“This is not making me happy,” Dirk, the only kid on Mars, thought as the alarm continued to sound. The alarm blasted in his helmet, transmitted over the Crane Farm Wi-Fi network. “Emergency – package astray, package astray. Alert Level 2. Take cover immediately.” Alert level 2 meant that it was a small package that was off course. Off course was not a huge deal – it only meant that he had a long hike to go retrieve it. Unless of course the area of uncertainty of the landing overlapped with his location, which would entail that the landing (or high speed crash) could be bad, very bad for anyone (well, he was the only one around) in the vicinity due to the non-negligible possibility that he and the package would meet with a splat.
“Oh no, not again,” Dirk grunted. He quit pushing the hydraulic lifter he was using to move the cargo the Sky Crane had just lowered to the Martian surface and started running. He’d left the Crane where it had landed at the edge of the landing zone. Due to the imminence of Space Elevator completion, the Crane was now a heap of junk, not worth the cost in fuel to re-launch. He’d push it over to the holding area or one of the garages dug into the other side of the hill north of the landing zone plateau later. He passed the small sandbag blast shelter and kept running. His dad had told him that unless he could see the package he should continue to the shelter on the City side of the hill.
The off course warning sounded whenever a package deviated more than 1% from its projected track. This made for not infrequent false alarms. He could usually bring the Crane back on course, after they were displaced by high altitude winds, but sounding the alarm when the package deviated by 1% was a necessary safety precaution – even a near miss could kill.
“But we don’t have any other deliveries scheduled for today, so what set off the alarm?” he wondered.
“It must be a special delivery package, off course and off schedule, as usual,” Dirk thought. They were often uncontrollable, and this one was completely out of tolerance and on its way at 3000 miles per hour.
Although the WiMAX network provided direct communications with Radius, out of habit he yelled, “Radius, come on!”
“Enroute,” said Radius’ voice in his ear. “We will reach the shelter in 45 seconds at our current rate.” Radius was 100 meters to the west, at about the same level on the slope as Dirk.
An unpleasant hum, increasing in volume and pitch indicated the air search radar, which activated when the “conditions normal” signal was lost from the orbital control point, had detected the package. In addition to helping him guide the deliveries to the landing zone, it also indicated the proximity of the errant package so the workers (worker, Dirk) could take emergency response actions consisting primarily of “Run and Hide!”
The sound increased in volume with package proximity. Dirk wasn’t sure it was an effective signal. It always distracted him – he wanted to rip his headphones out for two reasons. One, it was super annoying, and two, it made communicating with Radius difficult, and as the package drew closer, impossible, unless they were in the same shelter and could speak normally. He couldn’t even mute it.
“Xrrrrrr”, the sound increased in frequency as he crested the hill and turned onto the path to the shelter. The sound indicated that the package was still over five miles away which equaled at least 80 seconds before impact. Of course, that five miles could be anywhere on a hemisphere defined by the Crane Farm at the center. The package might be past and opening, on its way to landing ten miles or more away from the Crane Farm, activating the alarm only because its course bisected the five kilometer buffer zone around the landing zone. Alternatively, it could be heading for a spot Dirk was soon to occupy – at this point it was still too soon to tell.
“Radius is going to beat me there! No way!” Dirk thought as he sped up.
“This one is fairly close – within three km,” Dirk said to himself, judging by the pitch and frequency of the alarm sound as he hopped the four foot high sandbag wall outside the entrance and scooted into the shelter. His dad had built the L shaped shelter into the side of the berm before Dirk arrived. After four feet it made a 90 degree turn to the left for another four feet or so – and that was the extent of the shelter – barely big enough for two people. The 90 degree turn provided additional protection by allowing a person to duck behind the corner, thus avoiding potential impact debris.
“Dirk, whenever you are there, I want you to keep digging it deeper – every inch increases your margin of safety and will have a significant impact on your comfort by giving you more room,” his dad had said repeatedly.
Dirk had a different idea of shelter comfort. “The deeper I dig,” he said to himself, “The deeper I’ll get buried if things go wrong.” As a result, the time necessary to work on the shelter never materialized – he always had something else more important to do (even as he sat in the shelter). As someone who loved swimming, rock climbing and generally enjoying life outdoors, cowering in a cave was not his idea of fun. Yet he realized that the deeper he dug the range of impact he’d survive widened.
“To my mind,” he said to himself the last time he’d had to take shelter from a wayward package, “There are far too many situations like this on Mars, in which taking a specific action both increases and decreases my survival potential.”
As the sound reached its excruciating peak Dirk removed his helmet. “Radius, here we are again.”
“Yes, indeed,” said Radius.
“30 second to impact,” said the alarm.
“They provide the 30 second countdown so you know how much longer the movie of your life has to run,” Dirk said to himself – but ten seconds later the alarm stopped.
“Gotta love that accuracy,” Dirk said.
“Ching ching ching” – the “package landed/all clear” tone sounded. He could hear it issue from the helmet he held in his lap, his back against the far wall at the top of the L.
“Radius, our fiery death has been averted for another day,” Dirk said.
“Indeed,” agreed Radius. “Now we find the package.”
Dirk groaned. “And I was about to eat lunch.”