Update 9:55 p.m. EST: SpaceX and NASA scrubbed the launch due to poor weather.

晚上 9:55 更新美东时间：由于天气恶劣，SpaceX 和 NASA 取消了此次发射。

SpaceX is preparing to launch its second NASA mission of the year on Wednesday morning. A Falcon 9 rocket carrying the Earth-observing spacecraft PACE (Plankton, Aerosol, Cloud, ocean Ecosystem) was set to liftoff Tuesday morning, but teams had to stand down due to poor weather.

SpaceX 正准备在周三上午发射今年的第二次 NASA 任务。搭载地球观测飞船 PACE（浮游生物、气溶胶、云、海洋生态系统）的猎鹰 9 号火箭原定于周二早上升空，但由于天气恶劣，团队不得不暂停。

Teams from NASA, SpaceX and Space Launch Delta 45 (SLD45) are now aiming for the 24-hour backup opportunity: a 1:33 a.m. EST (0633 UTC) liftoff from Space Launch Complex 40 (SLC-40) at Cape Canaveral Space Force Station on Feb. 7.

来自 NASA、SpaceX 和 Space Launch Delta 45 (SLD45) 的团队现在的目标是获得 24 小时备份机会：东部标准时间凌晨 1:33（0633 UTC）从卡纳维拉尔角太空部队的 Space Launch Complex 40 (SLC-40) 升空2月7日车站。

This will be the eighth launch from Florida in 2024 and the seventh for SpaceX from the Space Coast this year. Spaceflight Now will have live coverage of the mission beginning at 11:30 p.m. EST (0430 UTC).

这将是 2024 年从佛罗里达州进行的第八次发射，也是 SpaceX 今年从太空海岸进行的第七次发射。 Spaceflight Now 将于晚上 11:30 开始对此次任务进行现场报道。美国东部时间（0430 世界标准时间）。

The PACE launch will be the first time a U.S. government mission has targeted a polar orbit from Cape Canaveral in more than 60 years. Polar flights were suspended after a cow in Cuba was killed by falling debris from a failed launch in 1960, sparking protests in Havana.

此次 PACE 发射将是 60 多年来美国政府任务首次从卡纳维拉尔角发射极地轨道。 1960 年，古巴一头牛被发射失败的碎片砸死，引发哈瓦那抗议，极地航班因此暂停。

“At that point, we as a government decided, let’s just take all our polar launch missions to the West and we’ve successfully launched into the polar orbit hundreds of times since the 60s from Vandenberg Space Force Base in California,” said Tim Dunn, the senior launch director for NASA’s Launch Services Program.

蒂姆·邓恩 (Tim Dunn) 表示：“当时，我们作为政府决定，将所有极地发射任务都转移到西方，自 60 年代以来，我们已经从加利福尼亚州范登堡太空部队基地成功发射了数百次极地轨道。” ，美国宇航局发射服务计划的高级发射总监。

SpaceX resumed launches from the Cape on southerly trajectories in 2020. The company has successfully flown 11 missions into polar orbit from the Florida spaceport without incident.

2020 年，SpaceX 恢复了从开普敦向南轨道进行的发射。该公司已成功从佛罗里达州航天港执行 11 次极地轨道飞行任务，没有发生任何事故。

“Along comes SpaceX a handful of years ago with the autonomous flight safety system and the ability to either bring the first stage booster back to land here at the Cape or land on a droneship off-shore,” Dunn said. “And by a combination of those two things, we were able to then do all of the calculations to protect the public, both here in the U.S. as well as our international neighbors in the Caribbean and especially in Cuba and to get the numbers right where we can now successfully do that.”

邓恩说：“几年前，SpaceX 就推出了自主飞行安全系统，并且能够将第一级助推器带回好望角着陆，或者降落在离岸的无人驾驶船上。” “通过将这两件事结合起来，我们能够进行所有计算来保护公众，无论是在美国还是在加勒比地区，特别是在古巴的国际邻国，并得到正确的数字我们现在可以成功做到这一点。”

The Falcon 9 first stage booster supporting this launch, tail number B1081, will be making its fourth flight. It previously launched the Crew-7 quartet to the ISS as well as a Cargo Dragon and a Starlink mission.

支持此次发射的猎鹰 9 号第一级助推器（尾号 B1081）将进行第四次飞行。此前，该公司曾向国际空间站发射了 Crew-7 四号机以及货运龙和星链任务。

Dunn said their consideration for reflights on a booster has less to do with the basic number as much as it has to do with what kinds of missions it has flown to date.

