Book Review: Ignition!

Subtitled “An Informal History of Liquid Rocket Propellants”, Ignition! is John D. Clark’s personal account of working with rocket fuels from 1949 until his retirement in 1970.

Dr. Clark is introduced to us by Isaac Asimov. Clark was roommates with L. Sprague de Camp during his undergrad years at Caltech, and wrote a pair of science fiction stories before deciding the market wasn’t for him, though he remained active in the community. Dr. Asimov met him during the war, when he came to work with de Camp and Heinlein at the Philadelphia Naval Yard.

John Clark, like Asimov, was a chemist, working on the problem of chemical rockets for the majority of his career. He writes this book, he tells us, both “for the interested layman” and for:

[T]he professional engineer in the rocket business. For I have discovered that he is frequently abysmally ignorant of the history of his own profession, and, unless forcibly restrained, is almost certain to do something which, as we learned fifteen years ago, is not only stupid but is likely to result in catastrophe.

For the layman, he attempts (and, I think, succeeds) at writing in a manner which is nevertheless very accessible. The sections with heavy technical content can be skimmed over without losing too much of the overall picture, though a little background knowledge certainly helps. I’m not sure you could use this book as a reference without a basic understanding of engineering thermodynamics, but if you haven’t studied that what business do you have designing rocket engines?

Unfortunately, Dr. Clark gives relatively little in the way of citations or suggestions for further reading. This is both an artifact of the era—when technical reports and journal articles were essentially inaccessible to the general public if your local library didn’t have a copy—and a consequence of the fact that much of the source material was at the time still officially classified. At several points the discussion is cut short because he’s not at liberty to discuss the matter. He acknowledges these difficulties and makes not pretense of this being an authoritative textbook.

On a related note, the content is heavily focused on the research done in America and the United Kingdom, with a chapter devoted to what information came out of the Soviet Union in later years. Due to the date of publication, this book does not cover modern developments (though the final chapter makes a series of predictions I might come back and grade).

Nor does Clark address solid propellants or hybrid combinations in any significant detail, which is slightly disappointing given my current studies, but would have made for a much longer and more complicated read. Not that I would have particularly minded; Dr. Clark is an engaging storyteller, frequently giving us various background information on the scientists and organizations trying to develop early rockets, first for abstract research, later for the military, and finally for the National Aeronautics and Space Administration.

These anecdotes keep the reading fun even through the most tedious of minutiae on monoprops and halogen fuels. Clark frequently (if unpredictably) goes into detail on the chemistry of a particular propellant and how the molecules interact with one another. Such interludes eventually rekindled my interest in chemistry as a subject, which is fortunate since I need another credit hour of it to graduate. Hopefully some of the material I learn this summer will be relevant to aerospace propulsion work.

Overall, I found this to be a good introduction to rocket fuels and the history of that field. While useful for beginners such as myself and as a refresher, it probably shouldn’t be treated as any sort of reference guide or definitive citation.

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An engraving by Dr. Clark’s wife, Inga Pratt, presented to NARTS in 1959.

Hopefully one day Ignition! will be in print again, but for now most of us are stuck reading it from PDFs found online. Hard copies went for hundreds of dollars before the likes of Elon Musk and Scott Manley began publicly praising the book.

Book Review: How to Live on Mars

I first read this book in high school, flushed on newly-found philosophy and bristling with plans for life as a commercial astronaut. SpaceX was just ramping up their ISS resupply program; Bigelow Aerospace was planning to launch another module before 2014. The possibilities seemed limitless.

That’s not the world we ended up living in. Astronauts haven’t launched from the United States in over five years. Virgin Galactic experienced LCOV during a 2014 test flight and put space tourism plans on hold while fixing the spacecraft’s control system. The biggest leaps forward has been landing Falcon 9 first stages, but it’s only in the last week that a used stage flew again. Falcon Heavy  still hasn’t been tested flown.

As such, the overall mood of Zubrin’s book feels….overconfident. Misplaced. Premature.

Our narrator is a congenial Martian colonist, giving us the down-low on what it takes to survive on Mars. It’s quite easy, he informs us, provided your follow his advice.

From choosing the correct transfer method to how to start a family, Zubrin (the Martian, not the 20th century astronautical engineer) walks us through the steps of becoming an economic and social success on the red planet. While many of the specifics are tailored to a fictional future history, the basic science is strictly factual.

It ranges from the mundane to the transcendental. At the more everyday end of things, we learn how to make plastics and almost every other raw material from the Martian soil and atmosphere. Through this avatar, Dr. Zubrin is making the case that living on Mars is entirely feasible. Steel and cement for construction, oxygen for breathing, nitrates for food—it’s all there. A few things would be a challenge (fictional Zubrin recommends stealing rocket parts as the best way to obtain aluminum), but the low-gravity environment greatly reduces the difficulty imposed by all sorts of engineering projects.

On the other end of the scale, we’re explained the general process of terraforming Mars into a habitable planet (and how to profit off it in the meantime). Now quite a few of these suggestions rely on a fairly specific potential architecture for the project, but the technical information holds.

This future history is amusing, though evokes a more cynical reaction from me after the last few years. I’m less optimistic about the odds of us reaching Mars before 2040, and less skeptical of NASA’s ability to get things done. To me, the issue seems to be less one of organizational competence and more of insufficient dedication at the highest levels (mostly Congress). While I’d like to believe that the private sector can fill that gap, it seems increasingly unlikely that they can achieve those ends at a plausible cost as the march of 21st century politics continues.

