President and CEO
Space and Communications
"Spacecraft: The Art of Designing and Crafting Space-Bound Platforms"
Columbia Graduate School of Engineering
New York, NY
June 01, 2002
Thank you for that introduction, Dean Zvi Galil. It's certainly good to be back at Columbia after all of these years. I travel to New York on occasion to talk to analysts but this is only my second time on campus since graduating in 1974. It brings back a lot of fond memories of great teachers, colleagues, and of course, this wonderful city.
The question I often get asked is, "How did I end up working in the space industry after getting my degree in Civil Engineering here at Columbia?"
Believe it or not, I originally wanted to build dams and focused my studies on structures, fluid dynamics and hydro dynamics. I learned all about Navier-Stokes, Bernoulli, and Von Karmen and from professors like Skalak, Bellafat, and others.
After I graduated, I found out that all the good dam sites in the US and around the world were already taken, so I got into rocket science instead.
Turns out rocket science and building dams have in a lot in common. Both are about flow and stress -- but instead of fluid flows and dams -- you have gas flows and rocket engines.
The same goes for another area of development that we're working on at Boeing these days -- directed energy -- or lasers. Now instead of fluid and gas flows, you have the flow of photons.
That's one of the great things about having a background in civil engineering -- you can do a lot of different things
From a personal perspective, I've been very lucky to graduate from Columbia where my education helped land me the "best job in the world". I get to work with 40,000 extremely talented people -- people who have changed the world in the 20th century and continue that legacy into the 21st century.
People who have put humans into space and landed a man on the moon.... People who have made our country safe and have revolutionized how we communicate with satellite-based systems
And today I want to talk about two of the engineering projects we work on at the Boeing Company -- that from an engineering standpoint -- are among the most complex systems engineering tasks ever undertaken
The first is the Space Shuttle built in the 1980s at Rockwell which is now part of the Boeing Company and the other is Missile Defense -- a shield to defend US, deployed forces, friends and allies from missile attack.
They're both -- in their own way -- signature products of American technology and reflect the unparalleled technical intellect and expertise of engineers.
And I would say -- with the possible exception of the Pyramids and the Manhattan Project -- that the Space Shuttle is the most challenging engineering project ever taken on.
Think about it...
- It's a launch vehicle for 8-1/2 minutes
- It's a reconfigurable science platform for up to two weeks
- It's a hypersonic reentry vehicle for an hour
- It's a piloted subsonic glider for about 5 minutes
- And, it's a man-rated and reusable launch vehicle
I can't think of any other system in the world that crosses such a broad spectrum.
It's really a symbol of what American technology is capable of.
Since the first flight in 1981, the shuttle has completed more than 100 missions and carried more than 600 passengers into space -- passengers like astronaut Mike Massimino, who you heard from earlier.
The Shuttle fleet has accumulated more than 2.5 years of operation in orbit and still has 75 percent of its design life left.
You know a lot of folks today think shuttle launches have become routine -- I can assure you, anytime you've got seven human beings sitting atop a rocket filled with 500,000 gallons of hydrogen and oxygen, it's anything but routine.
Now I would like to walk you through the sequence of a launch.
The shuttle is launched in a vertical position, with thrust provided by two solid rocket boosters -- called the first stage -- and three liquid fueled Space Shuttle Main Engines called the second stage
Stacked on the pad at the Cape, it's taller than the Statue of Liberty and weighs three times as much... more than 4.5 M lbs
To achieve orbit, the shuttle accelerates from zero to 18,000 miles per hour -- nine times the speed of a bullet -- in about 8 minutes.
How does it do that? Let me demonstrate...
Six seconds before launch the three liquid shuttle main engines ignite.
The liquid engines start before the solid rocket booster to ensure they are operating correctly since they can be shut down.
The solids, on the other hand, can't be shut down. Once they're started, you are going uphill.
At liftoff, both the boosters and the main engines are operating and together they generate some 7.3 million pounds of thrust so that the Shuttle is traveling at speeds of 100 mph before it even clears the pad.
The reason it gets out of there so fast is the thrust-to-weight ratio.
