Morata, Lorenzo (Part 1)
Dublin Core
Title
Morata, Lorenzo (Part 1)
Source
University of Alabama in Huntsville Archives and Special Collections, Huntsville, Alabama
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Format
.MP4
Language
en
Type
Interviews
Audio
Identifier
ohc_stnv_000026_A
Oral History Item Type Metadata
Interviewer
Bilstein, Roger E.
Interviewee
Morata, Lorenzo
Transcription
Morata Part 1
[00:00:00] Roger Bilstein: Okay, maybe you could just…If you would start by telling a little bit how you got on the Saturn program and what you did when you first started and what you've been doing since.
[00:00:13] Lorenzo Morata: Fine, fine. I graduated from the University of Oklahoma in 1960—June of 1960—and I came to work at the McDonnell Douglas, which at that time was the Douglas Aircraft Company-Missiles and Space Division. I went to work for…About the first four months that I was with the company, I worked on the Delta program, which was located at Santa Monica, and they were in the development of electronic black boxes. My first love at that time was I was an electronics design engineer supposedly when I got out of college, and I wanted to do a lot of initial design with transistors and this kind of circuit design kind of aspect. I requested to be transferred to the Saturn program. I went over on the Saturn program around November of 1960, which was pretty close to the initial design phase of the Saturn program. I believe the company had gotten a contract right about that summertime, and at that time I went to work in what they call the electronic design section. I worked on part of our propellant utilization system, which was developed for the S-IV program. The propellant utilization system at that time was a closed-loop type of system that maximized or minimized the residuals between the LOX and the hydrogen tank on IVB. What it did was regulate both the LOX flow in relationship to the hydrogen flow to make all both masses deplete at the same time and end up with minimal residuals. Therefore you could optimize payload kind of considerations.
[00:02:04] RB: Is this where this propellant utilization capacitor comes in?
[00:02:07] LM: Yes, yes. And the propellant utilization capacitor, as we know it, are continuous probes. In the LOX tank, it's one continuous probe, which is about twenty-some feet. In the hydrogen tank, we have one continuous probe, which is about forty feet. It's made up of two sections. What this does is give you a continuous monitoring reading device, which you're able to tell at any time what the mass in the tank or what level in the tank it is. As one depletes, it actually triggers the other one. We have a LOX valve going to the main engine. What happens is, as a function of what's happening in the hydrogen tank, there's an error between that probe and the LOX probe. The LH2 probe and the LOX probe compare itself and give you an error signal, which then is closed-loop transformed to open up the LOX valve or close it as a function of what mass is going through the hydrogen side of the engine. If it's going fast or slower, it always optimizes a certain mixture ratio. In our case, it's 5:1. What I did on that particular system—it was an analog computer device—and what I did for that system, the analog computer requires different voltages, both AC and DC voltages. My responsibility at that time was to design what we call—it was really a power supply—it's called an inverter/converter. What that means is that you take twenty-eight volts from a battery, and it converts it to AC voltages, which at that time we required something like 115 volts and 400 cycles to drive our servo motors, and one was on the LOX circuit. We had a valve on the LOX side of the engine, which was driven by a motor for opening and closing as a function of what was happening in the hydrogen tank.
[00:04:18] RB: This is on the side of the engine.
[00:04:19] LM: Right, it's up on the turbos. It's not on the side of the engine. It's coming down the line. It's on the pump on the engine. It's near the engine. It's sort of like a valve right in coming down from the tank to the engine. What you do is bypass some of the LOX and control it—either open it or shut it—to let more LOX or less LOX flow through. By regulating the LOX flow as a function of what's happening to the hydrogen side, you always make sure that the mixture ratio between LOX and hydrogen is 5:1. By doing that, by setting the mixture ratio to a constant number like that, what you're able to do is then deplete both masses at the same time. You load for hydrogen, and you load for LOX, and what you like to do is, at the end of mission, just be at zero, so you don't have to carry a lot of extra weight as far as LOX or hydrogen, and you can use all that for payload. If you can accurately predict how much mass you have to have to meet your mission and then make sure you use every drop of it, that's going to optimize how much payload you can put on because you don't have any extra mass weight around at the end of the mission.
