作者：2012年12月28日路透社
WASHINGTON, Dec 28 (Reuters) - Lockheed Martin Corp has won a contract valued at $1.9 billion to build two additional advanced military communications satellites for the U.S. Air Force, the Pentagon said on Friday.
The contract, which runs through January 2022, covers production of the fifth and sixth satellites in the Advanced Extremely High Frequency satellite program.
Lockheed welcomed the contract, saying it underscored the government's confidence in the company's work on the program.
"As protected and resilient satellite communications become increasingly vital to global security, the AEHF program has developed into an indispensable element of the nation's military space architecture," said Mark Calassa, vice president of Lockheed Martin's Protected Communications mission area.
He said the first two satellites were operating exceptionally in orbit, and the company was implementing several affordability initiatives together with the Air Force that were already reducing program costs.
The terms of the contract had been switched from cost-plus to fixed-price, with an incentive fee, which allowed the government to limit its risk, Calassa said in a statement.
The Air Force's decision to buy two satellites at one time also allowed Lockheed to significantly reduce costs through economies of scale, he said.
A top Air Force acquisition official last week told Reuters the service was unlikely to reach an agreement with Lockheed on the new satellites before the end of the year.
It was not immediately clear how the two sides managed to work through the remaining issues so quickly.
Agreement on the contract terms does safeguard funding for the satellites from automatic across-the-board cuts if U.S. lawmakers do not find a way to avert significant Pentagon reductions due to take effect in January.
Air Force officials had initially hoped to sign the contract with Lockheed this summer, with an eye to reaping savings of well over 10 percent over earlier contracts.
The cost of the contract had been projected at $2.6 billion, well above the level announced on Friday.
The two AEHF satellites already in orbit are designed to ensure that military communications continue among top military commanders and the White House in the event of a nuclear war.
The satellites also provide transmission of more routine communications such as targeting data and video data feeds, and serve international partners including Canada, the Netherlands and the United Kingdom.
美空军斥资19亿造两颗先进极高频（AEHF）卫星
作者：2013年1月1日观察者
据路透社报道，美国五角大楼28日宣称，洛·马公司获得美国空军19亿美元合同建造两颗先进极高频(AEHF)卫星。
合同期限到2022年1月，内容是建造第五颗和第六颗先进极高频（AEHF）卫星。
目前有首批两颗先进极高频卫星在轨，运行状态出色。这两颗在轨卫星旨在确保高层军事指挥官与白宫在核战争期间持续通信。卫星还提供更多的日常通信转发，例如瞄准数据，视频数据传送专线等。按照此前合同，洛马公司要为美国空军建造4颗AEHF卫星。
AEHF系统是美国新一代受保护通信卫星系统，可提供全球范围内的保密、抗干扰战术军事通信，例如实时视频、战场地图和跟踪数据等。其单颗卫星的通信容量相当于整个现役的“军事星”系统。更快的数据速度将允许战术军事通信的传输，如高质量实时视频，和快速访问战区地图及目标数据。
作为美军第三代军事通讯卫星，先进极高频通讯卫星”(AEHF)采用星间链路(不同在轨卫星间的互联)技术、星上处理技术等，能根据用户优先级别来提供点对点通信以及网络服务。该系统有非常强的战场生存能力，即便在地面控制站被破坏后，整个系统仍能自主工作半年以上。目前美军有两颗AEHF卫星服役。
全球卫星定位系统（GPS）主要借助空间卫星网络对军队移动和导弹飞行等提供技术支持。美军在1994年就建成该系统，随着技术的不断发展，需要发射改进型卫星来更替。美军的AEHF卫星，能提供增强的信号功率给地面接收机，以及多个新的军用信号频段，从而为美军提供具备高精度、高加密、强抗干扰能力的定位和导航服务。
