<div id="readability-page-1">Dec 19 (Reuters) - The Space Development Agency, part of the U.S. Space Force, said on Friday it has reached agreements with four defense suppliers to ‌build 72 satellites, worth about $3.5 billion collectively. The agency said ​Lockheed Martin, L3Harris Technologies, Northrop Grumman, and ‍Rocket Lab USA have signed ⁠fixed-priced contracts ⁠for 18 space vehicles each. The infrared satellites, which will ‌be used for missile ​warning, tracking and defense systems, are expected to be launched into low-earth ⁠orbit in 2029. &#34;The ‍addition of ​these satellites will achieve near-continuous global coverage for missile warning and tracking, along ‍with payloads capable of generating fire control quality tracks for missile defense,&#34; said the agency's Acting Director Gurpartap Sandhoo. These satellites belong to Tranche-3 and support the space ​agency's ‍objective of launching a new tranche every two years to refresh its satellite ​architecture with updated technology. In September, the first Tranche-1 space vehicle, a SpaceX Falcon 9 rocket, was launched from Vandenberg Space Force Base, California. The agency plans to include a total of 154 ​operational space vehicles in Tranche-1, which will be ready for initial warfighting capability in 2027. (Reporting by Aishwarya ‍Jain in Bengaluru; Editing by Krishna Chandra Eluri)</div>

RKLB

洛克希德马丁

诺斯罗普·格鲁曼

美国太空发展局，隶属于美国太空部队，已向洛克希德·马丁、L3Harris Technologies、诺斯罗普·格鲁曼和 Rocket Lab USA 下达了一项价值 35 亿美元的 72 颗卫星订单。这些卫星是 Tranche-3 的一部分，将用于导弹预警、跟踪和防御系统，预计将在 2029 年发射入低地轨道

美国空间发展局下达了价值 35 亿美元的订单，用于采购 72 颗卫星