AMICITAS FLIGHT THREE – MISSION DAY 224
ARES III SOL 222
[08:11] WATNEY: Dust storm has passed. I’m going out to sweep off the solar farm. While we were waiting, we made several repairs to Sojourner’s internal circuitry. What we found makes it unlikely that the probe survived. There was apparently a short circuit, we assume due to static buildup after the loss of Sojourner’s static points, that melted part of the wiring harness connecting the solar panels to the power board. That can’t have been good for the rest of the circuits, or the CPU. Our only reason for hope is that we also found a lot of broken connectors between the CPU and PROM chips and the board, so it’s possible the static surge missed those.
So we want to make one more test to see if there’s anything left to save. While I’m sweeping, let me know what I need to do to make the experiment.
[08:38] JPL: This is Tim at JPL, Mr. Watney, Ms. Dragonfly. The Pathfinder team is standing by to send Sojourner activation orders. We can’t do this while the Pathfinder chat is running, so we need you to close the client on Rover 1 and take Sojourner outside, in that order. We’ll order Sojourner to power up and execute one three-sixty rotation in place on its wheels. If nothing happens, we concur that further salvage efforts are probably futile. In any case, ninety minutes after closing out the chat, take Sojourner back inside the hab and reactivate Rover 1’s Pathfinder app. We’ll be listening.
[09:02] WATNEY: Roger. By the time you read this Rover 1 will be shut down.
Half of Sojourner’s brain resided in its own limited circuits- the CPU and the PROM chips that regulated its health on the flight to Mars and provided instructions on how to perform commands. The other half resided within Pathfinder, the parts that gave the instructions, which remembered what Sojourner had done, and which interpreted the data from the probe and relayed them back to Earth.
Almost forty years before, the two halves had been sundered when Pathfinder’s unreliable power systems, which had triggered several computer reboots and threatened its mission from the first day, finally died. The rover, lobotomized, had gone into safe mode, making its best guess where the lander was and returning to it, waiting for instructions the larger probe would never give.
For ninety days the little rover had been busy, performing miracles on a power supply designed to last only five days after separation from the lander. Then, after sputters and starts and garbled instructions, the only voice it could hear had gone silent, and not long after, so had the universe. It never sensed the internal damage that came later, over the years, as the cold of Mars and all its sand and dust did its work.
Now the universe returned. It was in an elevated position on a flat surface with a lot of unfamiliar surroundings, some of which moved on its own. Sojourner watched impassively. Nothing spoke to it in any way it could hear; there were no orders to follow and no remaining emergency protocols; so, it remained inert.
It sent out a ping to its mothership, asking for a response, and it heard nothing.
Its vision was a little scratchy from the play of Martian dust and sand on the covers protecting the various cameras. But it could see light and dark shapes, and some outlines, that suggested it was being lifted and carried somewhere. The world became very uniform for a few minutes, and then it emerged into the dimmer afternoon light of the place it had come to explore.
It was returned to the surface just outside the shadow of something large. It sent out another ping. No reply.
But before it could send a third ping, a voice came out of the silence, long awaited. It demanded a status update.
Sojourner performed a systems diagnostic and reported it, as if forty years had not passed.
The voice that gave orders commanded it move its wheels just so, performing a dance that would swing in a full circle.
Sojourner obeyed, notifying the lander as it began the requested maneuver and again when it was completed.
The voice gave one final command: stand by.
Sojourner obeyed. Its options in this regard were sharply limited, but it didn’t mind. It was a machine. It had infinite patience.
And yet…
It was too simple a robot to think for itself, but if Sojourner had a spirit, it might have cried tears of ghostly joy. For the first time in decades, it was whole.
And meanwhile, two large shapes danced around it, for no apparent reason.
“It lives!” Dragonfly giggled, dancing around the Martian surface in her spacesuit. “The robot lives!”
“You’ll have to feed it and clean up after it, you know,” Mark said over his improvised pony comms. “It’s a heavy responsibility, having your own rover.”
Dragonfly stopped dancing to give Mark a confused look. “What are you talking about?” she asked. “You humans are weird.”
[14:14] JPL: Venkat here. Congratulations on a miracle, Mark and Dragonfly. The Pathfinder team have begun work on software to install into both rovers that will allow either one to take over from Pathfinder and operate Sojourner. That way, even if Pathfinder fails, you have a rover that can go into tight places and look at things. Also, this will allow the Pathfinder chat and Sojourner to run at the same time.
[14:39] WATNEY: Thanks, but we can’t take credit. We don’t know what happened to cook only certain electrical connections inside Sojourner, but it left the CPU and PROMs alone- and that’s the only reason the little robot lives. Whatever stopped the lightning from frying Sojourner’s brains, that’s what deserves the thanks.
Also, we don’t think the bot’s much more than a pet at this point. Reviving it was a morale task. We could just as easily have taken up Martian rock scrimshaw as a hobby. In fact, it’s still on the table, as soon as Dragonfly finishes her fanfic about the forbidden love between BJ McKay and Enos Straite.
[14:42] WATNEY: Dragonfly here- I don’t know what Mark is talking about, and he won’t tell me what “fanfic” means. It’s not in the dictionary, either. Aren’t you his bosses? Make him tell me what it means!
[15:07] JPL: _Make_ him? Haven’t you got to know him better than that yet?
[15:34] WATNEY: Jokes aside, the work on Sojourner raises two questions. Why hasn’t Pathfinder had the same problems with electrical grounds and thermal contraction on the electronics board that Sojourner did? Or, if it did have those problems and is running anyway, how long until it breaks? I figure that’s a job for you guys, since if you break something taking it apart you can fix it in a few minutes. If I break Pathfinder taking it apart for maintenance, we’re down to Morse code via the pony radio.
[16:02] JPL: Thanks for bringing this up. We’ve had similar concerns, but we made the same conclusion you did. Breaking Pathfinder while trying to do maintenance on it is an avoidable disaster. We’ll have the Pathfinder team look into it, but only after the new Sojourner software is uploaded. We’re already discussing things we could do with the rover for bonus science data, both in Acidalia and at Schiaparelli if it lasts that long. But we need Pathfinder working for long enough to get the software update. That’ll take days at our current bandwidth.
[16:27] WATNEY: Roger. For now we’ll focus on the potato harvest, and then on setting up the engine test. After that we’ll begin tearing down Rover 1.