Angry Moon

Chapter 40a

     The buffeting grew worse as the shuttle descended. To Eddie, it felt as though he was racing down a mountainslope in a trolley with square wheels. His teeth were shaken in their sockets, but he thought it possible that his back was getting a really good massage. “Is this normal?” he asked. “Is this what a re-entry normally feels like?” He looked out the porthole beside him, but all he could see was yellow fire.

     “When we return to Earth, you'll be able to make a comparison,” said Benny. “And technically, this is a descent, not a re-entry, since this isn't the world we came from.”

     “I stand corrected,” Eddie replied. He could feel the vibrations warbling his voice. It seemed impossible that any man-made structure could survive this kind of punishment! He stared at the bulkhead beside him, half expecting to see cracks spreading through it. They were all wearing spacesuits, just in case there was a hull breach. Their helmets were sitting in their laps, there was enough gravity from their deceleration to hold them in place. If the shuttle sprang an air leak, they could put them on and screw them down in just a moment.

     “Actually, the deceleration feels a little less than it should,” the Swede replied. “That may mean that the atmosphere’s less dense than we expected, which would mean that it's not slowing us down as much as it should, although I prefer to believe that it's because we currently have a supersonic tailwind.”

     “What happens if the atmosphere doesn't slow us enough?”

     “Then we will hit the ground travelling at several thousand kilometres an hour and create a new crater that will last for maybe a day or two before what's left of the moon's solid crust sinks into the moon’s deep interior.”

     Eddie nodded thoughtfully. “So. A supersonic tailwind, eh? And that's better?”

     “Yes, because even though a tailwind means we are slowing less than we need, it will soon turn into a supersonic headwind that will slow us more than we need. The two will balance each other out and we will arrive at the surface with a low enough speed to make a safe landing.”

     “Of course, between the tailwind and the headwind, we have to pass through the transition layer,” said Paul.

     “What transition layer?” asked Eddie nervously.

     “When you have two currents of air travelling in opposite directions, there will be a layer of turbulence between them,” said Benny. “And when the two currents are both supersonic, the turbulence will be fierce. Thankfully, our own speed will still be great enough that we will pass through it very quickly, but it is still likely to be bumpy.”

     “More bumpy than this?”

     “Quite considerably more bumpy.”

     “Bumpy enough to damage the shuttle?”

     “Will you please shut up!” cried Susan desperately. “I'm trying very hard not to think about what might be about to happen to us!”

     “Sorry,” said Benny, “but the transition layer is very close now. We might be entering it at any time. Please put your helmets on now. We can’t have them hurling around the cabin like missiles.”

     They did so, lifting them over their heads and down so that their bases met the neck seals. They adjusted them until the screw threads matched and then secured them in place with a firm twist. Eddie saw the diagnostic display light up on the inside of his visor and saw a number of messages popping up to tell him that each of the spacesuit’s systems was operating correctly. He heard the others breathing over the helmet’s intercom connection. “Helmet on and secure,” he said. The others repeated the words one by one.