"So," Doretha said, plopping down in the chair next to my desk, "now that you're a certified super-genius, what's next? Are you going to bounce signals off Jupiter?"
I laughed. "Not quite. But I was reading about something almost as cool. Amateur satellites."
Her eyes lit up. "Like, spy satellites?"
"No, more like repeaters in the sky," I explained, pulling up a tracking website on my laptop. "There are dozens of them, launched by ham radio groups and universities. They orbit the earth, and for a few minutes when they pass overhead, you can use them to talk to people hundreds of miles away with just a little handheld radio."
The concept was a perfect fusion of our interests: my radio physics and her love of computers and space. The challenge was irresistible. Unlike HF radio, where you could sit on a frequency for hours, satellite passes were short, frantic windows of opportunity, lasting maybe ten minutes from horizon to horizon. It required planning, precision, and a bit of a black art.
We dove into the project together. We learned that you couldn't just use a standard handheld antenna. You needed a directional antenna, something you could point at the satellite as it streaked across the sky. Of course, Samuel insisted we build one ourselves out of a tape measure and some PVC pipe. It looked ridiculous, like some kind of sci-fi weapon, but the math was sound.
The next piece of the puzzle was tracking. Doretha found an app for our phones that showed the orbits of all the active amateur satellites in real-time. It would tell us exactly when a satellite would rise above our horizon, where to point our antenna, and what frequencies to use.
The final, and trickiest, part was accounting for the Doppler effect. Just like a train whistle changes pitch as it passes you, the frequency of the satellite's signal shifts as it screams through space towards and then away from you. You had to constantly adjust your radio's frequency during the pass to stay locked on.
Our first attempt was a complete failure. We stood in my backyard on a clear, cold night, the tracking app showing Satellite AO-91 approaching from the northwest. I held our bizarre-looking tape measure antenna, trying to point it at a patch of empty sky. Doretha was calling out the changing frequencies. All we heard was static. The ten-minute window slammed shut, leaving us in frustrated silence.
"This is harder than the Extra exam," I muttered.
"Don't give up," Gregory's voice said from the back porch. He'd been watching us with an amused smile. "You're trying to do three things at once. Split the workload."
He was right. We were fumbling over each other. For the next pass, we had a new plan. I would be the "antenna rotator," my eyes glued to the tracking app, keeping the antenna pointed at the invisible target. Doretha would be the "radio operator," her fingers flying across the radio's keypad to adjust for the Doppler shift.
The next satellite, SO-50, rose above the trees. "Okay, acquisition of signal!" Doretha shouted as a faint hiss resolved into a clear signal. The repeater was active.
"CQ satellite, this is 9W8ABC," she said into her microphone.
A voice came back instantly, "9W8ABC, you've got a station in Virginia, loud and clear!"
I swung the antenna to track the satellite's arc. Doretha made the contact, her voice electric with excitement. Then another station from Ohio called. Then another from North Carolina. For ten minutes, we were a whirlwind of activity, a perfectly synchronized team, dancing with a tiny box of electronics hurtling through the void a thousand miles above our heads.
When the satellite finally dipped below the southeastern horizon and its signal faded back into the static, we both just stood there, breathless and grinning like idiots. We looked at each other and burst out laughing. We had done it. We had talked through space. It was the coolest thing ever.
That night, as I lay in bed, I thought about the silent, empty space of my grief after Doretha died. It had felt infinite and terrifying. But now, I had reached into the literal silence of space and filled it with my voice, with my friend's voice. We had turned the vast emptiness of the cosmos into our own personal playground. There were no empty spaces anymore, just new frequencies to explore.