The latest addition to the United States’ Global Positioning System (GPS) constellation is set to be launched into medium Earth orbit on Friday afternoon.
The GPS III-7 Space Vehicle 08 (SV-08) will launch atop a SpaceX Falcon 9 rocket from Space Launch Complex 40 at Cape Canaveral Space Force Station. Launch teams are targeting liftoff at 1:23 p.m. EDT (1723 UTC), the opening of a 15-minute window.
Spaceflight Now will have live coverage beginning about two hours prior to takeoff.
During a prelaunch news briefing on Wednesday, Launch Weather Officer Mark Burger said that there was a 45 percent chance for favorable weather for launch on Friday. That outlook remained unchanged on Thursday.
“We’ll be looking at those cumulus cloud violations and associated thunderstorms in and close to the pad,” Burger said. “One thing that is working in our favor is that the time of the day isn’t as bad as we would see later in the day or evening in this pattern. So again, despite the relatively high POV [probability of violating weather rules], I suspect that there’s a good chance we’ll at least have some opportunity to work with on launch day.”
SpaceX will fly its Falcon 9 first stage booster, tail number B1092, on this mission, which will be its fourth flight. It previously launched the Starlink 12-13, NROL-69 and CRS-32 missions.
About 8.5 minutes after liftoff, B1092 will target a landing on the droneship, ‘A Shortfall of Gravitas.’ If successful, this will be the 111th booster landing on that vessel and the 454th landing to date.
Like with the previous GPS mission, the Falcon 9’s second stage will feature a gray band, which helps regulate the thermal temperatures of the propellant tank. It’s used for missions that require an extended coast phase or will spend long durations either in the Earth’s shadow or in direct sunlight.
“That goes back to our first launch, when we were exploring all these different options with SpaceX before our first launch with them,” said Walt Lauderdale, the Mission Director and Chief of Falcon Systems and Operations, Launch Execution Division within the Space System Command’s Assured Access to Space.
“One of the areas that we had concern that we shared with them was the very point there about the longer coast, being able to make sure that we had the propellants under proper thermal conditions for those missions. And it’s been a great journey together that has created this capability that SpaceX is able to use for multiple customers. So we’re really happy with the partnership.”
Rapid cadence
The SV-08 mission comes less than a half a year after the launch of the previous third generation GPS satellite, SV-07. That mission, initially referred to as the Rapid Response Trailblazer or RRT-1 was a relatively short turnaround time for getting a mission from contract to launch.
Typically, a government mission can have a timeline of 18 to 24 months from the initial launch award to getting to the launch pad. SV-07 shifted from a United Launch Alliance Vulcan rocket to a SpaceX Falcon 9 because by the middle of last year, Vulcan still wasn’t certified to launch national security missions and the Space Force wanted to get that GPS capability into the fleet.
In exchange, ULA will launch SV-10 instead of SpaceX.
Col. Andrew Menschner, commander of Mission Delta 31 at Peterson Space Force Base in Colorado, said one of the biggest lessons learned from RRT-1 was the possibilities for improving national security launch timelines, especially for something like the GPS program.
“We went through a process of maximizing our efficiency and we thought we did pretty well getting down to the five-month timeline. And then we looked at ourselves and said, ‘We can do that better,’” Menschner said. “And so this, what you see today, is just simply the evolution of that and we’re getting it down to just over three months.”
Lockheed Martin, the GPS III satellite manufacturer, received the letter calling up the SV-08 satellite out of storage on Feb. 21 and the call for launch to SpaceX was sent on March 7.
“I’ll say somewhat tongue-in-cheek, compared to SV-07, this was, I’ll say, a relatively less punishing path to launch, primarily because of the challenges we faced on SV-07, whether it was ground transportation or the RRT climate,” said Malik Musawwir, the vice president of Navigations Systems for Lockheed Martin.
During the previous mission, they had to forgo getting a C-17 plane flight and pivot to ground transportation because those aircraft were being used in hurricane response. That required creating a new, secure ground path, while also watching the storms in Florida at the time.
Normally, calling up a GPS satellite from storage can take four to five months just to ready the satellite itself before transportation. That’s because while they’re in storage, they’re not fully integrated.
So they had to fully integrate the vehicle, with features like the solar arrays, which are stored separately from the rest of the vehicle, and go through operational checkouts, like electrical and mechanical testing, before it could ship. Then once in Florida, it had to go through other processing, like attaching to the payload adaptor, encapsulating it in the fairings and transporting it to the launch pad.
“Every step of the way, where we can find opportunities to accelerate is the key to accelerating that speed even more so,” Musawwir said. “Having the open communication with our government team to make sure that we’re aware of launch needs, getting ahead of that integration and testing curve and iterating and improving upon each one of those processes of how we can test faster, test better, integrate faster and deploy faster are really how we can achieve the faster timelines today.”
There are two remaining GPS III satellites in storage at Lockheed Martin’s facilities in Littleton, Colorado, which are set to be launched on ULA Vulcan rockets. Lauderdale said there are no plans to reassign those missions to SpaceX “at this time.”
Adding resiliency
Getting this next GPS satellite into orbit as part of the constellation of 31 existing satellites is important in part because SV-08 includes Military Code or M-code capabilities. That’s additional software that protects the satellite from interfering communications and spoofing attempts.
Currently, 24 of the GPS satellites on orbit have this capability, which was a requirement for the Space Force, but according to a June 2023 Government Accountability Office (GAO) report on GPS Modernization, it was determined that “it needs at least three more to meet certain user requirements for accuracy.”
SV-07 was the 25th M-code-capable satellite and SV-08 will be the 26th. SV-09 was declared “available for launch” back in August 2022 and like the others, has been awaiting launch ever since.
ULA is set to launch its first national security mission with its Vulcan rocket, USSF-106, no earlier than this summer, following the launch of the Kuiper Atlas 02 mission in mid-June. There’s at least one other national security mission for ULA ahead of the flight of SV-09, so it’s unclear when that will launch.
Asked if the Space Force will try and get the remaining two GPS III satellites launched this year, Menschner said, “We’re ready to go. We would certainly defer to the Space Force prioritization of when vehicle should receive rides to orbit.”
“It’s one of the things I mentioned earlier about the foresight of the GPS III program, being able to qualify on multiple launch providers,” Menschner said. “That gives the Space Force and the GPS III program a tremendous amount of flexibility. We’re ready to go and we’re excited to whenever that opportunity comes.”
Menschner said even before these next satellites are launched into orbit, they’re helping to prove out the resilience of the GPS III constellation.
“We’re trying to prove that we can quickly respond to an on-orbit failure of a vehicle, but we’re also trying to show the best ways to be resilient now that we have the timelines of launch headed to much shorter durations,” Menschner said. “One form of resilience is having a completed vehicle in the factory and ready to go to respond.
“Said another way, we don’t always have to have a vehicle in orbit for it to be providing resilience in the constellation.”
