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ISDC 2024

 
Herrington
John Herrington has traded in his NASA spacesuit for a commercial flightsuit, working for Rocketplane as its chief test pilot. (NASA)

Astronaut Herrington makes no bones about it (part 2)

Testing Rocketplane

TSR: Will your tests push the envelope of all airplanes and rockets like X-15 or will they be well inside the envelope of spy planes?

Herrington: In terms of the SR-71 and things like that whatever regimes they fly in, this is going to be a particular regime this thing is going to fly in that no other vehicle’s flown in. Powered takeoff and landing into space. This is going to be the first vehicle that’s ever done that.

TSR: How do you write a test for something like that?

Herrington: Like everything, you start in the middle of the envelope and work your way out, based on what things you have to look at in the vehicle. We’ve got a test team here, and getting involved in that and process how to do that is going to be a learning experience for me too.

TSR: Lower altitudes, lower velocities.

Herrington: We’ll start in the middle of the envelope. Everything subsonic. Basic things: getting the flying qualities of the airplane, seeing how it handles, seeing what you need to do to tweak the flight control systems to get it to do what you want. Then as you get comfortable with one part of the envelope, you start looking at other portions of the envelope that you’re trying to get to.

TSR: So is it customizing the way that the joystick responds? With fly-by-wire do you have a lot of flexibility as to how to program it?

We’ll start in the middle of the envelope. Everything subsonic… Then as you get comfortable with one part of the envelope, you start looking at other portions of the envelope that you’re trying to get to.

Herrington: Yeah. When you look at what the basic airframe of the vehicle is going to do and what control surfaces you’re going to have, and what regime you’re going to fly it in, your going to have to look at it and say, “What do we need to do to the control surfaces to maintain stability in the vehicle?” People will program the flight control laws based on that. When you’ve got to fly it, my perspective is I don’t get deeply involved in the software aspect of it. I’m flying it. I’m a pilot. I know how to fly an airplane. When I see something that is disagreeable, if it requires more compensation than necessary, I go back and say, “It did this in this regime.” In a test plan, you look at your flight at a particular point and see how the vehicle responds to it based on whatever input you put into it. If the vehicle responds a certain way that’s objectionable, you come back and say, “Hey, this was objectionable here. How do we change the gains? Do we need to put a little more rudder into that? A little more aileron into that so that we can get a response?”

TSR: Would that be contingent on what the readings are, or would that be through all the regimes?

Herrington: It’s a response. Whatever response where that vehicle is at that point in time. You find a spot that’s objectionable, then you can go back and say “At this airspeed, at this altitude, with this input here resulted in this response in the vehicle. Unacceptable response. It took too much concentrated effort from the pilot to maintain this attitude.”

TSR: What roles have you had in testing? Could you program the avionics if you had to?

Herrington: In terms of writing the code? I’m not going to touch the code. That’s not my bailiwick. The flight tests I’ve done were for vehicles that were not fly-by-wire vehicles. This is my first opportunity to fly a vehicle that’s fly by wire. All flight testing has the same philosophy. You go out and fly the vehicle, be it a vehicle that flies with cables and pulleys, or be it a vehicle that flies with fly-by-wire. I will go out and do my job as a pilot. I’ll go out and I’ll fly the vehicle and I’ll say, “Hey, this input that I did, the vehicle responded this way.” The vehicle is going to respond a certain way because it’s cables and pulleys. It’s going to respond a certain way because it’s fly by wire. It’s just that response—and I document that response—we catch that response and record it. Engineers will look back at it and say, “Ah! Same thing! The airplane did this. We can change this to make it do that.” You take a box and you put an input into it and you want an expected output. That box could be a fly-by-wire system or that box could be cables and pulleys and ailerons.

TSR: Gradually increase the envelope until you are doing the pay trajectory?

Herrington: Eventually, you get to the point where you can fly it and light the rocket engine, and fly the trajectory and bring it back home.

TSR: Are you going to be the only test pilot on the project?

