After months of meticulous preparation, NASA’s 32-story-tall Space Launch System rocket was hauled to its seaside launch pad Jan. 17 in Florida, setting the stage for a long-awaited flight next month to send four astronauts on a trip around the moon.

The 10-day mission, called Artemis II, will lift off as soon as Feb. 6, taking NASA astronauts Reid Wiseman, Victor Glover, and Christina Koch as well as the Canadian Space Agency’s Jeremy Hansen to the vicinity of the moon for the first time since Apollo 17 in 1972.

The crew of four will travel beyond the far side of the moon, which could set a new record for the farthest distance humans have ever traveled from Earth, currently held by Apollo 13. It will also make history as the first trip beyond low-Earth orbit for a person of color, a woman, and a Canadian astronaut.

But why won’t Artemis II land on the lunar surface?

“The short answer is because it doesn’t have the capability. This is not a lunar lander,” said Patty Casas Horn, deputy lead for Mission Analysis and Integrated Assessments at NASA. “Throughout the history of NASA, everything that we do is a bit risky, and so we want to make sure that that risk makes sense, and only accept the risk that we have to accept, within reason. So we build out a capability, then we test it out, then we build out a capability, then we test it out. And we will get to landing on the moon, but Artemis II is really about the crew.”

Artemis I, the program’s 25-day, uncrewed debut mission, launched in November 2022 and orbited the moon. The upcoming flight is the first time that people will be on board the Artemis spacecraft: The Orion capsule will carry the astronauts around the moon, and the SLS rocket will launch Orion into Earth orbit before the crew continues deeper into space.

“Now, with our four humans on board, we’ll be testing out a lot of new capabilities that were not there for Artemis I,” Horn said. “For example, we need to keep the vehicle thermally stable, because humans need to be comfortable. But when you add people to a spacecraft, you add a lot of moisture to the air, too. They also need food. They need water. They need toilets. We … also have some exercise devices on Orion this time that we’re going to be testing.”

NASA’s priorities for Artemis II are clear, Horn added. Crew safety and health come first, which includes getting the astronauts back home. Vehicle safety and health are secondary, and the mission objectives — such as testing navigation, propulsion and other onboard systems — come after that.

Artemis II’s mission profile draws some parallels to Apollo 8, which launched in 1968 and took humans to the vicinity of the moon for the first time. That mission, too, did not land on the lunar surface. It was, however, the first crewed launch of the Saturn V rocket and the first time astronauts were able to see and photograph the far side of the moon.

The Artemis program’s first planned lunar lander is called the Starship HLS, or Human Landing System, and is currently under development by SpaceX. During the Artemis III mission, which is scheduled to lift off by 2028, astronauts will launch aboard the Orion capsule using the Space Launch System rocket.

经过数月的精心准备，美国宇航局高达32层的太空发射系统火箭已于1月17日运抵佛罗里达州海滨发射台，等待几周后的升空。

这项名为“阿尔忒弥斯2号”的10天任务，最早或将在2月6日发射，将美国宇航局宇航员里德·怀斯曼、维克多·格洛弗、克里斯蒂娜·科赫以及加拿大航天局的杰里米·汉森送往月球附近区域。这将是1972年阿波罗17号以来，人类首次重返月球附近。

四名机组人员将飞行至月球远侧之外，这有望创造人类离地球最远距离的新纪录（目前纪录由阿波罗13号保持）。此次任务也将创造历史：这将是首次有有色人种宇航员、女性宇航员和加拿大宇航员执行超越近地轨道的飞行任务。

但阿尔忒弥斯2号为何不登陆月球表面？

“简单来说它不具备这种能力。这不是一个月球着陆器，”美国宇航局任务分析与综合评估副主任帕蒂·卡萨斯·霍恩表示。“纵观美国宇航局的历史，我们所做的一切都伴随着一定风险。我们希望确保这种风险是合理的。因此，我们构建一项能力，然后测试它；再构建下一项能力，再进行测试。我们终将实现登月，但阿尔忒弥斯2号的核心在于验证载人飞行能力。”

阿尔忒弥斯1号于2022年11月发射，绕月飞行25天。即将到来的这次飞行将是首次有宇航员乘坐阿尔忒弥斯飞船：猎户座飞船将搭载宇航员绕月飞行，SLS火箭首先将飞船送入地球轨道，随后宇航员将继续飞往深空。

“现在，随着我们四名宇航员登船，我们将测试许多阿特米斯1号所不具备的新功能，”霍恩说。“例如，我们需要保持飞行器的热稳定状态，因为宇航员需要舒适的环境。但当你在航天器中加入人员，会给空气带来大量湿气。他们还需要食物、水和卫生间……我们此次还在飞船上配备了锻炼设备，将要进行测试。”

霍恩补充道，确保宇航员的安全与健康是首要任务。飞行器的安全与健康是次要任务，而诸如测试导航、推进及其他船载系统等任务位列其后。

阿尔忒弥斯2号任务与1968年的阿波罗8号任务有相似之处。虽然那次任务同样没有登陆月球表面，却是土星五号火箭的首次载人发射，也是宇航员首次看到并拍摄到月球远侧。

阿尔忒弥斯计划的星际飞船载人着陆系统目前正由太空探索技术公司研制。根据计划，在拟于2028年前发射的阿特米斯3号任务中，宇航员将搭乘猎户座飞船，由太空发射系统火箭送入太空。(Translated by DeepSeek)