[00:05:41] LM: Now, the inverter also, at that time, put out 115 volts, 400 cycles, plus it changed a lot of voltages DC-wise. You needed some different ranges of DC voltages like fifteen volts, twenty-five volts, five volts, and that's where you call it an inverter/converter. In one case, you usually end up changing DC to AC and DC to different levels of DC. Start out with a twenty-eight volt battery, and you can end up with 115 volts, 400 cycles for driving motors or lights or those kinds of things. You end up with different DC voltages like they want to shave, you know, you got a twelve volt battery, a five volt battery, a six volt battery. I designed that, designed/developed. I was the system engineer as well as the design engineer for that portion of the inverter/converter. It was a black box by itself. I did all the design on it circuit-wise. Then I was involved when we were laying it out mechanically from an RFI standpoint, radio interference standpoint, the packaging involved with it, plus the development of it, how we were building it in the shop, how we were qualifying it. I brought it through the whole gamut of checkout when we put it on the bird, and we married it to the propellant utilization electronics. When it went into checkout, I was instrumental in following that one through. At that time, it gave you a pretty good feel. At that time, I was the design guy, the systems engineer kind of guy that carried that design all the way through. I was involved in the initial design concept as well as the development and qualification of both the inverter and the PU systems for that matter.
[00:07:36] RB: One of the things that we're interested in is the evolution of technology in this aerospace, especially the Apollo thing. Was there any kind of similar system in development in the Centaur as the only other real liquid hydrogen vehicle?
[00:07:52] LM: No. At that particular time, I think, and that was done just before I had gotten here, there had been a canvassing made of the industry as far as propellant utilization systems were concerned. I think our concept was the first one where we continuously monitored a closed-loop system. Before I think the Centaur, and I can't speak with a lot of…I don't know what the Centaur system was at that particular time, but I know that they probably used level sensors. I don't know if the Atlas uses level sensors where there are discrete points, not a continuous probe.
[00:08:37] RB: Yeah, and boy, this is really out of my mind here, but how is this continuous probe…How do you get the feel out of it?
[00:08:47] LM: Well, what happens is electrically, when you build it, when you manufacture it, they can give you a calibration. Just like any other tool that you can calibrate it in the lab, and you know what it is actually in the lab. When we buy it—our particular manufacturer of the probes is Minneapolis Honeywell—and when they design it, they can design it so that you know it's so much capacitance change. Sort of like a thermometer kind of concept is, you know if it goes up—the mercury goes up so far—it's at a certain point. The vendor can build it so he knows what its capacitance is from the tip bottom to the top of the probe. That's really what we're interested in is a change of capacitance. He can tell you when he builds it, and he calibrates it, he'll tell you, “Okay, this point at the bottom, which we consider our empty point, is this capacitance, and as you fill it, you'll get a change of capacitance.” He can calibrate it for you. He'll check it out in his lab before he sends it to us. When we put it inside our tank, we know what it is at the bottom, which is our empty point. What we get…Capacitance is really electrical signal. We receive a very minute electrical signal from the probe, and that's what excites our electronics. As we fill from the bottom of the probe up, this mass changes the dielectric of the probe, and we get a change of capacitance. That change of capacitance stimulates the electronics. We know as we get this much change, we've got that much up above the empty point. Then we also know where the top of the probe is, and we know the tank geometry. Okay? Then we can correlate as the mass goes up the probe, the capacitance changes. We correlate that till we know how far that point or any point is above the bottom of the probe. Then we know what the tank geometry is, and we know how much can go in there, so we know that there's enough mass up here.
[00:11:03] RB: That comes to you as an automatic readout.
[00:11:05] LM: Yes, we get an automatic readout. This signal goes into our propellant utilization electronics, and those send a signal back to the ground to a computer that says, “Okay, you've got so much mass inside the tank at this point.” Okay? We've got ways to electronically look at it so we know where we are inside the tank. As you fill that up, you'll get a reading back in the block house, and you'll know exactly where you're at. The same thing, as we deplete down, both in flight and when we go through a static firing or when we go through a countdown demonstration test at the Cape, when we deplete, we see the same thing happening in reverse. We get a change back, and we can tell where we are until we're down at the bottom. It's a continuous reading, and I think that was one of the key factors that I think our design or our system helped evolve was that you could tell at any point in time. Up until that time, you had what they call, you could have level sensors, which are really discrete points. You can have a small capacitor at the bottom of the tank, one ten feet above that, one twenty feet above that, thirty feet above that. As your mass goes across that capacitor, you have a change of state, which also comes out as a function of voltage or some electrical signal. As the mass changes, your dielectric changes, your capacitance changes that gives you a different electrical stimulus to the ground so you know, hey, it was dry before, now it's wet. You know you've got that much mass. Then you keep on loading, and you won't know where you are until the next one picks up. Now, you could end up putting as many of these discrete points as you wanted to. You could put one every foot.
