阿尔特弥斯二号任务将是自1972年以来的首次登月任务，将宇航员送上人类从未到过的更远的深空。
一些专家告诉ABC新闻，尽管有所有的准备、安全系统和冗余，人类太空飞行的本质是固有的风险。
前美国国家航空航天局宇航员和工程师丹尼·奥利瓦斯告诉美国广播公司新闻说:“我认为，如果说所有的风险都降到了零，那会让每个人都感到欣慰。”。“事实是，它不是，也永远不会是。”
对于Artemis II，美国国家航空航天局领导人强调，这次任务是一次飞行测试，因为这是第一次机组人员将在选定的火箭配置上飞行。
“我们尽我们所能，尽可能将风险降至零，”美国国家航空航天局行政长官贾里德·伊萨克曼告诉美国广播公司新闻。“但在某些时候，当你探索我们以外的世界时，有些风险是值得冒的。”
美国国家航空航天局正在利用为期10天的任务测试各种系统，包括通讯和机组人员的生命支持系统。奥利瓦斯说，对于宇航员来说，太空探索带来的风险——尤其是试飞——是可以理解和接受的。
他补充说，像任何人类太空飞行任务一样，Artemis II充满了减轻的风险，这是由多年的测试和沿途的大量学习支持的
“从宇航员的角度来看，这些都被考虑在内了，”奥利瓦斯解释道。
美国国家航空航天局正在使用各种工具和系统来确保从发射到溅落的乘员安全:
救生服
四名宇航员将穿着定制的宇航服，名为猎户座乘员生存系统(OCCS)适合从发射到重返地球大气层。
亮橙色的宇航服与大型头盔相搭配，形成了众所周知的宇航员轮廓。
1988年，美国国家航空航天局从白色宇航服换成了亮橙色宇航服，以便宇航员在溅落回收过程中更容易被发现。根据美国国家航空航天局的说法，阿尔特弥斯二号宇航服是防火的，具有冷却能力和防减压功能。
这种宇航服还可以在去除二氧化碳的同时提供可呼吸的空气，使宇航员在紧急情况下能够存活长达六天左右。
发射中止系统
发射中止系统是44英尺高的结构，出现在猎户座飞船的顶部。它是为发射时最坏的情况设计的。
根据美国国家航空航天局的说法，如果火箭出现问题，三个强大的发动机可以迅速将乘员舱拉走，并在几秒钟内将宇航员带到安全的地方。
辐射检查
一旦猎户座离开地球的保护磁场，宇航员就会暴露在更高水平的太空辐射中。
猎户座飞船里有六个辐射传感器。它们每个都是美国国家航空航天局混合电子辐射评估系统的一部分，该系统测量机舱不同部分的辐射剂量率。
宇航员也有个人辐射追踪器，如果辐射水平过高，可以提醒他们。
保持联系
为了与飞船保持联系，美国国家航空航天局使用了多种通信系统，包括深空网络，美国国家航空航天局的巨型无线电天线国际阵列，以及临近空间网络由地面站和一队太空中继站组成。
重叠系统有助于确保如果一个连接断开，另一个可以恢复通信。
据报道，唯一一次预计的停电发生在飞船经过月球后面的41分钟左右美国国家航空航天局.
紧急出口系统
如果发射台发生紧急情况，宇航员和附近的工作人员可以使用电缆系统迅速逃离，类似于滑雪缆车，可以带他们离开火箭。
内置路径主页
Artemis II任务的部分设计包括自由返回轨道，这是一条依靠重力将猎户座飞船绕月球弹回地球的飞行路径，推进力最小。
如果主引擎失灵，美国国家航空航天局称之为“内置安全网”。这个概念可以追溯到阿波罗任务，并在1970年帮助拯救了阿波罗13号上宇航员的生命，当时一个氧气罐爆炸，使其电力和生命支持系统瘫痪。
How NASA plans on keeping astronauts safe during Artemis II moon mission
The Artemis II mission will be the first to the moon since 1972, sending astronauts farther into deep space than humans have ever traveled.
Despite all the preparations, safety systems and redundancies, the nature of human spaceflight is inherently risky, some experts told ABC News.
"I think it'd make everybody feel comfortable to say that all the risk was knocked down to zero," Danny Olivas, former NASA astronaut and engineer, told ABC News. "The truth is it is not and never will be."
For Artemis II, NASA leaders have emphasized that the mission is a flight test because it is the first time a crew will fly on the selected rocket configuration.
"We do everything we can to bring risk as close to zero as we possibly can," NASA Administrator Jared Isaacman told ABC News. "But at some point, when you're exploring the worlds beyond ours, there are some risks worth taking."
NASA is using the 10-day mission to test a variety of systems, including communications and the life support systems for the crew. Olivas said that, for astronauts, the risks that come with space exploration -- especially a test flight -- are understood and accepted.
He added that Artemis II, like any human spaceflight mission, is filled with mitigated risks supported by years of testing and lots of learning along the way
"From an astronaut perspective, that's all taken into account," Olivas explained.
NASA is using a variety of tools and systems to ensure crew safety from launch to splashdown:
Lifesaving suits
The crew of four will be wearing customized spacesuits calledOrion Crew Survival System(OCCS) suits from launch through re-entry into Earth's atmosphere.
The bright orange suits -- paired with large, helmeted visors -- create the very well-known astronaut silhouette.
NASA switched from white suits to bright orange suits in 1988 to make astronauts easier to spot during splashdown recovery from the ocean. The Artemis II suits are fire-resistant, have cooling capabilities and protect against depressurization, according to NASA.
The suits can also provide breathable air while removing carbon dioxide, keeping astronauts alive for up to about six days in emergency situations.
Launch Abort System
The Launch Abort System is the 44-foot-tall structure emerging out of the top of the Orion spacecraft. It's designed for worst-case scenarios during liftoff.
According to NASA, if something goes wrong with the rocket, three powerful motors can quickly pull the crew capsule away and carry the astronauts to safety within seconds.
Radiation monitoring
Once Orion leaves Earth's protective magnetic field, astronauts are exposed to higher levels of space radiation.
There are six radiation sensors inside the Orion spacecraft. They each form part of NASA's Hybrid Electronic Radiation Assessor system, which measures radiation dose rates in different parts of the cabin.
Astronauts also have personal radiation trackers that can alert them if radiation levels are too high.
Staying in contact
To stay in contact with the spacecraft, NASA uses multiple communication systems, including theDeep Space Network, NASA's international array of giant radio antennas, and theNear Space Network, made up of Earth-based ground stations and a fleet of space relay.
The overlapping systems help ensure that if one connection drops, the other can reinstate communication.
The only expected blackout is about 41 minutes when the spacecraft passes behind the moon, according toNASA.
Emergency egress system
In the event of an emergency on the launch pad, astronauts and nearby crew can quickly escape using a cable system, similar to a ski lift, that can carry them away from the rocket.
Built-in path home
Part of the Artemis II mission's design includes a free-return trajectory, which is a flight path that relies on gravity to slingshot the Orion spacecraft around the moon and back towards Earth with minimal propulsion.
NASA calls it a "built-in safety net" if the main engines fail. The concept dates back to the Apollo missions and helped save the lives of the astronauts onboard Apollo 13 in 1970 after an oxygen tank exploded, disabling its electrical and life-support system.
