1972 年，当阿波罗 17 号宇航员从月球返回时，他们不可能知道，自己将成为 50 多年来最后一批深入外太空的人类。但自那以后，没有宇航员冒险离开地球轨道，尽管乔治·W·布什、巴拉克·奥巴马、唐纳德·特朗普和乔·拜登总统都计划了登月任务。最后，NASA 正准备通过阿尔忒弥斯二号飞行器将人类送回月球，该飞行器计划于 2025 年秋季升空。为什么这么难？

这次新任务与 1968 年的阿波罗 8 号飞行类似，当时三名宇航员绕月飞行，但没有着陆，然后返回地球。阿尔特弥斯二号将派遣四名宇航员进行为期 10 天的绕月旅行，这是 NASA 新型太空发射系统 (SLS) 火箭和猎户座太空舱的首次载人测试。尽管美国花了几十年的时间来改进此类旅行，但即将到来的旅行与上世纪中叶的同类旅行相似，因为它绝非易事。

选择做某件事“不是因为它们容易，而是因为它们很难”，这是约翰·F·肯尼迪总统在 1962 年的一次著名演讲中提出的理由之一，他试图鼓励人们支持阿波罗计划。当时的情况今天依然如此——事实上，登月可能比几十年前更加困难。

美国宇航局的阿尔特弥斯计划一直受到长期拖延、成本超支和意外问题的困扰。它与许多地面计划有着共同之处，例如地铁升级和高速公路建设，这些计划似乎也比过去（令人怀疑的）美好时光花费的时间更长，而且往往花费更多。现在建造伟大的东西真的更难吗？说到月球，为什么复制美国半个多世纪前完成的壮举要花这么长时间？

阿尔忒弥斯下一步计划本质上是重做阿波罗 8 号计划，但该计划的宏伟目标远不止月球。“最终，我们的目标是火星，”Artemis II 任务经理马修·拉姆齐 (Matthew Ramsey) 表示。“这非常困难——到达火星并在火星上生活——所以我们会分阶段逐步实现。”

该计划的首次任务是阿尔忒弥斯一号，于 2022 年将一艘无人飞船送上月球并返回。继阿尔忒弥斯二号之后，第三至第六次任务将把人类送上这颗天然卫星，然后建立绕月空间站“月球门户”的部分设施。后续任务还将专注于在月球表面建立可居住的营地。

阿尔忒弥斯计划刚刚起步，就已经被长期推迟，而且美国宇航局监察长办公室最近的审计报告指出，该计划面临着重大问题。首先，到 2025 年，该计划将耗费 930 亿美元，比预期多出数十亿美元。其次，审计报告称，阿尔忒弥斯一号任务揭示了“在将宇航员派往阿尔忒弥斯二号任务之前需要解决的关键问题”。例如，猎户座太空舱的隔热罩出现故障，原因尚不明确，与工程师们的预测不同。航天器上的螺栓面临“意外的熔化和腐蚀”。电力系统出现异常，可能会导致未来的宇航员没有足够的能源和冗余，甚至可能没有推进力或增压。

报告称，这些“异常”——太空界用来描述大问题的术语——“对机组人员的安全构成重大风险”。而且，它们还面临着其他硬件、数据和通信挑战。此外，监察长发现，首次发射对系统造成了不可预见的损坏，导致维修费用超过 2600 万美元，这比团队预算的要高得多。这需要很多麻烦和大量资金——尤其是对于一项无法实现我们在 20 世纪 60 年代未能实现的许多第一的任务而言。

鉴于我们以前曾进行过登月任务，今天的登月任务如此具有挑战性似乎有些奇怪。但乔治华盛顿大学空间政策研究所所长斯科特佩斯说，现在的情况已经不同了。“世界环境非常不同，”他说。美国不再参与太空竞赛——这是一场为了保持领先于共产党国家并率先在地球以外进行探索的生存之战。当时，冷战形势正在发挥作用，新独立的国家正在决定遵循哪种治理体系——这一决定可能（理论上）受到民主国家探索太空的能力的影响。这种“软实力”认为，可以表明美国方式是最好的方式，同时利用该国类似导弹的火箭来暗示强硬的军事优势。考虑到这些利害关系，美国政府愿意在短时间内向阿波罗计划投入巨额资金。

