Delta 4-Heavy rocket deploys spysat on final planned mission from ‘Slick Six’
德尔塔4-重型火箭在“滑头六号”的最终计划任务中部署spysat
EDITOR’S NOTE: Updated Sept. 25 with satellite sightings and radio signal detections.
编者按：9月25日更新了卫星目击和无线电信号检测。
United Launch Alliance sent a triple-core Delta 4-Heavy with a top secret U.S. government spy satellite into orbit Saturday from California’s Central Coast, closing out a chapter in the tangled history of a launch pad originally built to support military astronaut missions on Titan rockets and space shuttles.
周六，美国联合发射联盟(United Launch Alliance)将一颗搭载美国政府绝密间谍卫星的三核德尔塔4-重型发射台从加州中部海岸送入轨道，为这个发射台错综复杂的历史终结了一章。这个发射台最初是为了支持泰坦(Titan)火箭和航天飞机上的军事宇航员任务而建造的。
The spy satellite on-board the Delta 4-Heavy is owned by the National Reconnaissance Office, which discloses few details about its spacecraft. The circumstances of the launch Saturday — its launch site, rocket configuration, and flight track after liftoff — led independent analysts to conclude the Delta 4 likely carried a high-resolution electro-optical surveillance satellite into orbit.
“德尔塔4-重型”号上的间谍卫星属于美国国家侦察局(National Reconnaissance Office)，该局很少披露其航天器的细节。根据周六发射的情况——发射地点、火箭配置以及发射后的飞行轨迹——独立分析人士得出结论，德尔塔4号可能携带了一颗高分辨率光电监视卫星进入轨道
Two more Delta 4-Heavy rockets are left in ULA’s inventory for launches in 2023 and 2024 from Cape Canaveral as the company transitions to the next-generation Vulcan Centaur rocket, the replacement for the Atlas and Delta launcher families that date back to the dawn of the Space Age.
ULA的库存中还有两枚Delta 4-重型火箭，将于2023年和2024年在卡纳维拉尔角发射，因为该公司过渡到下一代Vulcan Centaur火箭，这是可以追溯到太空时代黎明的Atlas和Delta发射系列的替代品。
The Atlas 5 and Delta 4 rockets currently flown by ULA show little resemblance to their forebears, but the names are steeped in history. Saturday’s launch from Vandenberg Space Force Base was the 95th and final flight of a Delta rocket from the military spaceport about 140 miles (225 kilometers) northwest of Los Angeles, and the 387th launch overall of a rocket bearing the Delta name.
The Atlas 5 and Delta 4 rockets currently flown by ULA show little resemblance to their forebears, but the names are steeped in history. Saturday’s launch from Vandenberg Space Force Base was the 95th and final flight of a Delta rocket from the military spaceport about 140 miles (225 kilometers) northwest of Los Angeles, and the 387th launch overall of a rocket bearing the Delta name.
It was the 10th launch of a Delta 4 rocket — and the fifth in the Delta 4-Heavy configuration — from Space Launch Complex 6, a picturesque launch site nestled on a hillside bluff overlooking the Pacific Ocean. The sprawling launch pad, known as SLC-6 or “Slick Six,” faces an uncertain future after the last Delta 4 flight from the site Saturday. The Space Force, which owns the pad and leased it to ULA, doesn’t yet have another tenant lined up to take over the facility.
这是德尔塔4型火箭的第十次发射，也是德尔塔4型重型火箭的第五次发射，发射地点在太空发射中心6号，这是一个风景如画的发射场，坐落在俯瞰太平洋的山坡峭壁上。这个被称为SLC-6或“Slick Six”的庞大发射台，在上周六达美航空最后一次从这里起飞后，面临着不确定的未来。太空部队拥有这个发射台，并将其租给了ULA，目前还没有其他租户准备接手这个设施。
“For us, seeing the last Delta launch from Vandenberg is bittersweet, for sure. We’re sorry to see it go,” said Col. Bryan Titus, vice commander of Space Launch Delta 30, the unit in charge of Vandenberg Space Force Base and the Western Range.