[00:12:58] RB: That's going to ask you about that, okay.
[00:12:59] LM: You could put one every foot or every ten feet or every twenty feet. But then you'd have to have different electronics for every one of them, so your system would be more complicated. You'd have to have wiring inside the tanks for every one of those things. You'd have to have connector feed-throughs. Your system could get more complicated. Just a number of equipment in this kind of thing.
[00:13:25] RB: It's beginning to come through now, the particular advantage of this single unit capacitor you're talking about now.
[00:13:31] LM: Yeah, you could always know at any point in time where you are mass-wise inside both tanks. I think it was a real…We felt real good about the system at that particular time. We still do.
[00:13:49] RB: Is this ultimately tied into the instrument unit up there?
[00:13:53] LM: No, no. The instrument unit provides all the guidance for all the stages below us. The instrument unit sits on top of the S-IVB and guides the S-IVB, S-II, and the S-IC. Now the only correlation that you have between the propellant utilization system is that the IU system will generate cutoff for the main engine—it'll just stop the main engine. It's not as a direct function that we're feeding them information, okay? We'll feed all our information to the ground. Now the ground has…They can issue commands from the ground—program commands—that they can shut off the engine through the IU. and/or the IU can be programmed for what we call velocity cutoff. At a certain point in the flight program, the IU could send a command based on time and shut us off. The PU itself is not closed loop with the IU. The propellant utilization system is only closed loop inside the S-IVB stage. That's the way the concept started out on the S-IV program.
[00:15:14] RB: Was this a…Now can you tell me again what the Thor was in terms of propelling utilization? Did you have any kind of similar…?
[00:15:21] LM: No, the Thor doesn't have a continuous probe.
[00:15:24] RB: Didn't have it at all, no.
[00:15:26] LM: The S-IVB I believe was the first time we used the, the S-IV program was the first usage of the continuous probe. Now there are some programs that have used what they call a short probe where concept-wise you've used either mass sensors…
[tape ends]
[00:00:00] Roger Bilstein: Okay, maybe you could just…If you would start by telling a little bit how you got on the Saturn program and what you did when you first started and what you've been doing since.
[00:00:13] Lorenzo Morata: Fine, fine. I graduated from the University of Oklahoma in 1960—June of 1960—and I came to work at the McDonnell Douglas, which at that time was the Douglas Aircraft Company-Missiles and Space Division. I went to work for…About the first four months that I was with the company, I worked on the Delta program, which was located at Santa Monica, and they were in the development of electronic black boxes. My first love at that time was I was an electronics design engineer supposedly when I got out of college, and I wanted to do a lot of initial design with transistors and this kind of circuit design kind of aspect. I requested to be transferred to the Saturn program. I went over on the Saturn program around November of 1960, which was pretty close to the initial design phase of the Saturn program. I believe the company had gotten a contract right about that summertime, and at that time I went to work in what they call the electronic design section. I worked on part of our propellant utilization system, which was developed for the S-IV program. The propellant utilization system at that time was a closed-loop type of system that maximized or minimized the residuals between the LOX and the hydrogen tank on IVB. What it did was regulate both the LOX flow in relationship to the hydrogen flow to make all both masses deplete at the same time and end up with minimal residuals. Therefore you could optimize payload kind of considerations.
[00:02:04] RB: Is this where this propellant utilization capacitor comes in?
[00:02:07] LM: Yes, yes. And the propellant utilization capacitor, as we know it, are continuous probes. In the LOX tank, it's one continuous probe, which is about twenty-some feet. In the hydrogen tank, we have one continuous probe, which is about forty feet. It's made up of two sections. What this does is give you a continuous monitoring reading device, which you're able to tell at any time what the mass in the tank or what level in the tank it is. As one depletes, it actually triggers the other one. We have a LOX valve going to the main engine. What happens is, as a function of what's happening in the hydrogen tank, there's an error between that probe and the LOX probe. The LH2 probe and the LOX probe compare itself and give you an error signal, which then is closed-loop transformed to open up the LOX valve or close it as a function of what mass is going through the hydrogen side of the engine. If it's going fast or slower, it always optimizes a certain mixture ratio. In our case, it's 5:1. What I did on that particular system—it was an analog computer device—and what I did for that system, the analog computer requires different voltages, both AC and DC voltages. My responsibility at that time was to design what we call—it was really a power supply—it's called an inverter/converter. What that means is that you take twenty-eight volts from a battery, and it converts it to AC voltages, which at that time we required something like 115 volts and 400 cycles to drive our servo motors, and one was on the LOX circuit. We had a valve on the LOX side of the engine, which was driven by a motor for opening and closing as a function of what was happening in the hydrogen tank.
