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Steve Bales – the man who said 'Go!' to the moon landing
Interviewed by Michael Burland
Apart from the three brave astronauts who flew to the moon – Neil Armstrong and Buzz Aldrin who made the momentous landing and Command Module pilot Michael Collins – the center of the moonshot project was Mission Control in Houston, TX. Right in the heart of things was Steve Bales, a NASA engineer who had worked on the Gemini space missions. It was Steve's awesome responsibility to give the final go-ahead for the Apollo 11 moon landing.
Steve, it's great to speak with you as we near the 50th anniversary of the first moon landing. What exactly was your role?
I was the guidance officer. My job was to monitor the landing computer on the vehicle, and for the 7 hours before they landed, to make sure it was running properly: that its inertial systems were correctly aligned, that its accelerometers were working, that its radars were ready to go, and that it knew exactly where it was – as best as we could tell it. Once the descent starts, the engine turns on and then you're in a different game. That thing is changing velocity and altitude every two seconds and my job was to make sure it still knew where it was all the way to the touchdown.
That's pretty fundamental – knowing where it was in space!
It is, and we were very lucky because we had some very brilliant people who took Doppler signals from the huge tracking stations around the globe – a Doppler tells you 'here's how long a signal takes to get to that vehicle and here's how long it takes to get back' – which they triangulated and worked out the location. The kind of genius that went into that, and that went into programming that little computer (your cellphone today would be at least a thousand times more powerful) was amazing. I call those guys the 'poets' of the business, and people that did the things like I did were the 'plumbers'. I couldn't have come up with the equations or the software, but I darn well knew where that water was supposed to go and how fast it was running in the pipe.
What kind of accuracy did you get with those measurements?
It couldn't measure altitude very well, that's why we had to get the landing radar to turn on later in the descent, but it could measure velocity within less than a foot per second in every axis.
You, and everybody in that room, had an incredible amount of responsibility, but you were young, weren't you?
I was 26, the flight dynamics officer sat next to me was 26, the backroom software expert was 24. The systems people that looked after the telecommunications and the environmental systems, we considered them the older guys – they were early 30s and the crew were in their late 30s. The people who did what I did were fairly young, probably the first generation in our families that went to college, and we all had undergraduate degrees. The 'poets' of the business, they were the PhDs.
Was being young a benefit because you'd be 'gung-ho', making instant decisions rather than thinking about things for too long?
Yes, but we were also lucky that we had good simulators. For months before the mission, the crew would get into theirs and we'd get in ours, and we would run training sessions together, that was a tremendous help. The generation that came before us, in the Mercury program, could've done what we did – probably better – but they had gone on to be managers. People like Chris Kraft and others had to manage thousands of people and couldn't be down there in Mission Control, so they had to rely on the new recruits like us to come in and they gave us a lot of responsibility.
One of the oldest guys in the room would have been the Chief Flight Director, Gene Kranz?
He was 35. I've got to tell you a story about Gene! The day of the landing, we got in on our shift at seven in the morning and we had eight hours of incredibly hard work. The vehicle was powered off, you had to power it up, turn on everything, start the computer, make sure it was working right, it's a lot of work and if anything went wrong – and it did from time to time in our simulations – you couldn't land. But we finally got all that done. Then there was about 30 minutes where the craft went behind the moon and we couldn't talk to the crew. Gene said 'I want everybody to go to the private loop' – that's so people outside our team couldn't hear what he wanted to say. Then, and I'll never forget this, he came online. I'll paraphrase it because nobody can find a recording of this. He said 'We have trained and this is what we were meant to do. I want to tell you this: no matter what happens' – and we all knew what could have happened -- 'no matter what happens, when we walk out of this room, we walk out just like we came in. We came in as a team and we're going to walk out as a team. No matter what. Now. Let's do it.' Then he told the guards to lock the doors so nobody could come into the room, and off we went.
That's a fabulous bit of man-management.
It's incredible management. Reflective of the man and reflective of the time, and I think reflective of the fact that he'd been through some more dangerous things and he knew some of us were younger.
The Apollo 11 project was one of the greatest things that humankind has achieved, I think most people would agree with that, and it ended up as a great success. But on the way to that magic moment did everybody feel confident in Mission Control at the time?
I think we all knew in the back of our minds that there was a chance we might not make it to the surface – I'm just giving you my personal view here. But I always felt that if we weren't going to make it to the surface, we probably could have aborted and made it back to the command module safely. But that other possibility was always there – that we might have hit the surface and it would have been a real disaster. In simulations we made mistakes and crashed.