“对我们来说，看到最后一次德尔塔从范登堡发射肯定是苦乐参半的。我们很遗憾看到它消失，“负责范登堡太空部队基地和西部靶场的航天发射三角洲30的副指挥官布莱恩·泰特斯上校说。
Three Aerojet Rocketdyne RS-68A main engines roared to life in the final seconds of Saturday’s countdown at SLC-6, sending a plume of red-hot exhaust out each side of the flame trench under the pad. After a staggered start sequence, the hydrogen-fueled engines powered the 233-foot-tall (71-meter) Delta 4-Heavy off the pad at 3:25:30 p.m. PDT (6:25:30 p.m. EDT; 2225:30 GMT).
周六，在SLC-6空间站倒数的最后几秒，三台Aerojet Rocketdyne RS-68A主发动机轰鸣着启动，发射垫下火焰沟里的每一侧都散发出一股炽热的废气。经过一个交错的启动顺序，氢燃料发动机驱动233英尺(71米)高的德尔塔4-重型在下午3:25:30太平洋时间(美国东部时间下午6:25:30;2225:30格林尼治时间)。
Ten seconds later, the rocket vectored thrust from its main engines to steer south-southeast from Vandenberg, taking an arcing trajectory over the Pacific Ocean riding 2.1 million pounds of thrust. The rocket broke the sound barrier in about 80 seconds as the RS-68A engines on the Delta 4-Heavy’s side boosters operated at full throttle, while the center engine throttled back to conserve fuel for the first few minutes of the flight.
10秒钟后，火箭从主发动机获得推力，从范登堡向东南偏南方向飞行，在太平洋上空以210万磅的推力呈弧形飞行。火箭在大约80秒内突破了音障，德尔塔4-重型飞机两侧助推器上的RS-68A发动机开满了油门，而中央发动机为了在飞行的前几分钟节省燃料而关闭了油门。
The engines burned 5,000 pounds of liquid hydrogen and liquid oxygen propellants each second, quickly burning through the 450,000 gallons of cryogenic fluids loaded into the Delta 4-Heavy’s three orange common booster cores during the countdown.
这些发动机每秒钟燃烧5000磅的液氢和液氧推进剂，在倒计时期间迅速燃烧掉装入德尔塔4-重型三个橙色公共助推器核心的45万加仑低温流体。
The side boosters shut down their engines and separated from the core stage about 4 minutes into the flight, heading for uncontrolled splashdowns in the Pacific a few hundred miles downrange from Vandenberg. The core stage then throttled up its RS-68A engine to burn for another minute-and-a-half before separation from the Delta 4’s cryogenic upper stage, which did the rest of the work to place the top secret spy payload into orbit.
飞行约4分钟后，侧助推器关闭发动机，与核心级分离，失控地坠入距范登堡几百英里的太平洋。核心级随后启动RS-68A发动机，在与德尔塔4号的低温上层分离之前再燃烧一分半钟，后者完成了将绝密间谍载荷送入轨道的其余工作。
The upper stage ignited its RL10 engine and released its clamshell-like payload fairing a few seconds later, and ULA ended its live coverage of the mission. The remainder of the flight occurred in a government-ordered news blackout.
上面级点燃了它的RL10发动机，几秒钟后释放了它的蛤壳状有效载荷整流罩，ULA结束了对任务的现场报道。航班的其余部分发生在政府下令的新闻封锁中。
The NRO and ULA issued press releases a little more than two hours after liftoff, confirming a successful conclusion to the launch, officially designated NROL-91.
