Leaving Earth cover

In 2019 I obtained from my former publisher the last 30 copies of the now out-of-print hardback of Leaving Earth. I sold about half of these, and with only a handful left in stock I have raised the price. To get your own autographed copy of this rare collector's item please send a $75 check (includes $5 shipping) payable to Robert Zimmerman to

Behind The Black, c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652

I will likely raise the price again when only ten books are left, so buy them now at this price while you still can!

Also available as an inexpensive ebook!

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.


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

On the road

Posting this weekend shall be very light. Today, Saturday, I was underground all day on a survey project in a cave north of Tucson. Tomorrow I will be underground again, taking a caver’s tour of the mines in Tombstone, Arizona.

Will be back full force I think on Monday, though I might end up on the road again that day for different reasons. I figure I will post for sure late Sunday.

Pioneer cover

From the press release: From the moment he is handed a possibility of making the first alien contact, Saunders Maxwell decides he will do it, even if doing so takes him through hell and back.

Unfortunately, that is exactly where that journey takes him.

The vision that Zimmerman paints of vibrant human colonies on the Moon, Mars, the asteroids, and beyond, indomitably fighting the harsh lifeless environment of space to build new societies, captures perfectly the emerging space race we see today.

He also captures in Pioneer the heart of the human spirit, willing to push forward no matter the odds, no matter the cost. It is that spirit that will make the exploration of the heavens possible, forever, into the never-ending future.

Available everywhere for $3.99 (before discount) at amazon, Barnes & Noble, all ebook vendors, or direct from the ebook publisher, ebookit.


  • Cotour

    Q: Are you choosing to clear each post yourself or is there still a program problem with the program that allows you to not have to clear each post personally?

    I ask because I have noticed that posters are not able, under what appears to be this new system, to interact as directly as before which causes the conversation threads to be very shallow. I know that you have your subject and trolling dislikes and standards but it seems to have caused a dilution of the intensity of the conversation here.

    I remember not long ago participating in a conversation thread that was about 62 comments deep. Now, if there are two or three comments that seems to be a lot.

  • The problem with spam and comments on BtB is about to be solved at last. I found a new software guy, who is in the process of cleaning up and upgrading the website. For the past four months in order to make the spam situation manageable, I have had to close comments on any posts after three weeks. This is one reasons the threads no longer last as long.

    We should have these fixes ready in about a week, when we will switch to them. The website will then change somewhat, but not radically. At that time, comments will hopefully return to what they were before. There will be one change which also should not hinder commenters significantly, and will likely improve things greatly. I will no longer have to approve each comment, but before a comment is accepted the commenter will have to fill out a Captcha box. This is not very hard, and will prevent spam from reaching the site.

  • Cotour

    Thanks for explaining. You must have had quite a time investment clearing all the comments in the last four months, a hat tip to you, you seem to be a busy man besides the web site.

Readers: the rules for commenting!


No registration is required. I welcome all opinions, even those that strongly criticize my commentary.


However, name-calling and obscenities will not be tolerated. First time offenders who are new to the site will be warned. Second time offenders or first time offenders who have been here awhile will be suspended for a week. After that, I will ban you. Period.


Note also that first time commenters as well as any comment with more than one link will be placed in moderation for my approval. Be patient, I will get to it.

Leave a Reply

Your email address will not be published. Required fields are marked *