阿尔特弥斯计划造价昂贵，但阿波罗计划也同样昂贵：根据行星学会的数据，该计划耗资约 2900 亿美元（以今天的美元计算），而阿尔特弥斯计划耗资 930 亿美元。在那些年里，NASA 通常能得到国家预算的 4%。如今，NASA 能得到 1% 左右的预算就已经很幸运了，因为除了载人航天之外，NASA 还要承担许多其他航天器、望远镜和研究项目的资金负担。

乔治华盛顿大学名誉教授、太空政策研究所创始人约翰·洛格斯顿认为，削减预算是有道理的。“没有理由把钱花在打仗上，”他说。“目前，确实没有任何国家利益或政治利益为这种动员提供基础。”

这些松散的政策使可用资金缩水，并使太空任务规划走上了一条更加曲折的道路。20 世纪 60 年代，肯尼迪宣布美国将在 60 年代登陆月球，而美国确实做到了。在现代，一位总统制定的太空飞行计划经常被另一位总统取消，但后来又以不同的形式重新提出。因此，通往月球（及更远的地方）的轨迹变得曲折离奇。

佩斯指出，世界秩序也发生了变化，太空任务现在往往是全球合作。阿尔特弥斯计划是日本、加拿大、阿联酋和欧洲航天局的合作项目。国际参与实际上是该计划的一大意义所在。“阿尔特弥斯计划有科学目的——重返月球等等，”佩斯说。“但它也是塑造太空国际环境的一种方式。”这种塑造比 20 世纪 60 年代重要得多，当时人类对地球上空基础设施的依赖较少。如今，轨道航天器可以实现从 GPS 功能到导弹预警再到银行业务等一切功能。通过与其他国家合作并建立行为规范，说服它们将太空视为宝贵资源并加以对待，有助于我们确保太空安全，并让太空参与者承担责任。“规则是由那些站出来的人制定的，”佩斯说。

这是一个比赢得比赛更模糊的目标。“如果有明确、清晰的动机，事情就会简单得多，”洛格斯顿说。但与其他国家合作（其中几个国家正在为阿尔特弥斯建造硬件）比单独行动需要更长的时间——就像做一个团队项目比简单地熬夜更令人厌烦一样。据 NASA 监察长称，该计划的全球性质也增加了成本，而且 NASA 没有一个总体战略来处理它所引入的所有合作伙伴。

然而，在佩斯看来，这些因素都不是月球轨道的主要绊脚石。最大的挑战是，尽管美国已经登月，但我们最近没有登月。“我们停下来，然后就忘了，”他说。他继续说，仅仅因为你 50 年前参加了奥运会马拉松比赛，并不意味着你明天可以再次参加。

就阿尔忒弥斯计划而言，这场马拉松还涉及新的、更复杂的技术。火箭方面的基本原理并没有发生太大变化：大型火箭本质上是将物体送入太空的炸弹。许多参与者都是一样的。波音公司参与了将阿波罗任务送上太空的土星五号火箭的研制。对于阿尔忒弥斯计划，该公司设计并制造了 SLS 核心级，这是一台巨大的机器，高 212 英尺，宽近 28 英尺。这个部件为发动机提供燃料，使 SLS 从地面升起并按正确方向飞行——这要归功于波音公司制造的航空电子系统。该公司目前因其飞机的质量控制问题以及导致两名宇航员被困在国际空间站的航天器故障而备受争议，该公司还负责后续阿尔忒弥斯任务的火箭级。

波音公司在土星五号火箭上的古董作品和现代作品之间存在很大差异。这一次，他们使用计算机控制的机械加工以及不会熔化和扭曲金属的摩擦焊接技术来制造火箭级。该公司还使用计算机分析火箭级的状态并实时监控它们的行为——这是阿波罗所缺乏的视角。