Once they'd landed, if something had gone wrong, they might not have have got back again?
They had two engines: they had a landing engine, but when they took off they separated the top of the Lunar Module and that second engine absolutely had to work or they were just stuck. That would have been a horrible way to end the mission. From the people that designed everything to the people that built the hardware, programmed the machines, worked in mission control and on computer systems and tracking stations around the world, thousands and thousands of people all had to do the job right. And when we made a mistake we all had to figure out a way we could recover. The easiest part of the mission was trying to figure out what we were going to do normally. A lot of our time was spent sorting out 'what if this happens' and 'what are we going to do about it?' We were lucky though, and sometimes the good Lord intervened! He did!
You had to choose whether to abort the mission or override the computers and give the 'Go'. What happened?
When we were landing we had a computer alarm that was never supposed to come up. Never. But in one of the simulations I was describing, we had gotten a similar case, just a couple of weeks before. Either something went wrong with the simulator, or the simulator guys were really sneaky and put this in and I aborted the simulation. When that happened everybody talks about what they did – Gene talks first and says 'Here's what I did and here's what I saw', then every position describes what they did and what they saw, and then the crew does the same thing. Then the people that are running the simulation describe what they think you should have done. We got in a huge argument, because I said that I think we should have stopped and they said 'ah, no, not necessarily'.
My software expert Jack Garman and I pulled together the people that had coded the system and the people that had built the hardware, and they told us 'You're not going to get these things on the landing, it couldn't possibly happen, we put them in there so we could check out the software.' Jack kept on going at them and they said 'Okay, in the unlikely event that these things happen, here are the ones that are safe and here are the ones that are not safe, and here are the ones that you've got to make a judgment on.'
The ones that we had during the actual flight – error codes 1202 and 1201 – were ones we had to make a judgment on. They were all about spurious signals that were overflowing the computer. It was getting overloaded with information and had to not do certain things. This computer normally ran at about 83 percent of duty cycle. Today if you ran a computer at 83 percent capacity, hardly any margin, people would think you were crazy! But at that time it was the best they could do. In fact there was a hardware box that was sending signals to the computer, and we were probably running between 94 and 96 percent all the time. Then when certain things happened, like when the landing radar came on and the crew would call up a certain display, it was enough to tip it over the edge for one or two seconds.
So you got the error messages, but the computer could catch up with itself?
Yes, and the good news is when we finally got to about 2000 feet the crew goes to manual control and that lowers the duty cycle on the computer, or we would have had a big mess.
And that last leg was when the crew proved that they were real pilots?
Tell me about it! We could only project the trajectory so well and there had been some unknown perturbations on the back of the moon when they separated the vehicles. When we started the descent I could see that there was a loss of about 20 feet per second, and I told the flight director that if it got up to 35 we'd have to stop. But the landing radar came on and corrected that error. Right after that we started getting the program alarms. They were going downrange about four miles, to quite a rocky place. Neil [Armstrong] killed off most of the velocity but when he pitched the vehicle up and he could see the moon, he was about to land in a crater that was as wide as a football field. He had to fly over the crater instead of gently landing like he'd hoped to do, which was a great piece of piloting.
On top of everything else, we didn't have a fuel gauge, per se, just an indicator that indicated 'low level' when you had 90 seconds fuel left. That's when the flight controller, Bob Carlton, a propulsion engineer, started his stopwatch. You have billions of dollars of programs, hundreds of thousands of people working on it, and you end up with three people – two crewmen and Bob and his stopwatch – because at that point there was nothing else the ground could do. The crew didn't have a fuel gauge either. Towards the end, on the recording, you hear '60 seconds' – that's Bob – then '30 seconds' and we see Neil flying across the surface, and then you finally get the contact light and Hallelujah, you know? Hallelujah!
If there's only enough fuel for one shot at landing, and you've got 90 seconds in which you need to fly it properly and land, why didn't they put more fuel on board? Was it just the weight?
Yeah, just the weight. They squeezed every pound out of the landing vehicle, they were trying to get it lower and lower. I think NASA offered [Northrop] Grumman some huge amount of money for every pound they could save. In fact, the reason we were doing rendezvous around the moon rather than flying one big ship to it is because we couldn't build a rocket big enough to take one vehicle to the moon and land on it.
The Saturn V is still the most powerful rocket to have taken off, isn't it?
