We all flopped to the ground instinctively, but the ship didn't attack. It blasted braking rockets and dropped to land on skids. Then it skied around to come to a rest beside the building site.
Everybody had it figured out and was standing around sheepishly when the two suited figures stepped out of the ship.
A familiar voice crackled over the general freak. "Every one of you saw us coming in and not one of you responded with laser fire. It wouldn't have done any good but it would have indicated a certain amount of fighting spirit. You have a week or less before the real thing and since the sergeant and I will be here I will insist that you show a little more will to live. Acting Sergeant Potter."
"Here, sir."
"Get me a detail of twelve men to unload cargo. We brought a hundred small robot drones for target practice so that you might have at least a fighting chance, when a live target comes over.
"Move now; we only have thirty minutes before the ship returns to Miami."
I checked, and it was actually more like forty minutes. Having the captain and sergeant there didn't really make much difference; we were still on our own, they were just observing.
Once we got the floor down, it only took one day to complete the bunker. It was a gray oblong, featureless except for the air-lock blister and four windows. On top was a swivel-mounted bevawatt laser. The operator-you couldn't call him a "gunner"-sat in a chair holding dead-man switches in both hands. The laser wouldn't fire as long as he was holding one of those switches. If he let go, it would automatically aim for any moving aerial object and fire at will. Primary detection and aiming was by means of a kilometer-high antenna mounted beside the bunker.
It was the only arrangement that could really be expected to work, with the horizon so close and human reflexes so slow. You couldn't have the thing fully automatic, because in theory, friendly ships might also approach.
The aiming computer could choose up to twelve targets, appearing simultaneously-firing at the largest ones first. And it would get all twelve in the space of half a second.
The installation was partly protected from enemy fire by an efficient ablative layer that covered everything except the human operator. But then they were dead-man switches. One man above guarding eighty inside. The army's good at that kind of arithmetic.
Once the bunker was finished, half of us stayed inside at all times-feeling very much like targets-taking turns operating the laser, while the other half went on maneuvers.
About four clicks from the base was a large "lake" of frozen hydrogen; one of our most important maneuvers was to learn how to get around on the treacherous stuff.
It really wasn't too difficult. You couldn't stand up on it, so you had to belly down and slide.
If you had somebody to push you from the edge, getting started was no problem. Otherwise, you had to scrabble with your hands and feet, pushing down as hard as was practical, until you started moving, in a series of little jumps. Once started, you would keep going until you ran out of ice. You could steer a little bit by digging in, hand and foot, on the appropriate side, but you couldn't slow to a stop that way. So it was a good idea not to go too fast, and to be positioned in such a way that your helmet didn't absorb the shock of stopping.
We went through all the things we'd done on the Miami side; weapons practice, demolition, attack patterns. We also launched drones at irregular intervals, toward the bunker. Thus, ten or fifteen times a day, the operators got to demonstrate their skill in letting go of the handles as soon as the proximity light went on.
I had four hours of that, like everybody else. I was nervous until the first "attack," when I saw how little there was to it. The light went on, I let go, the gun aimed and when the drone peeped over the horizon-zzt! Nice touch of color, the molten metal spraying through space. Otherwise not too exciting.
So none of us were worried about the upcoming "graduation exercise," thinking it would be just more of the same. Miami base attacked on the thirteenth day with two simultaneous missiles streaking over opposite sides of the horizon at some forty kilometers per second. The laser vaporized the first one with no trouble, but the second got within eight clicks of the bunker before it was hit.
We were coming back from maneuvers, about a click away from the bunker. I wouldn't have seen it happen if I hadn't been looking directly at the bunker the moment of the attack.
The second missile sent a shower of molten debris straight toward the bunker. Eleven pieces hit, and, as we later reconstructed it, this is what happened.
The first casualty was Uhuru, pretty Uhuru inside the bunker, who was hit in the back and head and died instantly. With the drop in pressure, the LSU went into high gear. Friedman was standing in front of the main airco outlet and was blown into the opposite wall hard enough to knock him unconscious; he died of decompression before the others could get him to his suit.
Everybody else managed to stagger through the gale and get into their suits, but Garcia's suit had been holed and didn't do him any good.
By the time we got there, they had turned off the LSU and were welding up the holes in the wall. One man was trying to scrape up the unrecognizable mess that had been Uhuru. I could hear him sobbing and retching. They had already taken Garcia and Friedman outside for burial. The captain took over the repair detail from Potter. Sergeant Cortez led the sobbing man over to a corner and came back to work on cleaning up Uhuru's remains, alone. He didn't order anybody to help and nobody volunteered.