the Martian atmosphere could move a prototype on sandy ground. The engineers also did similar tests successfully on rocky and coarse ground.

In July 2025, Team Tumbleweed conducted a week-long experimental campaign, supported by Europlanet, at Aarhus University’s Planetary Environment Facility. Using scaled prototypes with 30-, 40- and 50-centimetre diameters, the team carried out static and dynamic tests in a wind tunnel with a variety of wind speeds and ground surfaces under a low atmospheric pressure of 17 millibars.

Results showed that wind speeds of 9-10 metres per second were sufficient to set the rover in motion over a range of Mars-like terrains including smooth and rough surfaces, sand, pebbles and boulder fields. Onboard instruments successfully recorded data during tumbling and the rover’s behaviour matched fluid-dynamics modelling, validating simulations. The scale-model prototypes were able to climb up a slope of 11.5 degrees in the chamber – equivalent to approximately 30 degrees on Mars – demonstrating that the rover could traverse even unfavourable slopes.

Their concept is to send a swarm of Tumbleweeds to Mars, where they could cheaply document prevailing wind and speeds globally. More sophisticated versions could act as full weather stations, as well as provide in situ data about the landscapes they traverse.

The concept is still in its development stage. The next stage of testing will see if Tumbleweed will work with some science sensors attached.

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 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

8 comments

  • Ryan Lawson

    Absolutely brilliant!

  • Patrick Underwood

    I keep seeing a hamster in a pressure suit.

  • Ray Van Dune

    I scanned the overview paper and did not see any reference to temporarily STOPPING the rover and holding it stationary. Surely this would be a useful capability that could enhance data gathering, although perhaps it is not absolutely necessary.

  • Jeff Wright

    Knowing the Great Galactic Ghoul, it will snag on a spike of rock and be immobile.

  • cmeat

    unmistakable sudden desire to hear the sons of the pioneers…

  • Jeff Wright

    Look for Vash the Stampede and Wolfwood

  • In Star Wars Episode 1, we were introduced to the skeletal C-3PO.

    This, is the skeletal BB-8.

    And Patrick, I could see what you described, though these days hamsters drive KIAs.

  • pzatchok

    So a big clear beach ball with bunch of cameras hung in the center. The bigger the ball the more cargo it can carry and still role.

    And how many millions did I just get for this brilliant idea.

    NASA should be supporting this web sight.

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