Interview: Meg Tuma, Scientist and Mentor


In the course of doing my job, I frequently get to work with a lot of very smart people, among them Margaret L. (Meg) Tuma, Ph.D., one of the engineers ("rocket scientists") at Marshall Space Flight Center.


What do you do at Marshall Space Flight Center?
I’m the project lead for the Ares I Integrated Vehicle Ground Vibration Test. That’s a mouthful – and means I’m responsible for the modal test on the new Ares rocket. We need to understand the natural frequencies and damping of the Ares V vehicle in order to adequately control the vehicle during ascent and flight. My responsibilities include getting the test rocket hardware from each of the rocket component elements (First Stage, Upper Stage, Upper Stage Engine, and Orion), coordinating transportation to MSFC and the Test Stand, getting the Test Stand (4550) ready for testing, the hydrodynamic stands (ie big shock absorbers), stacking the hardware, conducting the test, and disassembling the vehicle.




What degrees do you have? B.S. Physics, M.S. Physics, Ph.D. Electrical Engineering
Did you pursue these degrees with space in mind? Always in the back of my mind, but not my ultimate goal. I really didn’t think I had a chance to work at NASA, so when I got the opportunity, I jumped on it!


When did you know you wanted to work in a scientific or technical field?
In high school. I always liked math and science and in high school was challenged in physics and calculus and realized that’s what I wanted to pursue in college.


How did you make the switch from research to management?
I was in the NASA Professional Development program in 2000-2001. During that year, I worked at JPL, a University, and HQ. These experiences broadened my horizons and made me realize my talents would be put to better use if I shifted from research into project management. It was a fairly smooth transition. Although, I miss research from time to time. I still work on one of my inventions in my “spare” time. It’s a miniature light bulb (aka a “light bulb on a chip”) that can be used as a calibration source for spectrometers on satellites or remote terrestrial applications.



What's the biggest difference between science and engineering?
Engineering is much more applied. Science is a broader field trying to understand nature at its core (forces, electricity, etc.) Engineering takes science and applies it to make things work.



What advice would you give to young women interested in pursuing STEM careers?
Study study study! In groups if you can find a good study group. Take an internship or summer job in the field you are pursuing to “test drive” it. It’s much easier to change a major to match the career you’re interested in. Get a mentor. This is really important. There are several mentoring programs. One is MentorNet – an online mentoring program.



You participate in a mentoring program through the University of Akron. What can you tell me about that experience?
It’s wonderful! Each year I’m paired with one or more students and meet with them in person monthly usually at a social event (bowling, touring a museum, etc) and via email on a weekly basis. In fact, I’m still in contact with students I mentored 10 years ago! I was able to help them with class choices, provide career advice, and just listen to their problems when they needed to talk. I like helping others so I find it very fulfilling. I’m also a charter member of MentorNet – an online mentoring program where I’m paired with a graduate student in the US and we communicate via email a few times a month. My current mentee is in California and had a side project working on research for microwave popcorn. It was very interesting. I’m also involved in the “Adopt-A-Physicist” program. Twice a year I get paired with 2 or more high school classes from across the US and communicate via email. They ask lots of questions! Like, what made me decide to go into my current career, my favorite class, most interesting work experience, toughest work experience, etc. I was mentoring 3 classes during the Ares I-X launch, and they were tracking the progress and stopped their school work to watch the launch. It was neat to share that excitement with so many young students.



In addition to technical knowledge, what skills have you found the most valuable in your career?
People skills! It is so important to understand how to manage a team and understand your team’s personal dynamics.



What's been the coolest moment in your career so far?
Ares I-X launch. Followed by aero flight tests. And riding in the vomit comet.


Where do you go from here?
The moon! Still trying to be an astronaut. Hopefully we’ll have a replacement vehicle for the shuttle to take us there.

Potpourri CVII


My fellow (and much higher-profile) space blogger friend Jeff Foust has a great lineup of editorials today on The Space Review. Topics include:

• The potential impact of "ClimateGate" on NASA's scientific reputation.
• A good defense of the Ares I-X flight test and a plea for civility in the pro-space community.
• A discussion on safety and the Ares I crew launch vehicle based on Jeff's observations of the House subcommittee re: space safety last week.
• An editorial discussing other uses of the soon-to-be-happening suborbital spaceflight industry besides space tourism.

There's a Washington Post article on the environmental impact of rockets.

Speaking of the Washington Post, they wrote an article recently on a competition the Department of Defense created to see how social networking could be used to gather information. This is pretty wild.

This appears to be a clearing house page that provides links to a variety of astronomy-related blogs.

A Popular Mechanics reporter recently visited Marshall Space Flight Center and got access to a lot of the work the Ares Projects has been doing.

