“Well, that’s a relief,” Luke said. He was folding his launch seat out of the way to make room for his spacewalk. “That Saturn V sure gave us a hell of a ride!”
Michael chimed in. “I felt like a crash test dummy!”
Chad interrupted. “Boys, you got any snags we should tell Houston about?”
They both shook their heads at Chad, who was still strapped into the left seat. Making eye contact while weightless was new to them all; it was strange to have no common up or down as a reference.
Chad confirmed the S-band comm switch was in transmit/receive. He leaned to his right and watched as the radio signal strength jumped, showing communications lock with the Rose Knot relay ship, 106 miles below, off the Australia coast. He pushed the black transmit trigger on his rotational joystick.
“Houston, Apollo 18’s back with you.”
No response.
Chad rechecked his switches and leaned over to the communications sub-panel to verify that everything was set correctly. He called again, and frowned when Houston didn’t respond. Michael floated over and tapped the keyboard display that showed digital uplink activity from the ship.
“Data’s flowing fine, Boss.”
The CAPCOM’s voice broke in. “Apollo 18, it’s Houston, how do you read?”
Both men exhaled in relief. “Try using your mic to answer,” Chad told Michael, who pushed his trigger. “Loud and clear, Houston, how us?”
No response.
Michael pictured the communications system in his head, considering possible causes. “Data’s good both ways, and we’re hearing them fine. So we have a problem with voice downlink.”
Chad agreed. “Houston, if you hear, we’re swapping to VHF.” He reached up and threw the switches to select the simpler, traditional aircraft radio system, and tried again.
“Houston, this is 18 on VHF, how do you hear?”
There was a light buzz of static in the headsets. Luke had stopped what he was doing to watch them work the problem. This had suddenly gone from annoying to serious. He said, “Can you send a null data command to let them know we’re hearing them?”
“Good idea,” Chad responded. He thought for a second, and then punched in five zeroes and pushed Enter. The computer rejected the command and the Operator Error light came on. He typed 11111, reselected S-band communications and waited for Houston to call again.
“Apollo 18, Houston, we see your null entry. How do you read?”
Chad pushed Enter. The Operator Error light came on again.
A smile spread on Michael’s face. “You’re setting up a code!”
Chad shrugged. “Let’s see if they catch on.” He ran his thumb down the flight plan. “We only have comms via this ship for another ninety seconds or so.”
“Apollo 18, Houston. If you hear us, please retype all ones and Enter.”
“Bingo!” Chad said, punching in the numbers.
The CAPCOM’s voice sounded relieved. “18, we see that, thanks. All systems look good to us except downlink voice. It might be a weak transmit signal, so we’ll try again on the big dish at White Sands in twenty-two minutes, and will have other ideas there. If you copy, press all zeroes and Enter.”
Chad did as instructed.
“18, we see that. If you have any serious issues on board, type all ones. If nominal, type zeroes.”
Chad sent five zeroes.
“Good to see, 18, thanks. Talk to you in twenty.”
Chad turned to his crew.
“Looks like we’re still on for now, but this is a primitive workaround. Luke, keep getting things set for the spacewalk. Michael, get out the comm system schematics. I do not want a simple comm problem to lose us the Moon.”
Michael was by the window, his face lit by a faint glow. “I’m on it, but guys, stop for a minute and watch this. First sunrise in space.”
Chad and Luke looked up through the windows to see the sunrise happening as they raced towards it at five miles a second, the faint purple glow of the night horizon quickly overtaken by the dawn.
Luke gasped as the Sun burst into view.
“That’s the most beautiful thing I ever saw,” Michael said reverently. “It’s like someone just poured a rainbow onto the edge of the world.”
“Nice,” Chad said. “But it also means we’ve got ninety minutes. By the next sunrise, Almaz should be in our sights.”
“Right,” Luke said, and began gathering more gear for his spacewalk.
“Where are you in EVA prep?”