与此同时，诺斯罗普·格鲁曼公司负责火箭助推器，它们被绑在核心级的两侧。它们为 SLS 发射提供 75% 以上的动力。助推器的大部分工程设计源自航天飞机计划，在某些情况下，它们的部分硬件实际上曾在航天飞机任务中飞行过。这些助推器与导弹一样，使用固体火箭燃料而不是液体燃料。“你要尽快摆脱地球引力，离开阻力很大的厚大气层，”SLS 助推器副工程师马克·托拜厄斯说。“这就是固体推进的真正作用。它是原始的马力。”

但使用以前太空计划硬件的计划有点拼凑起来。例如，太空发射系统最初是为星座计划设计的，这是乔治·W·布什政府为完成国际空间站建设并重建人类月球基地而制定的战略。国会要求火箭重复使用当时已停止的航天飞机计划的技术。但奥巴马在 2010 年取消了星座计划，特朗普在 2017 年启动了阿尔忒弥斯计划，目标是最终将人类送回月球并为探索火星铺平道路。新计划再次要求 NASA 使用为星座计划开发的一些技术，这又需要重新利用旧的航天飞机技术。这些要求是由代表航天飞机零部件制造中心所在地区的国会议员推动的。但事实证明，这些技术的延续和转换很困难。根据美国宇航局监察长的报告，将火箭部件带入现代时代（例如更换石棉部件）并对其进行改装以适应新的火箭系统的成本远远超出预期。

航空航天公司 Aerojet Rocketdyne 制造发动机，与火箭助推器一样，让旧的航天飞机发动机为阿尔特弥斯号工作既困难又昂贵。SLS 火箭比航天飞机高得多。尺寸的扩大需要改变发动机以应对更高压力下的氧气流入。发动机也比航天飞机上的更靠近助推器。“这是一个极端的加热环境，”发动机项目主管迈克·劳尔说，因此需要极端的绝缘。

与在航天飞机轨道上运行相比，Artemis 发动机在前往月球（以及随后前往火星）的途中将面临更严重的辐射环境。应对这种变化需要对每个发动机上的计算机进行调整，劳尔称之为“大脑”。这些“大脑”也需要现代化，因为现在的计算机与 20 世纪 90 年代的计算机大不相同（你可能已经注意到了）。新改进的“大脑”可以监控发动机，包括在即将发生灾难时。“可以采取措施纠正或挽救任务，在最坏的情况下，可以在发动机爆炸前将其关闭，”劳尔说。在阿波罗计划期间，工程师们不可能足够快地发现问题并加以解决。今天，他说，尽管宇航员基本上是骑着一枚炸弹，“但那枚炸弹正受到密切关注。”

“阿尔特弥斯计划有科学目的。但它也是塑造太空国际环境的一种方式。” 
——斯科特·佩斯乔治华盛顿大学

不过，改造工作很有挑战性，需要寻找新的供应商，因为许多曾在航天飞机上工作的人不再制造相关部件。最终的要点是：有时设计和建造你想要的房子比翻新一间浴室紧挨着厨房、橱柜高度不合适的待修房屋更容易。

在乘坐炸弹的高峰期，NASA 对待人类的态度比 20 世纪 60 年代更为温和，当时它正在将战斗机飞行员空降并送入太空。这在洛克希德·马丁公司制造的猎户座飞船的设计中很明显。

猎户座飞船机械系统主管布莱恩·布朗及其团队计算了这些系统能够承受的严酷考验，并将其设计成能够承受人们预期的数倍的考验，无论是高温还是强烈的加速力。在改进飞船的同时，工程师们继续对猎户座飞船的材料和太空舱将承受的压力进行详细的模拟，以 20 世纪 60 年代的计算尺无法处理的方式详细分析潜在弱点。他们还对焊缝和构成隔热罩的块体进行 X 射线检查，隔热罩可防止太空舱在穿越大气层时燃烧起来。与过去相比，该团队将获得更多关于太空飞船飞行情况的数据（就像火箭承包商一样），以及更好的沟通能力。