NRO和ULA在发射后两个多小时发布了新闻稿，确认发射成功，正式指定为NROL-91。
“The Delta 4-Heavy has proven to be an integral part of the NRO’s history, helping us build the architecture for the world’s best space-based intelligence, surveillance and reconnaissance,” said Chris Scolese, director of the NRO. “As our agency and the aerospace industry continue to innovate and evolve, we will explore new vehicles for launching payloads even more efficiently and effectively, with even greater capacity, agility, speed, and resilience. We are excited about the new technologies and partnerships that will define our next chapter.”
NRO主任Chris Scolese说:“事实证明，德尔塔4-重型无人机是NRO历史中不可分割的一部分，帮助我们为世界上最好的天基情报、监视和侦察建立架构。”“随着我们的机构和航空航天工业继续创新和发展，我们将探索新的运载工具，以更高效和有效地发射有效载荷，具有更大的容量、灵活性、速度和弹性。我们对新技术和新伙伴关系感到兴奋，它们将定义我们的下一个篇章。”
The NRO has flown payloads on 15 Delta 4 missions to date. The final two Delta 4-Heavy rockets set for launch from Cape Canaveral in 2023 and 2024 will also loft classified NRO satellites.
到目前为止，NRO已经在15次德尔塔4任务中运送了有效载荷。定于2023年和2024年从卡纳维拉尔角发射的最后两枚德尔塔4重型火箭也将发射机密NRO卫星。
NRO satellites collect optical and radar imagery, intercept radio transmissions, and gather other intelligence data for U.S. government leaders, deployed military forces, and intelligence agencies.
NRO卫星收集光学和雷达图像，拦截无线电传输，并为美国政府领导人、部署的军队和情报机构收集其他情报数据。
“We like to say we’re the nation’s eyes and ears in space,” said Space Force Col. Chad Davis, director of the NRO’s Office of Space Launch. “So we provide that capability for our warfighters, allied and U.S., for our national decision makers to put them in the best spot they possibly can to either make decisions or execute what they need to on the battlefield.”
NRO太空发射办公室主任、太空部队上校查德·戴维斯说:“我们喜欢说我们是国家在太空中的眼睛和耳朵。”因此，我们为我们的作战人员、盟国和美国提供这种能力，为我们的国家决策者提供这种能力，让他们尽可能地在最好的位置上做出决定或执行他们在战场上需要做的事情。”
Satellite trackers using publicly-available information on the Delta 4 rocket’s flight track after liftoff predicted the mission would place its payload into an orbit less than 250 miles (400 kilometers) above Earth, and at an orbital inclination of 73.6 degrees to the equator. It turned out the prediction was close to the mark.
利用德尔塔4火箭发射后飞行轨迹的公开信息的卫星跟踪器预测，该任务将把其有效载荷置于地球上方不到250英里（400公里）的轨道上，轨道倾斜度为赤道73.6度。事实证明，这个预测很接近实际。
Sky watchers spotted the satellite from the NROL-91 mission in the skies over the Netherlands early Sunday. Scott Tilley and Cees Bassa, both radio astronomers, also detected encrypted radio transmissions from the satellite, suggesting the spacecraft was healthy and in the expected orbit after launch.
天空观察人士周日早上在荷兰上空发现了NROL-91任务的卫星。射电天文学家斯科特·蒂利(Scott Tilley)和希斯·巴萨(Cees Bassa)也检测到了来自该卫星的加密无线电传输，这表明该航天器很健康，在发射后处于预期轨道上。
The NROL-91 mission likely deployed a sister satellite to a payload launched on a Delta 4-Heavy rocket on the NRO’s NROL-71 mission in January 2019, according to Marco Langbroek, a Dutch archaeologist and an expert in the orbits of military spacecraft.
荷兰考古学家、军事航天器轨道专家马尔科·朗布鲁克（Marco Langbroek）表示，NROL-91任务可能会在2019年1月NRO的NROL-71任务中用德尔塔4重型火箭发射的有效载荷上部署一颗姐妹卫星。
Both satellites launched into similar orbits. Seasoned trackers of spy satellites believe the NROL-71 and NROL-91 missions launched the first members of a new generation of Keyhole, or KH-11, optical reconnaissance satellites.
