本帖最后由 深海鳗鱼 于 2019-4-22 17:27 编辑
有关黑洞的上一篇文章 https://www.hanxiangtang.com/forum.php?mod=viewthread&tid=3650 相对比较简单,适合小五-小六的孩子们阅读。而这篇文章ReadingLevel为760L,难度有所增加,孩子们阅读过程中有遇到什么问题可以留言,常乐会给你答复。
Science Space Moon Mission
September 14, 2018 Jeffrey Kluger for TIME, adapted by TFK editors
CHARGED UP An illustration shows the Gateway orbiter circling the moon. Solar panels will turn sunlight into electric energy to power the orbiter’s propulsion system.
BOEING ILLUSTRATION
People first set foot on the moon on July 20, 1969. Astronauts Neil Armstrong and Buzz Aldrin stepped from the Apollo 11 spacecraft. They planted an American flag on the moon's surface. After that, NASA sent six more missions to the moon. Then the United States government stopped funding them. NASA hasn't sent a crew to the moon since 1972. Now the space agency is planning a return trip. In December 2017, President Donald Trump signed a Space Policy Directive. It put lunar exploration back at the top of NASA's agenda.
GIANT LEAP Astronaut Buzz Aldrin poses for a photo on the moon, on July 20, 1969. NASA
NASA wants to change the way astronauts explore the moon. The Apollo 11 crew spent 21 hours, 36 minutes there. Future astronauts could spend up to six weeks at a time orbting the moon and visiting its surface. This will be made possible by the Lunar Orbital Platform-Gateway. Gateway will be a sort of mini space station. It will be much smaller than the International Space Station. Gateway will have five modules, or interlocking parts. One or two of them will house astronauts. Another will provide solar electric power. Others will serve as an air lock for spacewalking astronauts and a docking port for vehicles. Astronauts will travel to the moon's surface and back in a small craft. NASA plans to use unmanned rockets to send parts for Gateway into lunar orbit. “We're working to have astronauts on the moon by the mid-2020s,” says Bill Gerstenmaier. He is a NASA administrator for human exploration and operations.
THINK BIG President Trump holds a toy moonwalker during the signing of a directive that put moon exploration back on NASA’s agenda. SAUL LOEB—AFP/GETTY IMAGES
All Aboard Gateway will allow astronauts to explore more of the moon than Apollo could. Apollo flew a circular path around the moon. It stayed about 60 miles away. It could land only near the moon's equator Gateway will travel an egg-shaped orbit. It will fly between 1,200 and 47,000 miles away. Astronauts will pick their landing spot. They'll adjust Gateway's orbit to fly over that spot. Then they'll take the landing vehicle down. Other countries may pitch in. Russia may build the air-lock module. Japan might provide a module that will assist with propulsion and communications. Canada could build a robotic arm for outdoor work on Gateway. The U.S. Congress will have to get on board too. It's up to them to provide money to build Gateway. In 1962, President John F. Kennedy encouraged Americans to support the space program. He said in a speech, “We choose to go to the moon.” The most powerful word in that line was choose. We chose then. We can choose again. It's entirely up to us.
On Deck: MarsNASA sees Gateway as a base for staging missions beyond the moon. What’s the next stop? Mars. The space agency plans to build a special craft for the trip. The Deep Space Transport will carry astronauts from Gateway to the Red Planet and back. This will reduce the cost of shuttling supplies for a Mars mission all the way from Earth. The Mars transport could even expand its size by attaching one of Gateway’s habitat modules.
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