High above the Earth, a new generation of robots designed to keep satellites working longer is replacing its predecessor — quite literally.
This week, a spacecraft built and operated by Northrop Grumman called a Mission Extension Vehicle (MEV) unplugged from a communications satellite operated by the Australian firm Optus. For more than a year, the MEV spacecraft has been stuck to the back of the Optus satellite, keeping it in the right place in space so it can continue its mission.
Here’s an exclusive view from the MEV’s on-board camera, showing the Optus satellite and the Earth behind as the two spacecraft moved apart.
A view of the Optus-D3 satellite and the Earth, taken by Northrop Grumman’s MEV spacecraft.
The satellite life-extension spacecraft is leaving to make room for its replacement. In July, four new Northrop spacecraft launched into orbit on a SpaceX Falcon 9 rocket. One is called the Mission Robotic Vehicle (MRV), a powerful satellite equipped with two advanced robotic arms that was developed by DARPA, the U.S. military research organization. The other three are called Mission Extension Pods, or MEPs, smaller, simpler satellites that are e…
这四艘航天器目前正在前往距离地球约27,000英里的目标。2027年，MRV将使用其机械臂将其中一个MEP舱段连接到Optus卫星，这应该能使其在轨道上运行多年。
The satellites that provide communications or scan the planet with various sensors only last for so long. They typically fail when they run out of fuel to stay in the right place, not because their computers and transceivers stop working. The Optus satellite was launched in 2009, and designed for a 15-year lifespan. If all goes well, the satellite could fly — and generate revenue — for another six years.
现在，更低的发射成本和低成本的空间组件使航天器维修任务成为现实。
目标是“实现一种范式转变，使我们能够将太空视为可持续的，拥有更加韧性的架构和基础设施基础，从而可以进行航天器维修、寿命延长，甚至卫星的升级和维护，”诺斯罗普·格鲁曼公司的物流和服务总监卡西·王表示。
目前有两颗MEV在轨道上运行，分别于2019年和2020年发射，已为三位客户提供了10年的寿命延长服务，其中包括两颗不同的Intelsat卫星和一颗Optus卫星。MEV-1将在一个停车轨道上等待另一位客户，而MEV-2目前则连接在其Intelsat客户上，直至2030年。
任务机器人车辆（Mission Robotic Vehicle，简称MRV）代表了商业模式的进化。卫星运营商购买并拥有MEP，这些设备永久安装在他们的航天器上。这使得MRV可以为更多的航天器提供服务，从而创造更便宜的解决方案。
该方案需要一些高超的技术。这些车辆需要自主地相互接近并安全对接，当两者都以每小时数千英里的速度移动时，这并非易事。MEVs 使用对接探针连接并抓住卫星推进器喷嘴。与此同时，MRVs 需要使用其机械臂仔细地安装 MEPs。
与大多数卫星不同，MRV 被设计为可以在轨道上加油——部分是为了证明如果这种在轨服务成为常态，其他卫星所需的能力。目前，这种适应措施的额外成本和重量使航天器运营商不愿投资它们。
Indeed, the current trend in satellites is flying lots of cheap, effectively replaceable spacecraft in low orbits, as Starlink and Amazon LEO do. On the other hand, spacecraft keep getting bigger, and there are plenty of expensive, large satellites in orbit that could benefit from life extension. Wong hopes that the MRV will take on other missions in the future, adding new components to satellites as well as adjusting their orbits.
这很可能包括国防客户，考虑到它在高轨道上拥有大量昂贵的卫星，以及DARPA在开发MRV的机械臂方面的参与。事实上，美国太空军此前曾将中国的一款带有机械臂的在轨服务航天器视为武器，因为理论上它可以捕获并削弱对手的卫星。诺斯罗普·格鲁曼公司表示，其车辆专注于服务任务。
王说，该飞行器也可以用于低地球轨道（LEO），以延长那里的宝贵资产的使用寿命。初创公司Katalyst Space正在尝试执行类似的使命，以在发生故障后延长NASA太空望远镜的使用寿命。