两颗卫星都发射到相似的轨道上。经验丰富的间谍卫星追踪者认为，NROL-71和NROL-91任务发射了新一代钥匙孔或KH-11光学侦察卫星的第一批成员。
But previous KH-11 satellites launched into sun-synchronous polar orbits, at a different inclination than the 73.6-degree orbits achieved on the NROL-71 and NROL-91 missions. A Delta 4-Heavy launch from Vandenberg last year — between NROL-71 and NROL-91 — deployed its NRO payload into a more conventional sun-synchronous orbit, which is tailored for regular, repeatable observations of strategic sites, military installations and other targets of interest to U.S. intelligence agencies.
但之前的KH-11卫星发射到太阳同步极地轨道，其倾角与NROL-71和NROL-91任务实现的73.6度轨道不同。去年，范登堡的一枚德尔塔4-重型火箭在NROL-71和NROL-91之间发射，将NRO载荷部署到更传统的太阳同步轨道上，这是为定期、可重复观察战略地点、军事设施和美国情报机构感兴趣的其他目标而量身定制的。
The KH-11 satellites are essentially bus-sized telescopes peering down on Earth, with primary mirrors measuring 7.9 feet (2.4 meters) across, the same size as the mirror on the Hubble Space Telescope. The ultra-sharp, very-high-resolution imagery produced by such satellites is believed to be unparalleled, and the spy craft relay their observations to the ground via the NRO’s dedicated network of communications satellites.
KH-11卫星基本上是公共汽车大小的望远镜，俯视地球，主镜直径为7.9英尺（2.4米），与哈勃太空望远镜上的镜子大小相同。这种卫星产生的超清晰、非常高分辨率的图像被认为是无与伦比的，间谍飞船通过NRO专用的通信卫星网络将他们的观测转播到地面。
Delta 4-Heavy missions from California in 2011 and 2013 deployed gap-filler KH-11-type satellites to continue supplying the government with reconnaissance imagery after the NRO canceled a contract with Boeing for a replacement line of optical imaging craft as part of the Future Imagery Architecture program. Keyhole satellites before 2011 launched on Titan rockets from Vandenberg.
2011年和2013年，加州的德尔塔4-重型任务部署了缺口填充kh -11型卫星，继续为政府提供侦察图像，此前NRO取消了与波音公司的光学成像飞船替换线的合同，这是未来图像架构计划的一部分。2011年之前，钥匙孔卫星在范登堡的泰坦火箭上发射。
The NRO eventually selected Lockheed Martin — the same company that built the past generation of KH-11 satellites — to construct at least two new-generation spacecraft, introducing new technology and other upgrades into the spy satellite constellation.
NRO最终选择洛克希德·马丁公司--制造上一代KH-11卫星的同一家公司--建造至少两艘新一代航天器，将新技术和其他升级引入间谍卫星星座。
The new electro-optical surveillance satellites, sometimes called KH-11 Block 5, have the same 2.4-meter mirror diameter as the earlier Keyhole-type Earth-imaging platforms, according to past public statements by government officials.
根据政府官员过去的公开声明，新的光电监视卫星有时被称为KH-11 Block 5，与早期的钥匙孔式地球成像平台的镜面直径相同，为2.4米。
The launches of NROL-71 and NROL-91 into an orbit at a different inclination than the KH-11 satellites customarily fly caused some spy satellite observers to consider whether those missions carried a different kind of NRO payload, such as a radar imager. But without clear evidence otherwise, the consensus remains that NROL-71 and NROL-91 most likely delivered KH-11-type optical telescopes to orbit.