The Shuttle's thrust-to-weight ratio is 1.75 to 1. Compare that to a Saturn 5 that carried our Apollo astronauts to the moon with a thrust-to-weight ratio of -- 1.15 to 1. If you remember watching it, the Saturn 5 looked like it literally staggered off the pad in comparison to the Shuttle.
Each of the shuttle's solid rocket motors burn more than 5 tons of propellant per second and generate 3 million pounds of thrust. Compare that to 747 engines, which is around 70K lbs of thrust. So you can see how powerful these engines are.
The speed of the gases exiting the nozzle is more than 6,000 miles per hour; about seven times the speed of sound.
The energy developed is equivalent to the output of 23 Hoover Dams
By the time the first minute has passed, the shuttle is traveling more than 1,000 mph and has already consumed more than one and a half million pounds of fuel.
After two minutes, when the shuttle is 28 miles high and traveling more than 3,000 mph, the propellant in the first stage is spent and the boosters separate from the vehicle
They parachute into the Atlantic Ocean, splashing down 140 miles from the Cape.
That's the first stage of launch -- the part most people usually see on TV.
It's also the point at the Cape where all of the tourists get back in their Winnebagos and buses because they assume the show is over.
For me, since I've worked on the Space Shuttle Main Engines, I still have six minutes of holding my breath left. The mission is far from over.
I'd like to talk about main engines for a bit, because I think they're the most highly sophisticated examples of rotating equipment known to man.
The engines generate about 450,000 lbs of thrust each. The hydrogen fuel pump, which feeds the engine, weighs the same as your car engine. But instead of generating 200-300 horsepower, it generates 700,000 horsepower.
Each of the 122 high-pressure fuel pump turbine blades, which are about the size of a half-dollar, generates 700 horsepower while spinning at 37,000 rpm.
The Space Shuttle Main Engines also operate at greater temperature extremes than any mechanical system I can think of in use today. The fuel, liquid hydrogen, is -423 degrees Fahrenheit -- the second coldest liquid on earth. And when burned with liquid oxygen, the temperature in the combustion chamber reaches +6000 degrees Fahrenheit -- that's higher than the boiling point of iron.
Think of the thermal stresses associated with that.
If you look at the turbo pump, which is a massive piece of equipment, you've got the hot gases on the turbine side of the pump where you have several thousand degree temperatures and minus 400 degrees on the impellor side where you're pumping the hydrogen -- all connected by one shaft.
You can imagine the great engineering associated with designing and building a piece of equipment like that.
When the Space Shuttle Main Engines were developed in the 1970s, it took ten years and twelve engine failures to certify the engine for flight. All at a cost of $3 billion.
It was only last year that a new engine built by Boeing was certified in the U.S. It's an engine that develops 50% more thrust, costs around 10% as much to build ($500M) and was developed in five years with no engine failures.
The reason for the reduction was improvement in our modeling capabilities that we have developed over the years which enabled us to simulate engine performance. We did our failures on the computer rather than on the test stand. That's why we've come so far in our propulsion technology.
Now let's get back to the launch.
Eight and a half minutes after launch, with the shuttle traveling five miles a second, the engines finally shut down as they consume the last of their fuel.
A few seconds later, the external fuel tank is released.
Next comes orbital insertion.
After the main engines shut down, the shuttle orbiter -- the part that looks like a space plane -- is in an egg-shaped orbit that, if left unchanged, would re-enter the atmosphere and splash into the Pacific.
To make sure that doesn't happen, about 35 minutes after main engine-shut down, two orbital maneuvering system engines, located in the shuttle's tail, are fired for about three minutes to circularize the orbit.
To me, that's the most exciting part of the mission.
If you talked to a scientist, he'd probably say the on-orbit research is where the mission starts. But as an engineer, to have overcome the most basic of forces, gravity, is always a thing of amazement
When it's time to return to Earth, the shuttle rotates tail-first into the direction of travel and performs a three-minute engine firing to slow itself enough to begin descent toward the atmosphere.
The drag, produced by the atmosphere, will take care of the rest.
To dissipate energy, the shuttle performs a series of four steep banks, rolling back and forth to slow down to about Mach 3.
Only twenty-five miles before from touchdown, and at an altitude of 50,000 feet, the shuttle's speed finally drops below the speed of sound and the commander takes over manual control.
