Chapter 3: Testing

My first task after planning the website was to obtain the means that would enable us to identify a star uniquely. Thinking about the problem, I decided that we needed four telescopes to cover the sky without complicating the individual mountings.

I settled on seven-inch remotely controlled Cassegrain electronic telescopes, each with seven ICCDs (Intensified Charge Coupled Device) filtered to measure wavelengths from the infrared to the ultraviolet. Star data for these instruments is readily available. I loaded the data into my computers and kept a backup copy on DVD.

We mounted the telescopes in optically transparent polycarbonate blisters in both the nose and the bottom of the airframe as well as the two upper quarters. This tetrahedral arrangement gave us all round vision.

A fractal antenna and a retractable dish antenna provided us with communication facilities on and near the Earth.

The installation of the control system was progressing apace. We would not calibrate the gyroscope system until we could rotate the craft freely in space.

I had just finished marking one of my programming classes' exercises when a thought struck me. How are we going to hover? I rang the workshop and got a voice.

"JBS Research, how may I help you?" came the voice I recognized, Corporal Benson.

"Hullo Corporal, it's Bill Axon. Is Miss Chalmers available?"

"She's in her office. I'll put you through, Sir."

There was a pause and then, "Chalmers!"

"Hullo Susan, it's Bill. I've been wondering. How do we hover? Or rather, how does the craft maintain a fixed distance from another object? Or to be even more general, what controls the drive?"

"Well, Bill, to answer your last question first, the drives are controlled by a voltage of zero to ten volts. There are six separate drives in linked pairs. To engage the drive in the reverse direction, we reverse the controlling voltage. We change from a positive voltage to negative. I imagine you will solve the other questions by using some sort of radar. Does that help you?"

"I think so, but I've had another thought. Isn't having just a down pointing drive unstable, rather like balancing on a pogo stick?"

"Yes, but that's easily solved. We build the drive assembly at forty-five degrees to the three main axes. That way, we hover on three drives and use three drives for forward motion."

It took me a moment to visualize how that would work. Then another thought occurred to me.

"Does that mean that in normal travel, the three rear pointing drives are fighting each other?"

"Not really. It's the combined field that counts. It's about twice as strong as the field from a single drive. Does that give you what you want to know?"

"I'll let you know when I've had a chance to think my way through it. Thanks! Bye, now," I said and rang off.

Hmm! Radar! A couple of hours later, I thought I had the answer sorted out. There were Radar catalogs spread across my desk and I had just got off the phone after ordering seven sets. That was two on each axis and a spare. They had sent me a manual as a 'pdf' file, so I could start work on the software to match the input information from the radar, etcetera and the control system to the input control voltage for the drives.

For example, you could set the height, at which to hover, on the control system and then the radar controls the drives.

I had installed three computers in the cockpit; two are used to control the craft. The third remained a working spare, which could be switched in to replace either of the other two. Any one of them could carry the whole load of control, both of the craft's motion and the environment within the craft.

Eventually, four months later, we had completed the installation work. It was the summer break, and we were ready to start testing. The guys had started to couple up a truck to tow the craft out to the car park, when I suggested we fly it outside. They looked a bit sheepish.

James, looking a little apprehensive, said, "Are you sure you want to try that?"

"Of course I do," I replied.

What I did not tell them was that I had already tried it on my own; I had calibrated the zero on the down-looking radar. I could lower the craft to any height above 'zero' and still have room to lower the aircraft's undercarriage.

Two of the men opened the large doors to the workshop. Susan, James and Corporal Benson, our designated radio operator, boarded the craft. I turned to James and asked.

"What are we going to call her?"

"We're going to call her the 'Enterprise', of course."

"Benson, the U.S.S. Enterprise seeks permission to depart. Make it so!"

"Aye-aye, Captain," he said grinning.