NROL-71和NROL-91发射到与KH-11卫星通常飞行的不同倾角的轨道上，这引起了一些间谍卫星观察员的考虑，这些任务是否携带了不同类型的NRO有效载荷，如雷达成像仪。但由于没有明确的证据，一致认为NROL-71和NROL-91最有可能将KH-11型光学望远镜送入轨道。
There are no other known hefty satellites in the NRO’s pipeline that require the Delta 4-Heavy’s lift capability. The Delta 4-Heavy can deliver payloads up to 62,540 pounds (28.3 metric tons) to low Earth orbit, making the Delta 4-Heavy the most powerful rocket in ULA’s fleet, and one of the most powerful operational launchers in the world.
在NRO的管道中，没有其他已知的大型卫星需要德尔塔4-重型的提升能力。德尔塔4-重型可以向低地球轨道运送高达62,540磅（28.3公吨）的有效载荷，使德尔塔4-重型成为ULA舰队中最强大的火箭，也是世界上最强大的作战发射器之一。
Saturday’s launch was the the 43rd Delta 4 flight overall, and the 14th in the Delta 4-Heavy configuration, created by combining three expendable hydrogen-fueled booster cores together to haul the military and NRO’s most massive payloads into orbit.
周六的发射是德尔塔4号的第43次飞行，也是德尔塔4重型配置中的第14次飞行，该配置是通过将三个消耗性氢燃料助推器核心结合在一起，将军方和NRO最大规模的有效载荷拖入轨道而创建的。
“The National Reconnaissance Office puts absolutely exquisite capabilities on orbit,” Davis said. “And the natural extension to that is the Delta 4-Heavy is used for some of those even most exquisite and most sensitive kinds of capabilities that I wish we could share with the broader community. But that’s part of the idea, is that people don’t know that we can do the kinds of things that we can do in space, and that vehicle is just part and parcel to those absolutely exquisite capabilities on orbit delivering for this nation.”
戴维斯说：“国家侦察办公室将绝对精湛的能力放在轨道上。”“对此的自然延伸是德尔塔4重型被用于一些最精致、最敏感的功能，我希望我们可以与更广泛的社区分享。但这是想法的一部分，人们不知道我们可以做我们在太空中可以做的事情，而这种飞行器只是为这个国家提供的轨道上绝对精湛的能力的一部分。“
After retirement of the Delta 4-Heavy, the NRO’s heaviest payloads will launch on SpaceX’s Falcon Heavy rocket or ULA’s Vulcan. Both are less expensive than the Delta 4-Heavy, which is priced at more than $400 million per mission.
德尔塔4重型退役后，NRO最重的有效载荷将在SpaceX的猎鹰重型火箭或ULA的火神上发射。两者都比德尔塔4重型便宜，德尔塔4重型每次任务的价格超过4亿美元。
SPACE FORCE LOOKING FOR NEW TENANTS AT SLC-6
太空部队在SLC-6寻找新的租户
Built among hills that hide the pad from public view, the SLC-6 launch site was originally constructed to support flights of military astronauts and NASA space shuttles.
SLC-6发射场建在群山之间，将发射台隐藏在公众视野之外，最初是为了支持军事宇航员和美国宇航局航天飞机的飞行而建造的。
The Air Force developed the SLC-6 launch site in the 1960s for the Manned Orbiting Laboratory program. Pentagon officials envisioned launching military astronauts on top of Titan rockets for orbital spy missions, but the program was canceled in 1969 before any launches from the SLC-6 pad.
空军在20世纪60年代为载人轨道实验室计划开发了SLC-6发射场。五角大楼官员设想在泰坦火箭上发射军事宇航员进行轨道间谍任务，但该计划在1969年从SLC-6发射台发射之前被取消。
NASA and the Air Force agreed in the 1970s to launch space shuttles from SLC-6, allowing astronauts to conduct military missions and deploy spy satellites in polar orbit. The space shuttle Enterprise, used for ground demonstrations and atmospheric test flights, was stacked on the SLC-6 launch with external tank and solid rocket booster test articles for fit checks in early 1985.