布朗说：“我们比阿波罗计划期间的工程师了解得更多”。然而，意外还是会出现，比如猎户座飞船的隔热罩退化，尽管经过了各种精妙的计算机模拟，但第一次重返大气层后，隔热罩还是缺失了一块。即使有了今天的计算能力，也不能保证结果完美无缺。阿波罗计划显然没有进行过这种分析。但一旦有了这种预测能力，工程师几乎就有道德义务利用它们来准确了解宇航员将要经历什么。

约翰霍普金斯大学生物伦理学家杰弗里·卡恩表示，自太空竞赛以来，社会对风险的态度发生了变化。他曾参加过美国国家科学院独立分析宇航员生活伦理问题的小组，包括哪些危险值得一试。20 世纪 60 年代，成本效益方程式产生了不同的计算结果。赢得与共产主义的太空竞赛的潜在巨大回报通常被认为值得冒更多风险。如今，任务的动机更加模糊，赌注更低，因此获得的回报并不值得冒那么多风险。

当时，当权者还不知道我们现在知道存在的一些风险，因为当时太空还是一个新领域。宇航员来自旧时的“正确人才”模式。“宇航员骑摩托车，开快车，”卡恩说，除了担任试飞员之外。如今，各种各样的人进入太空的原因也越来越多。“宇航员并不是一个独立的物种，”佩斯说。也许，我们更珍惜他们的生命，就像珍惜我们自己的生命一样。

如果真的出了问题，人们对那次假设事故的反应可能会比 1967 年阿波罗一号火灾中三名宇航员死亡时的反应更强烈。在那场悲剧发生后，几乎没有人呼吁取消或甚至大幅推迟。现在，洛格斯顿说，阿尔忒弥斯计划可能没有足够的政治支持来度过一场死亡事件。因此，阿尔忒弥斯二号和随后的任务都必须尽可能安全，才能继续下去。

重返月球并不是唯一一个面临延误和预算超支的现代挑战。随着时间的推移，许多大规模项目变得越来越难，成本也越来越高。例如，纽约地铁系统最初只用了四年多的时间就建成，有 28 个站点；而该市一条只有 3 个站点的新地铁线路于 2017 年完工，耗时 17 年。20 世纪 40 年代，科学家们用三年时间从零开始研制了核武器，以今天的货币价值计算，耗资约为350 亿美元；而目前的核武器现代化计划将至少需要 30 年，耗资超过 1.5 万亿美元。第二次世界大战结束时，美国每个月就能建造一艘航空母舰；而最近一次建造耗时超过十年。

高速公路延误和巨额开支是乔治华盛顿大学特拉赫滕贝格公共政策与公共管理学院教授 Leah Brooks 的专长。她的研究发现，要求公民对项目提供意见（这是当今许多大型政府企业的要求）是道路问题的一个重要原因。这种意见通常是项目开始前必须进行的环境评估的一部分。考虑到 Brooks 所说的“公民声音”，可以制定更昂贵的路线，这些路线对环境的负面影响更小，对公民生活的干扰更小，但也可能需要额外的缓解基础设施，如隔音屏障。过去，当局不必征求每个人的意见（或太关心环境）。以田纳西流域管理局为例，Brooks 说，这是一个成立于 20 世纪 30 年代的实体，旨在修建水坝以减少洪水和发电。“他们不咨询任何人，”她说。“他们只是建造它。”肯尼迪也不是因为询问了大家的想法而选择登月的。

布鲁克斯的发现可能适用于任何涉及环境影响声明的行动——一份列出自然环境后果并要求公众公开评论的文件。之前的星座计划就有一份这样的文件；NASA 的“航天飞机后载人航天计划”重新提出了这份文件。

