At the USA Science and Engineering festival, Dan Hedges spoke with Larry Price from Lockheed Martin. Larry works on the Orion Space Program. In this discussion, Larry explains the benefits of the multi-purpose spacecraft.
Tell us about the Orion space program.
"So the Orion program is a phenomenal capability to take humans into the solar system. Or to be able to follow what the great astronomical telescopes … robotic missions … have done first. Say that you are going to Mars or exploring the other satellites and other planets. We'll be able now to follow them with humans."
"Humans can do things you can't pre-plan into an instrument. They can think on the job. And you don't have the time delay in long transmission say from Mars. So we're building a multi-purpose system that can do all these different missions: chase asteroids, go to neutral gravity points, and eventually go to Mars."
What are some other points that we can go to beyond low-earth orbit. Because we have been stuck in low-earth orbit for quite a while.
"So low Earth orbit: like the shuttle is a marvelous machine, the space station is a marvelous capability (a million pounds of laboratory in orbit). But it is just three hundred miles above the surface. On a globe of the earth, 8 thousand miles wide, 300 miles is like a quarter of an inch."
"So I heard a story that 'If Columbus was going to set out to discover the new world the way that we're discovering the universe, he would build a raft 200 yards offshore and declare discovering the new world."
"So we've done marvelous things in low-earth orbit. The space station is going to enable us to learn how to work and live in neutral gravity in the vacuum of space."
"But now we need the machine that can go beyond that. Back to the moon and the neutral gravity points around the moon. Go to asteroids … and eventually the moons of Mars and then Mars. By being a small vehicle that has this multi-purpose capability."
Orion is built "in collaboration with the Europeans to build the propulsion section, so it's an international capability that's led by the United States."
How did you deliver the multi-purpose aspect of the mission?
"So for example … from Mercury, Gemini, and Apollo (we were) learning how to operate in space. [Apollo] was designed to go to the moon and come back. Landing on the moon and come back."
"With that experience we're designing this vehicle to be doing all of these other interesting scientific missions. Like neutral gravity points, back to the moon, low-earth orbit even. But then to the moons of Mars and Mars."
"So one thing to do with that is to try to minimize the amount of consumables that the spacecraft requires for durations. So for example carrying solar arrays (points) rather than fuel cells. [Now] you don't have to carry fuel for the fuel cell. And you can just adjust the solar arrays for an infinite amount of power."
"Other consumables you have to tailor to whatever the mission is. For example rocket propellant, we need to have enough propellant. We'll probably in the architecture deliver it to a trajectory to go to a distant place. But we're designed to be totally contained so we can do a contained return, whether there's an emergency aboard, or just nominal return. So we carry the rocket propellant to be able to return the vehicle back to earth. And we'll adjust the size of all of those so that we can do all these missions without building a new vehicle."
How much rocket propellant does a capsule of this size need?
"Well we carry about 17,000 pounds of fuel. The whole vehicle weighs about 60,000. So it's about a third fuel."
"Because the whole game, right, is to get out into low-Earth orbit on the launch vehicle. And then there you are about half the energy, half the velocity of anywhere in the universe."
"However, it took you 95% of the weight of the rocket on the ground so now you have to be very elegant about the physics of how you use the other gravitational bodies to move around in the solar system."
"So there are other propulsion techniques like ion drive and things to try to improve the efficiency of in space propulsion. But they are very low thrust levels."
"One of the real breakthroughs we can have, since we don't have dilithium crystals yet. It would be really great to have propulsion capabilities."
"But we're building a machine that will be able to be evolved to accommodate different propulsion and technologies. Solar cells for example, when the cell efficiencies improve, like computer chips are improving and doubling about every two years, solar cells are improving. We can put the newer generation solar cells on. So it's designed to be very adaptable."
"So you heard about the asteroid retrieval mission. Now a very intriguing mission to go perform. That could be first. We can do some other things around the moon. The point is that we can do a lot of things with the same machine without redesigning it significantly."