美国宇航局和空军在20世纪70年代同意从SLC-6发射航天飞机，允许宇航员执行军事任务，并在极地轨道上部署间谍卫星。用于地面演示和大气试飞的航天飞机企业号在1985年初与外部坦克和固体火箭助推器测试物品一起堆放在SLC-6发射器上进行适配检查。
But the Air Force abandoned plans to launch military space shuttle flights from Vandenberg in the wake of the Challenger accident in 1986, and the shuttle-era buildings at the SLC-6 site sat mothballed for years. Lockheed Martin used the SLC-6 pad for four launches of its light-class Athena rockets in the 1990s, but those missions didn’t utilize much of the shuttle-era infrastructure at the site.
但在1986年挑战者号事故后，空军放弃了从范登堡发射军用航天飞机的计划，SLC-6场地的航天飞机时代建筑被封存了多年。洛克希德·马丁公司在20世纪90年代的四次轻型雅典娜火箭发射中使用了SLC-6发射台，但这些任务没有利用航天飞机时代的基础设施。
Boeing took over the SLC-6 pad and modified the shuttle infrastructure for the Delta 4 rocket, which first launched there in June 2006. ULA was formed later in 2006 by the merger of Boeing’s Delta and Lockheed Martin’s Atlas rocket programs. SLC-6 hosted its first launch of the triple-core Delta 4-Heavy rocket configuration in January 2011.
波音公司接管了SLC-6发射台，并为2006年6月首次在那里发射的德尔塔4火箭修改了航天飞机基础设施。ULA于2006年晚些时候由波音公司的德尔塔和洛克希德·马丁公司的阿特拉斯火箭项目合并而成。SLC-6于2011年1月首次发射了三核德尔塔4重型火箭结构。
Read our 2011 story detailing the history of the SLC-6 launch pad, written just before the first Delta 4-Heavy flight from Vandenberg.
阅读我们2011年的故事，详细描述了SLC-6发射台的历史，写于第一次从范登堡起飞的德尔塔4重型飞机之前。
“SLC-6 is iconic here,” Titus said. “It’s legendary. It’s kind of what people think about when they think about Vandenberg. It’s had many lives. It started in the mid 1960s. They were going to support something called the Manned Orbiting Laboratory. In the ’70s and ’80s, it was built up for a shuttle program, and they ended up not going down that path. And then in the ’90s and 2000s, we started going down this path of launching Deltas from there, and we’ve had mission success after mission success out of that place for the last almost 20 years.
“SLC-6在这里是标志性的，”泰特斯说。“太传奇了。这是人们想到范登堡时所想的。它有过很多次生命。它始于20世纪60年代中期。他们将支持一个叫做载人轨道实验室的东西。在70年代和80年代，它是为航天飞机项目而建立的，但他们最终没有走上这条路。然后在90年代和2000年代，我们开始沿着从那里发射三角洲的道路前进，在过去的近20年里，我们在那个地方取得了一次又一次的任务成功。
Northrop Grumman planned to use the SLC-6 launch pad for its now-canceled OmegA rocket, which the company proposed to the Pentagon in a competition for military launch contracts. But the Defense Department selected ULA’s Vulcan rocket and SpaceX’s Falcon 9 and Falcon Heavy launchers in 2020 for eligibility to compete for military launches scheduled through 2027.
诺斯罗普·格鲁曼公司计划将SLC-6发射台用于其现已取消的欧米茄火箭，该公司在争夺军事发射合同的竞争中向五角大楼提出了这一建议。但国防部在2020年选择了ULA的火神火箭和SpaceX的猎鹰9号和猎鹰重型发射器，以竞争定于2027年进行的军事发射。
Northrop Grumman shut down development of the OmegA rocket after losing the military launch procurement.
诺斯罗普·格鲁曼公司在失去军事发射采购后关闭了欧米茄火箭的开发。
And now ULA will leave SLC-6 after the final Delta 4-Heavy launch from the West Coast spaceport.