[00:04:18] RB: This is on the side of the engine.
[00:04:19] LM: Right, it's up on the turbos. It's not on the side of the engine. It's coming down the line. It's on the pump on the engine. It's near the engine. It's sort of like a valve right in coming down from the tank to the engine. What you do is bypass some of the LOX and control it—either open it or shut it—to let more LOX or less LOX flow through. By regulating the LOX flow as a function of what's happening to the hydrogen side, you always make sure that the mixture ratio between LOX and hydrogen is 5:1. By doing that, by setting the mixture ratio to a constant number like that, what you're able to do is then deplete both masses at the same time. You load for hydrogen, and you load for LOX, and what you like to do is, at the end of mission, just be at zero, so you don't have to carry a lot of extra weight as far as LOX or hydrogen, and you can use all that for payload. If you can accurately predict how much mass you have to have to meet your mission and then make sure you use every drop of it, that's going to optimize how much payload you can put on because you don't have any extra mass weight around at the end of the mission.
[00:05:41] LM: Now, the inverter also, at that time, put out 115 volts, 400 cycles, plus it changed a lot of voltages DC-wise. You needed some different ranges of DC voltages like fifteen volts, twenty-five volts, five volts, and that's where you call it an inverter/converter. In one case, you usually end up changing DC to AC and DC to different levels of DC. Start out with a twenty-eight volt battery, and you can end up with 115 volts, 400 cycles for driving motors or lights or those kinds of things. You end up with different DC voltages like they want to shave, you know, you got a twelve volt battery, a five volt battery, a six volt battery. I designed that, designed/developed. I was the system engineer as well as the design engineer for that portion of the inverter/converter. It was a black box by itself. I did all the design on it circuit-wise. Then I was involved when we were laying it out mechanically from an RFI standpoint, radio interference standpoint, the packaging involved with it, plus the development of it, how we were building it in the shop, how we were qualifying it. I brought it through the whole gamut of checkout when we put it on the bird, and we married it to the propellant utilization electronics. When it went into checkout, I was instrumental in following that one through. At that time, it gave you a pretty good feel. At that time, I was the design guy, the systems engineer kind of guy that carried that design all the way through. I was involved in the initial design concept as well as the development and qualification of both the inverter and the PU systems for that matter.
[00:07:36] RB: One of the things that we're interested in is the evolution of technology in this aerospace, especially the Apollo thing. Was there any kind of similar system in development in the Centaur as the only other real liquid hydrogen vehicle?
[00:07:52] LM: No. At that particular time, I think, and that was done just before I had gotten here, there had been a canvassing made of the industry as far as propellant utilization systems were concerned. I think our concept was the first one where we continuously monitored a closed-loop system. Before I think the Centaur, and I can't speak with a lot of…I don't know what the Centaur system was at that particular time, but I know that they probably used level sensors. I don't know if the Atlas uses level sensors where there are discrete points, not a continuous probe.
[00:08:37] RB: Yeah, and boy, this is really out of my mind here, but how is this continuous probe…How do you get the feel out of it?
