The Pentagon’s Space Development Agency hasn’t moved as fast as anyone would like

五角大楼的太空发展局（SDA）进展并未达到预期

The Space Development Agency was established in 2019 to help speed up the deployment of US military space systems by sidestepping the Pentagon’s traditional sluggish bureaucracy. Seven years later, SDA is finally launching its first batches of operational satellites, just as the Pentagon plans to shutter the semi-autonomous agency and fold it back into the Space Force’s procurement pipeline, newly reorganized under several program acquisition executives in a bid to streamline weapons buying.

太空发展局（SDA）成立于 2019 年，旨在通过绕过五角大楼传统的官僚主义，加快美国军事太空系统的部署。七年过去了，SDA 终于发射了首批作战卫星，但与此同时，五角大楼正计划关闭这一半自主机构，将其重新并入太空军的采购渠道。该渠道近期已在几位项目采购高管的领导下进行了重组，以期简化武器采购流程。

SDA’s fate is not a surprise, and lawmakers in both houses of Congress have backed the agency’s closure in drafts of this year’s National Defense Authorization Act. The Space Development Agency’s primary mission has been to develop a constellation of several hundred missile warning and data relay satellites in low-Earth orbit designed to detect, track, and target ballistic and hypersonic missiles. The military calls the constellation the Proliferated Warfighter Space Architecture (PWSA).

SDA 的命运并不令人意外，国会两院的议员们已在今年《国防授权法案》的草案中支持关闭该机构。SDA 的主要任务是开发一个由数百颗低地球轨道导弹预警和数据中继卫星组成的星座，旨在探测、跟踪并锁定弹道导弹和高超音速导弹。军方将该星座称为“扩散型作战人员太空架构”（PWSA）。

The Pentagon currently has a small fleet of legacy missile warning satellites in much higher geosynchronous orbits. These satellites are expensive and vulnerable to attack, and their distance from Earth makes them less sensitive to smaller, dimmer missiles. The idea was to rapidly procure, develop, and field new generations, or tranches, of tracking and data “transport” satellites every two years. SDA’s strategy was to cast a wide net across the US space industry, using satellites and sensors developed by many companies. Launches of SDA’s new satellites were supposed to occur at a cadence of about once per month.

五角大楼目前拥有一小批位于更高地球同步轨道的传统导弹预警卫星。这些卫星造价昂贵且易受攻击，由于距离地球较远，它们对小型、暗淡导弹的探测灵敏度较低。SDA 的初衷是每两年快速采购、开发并部署新一代（即“批次”）跟踪和数据“传输”卫星。SDA 的策略是在美国航天工业中广泛撒网，利用多家公司开发的卫星和传感器。SDA 新卫星的发射频率原定为每月一次左右。

Rough waters

艰难前行

Much of SDA’s mission will continue under a different banner within the US Space Force. The missile-warning and data-relay satellites will eventually be part of the Pentagon’s planned Golden Dome missile shield, one of the Trump administration’s top priorities for the Space Force. The capabilities foreseen for SDA’s satellite constellation predate President Trump’s announcement of Golden Dome last year, and are far less controversial than the White House’s push to include space-based weapons as part of the missile shield.

SDA 的大部分任务将在美国太空军的旗帜下继续进行。这些导弹预警和数据中继卫星最终将成为五角大楼计划中的“金穹”（Golden Dome）导弹防御系统的一部分，这是特朗普政府对太空军的首要任务之一。SDA 卫星星座所预期的能力早在特朗普总统去年宣布“金穹”计划之前就已经存在，且相比白宫推动将天基武器纳入导弹防御系统的做法，其争议性要小得多。

SDA’s history has been marred by schedule delays, production and supply chain bottlenecks, and technical issues with the organization’s first batches of operational data relay satellites after their launch last year. The purpose of the data relay, or “transport,” satellites is to receive tracking data from SDA’s missile-warning satellites via inter-satellite laser communication links and relay the information to the ground for action.

SDA 的发展史一直伴随着进度延误、生产和供应链瓶颈，以及去年首批作战数据中继卫星发射后出现的技术问题。数据中继（或称“传输”）卫星的目的是通过星间激光通信链路接收来自 SDA 导弹预警卫星的跟踪数据，并将信息传回地面以供采取行动。

SDA started launching prototype tracking and data transport satellites in 2023 and launched its first two batches of transport satellites last year. The third group of data transport satellites launched Thursday on a SpaceX Falcon 9 rocket from Vandenberg Space Force Base, California, bringing the total number of transport satellites launched in Tranche 1 to 63.