As it aligns with the runway, the shuttle then begins a descent seven times steeper than the average commercial airliner.
Think about it -- this is like a glider descending almost at the speed of sound -- you don't get a second chance to go around for another shot at landing.
It looks like it's dropping out of the sky like a rock. I still can't get used to it!
Less than 2,000 feet above the ground, the commander pulls up the nose and slows the rate of descent in preparation for touchdown.
Sounds pretty simple, but believe me, there's a lot of complex engineering that goes into it.
Now I've described to you some of the engineering challenges behind how a Space Shuttle mission works. Now let's look at the art of it in operation.
I encourage you to talk to Mike and listen to his thoughts about what it's really like to go through the process I just talked about.
In my job I have the chance to meet a lot of astronauts. And when I ask them why they want to go to space, they almost all say that it's for the ride. That first eight and a half minutes of adrenaline we just saw.
I have admiration for their technical knowledge, courage, and what they've done to open new frontiers.
The great research they've performed tell us what's outside the earth's atmosphere.
When you think about it, to become an astronaut is to become a member of a very exclusive club. Only a select number of people have flown to space and back. They carry a secret that none of us will ever really know.
Looking ahead to the future of the Space Shuttle, there is a lot of talk about replacing it with a redesigned, more efficient spacecraft.
We have a design at Boeing that could replace the Shuttle tomorrow. But it would cost up to $10-15 B and I'm not convinced it would be any better than what we have today.
Instead, we think that prudent upgrades to the Shuttle will be more cost-effective and improve reliability and safety.
The Shuttle is currently scheduled to fly to 2020 -- some 40-50 years -- a half of a century -- after its debut in 1981. That's a tremendous tribute to the great engineering minds at Rockwell and NASA for designing such an incredible flying machine.
I've just discussed what we, at Boeing, call complex, large scale systems engineering, involving human space flight.
Now I want to look at an example of integrating multiple, complex systems -- or what we call "systems of systems" engineering. What that essentially means is taking multiple platforms or systems not designed to work together and integrating them into a single entity that provides more value to the customer than if they were operating alone.
The example I want to use is a missile defense intercept in space.
While I'm not here to tell you about the political issues surrounding missile defense -- that's for the Administration and Congress to debate -- I do want to walk you through the technical complexities of hitting a bullet with a bullet.
Sounds like Star Wars? Let me tell you, it truly is.
Using a scenario, these are the chain of events in a missile defense intercept:
- An enemy missile is launched.
- Our infrared early warning satellites detect the plume coming out of the end of the rocket.
- The satellite's pixels light up and communicate this data down to a battle command and control center in Colorado or Alaska.
- By looking at how the infrared pixels light up, we can plot a ballistic trajectory of where the missile might come down.
- The threat state vector determines the impact point prediction.
- The rules of engagement are met and the ground missile defense system is alerted.
- The battle management control center begins engagement planning and orders weapons free.
- Our radars are cued to track and report the threat.
- After the first stage of launch, the incoming missile releases a reentry vehicle and a number of decoys.
- The reentry vehicle could be a warhead of mass destruction.
- Our X-Band radar discriminates the reentry vehicle from the clutter of decoys and performs a hit to kill assessment.
- The battle management control center plots an intercept course and launches a two-stage Minuteman II booster missile with an exoatmospheric "kill vehicle" to intercept the incoming warhead for a "body-to-body" kinetic kill.
- Our job is to fly and pick out the reentry vehicle from the decoys to perform the kinetic kill intercept.
- We fly the kill vehicle into the approximate location of where we think the reentry vehicle is going to be.
- The kill vehicle separates from the booster.
- The kill vehicle's computer uses stars to determine its position and navigation to guide itself to complete the mission.
- It receives continual updates from the ground radar system of the reentry vehicle's location.
- The kill vehicle discriminates the target from the decoys using its own sensors and very powerful algorithms, its infrared radar, and data from the battle management control center.
- The kill vehicle closes in to a lethal intercept with its own divert and attitude control system at a closing velocity in excess of 15,000 mph.
- Both vehicles are destroyed on impact.
Now while this may sound easy -- when you think about it -- you have to track, discriminate, and destroy an incoming enemy missile in a matter of minutes to potentially save the lives of millions. In other words, you have to get it right the first time. Nothing short of perfection will do.
