Book Review: Stages to Saturn

Roger Bilstein's Stages to Saturn: A Technological History of the Apollo-Saturn Launch Vehicles has been around awhile (first published in 1979), but it is one of the standard textbooks found around Marshall Space Flight Center in Huntsville, Alabama. And for good reason: this is one of THE definitive histories of the development of the Saturn rockets that took human beings to the Moon, and it is a paean to the Huntsville team, and especially the work of Wernher von Braun and his team.

I read this book over the course of a weekend, despite its hefty size (450+ pages), but I won't lie to you--there's a reason it's a big hit at MSFC but isn't necessarily as popular as Chaikin's A Man on the Moon or some of the other Apollo histories--it is as advertised: a technological history. You have to have a real interest in the program background, the design history, the testing problems, and management and logistical processes that went into making America's (so far) largest rockets. If you are interested in the Apollo Command and Service Module, the Lunar Module, or the astronauts, this is not the book for you. This is a book about building very large rocket stages and engines.

I happened to have a need for this book: my job requires me to know both what's going on with the Ares Project, how rockets work in general, and also have some historical notion of how we did things the first time. In this, Stages to Saturn was very instructive. What was interesting to me, in fact, was how much the book reflects my daily life: in Huntsville, the work there is all about the launch vehicle. There are passing references to other things, like the payload (CSM, LM, astronauts), but that isn't the focus of MSFC. That's fine, as long as you're aware of the fact; but if you want to get a broader experience of what it was like to build the U.S. space program in the 1960s, you'll need to pick up a few more books, like the aforementioned A Man on the Moon, Angle of Attack: Harrison Storms and the Race to the Moon, Chariots for Apollo, and several others in the field.

So what does Bilstein offer us? Despite discussing technical issues and narrating some of the bureaucratic in-fighting that occurred in the build-up to Apollo, the author is careful not to give the reader a LOT of details that matter--for instance, the Russians and the Chinese, while they might find this book somewhat interesting, could not reverse-engineer Saturn based on its contents. Instead, Bilstein offers the reader rather general information about what sorts of thinking went into the design process, why some engines and propellants were chosen over others, what sorts of problems the engineers had during ground and flight testing, and some insight into how the National Aeronautics and Space Administration organized itself and its contractors to build, deliver, and launch the rockets.

Some of the more interesting parts for me included the remarkable similarities between Apollo and Ares, even given the 40-to-50-year time difference. Up through around 1963, for instance, the massive, 12-million-pounds-thrust Nova rocket, capable of direct launch to the Moon, was still "in play." There was also work being done on researching in-space nuclear rockets (Orion, NERVA, etc.) as possible backups to the Saturn vehicle that was eventually selected. Another area Bilstein covers well is the intellectual and design history of the powerplants, specifically the massive F-1 main engines that powered Saturn V's S-IC stage and the J-2 and RL-10 liquid hydrogen/liquid oxygen engines. One thing he makes clear--and this is something the Constellation doubters would do well to keep in mind--is that every serious rocket engine development program usually takes five to seven years to build. Even when the engine is derived from previously known technologies, like the F-1, the process of scaling up a known engine can create problems of its own.

And let there be no doubt: Saturn had problems. There's this halo effect around Apollo now, thanks to Apollo 8, Apollo 11, and the rest. We honor the memories of Gus Grissom, Ed White, and Roger Chaffee, but those of us born after Apollo might not know of all the problems that the Saturn V program had before it finally launched for the first time in 1967. The Douglas Aircraft Company (later McDonnell-Douglas, later part of Boeing) had an S-IV third stage rupture on them. North American Aviation (later Rockwell North American, later Rockwell International, later part of Boeing) lost two S-II second stages before the von Braun team sent out a team led by General Phillips from the Air Force to investigate NAA's problems. The Phillips Report is mentioned briefly in From the Earth to the Moon as an exhibit Senator Walter Mondale used as proof that NASA wanted to replace NAA. NASA did not want to replace North American, but they made it quite clear that NAA needed to clean up its act, up to and including changing management structure and personnel.

One thing that will probably irk libertarians about Stages to Saturn is its uncritical view of government (especially MSFC's) interference in contractor operations and decision making. At one point Bilstein quotes a contractor complaining that NASA "wanted to be in your pants all the time." However, despite one or two references like this, Bilstein quickly backs off from any criticism of the von Braun team. He is quick to admire MSFC's desire to maintain control over its contractors as well as maintain its in-house knowledge.

This is a process Ares is repeating by going back to the "arsenal model" of management, where the government does most of the design and development work in-house and contractors are used to build only what the arsenal cannot. Von Braun's preference for maintaining in-house knowledge is not surprising, given his wartime experiences and later work with the Army Ballistic Missile Agency (ABMA). It is obviously a workable model--Saturn's success speaks for itself--but it is not a model preferred by contractors, which had assumed more and more authority in the Shuttle program. Given the current friction between NASA and some folks in the private sector, it will be interesting to see which management model comes out on top.

