(10) Day 3 The Crane Farm

“Dirk, you’ve read the Book concerning your responsibilities, right?”
“Yes,” Dirk responded sullenly. He’d enjoyed working out with Tom, but that couldn’t make up for the rest of his Martian life. He’d arrived on Friday, and his dad had only allowed him the weekend before insisting that he immedi-ately get to work! On the ship they had gradually adjusted the pressure and oxygen content so that when people ar-rived they were already 95% acclimatized, but he still felt weird, with a touch of altitude sickness – his head ached and he felt a little nauseated.
That Monday his dad could tell he wasn’t happy. “Dirk, I know you don’t want to start work immediately, but the Company needs you on the job. The delivery pace is in-creasing significantly in order to get all the necessary Ele-vator parts down to the anchor point so we are ready when the top assembly arrives in orbit.”
The Book described his job as follows:
“Two landing zones constitute the Elevator staging and construction area (which Dirk referred to as the ‘Crane Farm’) – Zone 1 is a 100 meter dynamic net system into which low mass but high value packages land, bounce, re-leasing their kinetic energy, and eventually roll down into the center to the collection point.” (Loc 270)
Dirk referred to it as the ‘spiderweb’, and it had proven less expensive than including a 100lb parachute in each delivery package. (The thinness of the Martian atmosphere, even after 100 years of terraforming, entailed extremely large, and thus heavy, parachutes (even when made of ex-pensive Zylon) were required to slow reentry effectively. As a result, the parachutes were so big it cost more energy to get the parachute assemblies to Martian orbit than any possible payload they would deliver. Once the packages ceased bouncing, he’d walk underneath the net, and deflate the "bubble wrap" as he referred to the Vectran composed impact container/air bag assembly in which the packages were encased. Leaving the Vectran there as extra cushion-ing for the next delivery, he took the package to the hold-ing area for delivery to the City when his shift concluded and he went home for the day. Except for the addition of the spider web (carbon nanofibers strung above 2 million year old meteor impact crater) the system was nearly iden-tical to that used for delivery of the Martian rovers Spirit and Opportunity by NASA in 2003.
“The only problem with it,” Dirk said to his dad after the first few deliveries, “Is that more often than not the little packages blow off course, setting off the alarm and making me hike out to retrieve them.”
The second area was more fun – there he guided the Sky Cranes through the final landing sequence. As the Book explained, “The Cranes are designed for heavy load delivery, and are descended from the ‘Sky Cranes’ that landed the Curiosity Rover on Mars in 2012. An expenda-ble heat shield covers the lower half of the Crane, protect-ing it as it skids through the atmosphere. Released by ex-plosive bolts, it spins up and over the Crane once it is with-in 100 km of the Crane Farm. At that point the retrorockets in the Crane begin to fire, slowing and finally bringing the Sky Crane above it to a stop above the main landing zone. In order to keep the unit cost of the Cranes down, (and to ensure that a failure to the guidance system caused by the bouncing through the atmosphere on entry is not fatal to the City) a simple homing system guides the Crane into the landing zone where the terminal phase is directed manually by the Crane Farm operator.”
“The Book leaves out a lot of this description,” his dad had explained to Dirk. “The Cranes can get themselves close to the landing pad, using the few GPS satellites in or-bit. But once they get within 40 miles of the landing zone they require active guidance.”
“But why not use Artificial Intelligence, like they have for all transportation modes on Earth?” Dirk asked.
“A simple artificial intelligence system coupled with a robust ground architecture (glide slope indicators, location broadcasting beacons in place, etc.) could provide the Cranes with sufficient organic intelligence to steer them-selves down. However, creating systems capable of func-tioning reliably through the heat, bumps and dust storms was too expensive - especially for a single use delivery Crane. So instead of building the intelligence into each sin-gle use Crane, the decision was made to rely on an intelli-gent actor on the ground – and that is you,” his dad ex-plained.
“What about Robots?” Dirk asked. “They could use ro-bots to provide the on ground guidance.”
“The Company does employ robots, but remember, on Mars we lack the Robot infrastructure present on Luna and on Earth. We have spare parts here, of course, but not eve-ry possible part potentially required. In addition, Robots require power. This is not a big deal on Earth or Luna, where batteries are plentiful and the energy network ubiq-uitous. But here on Mars we are energy poor and at the very end of the industrial/technological supply lines. This is the frontier, and every decision incorporates the fully em-bedded cost of energy, especially the availability oppor-tunity cost, into account. We live in a world of scarcity more similar to the Old West in the 19th century in the early days of the railroad than the 22st Century United States. Shift your thinking from a world in which energy is basi-cally free back on Earth to one in which energy produc-tion, storage and distribution constitutes one of the biggest challenges we face.”
“Then how are humans better than Robots in this situa-tion? We have the food, housing and water infrastructure requirements that Robots don’t.”
His dad paused. “We’ll talk about it later.”