As far as I know, but it would have been small potatoes compared to if we had gone with what they call 'direct descent', a big one-lander. That's why you had the command module and the lunar module – to save an incredible amount of weight.
There were three or four times where you've got the 1202 and 1201 alarms, you've got the craft going too fast, and you have to make the call. You personally could have vetoed the whole mission and aborted the landing.
Yeah, it could have happened. If it happened higher up, we were likely to have a successful abort and rendezvous but what a huge disappointment. The thing was, we were following, as best we knew, the rules, but, there was no guarantee that something else would not have happened. If something happened at 10,000 feet before the crew can see the ground and it does something really strange to them...
Thankfully it didn't. And then you reached that incredible moment when everybody gives the final 'Go'. Gene Kranz calls all the different positions and you all reply 'Go', 'Go', 'Go'. That is spine-tingling every time I hear it. Where does that moon landing sit in your life? Is it right at the very top?
It's close. I got married later in life so my marriage ranks a little higher and my children are a little higher but I'm just thankful y'know. I didn't think about it for years, but as I've gotten a bit more mature, shall we say – I'm 76 now – you think about 'What if something really would have gone wrong'. What would your life have been like? What would America have been like? What would the incredible disappointment and the sorrow have been like, even if it hadn't had been my mistake or anybody else's mistake, if it were just the circumstances? How horrible would things have been every time you looked up at the moon?'
And yet, it was such a great success. It was one of the few times in history that most everybody on the Earth was following something, and it was a positive thing! A lot of things that everybody follows – 9/11, the Kennedy assassination – are horrible, negative things. But the moon landing grabbed you and it was so positive. And what a wonderful view of the Earth – we went to space to look back and say, what a beautiful place we have back here too. I don't dwell too much on what if it had gone wrong 'cos it didn't. But every once in a while you glimmer into that and you say 'Thank the Lord you didn't let something really bad happen. You made it work'.
There are a couple of quotes about you at the time. President Nixon said 'This is the young man who, when the computers seemed to be confused and when he could have said 'stop' or when he could have said 'wait', said 'go''. How did it feel to hear him say that?
I was there, it was at a big celebration in Los Angeles and I was lucky to go. One of the marine guards grabbed me and took me to this room where the President and the astronauts were doing interviews. The President came over and said 'I'm glad to know you. Thank you for everything. I'm going to say a few words about you and all you have to do is smile and shake my hand', which is what I did. [laughs] I don't know if I'd have been able to say anything else. Yeah, that was quite a thing. But I was not given the honor for me, I was representing everybody that worked on this mission. I happened to be the one that had the most problems during the landing. Although, it could've been given to Bob Carlton or Gene Kranz.
Buzz Aldrin said 'When Mike, Neil and I were presented with medals of freedom by the President Steve also received one, he certainly deserved it 'cos without him we might not have landed'. He was talking about that whole team too?
He was. He was really talking about the whole team. He was talking about one incident which was mine but he could have been talking about anybody else's. In fact I remember, when I was leaving the podium I didn't know who to look at or what to say and I saw Buzz at the end and I had to stop and shake his hand – I had to shake somebody's hand because I was still in shock! [laughs]
Finally, do you have anything to say to moon landing denying conspiracy theorists?
[Laughs] I'd say, go and have a look at the pictures from the orbiters that go round the moon. You can see the shadow of the Descent Stage [the 'bottom half' of the lunar lander that remained on the Moon after the astronauts took off]. I guess somebody could fake those, but there's no way it was faked – there were too many people, too much tracking... I'd say, if you want a conspiracy, try to think of one that would be more productive!
Watch the incredible story of the Apollo program between now and the 50th anniversary in Smithsonian Channel's amazing series Apollo's Moon Shot. It tells the entire story of America's Moon program through rare, newly restored archival film and unique access to the artifacts of Apollo. From John Glenn's camera, to Apollo 11's command module, to the last space boots on the Moon, still covered in lunar dust – the series reveals the stories of the men and women who made the mission possible. Stunning footage of each mission – some of it rarely seen – is combined with NASA's oral histories taken directly from the astronauts' debriefings upon their return to the Earth. In-depth explorations of astronaut artifacts from the Museum's vaults form an intimate connection between the viewer and the men on the face of the Moon. Smithsonian Channel is available in the UK on Sky, Freesat, Freeview and Virgin Media.
See www.smithsonianchannel.com for details.