不过，在布鲁克斯看来，过去和现在最大的区别可能在于我们现在建造的东西更好，但成本更高，耗时更长。家用电器可能并非如此，但高速公路音障和宇宙飞船却可以。对于阿尔忒弥斯计划而言，拥有更强大的火箭系统、询问人们的想法、保障人们的安全以及与全球伙伴合作可能对这个世界更有利——即使它们不会带来外星便利。缺乏便利甚至可能是一件好事。洛格斯顿说，今天，你听不到很多人反对阿尔忒弥斯计划。相比之下，阿波罗计划实际上并不受公众欢迎。1961 年，反对政府资助载人登月旅行的人多于支持的人。根据太空历史学家罗杰·劳尼乌斯的研究，1965 年，大多数人反对此类旅行，1967 年，“支持”和“反对”之间的差距已经扩大到近 20 个百分点。

深入太空的新方法最终将带来更安全、更易于理解的系统，并可能得到国内外公众的更多认可。此外，我们之所以选择这样做，一向是因为它很难——即使更难又如何呢？为什么要着急呢？这不是一场比赛。

When the Apollo 17 astronauts returned from the moon in 1972, they couldn’t have known that they would be the last humans to travel deep into outer space for more than 50 years. But no astronauts have ventured be­­yond Earth orbit since, even as Presidents George W. Bush, Barack Obama, Donald Trump and Joe Biden have all planned lunar missions. Finally, NASA is preparing to send people back to the moon on the Artemis II flight, scheduled to lift off in the fall of 2025. Why has it been so difficult?

This new mission is similar to the Apollo 8 flight of 1968, when three people circled the moon without landing and then traveled back to Earth. Artemis II will send four astronauts on a 10-day trip around the moon on the first crewed test of NASA’s new Space Launch System (SLS) rocket and Orion space capsule. Although the U.S. has had decades to get better at such journeys, the upcoming trip resembles its mid-century cousin in that it will be far from easy.

Choosing to do things “not because they are easy but because they are hard” is part of the rationale President John F. Kennedy gave in a famous 1962 speech trying to galvanize support for the Apollo program. And what was true then remains so today—in fact, reaching the moon may be even more difficult than it was decades ago.

NASA’s Artemis program has been plagued by long delays, cost overruns and surprise problems. It has those in common with many terrestrial programs, such as subway upgrades and highway construction, which also seem to take much longer, and often cost much more, than they did in the (dubiously) good old days. Is it really harder to build great things now? And when it comes to the moon, why should replicating a feat the U.S. accomplished more than half a century ago take so long?

Artemis’s next step is essentially an Apollo 8 redo, but the program has grand ambitions that reach beyond the moon. “In the end, our stated goal is Mars,” says Matthew Ramsey, Artemis II’s mission manager. “That’s very difficult—getting to Mars and living on Mars—and so we take it in bite-­sized chunks.”

The program’s first mission, Artemis I, sent an uncrewed spacecraft around the moon and back in 2022. After Artemis II, the third through sixth installments will put people on our natural satellite and then set up pieces of the Lunar Gateway, a space station orbiting the moon. Later missions will also focus on setting up habitable camps on the lunar surface.

The Artemis program, barely off the ground, has already seen long delays, and the program faces significant problems, laid out in a recent audit from NASA’s office of the inspector general. First, it will have devoured $93 billion by 2025, billions more than anticipated. Second, the Artemis I adventure revealed “critical issues that need to be addressed before placing crew on the Artemis II mission,” according to the audit. The Orion capsule’s heat shield, for instance, broke down differently than engineers had predicted, for reasons they don’t yet understand. Bolts on the spacecraft faced “unexpected melting and erosion.” And the power system experienced anomalies that could leave the future crew without adequate energy and redundancies and maybe without propulsion or pressurization.

These “anomalies”—the term space types use for big problems—“pose significant risks to the safety of the crew,” according to the report. And they came on top of other hardware, data and communications challenges. Furthermore, the inspector general found that the initial launch caused unforeseen damage to the system, resulting in repairs to the tune of more than $26 million, a much heftier bill than the team had budgeted for. That’s a lot of hitches and a lot of money—especially for a mission that won’t accomplish many firsts we didn’t achieve back in the 1960s.