Herrington: Right now I’m the only test pilot. I’d like to see some other folks that come in that have some experience certainly in fly-by-wire systems, folks that have been doing it more recently than I have.

TSR: Who backstops your decisions on the test plan?

Herrington: I don’t have all the answers. All the folks here in the software world that are doing all the avionics, doing the flight control stuff, those are the folks you go to and you work as an entire group. I have my area of expertise; they have their areas of expertise. It certainly would be nice to have another test pilot to bounce these things off of because everybody has an opinion.

The flight experience

TSR: A long time ago you were a waiter.

Herrington: Among other things, yeah.

TSR: Will you serve drinks on Rocketplane XP during the flights?

Herrington: I’ll be flying it. Nope… What I’d like to see is for folks to get to experience what weightlessness is like. Part of doing that is playing with liquids. I’m sure people will come up with some ideas for what they want to do to capture their moment in zero G.

TSR: Maybe M&Ms [like Mike Melville in SpaceShipOne], maybe not.

Herrington: You can’t have liquid in a glass because nothing is going to stay in it.

TSR: Touché. The rest of the flight are you going to tell jokes like on the Disney Jungle Cruise?

What I’d like to see is for folks to get to experience what weightlessness is like. I’m sure people will come up with some ideas for what they want to do to capture their moment in zero G.

Herrington: Like Captain Nemo? I had a guy on one of my flights, when I flew P-3s, who used to do the Captain Nemo ride at Disneyland and he had this whole spiel. We’d be out late night flying off the coast of Russia and he’d be doing this Captain Nemo spiel over the radio. It was pretty funny.

TSR: That was E-ticket.

Danger

TSR: So is P-3 the same kind of plane that crash-landed in China after a mid-air collision with a Chinese fighter pilot?

Herrington: EP-3 was that version. I flew EP-3 as well when I was a flight tester, I did some tests on EP-3.

TSR: It’s pretty dangerous to be a test pilot.

Herrington: You mitigate the risk as best you can. Hopefully you’ll find everything you can, but some things, they may surprise you.

TSR: To be an astronaut is pretty risky too, isn’t it?

If I knew it was going to fail, I’m not going to go out and kill myself. I don’t want to go out and do something knowing that I’m going to die. I want to go up and experience it and come home.

Herrington: Yeah. When I took off, they told us anywhere from 1-in-300 to 1-in-400 chance of losing the vehicle. Would you buy a lottery ticket? People would be willing to spend money for a one-in-five-million chance of winning a million bucks. There are people willing to climb aboard the vehicle because it’s something they set out to do most of their entire life. The nature of the person is such, that, “It’s not going to happen to me. 399-in-400 chance? Yeah. I’ll take the chance.”

TSR: That was a little low. It turned out to be closer to—

Herrington: 1 in 50.

TSR: Looking back if you knew it was 1 in 50, would you still have taken the risk?

Herrington: I would have climbed on board Discovery. I had friends that climbed on board Discovery. Why not?

TSR: It’s once in a lifetime.

Herrington: Hopefully twice in a lifetime.

TSR: What if it was a one-way trip? Would you still have done it if you knew it was going to fail?

Herrington: If I knew it was going to fail, I’m not going to go out and kill myself. I don’t want to go out and do something knowing that I’m going to die. I want to go up and experience it and come home.

TSR: That’s fair.

Herrington: “Go to Mars and go on a one way trip?” No. I’d want to go to Mars and come home. I have kids. I want to experience my kids growing up. People don’t get into this business to go up for the glory of dying. They go up for the business of doing something, and come home.

TSR: So what do your kids say about your being a test pilot?

Herrington: “Daddy wore a blue flight suit.” “Daddy was gone a lot.” That was more the big thing. Other than that, my kids are excited about it. I think it’s fun for them. They’re my kids. They’re like all kids growing up. Daddy’s Daddy. It doesn’t matter if Daddy’s an astronaut or drives a taxi. Daddy’s Daddy.

Next time: Awe and satisfaction


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