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Friday, May 31, 2013

Reading List: The Rocket Company

Stiennon, Patrick J. G., David M. Hoerr, and Doug Birkholz. The Rocket Company. Reston VA, American Institute of Aeronautics and Astronautics, [2005] 2013. ISBN 978-1-56347-696-9.
This is a very curious book. The American Institute of Aeronautics and Astronautics isn't known as a publisher of fiction, and yet here we have, well, not exactly a novel, but something between an insider account of a disruptive technological start-up company along the lines of The Soul of A New Machine and a business school case study of a company which doesn't exist, at least not yet.

John Forsyth, having made a fortune in the computer software industry, decided to invest in what he believed was the next big thing—drastically reducing the cost of access to space and thereby opening a new frontier not just to coercive governments and wealthy tourists but to pioneers willing to bet their future on expanding the human presence beyond the planet. After dropping a tidy sum in a space start-up in the 1990s, he took a step back and looked at what it would take to build a space access business which would have a real probability of being profitable on a time scale acceptable to investors with the resources it would take to fund it.

Having studied a variety of “new space” companies which focussed on providing launch services in competition with incumbent suppliers, he concluded that in the near term reducing the cost of access to orbit would only result in shrinking overall revenue, as demand for launch services was unlikely to expand much even with a substantial reduction in launch cost. But, as he observed, while in the early days of the airline industry most airlines were unprofitable, surviving on government subsidies, aircraft manufacturers such as Boeing did quite well. So, he decided his new venture would be a vendor of spacecraft hardware, leaving operations and sales of launch services to his customers. It's ugly, but it gets you there.

In optimising an aerospace system, you can trade off one property against another. Most present-day launch systems are optimised to provide maximum lift weight to orbit and use expensive lightweight construction and complex, high-performance engines to achieve that goal. Forsyth opted to focus on reusability and launch rate, even at the cost of payload. He also knew that his budget would not permit the development of exotic technologies, so he chose a two stage to orbit design which would use conventional construction techniques and variants of engines with decades of service history.

He also decided that the launcher would be manned. Given the weight of including crew accommodations, an escape system, and life support equipment this might seem an odd decision, but Forsyth envisioned a substantial portion of his initial market to be countries or other groups who wanted the prestige of having their own manned space program and, further, if there was going to be a pilot on board, he or she could handle payload deployment and other tasks which would otherwise require costly and heavy robotics. (I cannot, for the life of me, figure out the rationale for having a pilot in the first stage. Sure, the added weight doesn't hit the payload to orbit as much as in the second stage, but given the very simple trajectory of the first stage the pilot is little more than a passenger.)

The book chronicles the venture from concept, through business plan, wooing of investors, building the engineering team, making difficult design trade-offs, and pitching the new vehicle to potential customers, carefully avoiding the problem of expectations outpacing reality which had been so often the case with earlier commercial space ventures. The text bristles with cost figures and engineering specifications, the latter all in quaint U.S. units including slugs per square foot (ewww…). Chapter 6 includes a deliciously cynical view of systems engineering as performed in legacy aerospace contractors.

I noted several factual and a number of copy-editing errors, but none which call into question the feasibility of the design. The technologies required to make this work are, for the most part, already in existence and demonstrated in other applications, but whether it would be possible to integrate them into a new vehicle with the schedule and budget envisioned here is unclear. I do not understand at all what happens after the orbital stage lands under its parawing. Both the propellant tanks and interstage compartment are “balloon tanks”, stabilised by pressure. This is fine for flight to orbit, orbital operations (where there is no stress on the interstage when it is depressurised for payload deployment), or re-entry, but after the stage lands horizontally how does the pilot exit through the crew hatch without the interstage losing pressure and crumpling on the runway? Some of the plans for lunar and planetary applications in the final few chapters seem wooly to me, but then I haven't seriously thought about what you might do with a reusable launcher with a payload capacity of 2250 kg that can fly once a day.

The illustrations by Doug Birkholz are superb, reminiscent of those by Russell W. Porter in Amateur Telescope Making. Author Stiennon received U.S. patent 5,568,901 in 1996 for a launch system as described in this book.

Posted at May 31, 2013 23:40