It may seem strange that today’s lunar missions are so challenging given that we’ve done this before. But the circumstances aren’t the same, says Scott Pace, director of the Space Policy Institute at George Washington University. “The world environment is very different,” he says. The U.S. is no longer in a space race—an existential battle to stay ahead of the communists and be the first to do things beyond Earth. Back then, cold war dynamics were at play, and newly independent countries were deciding which governing system to follow—a decision that might (theoretically) be influenced by a democratic nation’s ability to explore space. Such “soft power,” the thinking went, could show that the American way was the best way while using the country’s missilelike rockets to imply hard military dominance. Given those stakes, the U.S. government was willing to throw huge amounts of money at the Apollo program in a short time.

Artemis is expensive, but Apollo was exorbitant: the program cost around $290 billion in today’s dollars, according to the Planetary Society, compared with Artemis’s $93 billion. In those years NASA was often blessed with 4 percent of the nation’s budget. Today it’s lucky to get around 1 percent, with the additional burden of many other spacecraft, telescopes and research projects beyond human spaceflight to fund.

That budgetary decrease makes sense, according to John Logsdon, professor emeritus at George Washington University and founder of the Space Policy Institute. “There’s no reason to spend money like it was a war,” he says. “There’s really no national interest or political interest that provides the foundation for that kind of mobilization at this point.”

Those looser dynamics shrink the wad of cash available and set the planning of space missions on a more meandering path. In the 1960s Kennedy declared the country would go to the moon in that decade, and it did. In modern times spaceflight plans established by one president are often canceled by another, only to be resurrected later in a different form. As a result, the trajectory toward the moon (and beyond) zigs and zags.

The world order has also changed, and space missions tend to be global cooperations now, Pace notes. The Artemis program is a collaboration involving ­Japan, Canada, the United Arab Emirates and the European Space Agency. That international participation is in fact a big part of the program’s point. “Artemis has scientific purposes—going back to the moon and all that,” Pace says. “But it also is a way of shaping the in­­ter­na­tion­al environment for space.” That molding is much more im­­portant than it was in the 1960s, when humans re­­lied less on above-Earth infrastructure. Today orbiting spacecraft enable everything from GPS capabilities to missile warning to banking. Convincing other countries to see and treat space as a valuable resource, by working with them and establishing behavioral norms, helps us keep space safe and the players up there responsible. “Rules are made by people who show up,” Pace says.

That’s a more nebulous goal than winning a race. “If there were nice, sharply defined motivations, things would be a lot simpler,” Logsdon says. But working with other countries, several of whom are building hardware for Artemis, takes longer than going it alone—just as doing a group project can grate more than simply pulling a solo all-nighter. According to the NASA inspector general, the global nature of the program is also increasing the costs, and NASA doesn’t have an overarching strategy for dealing with all the partners it’s brought onboard.

In Pace’s view, however, none of those factors is the main stumbling block on the lunar trajectory. The biggest challenge, even though the U.S. has already been to the moon, is that we haven’t been to the moon recently. “We stopped, and then we forgot,” he says. Just be­­cause you ran the Olympic marathon 50 years ago, he con­tinues, doesn’t mean you could do it again tomorrow.

In the case of Artemis, the marathon also involves new, more complicated technology. The basics of the rocket side of the equation haven’t changed that much: big rockets are essentially bombs that boost things to space. And many of the players are the same. Boeing worked on the Saturn V rocket that sent Apollo missions upward. For Artemis, the company designed and built the SLS core stage, a massive piece of machinery that stands 212 feet tall and is nearly 28 feet across. This component provides fuel to the engines that heave SLS from the ground and sends it flying the right way—courtesy of the Boeing-created avionics system that’s also onboard. The company, currently beset by controversy over quality-control issues in its planes as well as a malfunctioning spacecraft that stranded two astronauts on the International Space Station, is also responsible for rocket stages for later Artemis missions.

There are some big differences between Boeing’s antique work on Saturn V and its modern cousin. This time they built the rocket stages using computer-controlled machining, as well as a friction-based welding technique that doesn’t melt and warp metal. The company also uses computers to analyze the rocket stages’ states of being and monitor how they’re behaving in real time—a perspective Apollo lacked.