邓恩表示，他们对助推器重新飞行的考虑与基本数量关系不大，而与迄今为止已执行的任务类型有关。

“We don’t look at the number of particular flights of a booster. We look at the qualification status of all the components that go into that booster,” Dunn explained. “We do an evaluation and as long as we do not exceed [qualification] status, and some components do get replaced in between flights, and then we do analysis on some of the structures that are not replaced, we’re comfortable.”

“我们不会考虑助推器的特定飞行次数。我们会检查该助推器中所有组件的资格状态，”邓恩解释道。 “我们会进行评估，只要我们不超过[资格]状态，并且在两次飞行之间确实更换了一些组件，然后我们对一些未更换的结构进行了分析，我们就放心了。”

NASA’s Europa Clipper will be the first time the agency will rely upon boosters that have flown five previous missions. Those Falcon Heavy side boosters most recently supported the launch of NASA’s Psyche spacecraft.

美国宇航局的欧罗巴快艇将是该机构首次依赖已完成五次飞行任务的助推器。这些猎鹰重型侧面助推器最近支持了美国宇航局灵神飞船的发射。

Following stage separation, the booster will flip to return for a landing at Landing Zone 1 (LZ-1) at the Cape about 7.5 minutes after liftoff. This will be its third LZ-1 landing out of four flights.

级分离后，助推器将在升空后约 7.5 分钟翻转返回，在海角 1 号着陆区 (LZ-1) 着陆。这将是 LZ-1 的四次飞行中的第三次着陆。

This landing will mark the 36th for LZ-1 and the 45th in Florida. Assuming SpaceX doesn’t squeeze in a Starlink launch from VSFB on Monday night and that the PACE mission is successful, this will be the company’s 270th booster landing to date.

此次着陆将是 LZ-1 的第 36 次着陆，也是佛罗里达州的第 45 次着陆。假设 SpaceX 没有在周一晚上从 VSFB 进行星链发射，并且 PACE 任务成功，这将是该公司迄今为止第 270 次助推器着陆。

The total cost of the mission, between building the spacecraft, the launch operations and the mission support once on orbit, is $948 million, according to Dunn. For the launch services of the Falcon 9 rocket, NASA paid SpaceX about $81 million.

邓恩表示，此次任务的总成本（包括建造航天器、发射操作和进入轨道后的任务支持）为 9.48 亿美元。对于猎鹰 9 号火箭的发射服务，NASA 向 SpaceX 支付了约 8100 万美元。

Dunn said they are using new payload fairings on this flight, but are evaluating that possibility for the future.

邓恩表示，他们在这次飞行中使用了新的有效载荷整流罩，但正在评估未来的可能性。

“We are under evaluation with SpaceX right now and I would anticipate that to happen in the next year-and-a-half or two,” Dunn said. “We’ll see how that goes for the fairing.”

“我们现在正在接受 SpaceX 的评估，我预计这将在未来一两年内发生，”邓恩说。 “我们将看看整流罩的情况如何。”

Weather concerns for atmosphere observing mission

As the launch teams were heading towards the launch window overnight, weather remained a watch item. During a prelaunch briefing with press, Brian Cizek, a launch weather officer with the 45th Weather Squadron for the U.S. Space Force, said the probability of violating weather was 60 percent for the Tuesday morning launch opportunity.

大气观测任务的天气问题当发射团队连夜驶向发射窗口时，天气仍然是一个观察项目。美国太空军第 45 气象中队的发射气象官员布莱恩·西泽克 (Brian Cizek) 在发射前新闻发布会上表示，周二上午的发射机会出现违反气象规定的可能性为 60%。

“We’re going to see this wind surge kind of come down the Florida coast from north to south. That’s also going to bring some additional moisture into the air,” Cizek said. “So, a few concerns with the launch tonight due to that.”

“我们将看到这股风潮从北向南席卷佛罗里达海岸。这也会给空气带来一些额外的水分，”西泽克说。 “因此，因此对今晚的发射产生了一些担忧。”

Cizek said the liftoff winds would be “getting close to the limits” around launch time with the winds “increasing as the night progresses.” He said those winds will decrease by Tuesday night, which is partly why the launch forecast improves to only 40 percent chance of violating weather on Wednesday morning.

西泽克表示，发射时的升空风力将“接近极限”，“随着夜间的进行，风力会增强”。他表示，到周二晚上，风力将会减弱，这就是为什么发射预报将周三早上出现异常天气的可能性提高到只有 40% 的部分原因。

He also said forecasters with SLD45 also have concerns about showers along the coastline creating a violation of the cumulus cloud rule. The corresponding clouds also bring the thick cloud layers rule into play for this first launch opportunity as well.