In any case, Stages to Saturn is well worth reading. When you consider the fact that the Saturn guys were performing research and development in the midst of building a massive infrastructure and trying to meet a nine-year time line, you cannot help but think: given that NASA is building on much that they learned 45 years ago, we've got it easy. Bilstein's book makes that very clear.

Busy Day in the Life of a Middle-Aged Geek

So today began with some quality time helping clean up my church. This was followed by a VERY long day helping the Huntsville Alabama L5 (HAL5) Society set up for a rocket motor firing test. This was a big deal, because we haven't had a live firing test in over a year and because the last two motors blew up.

HAL5, I should explain, is the local chapter of the National Space Society, and has been the incubating organization for several new ventures, including HARC and Orion Propulsion, the latter of which was founded by Tim Pickens, who was chief propulsion engineer for SpaceShipOne. In other words, this is a group of serious rocket enthusiasts who just happen to turn their hobby into reality. Aside from helping with publicity on occasion or small, non-technical tasks on the rocket motor ("C'mere and do this; you can't possibly screw it up"), I take no credit for their successes. It's just a fun group to be around.

First, I'll take a moment to describe the motor, which is a nitrous oxide/HTPB (industrial rubber) hybrid. The motor--an "engine," the English major was informed, has moving parts, motors do not--is about 30 inches long and 4 inches in diameter. Obviously there's more to it than that, but why mess with ITAR, right?

A static rocket motor test involves securing the motor to a firm horizontal surface (test stand). The motor has the HTPB; nitrous is provided by tanks attached to the test stand and fed to the motor through "plumbing." The bulk of the setup time is spent setting up the remote actuators that control the various valves for the nitrous tank; the rest of the time is taken up by "instrumentation," in this case strain gages, which measure how much pressure the motor is experiencing during firing, and load cells, which measure how much thrust the motor is generating.

Because we'd had two motors blow up on us (one of them 1.5 seconds after ignition), we used a "battleship" motor, which is made of very thick, heavy material to prevent an eruption. It won't fly, but it shouldn't shatter, either.

I did make one "useful" run during the day, when I wasn't laying cables or tightening bolts on the test stand: I went to Wal-Mart for bottled water (for the group--Disney taught me well), rags, cookies, and ear plugs, all of which were necessary.

You might have seen a Space Shuttle launch on TV or been lucky enough to go to Florida and see one first-hand. Let me confess here that our motor firing is nowhere near as majestic a sight. However, it does offer something your typical Shuttle launch does not, and that is immediacy. We stand behind a steel-reinforced cargo container, inside a semitrailer that doubles as "mission control," or out in the fields a hundred yards off. And brother, it is STILL loud!

I've heard rocket motor firings described as "white noise." Another description might be that of a long-drawn-out roar of flame. For me, the best way to describe the blast of sound is like having a trumpet belt out a high F from a rock concert speaker directly in your ear, and then sustaining that sound for five to 20 seconds. The flame itself is bright yellow, starting out as a cylinder directly out of the nozzle, widening slightly as it expands into the air, and the gradually tapering into a narrow, thin tail about 20 feet behind the test stand. The sound comes on suddenly, and it can either shake the ground or your nerves (I must suspect the latter, given my inability to keep my camera centered). And then suddenly, it is over--like you've been standing beside Niagara Falls for ten seconds and then are suddenly transported to an empty desert. Boom--it's over. The only thing left is a ringing in your ears and a dirty cloud in the air behind the test stand. Pretty cool for 20 seconds' work.

And the good news for this firing was that our motor lasted 18 seconds or so. It might have gone the full, planned 20 seconds, but our chief engineer was detecting some instability in the combustion, either because we were running low on propellant or the combustion itself was failing. In any case, no one complained, and I distinctly heard a "Yaa-HOO!" from one of our normally unflappable engineers.

When the nitrous tanks had been safed and we could approach the motor, the nozzle was still smoking and the casing oven-hot. Lots of beaming smiles all around, as the group finally had its first successful firing in nearly two years. Even as wires and tubes were being disconnected, someone asked eagerly, "Okay, which motor do we test next?" The sun was nearly set by this point, but we decided to hurry up, detach the battleship motor and attach the flight-weight motor. Setup is relatively easy after all the valves and data collection wires are hooked up.

Sunset came and went, flashlights were quickly replaced by driving up someone's car to illuminate the area. The nitrous piping was running fine, and even the instrumentation was functioning fine. It was the igniter that gave the group fits. Three or four shouts of "Five...four..." were followed by thirty seconds of absolute, baffling silence. After the fourth igniter failed, we gave it up, purged the tanks, and called it a day. "The squibs were just no damn good," our chief engineer muttered in disgust. Perhaps we'll try again tomorrow, perhaps not. Most of the group is married now (as opposed to ten years ago, when they were just starting out on this rocket-building adventure), and spouses are only so forgiving toward loud and balky machinery.

I'll try to repost this report with pictures tomorrow, if Blogspot doesn't burp again. Right now I'm exhausted and ready for some down time. But that, dear readers, is what it's like to be a serious rocket geek in these United States.