Northrop Grumman, meanwhile, handles the rocket boosters, which are strapped onto the sides of the core stage. These give SLS more than 75 percent of its oomph at launch. Much of the boosters’ engineering hails from the space shuttle program, and in some cases parts of their hardware actually flew on shuttle missions. These boosters, like missiles, use solid rocket fuel rather than liquid. “You want to get away from Earth’s gravity well and out of the thick part of the atmosphere where drag is high as fast as you can,” says Mark Tobias, SLS booster deputy engineer. “And that’s what solid propulsion really does. It’s raw horsepower.”

But the plan to use hardware from previous space programs is a bit cobbled together. The Space Launch System, for instance, was originally designed for the Constellation program, a strategy set up under the George W. Bush administration to finish building the International Space Station and to reestablish a human presence on the moon. Congress mandated that the rocket reuse technology from the then defunct space shuttle program. But Obama canceled Constellation in 2010, and in 2017 Trump anointed the Artemis program, with the goal of finally sending people back to the moon and paving the way for exploring Mars. Again, the new plan required that NASA use some of the technology that had been developed for Constellation, which in turn entailed repurposing old space shuttle technology. These mandates were pushed by congresspeople representing regions that housed manufacturing centers for shuttle parts. But the carryover and conversion of those technologies have proved difficult. According to a report from the NASA inspector general, bringing the rocket parts into the modern era—for instance, replacing asbestos parts—and retrofitting them for a new rocket system has cost much more than anticipated.

Aerospace company Aerojet Rocketdyne builds the engines, and as with the rocket boosters, making old shuttle engines work for Artemis has been hard and expensive. SLS is a much taller rocket than the space shuttle. The stretched dimensions required changing the engines to deal with oxygen flowing in at higher pressures. The engines are also closer to the boosters than they were on the shuttle. “It’s an extreme heating environment,” says Mike Lauer, director of the engine program, so it requires extreme insulation.

The Artemis engines will also experience a more irradiated environment going to the moon (and later to Mars) than they did in orbit on the shuttle. Dealing with that change involved tinkering with the computer that lives on each engine, which Lauer calls its “brain.” Those brains also needed a modernization, as computers are much different than in the 1990s (you might have noticed). The new and improved brains can monitor the engines—including during an impending disaster. “Things can be done to correct or save the mission and, in a worst-case scenario, shut an engine down before it blows up,” Lauer says. During Apollo, engineers couldn’t have known about problems fast enough to solve them. Today, he says, even though astronauts are basically riding a bomb, “that bomb is being watched very closely.”

“Artemis has scientific purposes. But it also is a way of shaping the international environment for space.”
—Scott Pace George Washington University

The retrofit was challenging, though, and re­­quired finding new suppliers because many who had worked on the space shuttle didn’t make the relevant parts anymore. Ultimately the point is this: sometimes it’s easier to design and build the house you want than to renovate a fixer-upper with a bathroom next to the kitchen and cupboards at awkward heights.

Speaking of riding bombs, NASA treats humans with a softer touch than it did in the 1960s, when it was swooping up fighter pilots and shooting them into space. That’s apparent in the design of Orion, built by Lockheed Martin.

Blaine Brown, director of Orion’s mechanical systems, and his team ran calculations about what kinds of rigors those systems would hold up against and designed them to withstand multiples of what anyone expects them to experience, whether high temperatures or intense acceleration forces. As they refine the spacecraft, engineers continue to run detailed simulations on Orion’s materials and the stresses the capsule will be under, getting down into the details of potential weaknesses in a grainy way that the slide rules of the 1960s couldn’t handle. They also do x-ray inspections of the welds and the blocks that form the heat shield, which keeps the capsule from burning up as it streaks back through the atmosphere. The team will get more data than in the past on how the space vehicle does in flight—just as the rocket contractors do—as well as a better ability to communicate.

“We understand way more” than engineers during Apollo did, Brown says. Still, the unexpected pops up, as with Orion’s degraded heat shield, which, despite all the fancy computer simulations, was missing chunks after its first reentry. Even with today’s computational power, there’s no guarantee of perfect results. Apollo obviously worked without that analysis. But once such predictive capabilities are available, engineers are almost under an ethical obligation to use them to understand precisely what they’ll be subjecting the astronauts to.

