美国国家公共电台 NPR China's Lunar Lander To Explore Moon's Far Side（在线收听）

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There's a new probe in orbit around the moon. And sometime earlier in this new year, it's expected to land on the Moon's far side, the side we never see from Earth. It is a Chinese probe. And as NPR's Joe Palca explains, although it's essentially a scientific mission, it's also laying the groundwork for sending Chinese astronauts to the moon.

JOE PALCA, BYLINE: It only makes sense to send machines to the moon before trying to send humans.

JIM HEAD: Before Neil Armstrong set foot on the moon, the United States sent 21 robotic missions to the moon to prepare the way.

PALCA: Jim Head is a planetary scientist at Brown University. He says he's convinced the Chinese are doing the same thing.

HEAD: The robotic program is providing all the kinds of background that you would need for building space suits and things like that, like lunar rovers. So they're building towards human exploration, for sure.

PALCA: That's not to say there won't be interesting science to come from the mission. Briony Horgan is a planetary scientist at Purdue University.

BRIONY HORGAN: This mission is really exciting because it's the first time any space agency will have landed on the far side of the moon.

PALCA: Horgan says scientists know the far and near sides are very different.

HORGAN: The far side is actually much more primitive. It contains really ancient crust that dates back to the very, very early solar system. There's rocks all over the far side that are over 4 billion years old. And now we're really excited to see what those look like up close.

PALCA: Now, it may seem odd that, with so much to explore on the far side, all the landing probes to date have gone to the near side.

HORGAN: That's mostly because it's a lot easier to communicate with, right? I mean, we can actually see the near side. And so we get direct radio communication with the entire near side of the moon.

PALCA: Horgan says the Chinese have solved that problem by adding a third component to the mission. The first component is a lander. The lander carries the second component, a mobile rover.

HORGAN: And then the third component is a satellite that's going to stay in orbit above the far side of the moon and act as a relay between the Earth and the far side of the moon.

PALCA: It might be handy if U.S. lunar missions could also use the relay satellite. But that's not likely. Official collaboration between NASA and the Chinese space program is essentially prohibited by law. There are also restrictions on exporting U.S. space technology to China. But Brown University's Jim Head says some amount of collaboration just makes sense.

HEAD: Why would we send a spacecraft to the same location to do exactly the same thing when we can optimize the amount of scientific return for the United States and for other countries by collaborating as best we can?

PALCA: And while China may not be as forthcoming as NASA about what their civilian space program is up to, Head says they're not completely opaque, either.

HEAD: If you talk to the right people, they are not holding things back. There are security issues there from their point of view, as well as ours. But nonetheless, they've been very forthcoming with their civilian space program.

PALCA: The United States has its own lunar ambitions. The Trump administration has asked NASA to focus on returning humans to the moon. It's just possible there will already be Chinese astronauts there when they arrive. Joe Palca, NPR News.