SDA 于 2023 年开始发射原型跟踪和数据传输卫星，并于去年发射了首批两组传输卫星。周四，第三组数据传输卫星搭乘 SpaceX 的猎鹰 9 号火箭从加利福尼亚州范登堡太空军基地发射升空，使“第一批次”（Tranche 1）发射的传输卫星总数达到 63 颗。

“This launch continues to expand warfighting capability to deliver persistent tactical satellite communication for the warning and tracking of advanced missile threats,” said Gurpartap “GP” Sandhoo, director of the Space Development Agency, in a statement. Sandhoo also serves as the Space Force’s portfolio acquisition executive for missile warning and tracking, which would keep him in charge of much of the SDA’s mission after the agency’s dissolution.

“此次发射继续扩大了作战能力，为预警和跟踪先进导弹威胁提供了持续的战术卫星通信，”太空发展局局长 Gurpartap “GP” Sandhoo 在一份声明中表示。Sandhoo 同时担任太空军导弹预警与跟踪领域的采购主管，这意味着在 SDA 解散后，他仍将负责该机构的大部分任务。

“The deployment of Tranche 1’s proliferated capability will soon deliver continuous overwatch—neutralizing any first-mover advantage by delivering data to warfighters around the world, nearly instantaneously,” Sandhoo said.

“第一批次扩散能力的部署将很快实现持续监视——通过近乎实时地向全球作战人员提供数据，从而抵消任何先发优势，”Sandhoo 说道。

Thursday’s launch marked the resumption of SDA satellite deployments after standing down for nine months due to issues with the spacecraft on the first two Tranche 1 launches last September and October. Those launches were successful, but ground teams ran into problems activating and commissioning satellites made by York Space Systems and Lockheed Martin.

周四的发射标志着 SDA 在因去年 9 月和 10 月前两次“第一批次”发射中出现的航天器问题而停飞九个月后，恢复了卫星部署。尽管那两次发射本身是成功的，但地面团队在激活和调试由 York Space Systems 和洛克希德·马丁公司制造的卫星时遇到了问题。

Sandhoo identified several issues with the first Tranche 1 satellites during a roundtable with reporters before this week’s launch. Ground controllers lacked sufficient ground station coverage to communicate with the satellites after last year’s launches. Some of the satellites encountered thermal control and propulsion system problems as they climbed from their insertion orbit to an operational altitude of more than 600 miles (1,000 kilometers), significantly higher than SpaceX’s Starlink Internet network, Sandhoo said.

在周四发射前与记者的圆桌会议上，Sandhoo 指出了第一批次卫星存在的几个问题。去年发射后，地面控制人员缺乏足够的地面站覆盖范围来与卫星通信。Sandhoo 表示，一些卫星在从初始轨道爬升至超过 600 英里（1000 公里）的工作高度时，遇到了热控和推进系统问题，这一高度远高于 SpaceX 的星链互联网网络。

“We are in a pretty harsh radiation environment at 1,000 kilometers, so not all of our orbit raising has gone according to plan,” he said. “It has been sporadic. We’re working through it.” Sandhoo is optimistic that ground teams will eventually declare most of the satellites ready for operations, but it’s taking longer than expected.

“我们在 1000 公里的高度处于相当恶劣的辐射环境中，因此我们的轨道提升并非完全按计划进行，”他说，“这种情况时有发生。我们正在努力解决。”Sandhoo 对地面团队最终能宣布大部分卫星准备就绪持乐观态度，但这一过程比预期的要长。

Getting it right

步入正轨

SDA and its contractors “took a pause” after last year’s launches to “make sure we fixed at least the known issues,” Sandhoo said. “We expect this launch to be a lot smoother than the last one.” Thursday’s launch was the second SDA launch of York’s data transport satellites, and the third for Tranche 1 overall. Seven more launches will complete Tranche 1 with 63 additional data transport satellites and 28 missile tracking satellites manufactured by Lockheed Martin, Northrop Grumman, and others.

Sandhoo 表示，SDA 及其承包商在去年的发射后“暂停了一下”，以“确保我们至少修复了已知的问题”。“我们预计这次发射会比上一次顺利得多。”周四的发射是 SDA 第二次发射 York 公司的卫星，也是“第一批次”的第三次发射。后续还将有七次发射，届时将完成“第一批次”的部署，包括由洛克希德·马丁、诺斯罗普·格鲁曼等公司制造的 63 颗额外数据传输卫星和 28 颗导弹跟踪卫星。