Transmitting to ISEE-3

“I VOLUNTEER AS TRIBUTE” is what Dana must have heard.

I probably said something to the extent of, “it sounds like fun to spend 2.5 hours sweating profusely in a barely ventilated dome in a confined space with a 400 kW transmitter requiring manual switching to talk to a spacecraft launched before my parents even considered having kids” or, “that might be fun to do later this week”. Not, “sure, I’ll go spend my afternoon plugging and unplugging a cord in the name of science and archaic flight hardware”. To Dana, this meant “absolutely, yes: today”.

Lunchtime conversations at Arecibo Observatory range from the mundane (“these pork chops are awful this week, save them for your dog; I’m getting a sandwich”) to scientific (“another way to think of the “dunite dilemma” is to consider that there may be an excess of olivine on Earth and that the asteroid belt is not actually depleted in this mineral”) to political (“… and that’s how we saved planetary radar at the observatory!”) to practical (“can we schedule that meeting for a time when everyone is around?”).

Dana’s usual henchman was away at a workshop in Berkeley building radio spectrometers with our favorite SETI hardware guy, so his usual partner in transmitter switching crime was gone.

I finished the press release draft about asteroid 2014 HQ124 we’d observed the day prior, a regular old asteroid but a real humdinger of a radar opportunity: predicted signal to noise of this object was in the tens of thousands per transit/receive cycle. My phone rang.

“Phil says we can go up now,” said Dana’s pitched voice. I ran over to the control room, grabbed a hard hat, and shoved a paper towel into the rim to catch sweat. We teetered down the hill to the cable car, waiting for our ride to the platform.

Late afternoon and the sky was mostly clear. Blue patches were hazy with Sahara dust, blown thousands of miles across the Atlantic and keeping it from raining here. When it rains you can’t go up to the platform, it isn’t safe, especially with the risk of lightning.  The afternoon looked clear, so we milled around the cable car building, waiting for our ride to the telescope platform.

Unlike in Goldeneye, the cable car doesn’t take off very fast: it’s a slow, steady ride up to the platform.  James Bond could have run up and down the catwalk several times before 006 reached the telescope platform via cable car.  A system of interlocks prevents the cable car from taking off without you.  After pushing the “up” button, the motor engages, wheels begin to spin, and the car gently lurches (if that’s at all possible) up a highly-greased cable.  Away from the cable car motor housing, you can just hear the squish of the wheels on the greasy cable and the jungle sounds below.

The dome grows larger and larger as the cable car ride continues, and eventually you hear the pulse tubes cooling the receivers in the dome.  My first night riding up the cable car in the dark I saw fireflies lazily drifting in the darkness below the dish.

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