• Mission Extension Vehicle
• Intelsat 901 Satellite Returns to Service Using Northrop Grumman’s Mission Extension Vehicle (Northrop Grumman)
• Mission Extension Vehicle: Breathing Life Back Into In-Orbit Satellites (Northrop Grumman)
• In historic first, an aging satellite is resurrected by another in a technology that could reduce junk in space (Washington Post)
• MEV 1, 2 (Gunter’s Space Page)

Speaking of Intelsat, they recently announced that IS-901 is once again fully operational thanks to a little help from MEV-1.

Regular listeners may recall that we talked about MEV-1 on Daily Space about a month ago when the satellites made contact on February 25th. Basically, MEV-1 is designed to attach itself to a satellite that is out of propellant and act as its motors to keep it in the correct orientation. This means that a satellite that has run out of propellant but is otherwise healthy can have its useful life extended for up to five years before moving the satellite out to a graveyard orbit.

IS-901 was declared operational on April 2nd, 2020.  Date of announcement: Intelsat, Northrop Grumman Press releases: 17 APR 2020 – “Intelsat (NYSE: I) today announced that Intelsat 901 has returned to service following the successful docking with the first Mission Extension Vehicle (MEV-1) from Northrop Grumman Corporation (NYSE: NOC) and the company’s wholly-owned subsidiary, SpaceLogistics LLC, on February 25 – the first time that two commercial spacecraft docked in geostationary orbit.”

“Our partnership with Intelsat was critical to delivering this innovative satellite technology into operation,” said Tom Wilson, vice president, Northrop Grumman Space Systems and president, SpaceLogistics, LLC. “This historic event, highlighted by the first in-orbit rendezvous and docking of two commercial satellites and the subsequent repositioning of the two-spacecraft stack, demonstrates the business value that MEV offers to customers. Now that MEV-1 has successfully delivered on its mission to place the Intelsat 901 satellite back into operational service, we will continue to pioneer the future of on-orbit servicing through our multi-year technology road map leading to additional services such as inspection, assembly and repair.”

The mission didn’t quite go off without a hitch — there were several attempts before docking was successful.  Contributing to the difficulty of the operation was the fact that at the time IS-901 was built, on orbit servicing was barely a hypothetical concept reserved for specially constructed systems like the Hubble Space Telescope.  Servicing anything beyond low Earth orbit was considered extremely futuristic.

But patience and perseverance paid off, according to a statement by Jean-Luc Froeliger, Intelsat’s Vice President for space systems engineering and operations. 

“It proves that in-orbit servicing is real.  This was a project that took years in planning. We had identified [Intelsat 901] three years ago and decided it’s healthy but it’s going to run out of fuel in early 2020. And so rather than having to discard the satellite and retire it, we teamed up with Northrop Grumman to do this in-orbit servicing mission.”

Currently IS-901 is scheduled to remain in service for at least the next five years, after which the plan is to retire the commsat back into a graveyard orbit.  That will allow the MEV-1 to perform the same 5 year mission on up to two other geostationary (GEO) spacecraft before its fuel & planned service life are expended. However, if there are no follow-on missions for MEV-1 at that time and if IS-901 is still healthy (meaning instruments on board are in good working order), Intelsat may choose to lease the extension vehicle’s services for up to ten more years. 

Because of the success of MEV-1, Intelsat has made a few adjustments to its plans regarding MEV-2.  Rather than moving IS 10-02 to a graveyard orbit before rendezvous, Intelsat has decided that IS 10-02 will remain in active service when MEV-2 docks with the aging satellite.  MEV-2 has already finished construction and was originally scheduled to be launched sometime this year, but launch has been postponed due to delays related to the ongoing pandemic.