The White House is pushing for more math and science. Good. Where's the money coming from? Though I suppose one could ask the same thing about NASA, NSF, and the rest of the stimulus. Hate it when my conservative spending habits get in the way of my scientific/space habits.

Paradoxes

The explosion must be powerful enough to lift, but controlled enough to be useful.

The tanks must be pressurized to hold as much propellant as possible, but not so much that they leak. The metal must be thin to reduce weight but not so thin that it bursts under pressure.

The propellants must be energetic, sometimes poisonous, but not so caustic as to make them impossible to handle.

The most powerful and useful propellant and oxidizer are elements necessary for life: hydrogen and oxygen. But at the temperatures and pressures at which they are kept for rocket travel, they are below freezing and deadly. Their cold is nearly the cold of space of space itself. Liquid hydrogen, allowed to burn, creates a fuel-air bomb mixture; liquid oxygen is aggressive in its corrosiveness. Ignite them and they produce a fire to rival the surface of the sun.

The shape of the rocket is determined by the nature of its flight. It must present as little surface area as possible moving forward to reduce wind resistance as it plows through the atmosphere at unbelievable speed to break free of Earth's gravity. To steer the contraption, directional controls are located in the rear, an arrangement that produces clumsiness on land. The controls must react quickly, faster than a human being, really--so that the travelers are at the mercy of their hopefully well crafted machines.

Most of the mass must be dedicated to propulsion--getting the beast off the ground, along with its fuel and control systems. And somewhere along the line, the rocket must carry a useful payload. Without it, the rocket is merely an experiment in ballistics and Newton's Third Law.

The best rockets built have a mass fraction of 0.90. That is, 90 percent of the rocket is dedicated to non-propulsion hardware. And most times we cannot even manage that. We must sacrifice scientific payloads for life support systems or stronger structures.

Then there is space itself. Materials that behave one way in the relatively benign and predictable atmosphere of Earth outgas or turn brittle in hard vacuum. Thermal management is a pain. On the sunward side of a spacecraft, the temperature is 250 degrees Fahrenheit. On the shadowed side, the temperature is -250 degrees, so spacecraft must have sophisticated radiators to release heat into the bitter cold, or they must rotate like a chicken on a spit, and then the structure must cope with repeated expansion and contraction through differential heating.

Did I mention acceleration? Human beings can withstand, at best, four or five times the force of Earth's gravity before their performance is impaired. We black out at 7 g. Mere machines can be built to handle many times that value, but every weld must be perfect, every angle accounted for, every scrap of junk and dust removed to ensure that the circuitry and wires not merely survive, but do what they're supposed to do.

Then there's radiation. The sun is a big nuclear reactor. Protected by the Earth's atmosphere, magnetic field, and SPF 15 sunblock, sunbathers can still get cancer. In space, beyond the Van Allen Belts, little protection exists, and shielding adds weight. Radiation mutates biological tissue. It kills. It disrupts electronic computers and communications. It weakens metals, making them brittle. Radiation is not kind to space travelers.

The space environment itself has deleterious effects on human beings without spacesuits. Exposed to vacuum, human lungs explode, blood boils and freezes. The longest an unshielded body can survive in space is 30 seconds.

The distances and speeds involved in space exploration are outside of most people's experience. You can talk about being 250 miles above the Earth, but to circle the entire planet--over 24,000 miles--in an hour and a half doesn't really compute. The distance to the Moon is about 240,000 miles--ten times around the Earth. You can almost wrap your head around that number. The distance to Mars, though, can be as far as 250 million miles away. It's so far that a radio signal traveling at the speed of light would take 22 minutes to reach Earth one way. And some people dream about going to the far planets or the nearest stars, where light-speed distances are measured in years. Crews must work out most of their problems on their own or on a substantial time delay.

All of the worlds in our solar system have atmospheres unsuitable to human life. Like the empty space between them, they will kill. If the death isn't by vacuum, it might be by pressures greater than the deep ocean, temperatures hot enough to melt lead, or poisons that would scald the lungs.

So this is this environment space advocates seek to enter--this is the universe we intend to explore. It is so far lifeless, barren, hostile, and unwelcoming. It requires supreme acts of technological virtuosity to reach, let alone survive in space. There is little immediate promise of welcome or gain.

And yet we dare to go. Despite the danger. Despite the loneliness and isolation from others. Despite the cramped quarters, limited life-support ssytems, and potentials for crew conflicts.

We go to learn and to challenge ourselves. At some deeper level, we even go because of the danger, to prove to ourselves or others that we are not afraid, that we are willing to challenge fate. That we truly have the minds, the moxie to go where no one has gone before...and return to tell the tale.

Girl Scouts and Rockets

For your consideration: http://blog.al.com/enjoy/2008/08/girl_scouts_learn_rockets_robo.html

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.