Eagle Station

“Understood,” Tian said. LOS meant loss of signal. It marked the point at which their spacecraft’s orbit would carry it around the curve of the moon — cutting off radio transmissions and observations from Earth or near-Earth satellites. Since their communications were routed through China’s Magpie Bridge relay at the L2 point, they would be completely unaffected by this transition. But the Americans, blind and deaf to anything happening on the moon’s far side, would no longer be able to see what they were doing. He entered a code on his screen. A new menu lit up. “Initiating final pre-separation checklists.”

Row after row of separate spacecraft systems flashed yellow and then cycled to green as the computer tested them and made sure they were properly configured. To ease the workload on their two-man crews, the engineers who designed China’s Chang’e landers had built in a high degree of automation.

Nevertheless, Tian and Lavrentyev followed along at every step. No sane pilot put his whole trust in automated systems, especially not on an incredibly complex brand-new space vehicle making its first real flight. “Lander life support is good. Thrusters are go. Docking latches are ready to release. Descent engine is on standby.”

Through their headsets, they could hear Liu and the other Russian cosmonaut, Captain Yanin, going through their own checklists aboard Federation 2. A tone sounded. Moments later, a computer-decrypted message scrolled across the top of their displays: at your discretion, you are go for undocking and descent burn as planned. good fortune. leonov. li jun. message ends.

The two men exchanged wry smiles. Did Marshal Leonov and President Li Jun honestly believe their explicit permission was necessary to men who were so far from their home planet? But since all crew conversations were automatically recorded and periodically downloaded to Moscow and Beijing, neither thought it especially wise to comment out loud.

“Checklist complete. All systems are nominal. Ready for separation at LOS plus sixty seconds,” Tian announced calmly, as the computer finished its work. He reached up and slid the visor of his helmet down. It clicked into place. He heard the comforting hiss of air flowing through his space suit’s umbilical hose. Next to him, Lavrentyev closed and sealed his own helmet.

Ahead through his window, Tian saw the moonscape change character. In contrast to the near side’s vast dark basalt plains, the moon’s far side was a rugged expanse of thousands of craters — some small, others hundreds of kilometers wide. A radio-antenna-shaped icon on his MFD turned red. “Loss of signal.”

He tapped another icon on the display, setting an automated undocking sequence in motion. A digital readout appeared on-screen, counting down the remaining seconds. The Chang’e’s sophisticated flight computer was now in complete control.

As a precaution, Tian put his hands on the two controllers mounted beneath his display. If the automated program glitched, he was ready to shut it down and take manual control.

“Ten seconds,” Lavrentyev said quietly, following the computer-driven countdown.

Tian tensed, waiting as the seconds ticked by. Then, with a muted clang-clang-clang, the latches holding the Chang’e and Federation released. The lander jolted as its thrusters fired, pulling it away from the larger Russian command module. A com icon changed shape, signaling the transition from hardwired intercom to low-powered, short-range radio.

“Good separation,” they heard Liu say. “Chang’e-Ten, this is Federation, you are clear. Fifty meters separation and increasing at five meters per second. We are commencing our own thruster maneuver to open the range faster.”

“Copy that,” Tian acknowledged. Looking ahead through his window, he saw a long chain of smaller impact craters curving roughly north to south across their flight path. He cued their nav system, and it confirmed his visual impression. They were approaching the Leuschner Catena. It was one of the aim points for their planned descent to the lunar surface. “All right, Kirill, let’s deploy the landing gear.”

Lavrentyev nodded. He opened another menu on his display and stabbed at it with a gloved finger. “Master Arm on.”

Tian saw the confirming light. “Go on that.”

“Landing gear deploy.” The Russian tapped his display again. “Firing.”

WHAANG. Another small vibration rattled through the Chang’e lander as tiny explosive bolts detonated. Released from the clamps holding them close against the spacecraft’s hull, their landing struts swung down and locked in position.

“Chang’e-Ten, this is Federation,” Liu radioed. “Your gear is down. We see all four struts.”