他还表示，SLD45 的预报员还担心海岸线的阵雨会违反积云规则。相应的云层也使厚云层规则在首次发射机会中发挥作用。

“The thing for the backup day, the major concern will again be the liftoff winds. We said they kind of peak during the morning and early afternoon on Tuesday and then when they do begin to decrease again as we head into Tuesday evening,” Cizek said. “And then the weather just continues to improve as we get beyond that.”

“备份日的主要问题将再次是起飞风。我们说，它们在周二早上和下午早些时候达到顶峰，然后当我们进入周二晚上时，它们确实开始下降，”Cizek 说。 “然后，当我们超越这个目标时，天气就会继续好转。”

Expanding ocean and atmosphere understanding

The PACE mission is designed to last three years nominally, but carries enough fuel to support a 10-year mission. NASA will reevaluate things about every three years to determine if they are able to and desire to extend the mission.

扩大对海洋和大气的了解 PACE 任务名义上设计持续三年，但携带的燃料足以支持 10 年的任务。美国宇航局将大约每三年重新评估一次，以确定他们是否能够并且愿意延长任务。

The goal of the Earth-observing spacecraft will be to increase our understanding of the interplay of the oceans and the atmosphere through the lens of some of the tiniest parts of each: phytoplankton and aerosols.

地球观测航天器的目标是通过浮游植物和气溶胶等海洋和大气中最微小的部分的镜头，增进我们对海洋和大气之间相互作用的了解。

“These micro-algae that are at the base of the marine food chain, they serve our fisheries and serve the health of the oceans, but they can also be toxic and we need to know that too,” said Karen St. Germain, the director of NASA’s Earth Science Division. “They’re also responsible, through photosynthesis, for absorbing a tremendous amount of carbon dioxide and converting that into oxygen in the atmosphere.”

“这些微藻位于海洋食物链的底部，它们为我们的渔业和海洋健康服务，但它们也可能有毒，我们也需要知道这一点，”凯伦·圣杰曼说，美国宇航局地球科学部主任。 “它们还通过光合作用吸收大量二氧化碳并将其转化为大气中的氧气。”

“We’re also looking at tiny things in the atmosphere. These are called aerosols. they’re tiny particles that play an enormous role in our weather, our air quality and even our climate,” she added. “They come from sources like dust flowing off the Sahara, wildfires and even human activities. They seed clouds that can grow into hurricanes coming across the Atlantic, but they also reflect a lot of the Sun’s energy. So, they play an important role in the long-term stability of Earth’s climate.”

“我们也在观察大气中的微小事物。这些被称为气溶胶。它们是微小的颗粒，对我们的天气、空气质量甚至气候起着巨大的作用，”她补充道。 “它们的来源包括撒哈拉沙漠的尘埃、野火甚至人类活动。它们产生的云可以发展成横跨大西洋的飓风，但它们也反射了大量的太阳能量。因此，它们对地球气候的长期稳定发挥着重要作用。”

St. Germain said the mission builds on both 20 years of NASA’s work observing the oceans and more than 60 years of overall NASA Earth observation. She noted that understanding these systems and their interplay is not only important for advancing scientific understanding, but it also has a big role for the U.S. economy.

St. Germain 表示，此次任务建立在 NASA 20 年海洋观测工作和 60 多年整体地球观测工作的基础上。她指出，了解这些系统及其相互作用不仅对于推进科学理解很重要，而且对美国经济也具有重要作用。

“The ocean economy makes up over $350 billion of our gross domestic product per year. It employs 3.1 million people in our country, but it can also experience adverse impacts from things like harmful algal blooms, which can cost $50 million a year or more,” St. Germain said. “So, the work we’re doing with PACE and the work we do in Earth Science is about making observations to help us understand the Earth System, capturing that understanding in models and predictive tools and putting that information into the hands of people who can use it to make better decisions every day.”

“海洋经济每年占我们国内生产总值超过 3500 亿美元。它在我国雇用了 310 万人，但它也可能遭受有害藻华等不利影响，每年可能造成 5000 万美元或更多的损失，”St. Germain 说。 “因此，我们在 PACE 中所做的工作以及我们在地球科学中所做的工作是进行观测，以帮助我们了解地球系统，在模型和预测工具中捕捉这种理解，并将这些信息交到能够帮助我们的人们手中。每天用它做出更好的决策。”