Society’s attitude toward risk has changed since the space race, says bioethicist Jeffrey Kahn of Johns Hopkins University. He’s sat on panels tasked with independently analyzing the ethics of astronaut life for the National Academy of Sciences—including which dangers are worth the trip at all. That cost-benefit equation churned out different calculations in the 1960s. The potential big reward of winning the space race against the communists was generally held to be worth more danger. Today the motivations for the mission are murkier, the stakes are lower, and the consequent rewards don’t justify as much risk.

Back then, the powers that be were also ignorant of some of the risks we now know exist, space being a new frontier at the time. Astronauts hailed from that “right stuff” mold of old. “Astronauts rode motorcycles and drove fast cars,” Kahn says, in addition to being test pilots. Today a wider variety of people go into space for a larger number of reasons. “Astronauts are not some separate species,” Pace says. Perhaps, then, we value their lives more like we value our own.

If something did go wrong, the reaction to that hypothetical accident would probably be more vehement than it was when, for example, three astronauts died in the 1967 Apollo I fire. After that tragedy there was minimal call for cancellation or even significant delay. Now, Logsdon says, the Artemis program might not have enough political support to survive a fatality. So Artemis II and the missions to follow all have to be as safe as they can be to continue to be at all.

Getting back to the moon isn’t the only modern challenge beset by delays and budget blowups. Many large-scale endeavors have grown harder and costlier over time. The New York City subway system, for instance, was initially built in just over four years and had 28 stops; a new subway line in the city with just three stops, finished in 2017, took 17 years. Scientists developed nuclear weapons from scratch in three years in the 1940s at a cost of about $35 billion in today’s money; the current nuclear weapons modernization program will take at least 30 years and cost more than $1.5 trillion. At the end of World War II the U.S. was whipping up an aircraft carrier a month; the most recent one took more than a decade.

Highway delays and big spending are the specialty of Leah Brooks, a professor at George Washington University’s Trachtenberg School of Public Policy and Public Administration. Her research has found that asking citizens for input on projects—a requirement of many large governmental enterprises these days—is one significant cause of road woes. This input is often part of an environmental review that is required before a project begins. Taking into consideration the “citizen voice,” as Brooks calls it, can result in more expensive routes that have fewer negative environmental impacts or are less disruptive to citizens’ lives but also might require additional mitigating infrastructure, such as sound barriers. In the past, authorities didn’t have to ask for everyone’s opinion (or care much about the environment). Take the Tennessee Valley Authority, Brooks says, an entity established in the 1930s to construct dams to reduce flooding and generate electricity. “They don’t consult anybody,” she says. “They just build it.” Kennedy didn’t choose to go to the moon because he had asked what everybody thought, either.

Brooks’s findings may apply to any endeavor that involves an environmental impact statement—a document that lays out the consequences for the natural environment and requires an open period of public comment. One such document exists for the previous Constellation program; it was re-upped for NASA’s “post-shuttle human spaceflight program.”

In Brooks’s view, though, the biggest difference between past and present may be that we build things better now, which is expensive and takes longer. That may not be true of, say, home appliances, but it is true of those highway sound barriers and, perhaps, of spaceships. For Artemis, having a more robust rocket system, asking people what they think, keeping people safer and working with global partners are probably better for this world—even if they don’t result in expedience off-world. That lack of expedience may even be a good thing. Today, Logsdon says, you don’t hear many people arguing against the Artemis program. In contrast, Apollo wasn’t actually popular with the public. In 1961 more people opposed government-funded human trips to the moon than were in favor. In 1965 a majority opposed such trips, and in 1967 the gap between “in favor” and “opposed” had grown to nearly 20 percentage points, according to research from space historian Roger Launius.

The new way of going deep into space ultimately results in a safer, better-understood system that might meet with more public approval—at home and abroad. And besides, it’s always been true that we choose to do it because it’s hard—so what if it’s harder? And what’s the rush? It’s not a race.