US Space Force grounds ULA's Vulcan

In the least surprising story in a while, the US Space Force has halted all National Security missions slated for ULA's Vulcan rocket for the foreseeable future due to the solid rocket booster failure that occurred in the February 12 launch of the fourth Vulcan mission. Out of the four missions, two have been affected by what appears to be the same sort of failure if not identical failures.

Although the failure dramatically changed the magnitude and the direction of the Solid Rocket Booster's (SRB's) thrust, the control systems controlling the rocket were able to compensate for that change to get the mission's payloads to their respective proper orbits. Nobody approaches 100% confident that will always work out positively if more SRBs have the same sort of nozzle failure.

"This is going to be a many-months process as we work through the exact technical issue that happened and the corrective actions we need to make sure, we need to take, to make sure this doesn’t happen again," Space Force Col. Eric Zarybnisky said during a media round robin during the Air Force Association’s Warfare Symposium on Feb. 25, as reported by Breaking Defense.
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“We are going to work through this anomaly until we launch again on Vulcan,” Zarybnisky told reporters ... "Until this anomaly is solved we will not be launching Vulcan missions."

On February 12, ULA's Vulcan rocket climbs towards orbit in a shower of sparks from its solid rocket booster. Image: Michael Cain/Spaceflight Now.

While the focus on national security missions is easy to grasp, an important application that's covered by the phrase may not come immediately to your mind: Space Force is responsible for the GPS constellation, a utility that touches nearly everyone, and the stewards of the satellite navigation network are eager to populate the fleet with the latest and greatest spacecraft.

Aside from routine replacement of GPS Satellites as they age and start to degrade there's more to consider. 

Another motivation is to replace the oldest active GPS satellites, some of which have been in space since the late 1990s, with newer satellites better suited for the modern world. Beginning in 2005, the military has deployed GPS spacecraft with additional civilian signals for aviation and interoperability with Europe’s Galileo navigation satellites. At the same time, the military introduced a new military-grade signal called M-code, designed for warfare.

M-code is more resistant to jamming, and its encryption makes it more difficult to spoof, a kind of attack that makes receivers trust fake navigation signals over real ones. The upgrade also allows the military to deny an adversary access to GPS during conflict, while maintaining the ability for US and allied forces to use M-code. 

Interference with GPS satellites is on the rise, particularly in the trouble spots that have probably popped into your mind already. Russia and Ukraine, for example, are the easy ones, but the middle east and rest of the eastern Mediterranean are trouble spots, as well. 

Recent high-profile examples of GPS interference include an incident in 2024 that resulted in a fatal airline crash, killing 38 people. The International Air Transport Association reported a 500 percent increase in GPS spoofing incidents in 2024.

For these reasons, the Space Force is prioritizing the launch of new GPS satellites better equipped to repel all of this jamming and spoofing. Currently, 26 of the 31 operational GPS satellites carry M-code capability, enough for global coverage with little margin. But just 19 of the 31 satellites broadcast the higher-power civilian L5 signal, which is more resistant to interference than the civilian signals onboard satellites launched before 2010.

The loss of ULA as a launch provider is going to affect the ability to get GPS satellites into orbit. It's also not a new problem. 

In a little more than a year, the Space Force has launched three GPS satellites in relatively quick succession on SpaceX Falcon 9 rockets. All three were originally booked to launch on ULA’s Vulcan rocket. The first of these three newest GPS satellites, manufactured by Lockheed Martin, was declared complete and ready for launch in August 2021. Three years later, with ULA’s Vulcan rocket still not ready, the Space Force decided to switch it to a SpaceX launcher. 

In addition to the GPS satellites, there are more and different Vulcan military launches scheduled for this year. All of their statuses are unclear. One that's particularly notable is a missile-warning satellite, which is one of the Space Force’s most expensive satellites ever, at over $4 billion. It was supposed to launch on a Vulcan rocket in the coming months and be parked in geosynchronous orbit to detect the heat plumes of ballistic and hypersonic missiles.

Switching over to a Falcon 9 is simple for the GPS satellites because they've already done the hard part, developing the interface between the satellite and booster. For payloads like this missile-warning sat., unless it has a common interface with other payloads, they'll have to develop that.