Friday, May 14, 2010

My Time in (Aero) Space

Today’s final launch of the shuttle Atlantis (and the two remaining launches before the entire fleet goes into mothballs) has me reminiscing. It was 1973 and I had just moved to Colorado after leaving the Navy. My first job was with A.R.F. Products. They had a little R & D Lab in Boulder on Valmont Reservoir with about 20 engineers and 10 support people. The main manufacturing plant was in Raton, New Mexico, and we did all the research and government work.

I was hired as an engineering technician (I had not completed my EE degree at that point), and worked on the design and test of “Command Receivers.” These were little UHF FM radios that received signals and activated relays. They were entirely self-contained and typically used to receive the dreaded “Command Destruct Signal.” This is a radio signal to a missile or rocket commanding the built-in explosive package to detonate. This was done if a missile or rocket booster went off course to prevent it from crashing into the ground. Instead, just pieces crash into the ground.

Now my high frequency experience from the Navy was all vacuum tube, klystron, magnetron, traveling wave tube, and stuff like that. The receiver I was working on at A.R.F. had a 500 MHz, integrated circuit, Phase Locked Loop local oscillator and complementary CMOS transistor RF front end; absolute state of the art. I was like a kid in a candy store working with this latest (for 1970) technology. It was very expensive in those days, but these were government contracts, so let the cost be damned!

My primary job was acceptance testing. We would manufacture about 30 of these babies a month, and I would put them through their paces. We called it “shake and bake.” I would put the receivers into a small environmental chamber, about the size of a microwave oven, and take them up to 100 degrees centigrade: that’s the boiling point of water. I would test them for sensitivity and spurious signal rejection and harmonic operation points and they had to pass perfectly. Then down to minus 40 degrees C (same temperature as minus 40 F) using CO2 as the cooling agent and repeat tests.

I would also put them on a vibration tester. This was a giant, water cooled coil about one foot across. It was just like the driver of a loudspeaker, only it was 1,000 watts. I would drive it from a signal generator sweeping the frequency from 5 Hz to 1000 Hz at 10 Gs of acceleration. (We later added random signal tests — I suggested we play Led Zeppelin, but the stuffy old engineer insisted on some signal source that matched milspec 100.17b — no Led Zep!)

If the receiver failed any of these tests, I would troubleshoot and fix it. I remember trying to hold a scope probe on one of the receiver’s circuit boards while it shook at 10 Gs. Finally soldered wires to the test points to do the signal trace.

I got to go to Wiz-Mar a few times (White Sands Missile Range) when we had some telemetry failures. The problem turned out to be static electricity. Solid state devices have always been sensitive to static discharge. When we assembled the CMOS devices, they came with a wire wrapping all the pins and grounding out the case. We would use special mats to solder on and had wrist straps grounding us out. I was not allowed to wear any jewelry. We built telemetry devices that would be taken out on the range and installed in these instrument boxes in preparation for a missile launch. When they plugged in the antenna, the static would zap the front end of the receiver. I actually saw a blue spark once. The wind and the sand at Wiz-Mar were awful.

Our command receivers were used in early Boeing cruise missiles. Then we got the call to design a receiver for the shuttle. We completely redid the design and built about 500 of the receivers. They are still used today, two of them, one in each solid fuel booster. (There have been about 130 shuttle launches, with two of our receivers on every one.)

When the Challenger shuttle disaster occurred, our receivers were used to destroy the solid fuel boosters because their parachutes failed due to the external fuel tank explosion. It was a sad day for all of us that had worked on the shuttle, but I was proud our little A.R.F. contribution worked as intended. I have a big picture in my office of the shuttle being prepared on the pad. It was a gift from a friend. I still look at that picture with the eyes of Arthur C. Clark. That, folks, is a space ship — well, maybe more of a delivery van — but it goes into space!

Later in the 70’s, I started teaching at Electronics Technical Institute in Denver, Colorado, but still worked at A.R.F. nights and weekends. I got involved in some power supply designs and also a special radio running at extremely low frequency to be used in mines. That never really worked out. We didn’t even get to creating prototypes because the math just didn’t work. It is just hard to get radio signals to pass through a mile or more of dirt. Wouldn't it have been great to have those underground radios during this recent coal mine disaster?

My entire early career was around two technical areas. One was testing and the other was radio. From my time as a radio station and later TV station engineer, to my Navy experience as a calibration technician and radio technician, to my teaching of microwave electronics and F.C.C. License preparation, to my work on UHF radio gear at A.R.F., I was the “analog guy.” It wasn’t until ten years later at IBM that I started working in computers. And then the focus became test. And that is where I still am today.

So, since graduating from Navy Electronics Technician 'A' School in 1967 to retirement some time in 2011, I've worked with technology for forty-four years, and that doesn't count my pre-High School experience with HAM radio. I think I probably started all this stuff in 1959 at the tender age of 12 — actually I think I started at the age of 9 with my first telescope. (Yup, I was gonna be an astronomer. Certain of that.)

Today I can play the radio, but I haven’t designed one in three decades. So this is how it ends for an old HAM Radio guy. No radio for you. No space shuttle for you. And in about one more year, no more computers for you.

So it is with some sadness (actually a lot of sadness) that I see my career coming to an end. I plan to be very involved with photography, video, and production business after I retire, but other than fixing people’s PCs, I don’t see much of a future in designing and programming computers. I did have a lot of fun this last week when a vendor was in Boulder and we got to install and check out a nice static analysis tool, and I got a fast refresh in UNIX, but you know I’ve already given all my UNIX text books away to old friends and I’m on the downward slide to social security.

Still I remember those heady days when the smell of alcohol was in the air and the frost from liquid O2 was on the side of the rocket and hearing the loud speaker in the block house count down: three, two, one, zero … all systems are go, we have LAUNCH.

What’s that honey? Oh, you said lunch. I thought … never mind!

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