One thing he’ll probably have gotten right: the decay of terrestrial society into atomized, post-modern nihilism. I hope he’ll be proven wrong but there’s no strong signals to suggest that that trend is slowing.

On the whole, though, an optimistic book about the capacity for human ingenuity to conquer new frontiers and expand our understanding of the universe. Those interested in the project of space colonization, but unsure where to begin learning about, would be well advised to start with How to Live on Mars.

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German Researcher Discovers Most Efficient Path to Mars

A civil engineer in Essen, Germany has determined the transfer orbit which will get astronauts to Mars the quickest.

Walter Hohmann, a civil engineer, spent several years studying physics and astronomy before publishing his book The Attainability of the Celestial Bodies. It may become required reading for NASA mission planners.

Fuel requirements will be central to the architecture of interplanetary spaceflights, Dr. Hohmann expects. To account for this, he solved for the trajectory which requires the least amount of velocity change, or what scientists call “delta V”. Spacecraft produce this acceleration by firing rocket engines.

The most efficient orbit between two planets turned out to be an ellipse that lies tangent to the planets’ orbital paths.

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Source: University of Arizona

Such an orbit requires the least amount of energy to achieve when starting from Earth, but has a serious drawback. Least-energy trajectories are also the slowest. For a crewed mission, taking along enough food and oxygen could make a less efficient path ultimately cheaper.

Another problem is waiting for planets to be in the right place for launch. Because Earth orbits the sun faster than the outer planets and slower than the inner planets, the possible alignment for such a transfer trajectory only occurs occasionally. The window to leave for Mars only opens every two years, for example. Launching interplanetary spacecraft at other times would require vastly more fuel.

Nevertheless, astronomers and aerospace engineers find Dr. Hohmann’s discovery extremely useful for designing space missions.


Happy Amazing Breakthrough Day!

The Worst Week of American Spaceflight

On January 27th, 1967,the crew of Apollo 1 was undergoing a simulated countdown when an electrical fire started within the spacecraft. The hatch was bolted tightly onto the capsule. Escape was impossible and the blaze quickly grew in a pure oxygen atmosphere. Astronauts Gus Grissom, Ed White, and Roger Chaffee died on the pad.

On January 28th, 1986, the space shuttle Challenger was destroyed was destroyed 73 seconds after lift off for the STS-51L mission. Cold weather in the days before launch had weakened the rubber o-rings sealing sections of the solid rocket boosters. Flames escaped and penetrated the external fuel tank, igniting an explosion of liquid hydrogen and oxygen that disintegrated the orbiter vehicle. The crew was not killed in the explosion—forensic investigation revealed that pilot Michael Smith’s emergency oxygen supply had been activated, and consumed for two and a half minutes: the amount of time between the break-up to when the remains of Challenger landed in the Atlantic Ocean.

On February 1, 2003, the space shuttle Columbia disintegrated during re-entry over the southern United States after sixteen days in orbit. During launch, a piece of cryogenic insulation foam fell from the external fuel tank and struck the left wing of the orbiter, damaging the thermal protection system. As Columbia streaked across the southern sky, atmospheric gases heated by its hypersonic flight entered the wing and melted critical structural members. Ground observers in Texas could see the shuttle breaking apart over their heads. Rapid cabin depressurization incapacitated the crew.

This is the worst week in the history of American spaceflight. These three disasters are not the only dark spots on that record, by they are by far the worst. We remember them, and vow not to repeat the mistakes that led to their deaths.

After Apollo 1, Flight Director Gene Kranz gave the following address to his mission controllers:

Spaceflight will never tolerate carelessness, incapacity, and neglect. Somewhere, somehow, we screwed up. It could have been in design, build, or test. Whatever it was, we should have caught it.

We were too gung ho about the schedule and we locked out all of the problems we saw each day in our work. Every element of the program was in trouble and so were we. The simulators were not working, Mission Control was behind in virtually every area, and the flight and test procedures changed daily. Nothing we did had any shelf life. Not one of us stood up and said, “Dammit, stop!”

I don’t know what Thompson’s committee will find as the cause, but I know what I find. We are the cause! We were not ready! We did not do our job. We were rolling the dice, hoping that things would come together by launch day, when in our hearts we knew it would take a miracle. We were pushing the schedule and betting that the Cape would slip before we did.

From this day forward, Flight Control will be known by two words: “Tough and Competent.” Tough means we are forever accountable for what we do or what we fail to do. We will never again compromise our responsibilities. Every time we walk into Mission Control we will know what we stand for.

Competent means we will never take anything for granted. We will never be found short in our knowledge and in our skills. Mission Control will be perfect.

When you leave this meeting today you will go to your office and the first thing you will do there is to write “Tough and Competent” on your blackboards. It will never be erased. Each day when you enter the room these words will remind you of the price paid by Grissom, White, and Chaffee.

Gene Kranz is right. Tough competence is what those of us in the space business must strive to be, every day, for lives are on the line, and the future of manned exploration of the cosmos is at stake.

These seventeen are not the only space travelers to die in the line of their work, and undoubtedly more astronauts and cosmonauts will perish in our conquest of the universe. That is no excuse for sloppiness. The Apollo 1 fire could have been prevented. STS-51L should not have launched. STS-107 could have been saved on-orbit. It’s the job of engineers, technicians, flight controllers, and fellow astronauts to see accidents before they occur and prevent them from happening.