So, what does this entail from an engineering standpoint?
It requires knowledge of the following:
- Rocket science and ballistics.
- Understanding of physics and orbital mechanics.
- Knowledge of physical property of reentry vehicles and decoys and how to discriminate between the two.
- Ability to write and generate very complex algorithms.
- Systems engineering among other things.
These are some of the skills and expertise that go into designing a "systems of system" solution.
Our job, as engineers, is to design a system that will put a kill vehicle in proximity to a rapidly moving target, discriminate the real thing from the decoys, and have it guide itself to complete the mission. In fact, we've accomplished this in five out of seven flight tests.
As with a Shuttle launch, talking about it doesn't really do it justice. Here's a short video of an intercept in action.
Here again, you don't get a second chance to do it right. Especially when potentially millions of lives depend on us to do it right the first time.
I always get emotionally involved in any mission -- whether it's a shuttle launch, missile intercept or satellite deployment -- because I know I'm looking at the work of thousands of men and women who are not just doing their jobs well. . . they're doing them perfectly.
And when you think about, there are millions of things that could go wrong - and don't.
These examples illustrate how we, at Boeing, provide solutions to very complex engineering problems. Now let me transport you to the future to give you an example of how we intend to take systems integration to another level.
Imagine a network centric world where space-based sensors and communications systems allow us to know with precision where everything is on earth and in the air and in relation to each other.
Where we have true situational awareness of everything that's around us.
Where, in real time, we collect data... communicate and share that data... turn that data into information... turn the information into knowledge and make decisions.
Where everyone has the ability to connect to the network:
- From the man on the street to the sailor on the bridge
- For the pilot en route to LaGuardia to the fighter pilot en route to a target
- For the student at Columbia to his friends and family back home
- For all of us in this room
This kind of situational awareness and Global Connectivity could apply to:
- The battlespace of the future
- To homeland security
- To air or commuter traffic management
- To inventory tracking
- To any complex system you can imagine
This is the glimpse of tomorrow through the lens of today.
While this sounds like the ultimate video game, I believe it's tomorrow's reality.
I'm excited to be working in an industry that truly is inventing the future.
I've got the best job in the world. I get to work on some of the most sophisticated "toys" on earth. We aren't building toasters or refrigerators at Boeing
We attract the best and the brightest engineers around the world to help us apply technologies that provide solutions that change the world.
I also get a lot of questions about how we attract young engineering talent in Southern California when we have to compete with Hollywood. I tell them that they can go work on "Star Wars" the movie or come to Boeing and work on the real thing.
In closing, I want to leave you with two homework assignments.
The first is to think creatively.
Many engineers don't think that they have the ability to be creative. I, on the other hand, have found it to be just the opposite. As we've seen today, to design complex systems that travel into space and withstand its harsh environment takes ingenuity and imagination and creativity.
Since the beginning of history -- we've had the desire to fly to escape the force of gravity. In fact, next year we'll celebrate the 100th anniversary of flight. It's amazing to think that we went from that first flight to putting men on the moon in just 66 years
When you think of the engineering marvels of mankind, I can think of nothing more impressive than putting humans in space. Spacecraft truly are engineering marvels and beautiful works of art. They represent art and science in motion. They are elegant solutions to very difficult problems
You've all heard the saying that "form follows function." Pilots say, "if it looks right, it flies right." Certainly the shuttle is an example of that -- it looks right and it flies right.
The question to ask yourself is -- "what do the next 100 years hold?" I don't know for sure, but I do know that it will be the creativity of engineers that will take us there -- many of whom are here today.
The second homework assignment I want to leave you with is to test knowledge through experience and persistence.
The greatest lesson a teacher imparts is a passion to seek out knowledge and intellectual curiosity. Certainly I got that from many of my professors here at Columbia. And I find that the best lessons you learn are the ones you learn yourself.
The most intimidating day of my life, I think, was my first day on the job. I realized I didn't have the answer in the back of the book -- that I had to come up with it myself.
I encourage you to become stargazers. To always ask the question, "what if?" in the quest for knowledge and wisdom.
As engineers, we are pioneers. We must continue to apply the knowledge of the universe -- the knowledge that will continue to change our world.