现在ULA将在从西海岸航天港进行最后一次德尔塔4重型发射后离开SLC-6。
“SLC-6 has done us well,” Titus said. “I think that everyone here at Vandenberg has a warm spot in their heart for that place, and we’re going to make sure that it’s continued to be utilized. What we don’t know is exactly what that’s going to look like. But I can say that, first of all, we’re working closely with ULA to make sure that we have a smooth transition. And secondly, there are many other launch service providers out there that could find utility in that location. There’s a lot of infrastructure there. So I’m fairly confident that it will be utilized. We just don’t know exactly how yet.”
“SLC-6对我们做得很好，”泰特斯说。“我认为范登堡的每个人都对那个地方有一个温暖的地方，我们将确保它继续被利用。我们不知道的是那会是什么样子。但我可以说，首先，我们正在与ULA密切合作，以确保我们有一个平稳的过渡。其次，还有许多其他的发射服务提供商可以在那里找到效用。那里有很多基础设施。所以我很有信心它会被利用。我们只是还不知道具体怎么做。“
ULA’s other launch pad at Vandenberg, Space Launch Complex 3-East, will be converted to support flights of the new Vulcan Centaur rocket in the next few days. SLC-3E is currently used to launch Atlas 5 rockets, and the final Atlas 5 flight from Vandenberg is scheduled for Nov. 1.
ULA在范登堡的另一个发射台，太空发射综合体3-EAST，将在未来几天内被改造成支持新的火神半人马座火箭的飞行。SLC-3E目前用于发射阿特拉斯5火箭，阿特拉斯5从范登堡的最后一次飞行定于11月1日。
Like the Delta rocket family, the Atlas 5 will be retired in the coming years for replacement by the Vulcan. The final Atlas 5 missions will be based out of Cape Canaveral.
像德尔塔火箭家族一样，阿特拉斯5将在未来几年退役，由火神取代。最后的阿特拉斯5任务将在卡纳维拉尔角进行。
Gary Wentz, ULA’s vice president of commercial and government programs, said the company chose the SLC-3E launch pad for the Vulcan rocket over SLC-6 for a few reasons. One was the similarity between the Atlas 5 rocket and the Vulcan, which both use Centaur upper stages, the same payload shroud design, and the same type of solid rocket boosters.
ULA负责商业和政府项目的副总裁加里·温特说，该公司选择SLC-3E发射台为火神火箭而不是SLC-6有几个原因。一个是阿特拉斯5号火箭和火神号之间的相似之处，它们都使用半人马座的上面级，相同的有效载荷罩设计，以及相同类型的固体火箭助推器。
Another reason was that SLC-6 is more expensive to maintain, and ULA is seeking to reduce costs to compete with SpaceX for military launch contracts. SLC-6 has the largest footprint of any launch site at Vandenberg, and is on a similar scale to NASA’s two Apollo-era launch pads at Kennedy Space Center — pads 39A and 39B.
另一个原因是SLC-6的维护成本更高，ULA正在寻求降低成本，以与SpaceX竞争军事发射合同。SLC-6是范登堡所有发射场中占地面积最大的，规模与美国宇航局在肯尼迪航天中心的两个阿波罗时代的发射台--39a和39B发射台相似。
SLC-6 has a 325-foot-tall Mobile Service Tower used to help stack and protect rockets on the pad, a structure originally built for the Manned Orbiting Laboratory program. There’s also a 270-foot-tall Mobile Assembly Shelter that dates back to the 1980s for space shuttle missions. Both buildings move on rail tracks.
SLC-6有一个325英尺高的移动服务塔，用于帮助堆放和保护发射台上的火箭，这是一个最初为载人轨道实验室计划建造的结构。还有一个270英尺高的移动组装舱，可以追溯到20世纪80年代，用于航天飞机任务。两座建筑都在铁轨上移动。
Wentz said ULA will “safe and secure” the launch pad after the final Delta 4-Heavy launch Saturday, ensuring that all hazardous systems to sit in an “idle condition” until officials decide what to do next with SLC-6.
