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

Telescopes of the future

Two stories were published on Thursday about two very different future space telescopes. Both are worthwhile, but the differences between them illustrate how the industry of space astronomy — like manned space — is evolving from Big Science and government to small, efficient, and privately built.

First there is this story describing how the nonprofit B612 Foundation’s project to launch an infrared telescope by 2017 had passed its first technical review.

The B612 Foundation plans to launch [the Sentinel Space Telescope] in 2017, placing the instrument near the orbit of Venus. Sentinel will look outward from there, scanning Earth’s neighborhood without having to fight the sun’s overwhelming glare — a serious impediment to asteroid-hunting instruments on or near our planet. The telescope’s infrared eyes should spot about 500,000 near-Earth asteroids in less than six years of operation, B612 officials say. That would be quite a feat, considering that researchers have discovered just 10,000 or so such space rocks to date.

The primary purpose of the B612 Foundation is to locate hazardous asteroids so that plans can be developed to prevent their impact on the Earth. The Foundation plans to raise the several hundred million dollars needed to build Sentinel privately.

That they consider this likely and possible tells us a great deal about how things have changed in the field of space technology in the past decade. It is no longer considered a wild idea to propose such a project and expect it to be funded and built from private sources.

Then there is this second story, an interview with Matt Mountain, the head of the Space Telescope Science Institute in Baltimore, Maryland, describing ATLAST, an optical space telescope with a proposed mirror 16 meters across, almost seven times larger than the mirror in the Hubble Space Telescope.

This project had been proposed by astronomers at the Institute several years ago as their recommendation to the committee considering the most important projects astronomers should build in the decade of the 2010s. Unfortunately, the committee decided against ATLAST, proposing other ideas instead.

In his interview, it is very obvious that Mountain is making a public relations effort to get ATLAST funded for the next decade, in the 2020s. Building and launching such a large optical space telescope is going to be a gigantic engineering challenge, requiring a budget in the billions, comparable if not exceeding the $8 billion that has been spent to build the James Webb Space Telescope. Thus, the lobbying effort to fund it will require a gargantuan effort lasting years. Mountain here is merely beginning that process.

So, which of these telescopes is more likely to get funded and built? Well, let’s compare them. ATLAST will take decades to build, will cost billions, and is designed like past Big Science projects like Webb and Hubble. It will push the engineering envelope as far as possible, launching a segmented mirrored optical telescope far larger than anything previously built.

Sentinel is aimed at a launch in less than five years, will cost only a few hundred million dollars, and is basically an upgrade of technology already tested and flown successfully on several past infrared telescopes, such as the Wide-Field Infrared Survey Explorer (WISE).

If I had to make a bet, I’d put my money on Sentinel. As much as I’d love to see ATLAST in orbit, I don’t see it happening, not for many decades, and especially not funded by the government. The money just isn’t there. Not only is the federal government broke, the astronomy community is not going to support such an expensive project. They have seen how the cost of Webb has caused the shut down of all other space astronomy projects at NASA and will be reluctant to back another such monster. Instead, I expect astronomers to focus on backing smaller and simpler space telescopes, easier to fund and easier to build.

Which is exactly what Sentinel Space Telescope is. By focusing on using already tested technology and avoiding being too ambitious, the B612 Foundation will be able to keep the cost for Sentinel relatively small and the construction period relatively short. Moreover, they reduce their engineering risks, which makes success far more likely.

Essentially, B612 is the future. The space projects will be smaller, and many of them will be funded privately, some for profit, some not. And while they might not be as ambitious or spectacular as the Big Science missions backed by the government that have been built these past few decades, we will eventually see many more of them. Moreover, their numbers and variety will feed the creativity of the space industry in ways that will be far more beneficial to future space development than any single monster space project from the government. Instead of a single project, we will see a plethora of designs, built by many different companies and individuals, all feeding off of each other as well as competing against each other.

The energy from that effort will get us to the stars very quickly.

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.

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