Scroll down to read this post.


My July fund-raising campaign, celebrating the 13th anniversary of the start of this website, has now ended. This was the second most successful monthly fund-raising campaign ever. Thank you again to everyone who has who donated or subscribed. It is difficult to explain what your support means to me.


You can still donate or subscribe to support my work if you wish, either by giving a one-time contribution or a regular subscription. There are four 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.

3. A Paypal Donation:

4. A Paypal subscription:

5. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652

Sierra Space powers up its Dream Chaser mini-shuttle for the first time

Sierra Space yesterday announced that it has successfully run electricity for the first time through its first Dream Chaser mini-shuttle, dubbed Tenacity.

The press release is remarkably lacking in detailed information, or graphics. This quote is really the only hard facts mentioned:

Sierra Space simulated the power that will be generated from Dream Chaser’s solar arrays once on orbit. Test engineers plugged that power into Dream Chaser and began turning on systems. Sierra Space exercised flight computers, base processors and low-voltage distribution units.

Tenacity has been under construction since 2016, when the company won its NASA contract to build it. That’s seven years to build a single spacecraft, and yet all they have done so far is feed electricity through it for the first time. In that time period SpaceX not only built multiple prototypes of Starship and Superheavy, it has flown multiple test flights.

Is money an issue? The actual contract amount NASA gave Sierra Space to build Tenacity has never been published, though NASA has said the total awarded for all the cargo missions to be flown by SpaceX, Northrop Grumman, and Sierra Space equaled $14 billion. Since these fixed price contracts also require the companies also commit some of their own funds, or obtain outside financing, it is possible that Sierra Space has had money issues slowing development.

Regardless, Dream Chaser was first supposed to fly in 2020. It is now three years late, with no clear indication that a launch will come anytime soon. In many way, Sierra Space is beginning to remind me of Blue Origin, endlessly issuing promises but never delivering.

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 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


  • Sippin_bourbon

    I think they are not as slow as Blue Origin.

    When was the last update on New Glenn. The engines seem to take one step forward and two back.

    Sierra Space needs a better marketing person, but they are not as opaque as BO. We are also spoiled a bit with SpaceX’s transparency. SS also has a more complicated vehicle than Dragon.

    I do not think Starship is a good comparison. Flown? Yeah sorta. But interior systems, storage, life support, RCS… There is nothing on that from SpX. SS is building the complete vehicle, not a shell with engines.

  • Edward

    Robert asked: “Is money an issue?

    It could be that it is their first spacecraft. Sierra Space came from Sierra Nevada, which built component assemblies. Their spacecraft is somewhat more complex than the capsules that Boeing and SpaceX chose to build — chose because they were not complex and could be designed and built quickly and inexpensively.

    Sierra Space is being bold with its first spacecraft. Hopefully, money is not a problem.

    Power up is an important milestone. It means that the wiring is complete, or nearly so. It means that some real testing can begin and has begun.

  • Jeff Wright

    Flight Com! She’s breaking up, she’s

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 *