Northrop's robot space mechanic: new way to keep satellites working longer

MEV-1 departs Optus satellite after life extension mission

This week, Northrop Grumman’s Mission Extension Vehicle (MEV-1) unplugged from the Optus communications satellite after more than a year of keeping it in position. The spacecraft had been attached to the satellite’s rear, maintaining its orbital slot so the Australian operator’s asset could continue its mission. The Optus satellite was launched in 2009 and designed for a 15-year lifespan. With the life extension provided by MEV-1, and future servicing planned, the satellite could fly—and generate revenue—for another six years.

MEV-1 will now wait in a parking orbit for another customer. Its sibling, MEV-2, remains attached to an Intelsat spacecraft until 2030. Together, the two MEVs launched in 2019 and 2020 have provided 10 years of life extension to three customers, including two Intelsat satellites and the Optus spacecraft. The departure clears the way for a new generation of servicing hardware, with the Mission Robotic Vehicle and Mission Extension Pods already heading toward targets roughly 27,000 miles above Earth.

New MRV and MEPs launched to continue servicing

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 essentially modular propulsion systems.

Those four spacecraft are currently headed for targets around 27,000 miles above the Earth. In 2027, the MRV will use its robotic arms to attach one of the MEP pods to the Optus satellite, which should keep it in orbit for years to come. The MRV represents an evolution of the business model: satellite operators buy and own the MEPs, which are permanently attached to their spacecraft. That frees up the MRV to service more vehicles, creating a cheaper offering.

Why satellites need life extension and how it works

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. That is why life extension vehicles are valuable: they keep a satellite in its correct orbit so it can continue generating revenue.

There are two MEVs in orbit right now, launched in 2019 and 2020, which have provided 10 years of life extension to three customers, including two different Intelsat spacecraft and the Optus satellite. MEV-1 will wait in a parking orbit for another customer, while MEV-2 is currently attached to its Intelsat customer until 2030.

The vehicles must autonomously approach one another and dock safely, a difficult task when both are moving at thousands of miles an hour. The MEVs use a docking probe to plug in and hang onto satellite thruster nozzles.

The future of in-orbit servicing and challenges

The MRV represents an evolution of the business model: satellite operators buy and own the MEPs, which frees up the MRV to service more vehicles and creates a cheaper offering. This requires serious technology chops, as the vehicles need to autonomously approach and dock safely while moving at thousands of miles an hour. Unlike most satellites, the MRV is designed to be refueled in orbit—in part, a proof of concept for capabilities other satellites will need if in-orbit servicing becomes a norm. Northrop sees defense customers in the future, given the number of expensive satellites the U.S. owns in high orbits and DARPA’s involvement in developing the MRV’s arms. The vehicle could also be used in LEO to extend the life of valuable assets there, according to Northrop’s director of logistics and servicing, Cassie Wong. Meanwhile, the startup Katalyst Space is attempting a similar mission to extend the life of a NASA space telescope after malfunctions left its vehicle tumbling last month; the company has a fix in place and hopes to complete the mission.