Northrop swaps out its robotic satellite mechanic in orbit

Northrop Grumman this week detached its Mission Extension Vehicle (MEV) spacecraft from a communications satellite operated by Australian company Optus, ending more than a year during which the MEV helped hold the satellite in its correct orbital position. The MEV is now departing to clear the way for a next-generation servicing system.

In July, four new Northrop spacecraft launched aboard a SpaceX Falcon 9 rocket: the Mission Robotic Vehicle (MRV), developed with DARPA and fitted with two robotic arms, along with three smaller Mission Extension Pods (MEPs). The spacecraft are heading toward an orbit roughly 27,000 miles above Earth, where in 2027 the MRV is expected to use its robotic arm to attach one of the MEPs to the same Optus satellite, potentially extending its working life by another six years.

Satellites usually run out of fuel, not function

According to Cassie Wong, Northrop's director of logistics and servicing, satellites typically stop operating not because their onboard electronics fail, but because they run out of fuel needed to maintain position. The Optus satellite launched in 2009 with an intended 15-year lifespan.

Two MEVs are currently in orbit, having provided a combined decade of life extension since 2019 and 2020 to three customers, including two Intelsat spacecraft. The new MRV system changes the business model: operators purchase and permanently attach MEPs to their own satellites, while the MRV itself can move on to service multiple customers, lowering overall costs.

The approach requires spacecraft to autonomously approach and dock with one another while both travel at thousands of miles per hour. Unlike most satellites, the MRV is designed to be refueled while in orbit, serving as a proof of concept for capabilities that could become standard if in-orbit servicing becomes more common. Wong said she hopes the MRV will eventually take on additional tasks, such as adjusting satellite orbits, and attract defense-sector customers. A separate effort by startup Katalyst Space is attempting a similar repair mission for a malfunctioning NASA space telescope.