温特说，在周六最后一次德尔塔4重型发射后，ULA将“保护”发射台，确保所有危险系统处于“闲置状态”，直到官员们决定SLC-6的下一步行动。
There are no immediate plans to demolish any of the structures at SLC-6, and ULA will turn over responsibility for the pad back to the Space Force, which will try to find a new tenant for the pad. Until then, officials don’t expect any significant changes to the site.
目前还没有拆除SLC-6任何结构的计划，ULA将把pad的责任移交给太空部队，太空部队将试图为pad找到一个新的租户。在此之前，官员们预计该网站不会有任何重大变化。
ULA will not lay off any of its workforce at Vandenberg, Wentz said. Instead, the workers will transition to ready for the final Atlas 5 launch at the West Coast spaceport, then prep for Vulcan missions.
温特说，ULA不会解雇范登堡的任何员工。相反，工作人员将在西海岸航天港为阿特拉斯5号的最后发射做好准备，然后为火神任务做准备。
“From a workforce perspective, the team is upbeat,” Wentz said. “There’s no concern about their future. We’re not in a position where we’re stepping down and going to have to lay off folks. So there are folks that are sticking around to launch these vehicles.”
“从员工的角度来看，团队是乐观的，”温特说。“没有人担心他们的未来。我们不是在下台和不得不裁员的位置上。所以有人留下来发射这些车辆。“
Startup launch companies like Firefly Aerospace and Relativity Space have signed agreements with the Space Force to fly their small satellite boosters from Vandenberg. SpaceX currently leases a launch pad at Vandenberg for Falcon 9 rocket missions, and ULA will continue using SLC-3 for the Atlas 5 and Vulcan rockets. Another small launch pad, SLC-8, has at least one more space launch on its schedule — a Northrop Grumman Minotaur 4 rocket set to take off in 2023.
像萤火虫航空航天和相对论空间这样的初创发射公司已经与太空部队签署了协议，从范登堡发射他们的小型卫星助推器。SpaceX目前在范登堡租赁了一个发射台用于猎鹰9号火箭任务，ULA将继续使用SLC-3用于阿特拉斯5号和火神火箭。另一个小型发射台SLC-8，在其计划中至少还有一次太空发射--诺斯罗普·格鲁曼公司的牛头怪4号火箭将于2023年起飞。
“The way that I think we envision this working is that once we identify who’s interested in taking over SLC-6, then we’ll work with them to understand what they want to do in order to facilitate launching whatever type of booster they have,” Titus said.
泰特斯说：“我认为我们设想这一工作的方式是，一旦我们确定谁有兴趣接管SLC-6，然后我们将与他们合作，了解他们想做什么，以便于发射他们拥有的任何类型的助推器。”
“Once we identify who it’s going to be, we’ll probably look at the current state of the infrastructure, identify some things that I think would be value-added, maybe some things that don’t need to be there anymore, and then that company will probably go through the same process that ULA went through 15 or 20 years ago when they took a pad that was designed for the space shuttle, and converted it to a pad that supports a Delta launch vehicle,” Titus said.
泰特斯说：“一旦我们确定了将是谁，我们可能会看看基础设施的现状，确定一些我认为会增值的东西，也许一些不需要再存在的东西，然后这家公司可能会经历15年或20年前ULA经历的相同过程，当时他们拿走了一个为航天飞机设计的垫子，并将其改造成一个支持德尔塔运载火箭的垫子。”
“So it’s really going to be up to the commercial provider to decide what changes they want to make, but we’ll be there to support and enable that in any way possible.”
“因此，这真的将由商业提供商决定他们想做什么改变，但我们将以任何可能的方式支持和实现这一点。”
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