[00:08:47] LM: Well, what happens is electrically, when you build it, when you manufacture it, they can give you a calibration. Just like any other tool that you can calibrate it in the lab, and you know what it is actually in the lab. When we buy it—our particular manufacturer of the probes is Minneapolis Honeywell—and when they design it, they can design it so that you know it's so much capacitance change. Sort of like a thermometer kind of concept is, you know if it goes up—the mercury goes up so far—it's at a certain point. The vendor can build it so he knows what its capacitance is from the tip bottom to the top of the probe. That's really what we're interested in is a change of capacitance. He can tell you when he builds it, and he calibrates it, he'll tell you, “Okay, this point at the bottom, which we consider our empty point, is this capacitance, and as you fill it, you'll get a change of capacitance.” He can calibrate it for you. He'll check it out in his lab before he sends it to us. When we put it inside our tank, we know what it is at the bottom, which is our empty point. What we get…Capacitance is really electrical signal. We receive a very minute electrical signal from the probe, and that's what excites our electronics. As we fill from the bottom of the probe up, this mass changes the dielectric of the probe, and we get a change of capacitance. That change of capacitance stimulates the electronics. We know as we get this much change, we've got that much up above the empty point. Then we also know where the top of the probe is, and we know the tank geometry. Okay? Then we can correlate as the mass goes up the probe, the capacitance changes. We correlate that till we know how far that point or any point is above the bottom of the probe. Then we know what the tank geometry is, and we know how much can go in there, so we know that there's enough mass up here.
[00:11:03] RB: That comes to you as an automatic readout.
[00:11:05] LM: Yes, we get an automatic readout. This signal goes into our propellant utilization electronics, and those send a signal back to the ground to a computer that says, “Okay, you've got so much mass inside the tank at this point.” Okay? We've got ways to electronically look at it so we know where we are inside the tank. As you fill that up, you'll get a reading back in the block house, and you'll know exactly where you're at. The same thing, as we deplete down, both in flight and when we go through a static firing or when we go through a countdown demonstration test at the Cape, when we deplete, we see the same thing happening in reverse. We get a change back, and we can tell where we are until we're down at the bottom. It's a continuous reading, and I think that was one of the key factors that I think our design or our system helped evolve was that you could tell at any point in time. Up until that time, you had what they call, you could have level sensors, which are really discrete points. You can have a small capacitor at the bottom of the tank, one ten feet above that, one twenty feet above that, thirty feet above that. As your mass goes across that capacitor, you have a change of state, which also comes out as a function of voltage or some electrical signal. As the mass changes, your dielectric changes, your capacitance changes that gives you a different electrical stimulus to the ground so you know, hey, it was dry before, now it's wet. You know you've got that much mass. Then you keep on loading, and you won't know where you are until the next one picks up. Now, you could end up putting as many of these discrete points as you wanted to. You could put one every foot.
[00:12:58] RB: That's going to ask you about that, okay.
[00:12:59] LM: You could put one every foot or every ten feet or every twenty feet. But then you'd have to have different electronics for every one of them, so your system would be more complicated. You'd have to have wiring inside the tanks for every one of those things. You'd have to have connector feed-throughs. Your system could get more complicated. Just a number of equipment in this kind of thing.
[00:13:25] RB: It's beginning to come through now, the particular advantage of this single unit capacitor you're talking about now.
[00:13:31] LM: Yeah, you could always know at any point in time where you are mass-wise inside both tanks. I think it was a real…We felt real good about the system at that particular time. We still do.
[00:13:49] RB: Is this ultimately tied into the instrument unit up there?
[00:13:53] LM: No, no. The instrument unit provides all the guidance for all the stages below us. The instrument unit sits on top of the S-IVB and guides the S-IVB, S-II, and the S-IC. Now the only correlation that you have between the propellant utilization system is that the IU system will generate cutoff for the main engine—it'll just stop the main engine. It's not as a direct function that we're feeding them information, okay? We'll feed all our information to the ground. Now the ground has…They can issue commands from the ground—program commands—that they can shut off the engine through the IU. and/or the IU can be programmed for what we call velocity cutoff. At a certain point in the flight program, the IU could send a command based on time and shut us off. The PU itself is not closed loop with the IU. The propellant utilization system is only closed loop inside the S-IVB stage. That's the way the concept started out on the S-IV program.
[00:15:14] RB: Was this a…Now can you tell me again what the Thor was in terms of propelling utilization? Did you have any kind of similar…?
[00:15:21] LM: No, the Thor doesn't have a continuous probe.
[00:15:24] RB: Didn't have it at all, no.
[00:15:26] LM: The S-IVB I believe was the first time we used the, the S-IV program was the first usage of the continuous probe. Now there are some programs that have used what they call a short probe where concept-wise you've used either mass sensors…
[tape ends]
Duration
0:15:49
Files
Collection
Citation
“Morata, Lorenzo (Part 1),” The UAH Archives and Special Collections, accessed July 9, 2026, https://oralhistory.uah.edu/items/show/618.