Of all the modern miracles enabled by spaceflight, global positioning satellites are among the most useful and ubiquitous. Military and civilian users across the globe depend on the 31 satellites, in six different orbital planes above Earth, to provide continual navigation signals.
And the newest member of this constellation, a spacecraft called called GPS III, is the next generation of these vital navigation satellites. Launched on December 23 by a SpaceX rocket, GPS III is now in the hands of ground control crews at Lockheed Martin who are manoeuvring the GPS satellite into its final orbit, a task that will be wrap up sometime next week.
“GPS III will ensure the availability of this critical utility with enhanced performance to billions of users worldwide for decades to come,” says Keoki Jackson, Lockheed Martin’s chief technology officer and former program manager of GPS III.
The launch of the GPS III satellite is considered a huge milestone in the US Air Force’s painful quest to upgrade the global positioning system. But this first satellite, was supposed to launch in 2014, and this four-year delay is only a glimpse of the problems that plague these satellites.
A Satellite With Benefits
It’s easy to be excited about what GPS III spacecraft has to offer. The new capabilities of the planned 10-satellite constellation will address some of the most common risks and shortcomings of our aging nav sats. But the upgrades coming should make the service more reliable and accurate for civilians, more secure against those who want to jam military users, and more cyber-secure for everyone. A GPS III is also expected to have a 15-year lifespan, twice as long as the current sats, and are designed to launch in pairs, which also cuts costs.
The spacecraft also benefits from advances in satellite design, especially electronics and power management. The navigation payload has more than three times reduction in range error and up to eight times increase in power than what’s in orbit now. That power increase means that the signals will be easier to pick up under treetops, within the canyons of cities, and inside buildings.
The spacecraft beams two civilian signals to the planet, which gives the GPS III the ability to directly detect and correct errors caused by the ionosphere. One of the civilian signals is compatible with other Global Navigation Satellite Systems, so the satellite also plays nice with GPS systems run by Europe, China, India and Japan.
But the serious benefits of GPS III are reserved for the military. Encrypted M-code signals will be up to eight times more powerful than current systems. This makes them more reliable but also enables the sats to overcome efforts to jam their signals.
This comes with some new orbital hardware. The GPS III has a high-gain directional antenna. Most GPS signals are broadcast on a wide antenna so it can cover the largest amount of area below. But this directional antenna aims signals in a spot beam, covering an area just 120 miles in diameter but blasting the signal at high power. That should be enough to counter jamming and get navigation signals to the weapons and vehicles that need it.
This rosy future is not guaranteed. Delays to the program, caused by problems with supplier parts, have placed pressure on the sat construction and development. The Government Accountability Office warned in late 2018 that the schedule is so tight that lessons learned during the operational testing of the satellite may come after others are built or even launched. Luckily, current GPS satellites are still far from obsolete.
“Projections for how long the current constellation will be fully capable have increased by nearly 2 years to June 2021, affording some buffer to offset any additional satellite delays,” reports the GAO. “While the first GPS III satellite has a known parts problem, six follow-on satellites—which do not —are currently scheduled to be launched by June 2021.”
A Long List of Bad News
But even more worrisome than the satellites themselves, the full use of GPS III depends on the development of the other segments of the global positioning system—some of which are in deep trouble.
A navigation satellite is just space junk unless there is hardware on Earth ready to receive its signals. The GPS III’s military upgrades in particular require new ground control stations, a replacement effort called OCX that began with a $3.4 billion price budget that the Air Force and Raytheon busted (to $4.25 billion) by 2016.
By now, that cost is $6 billion and the 2019 budget request for the GPS program sought more than $500 million for OCX.
The costs are painful but the delays are even worse. The USAF scheduled OCX to enter service in October 2016, but the date to start the M-code broadcasts delayed until 2022.
The program did the world a favour by decoupling the civilian signal, called L2C, from the OCX deployment. But the growing militarisation of space made these delays unacceptable to military commanders.
So the Air Force and Lockheed created a stop-gap ground station system upgrade called COps (a riff on “contingency operations”). Without COps, the military can’t use any GPS III satellite. Coders started working on this in 2016, and about $160 million and several years later, the stop-gap seems on track to be delivered in April 2019. In another effort, military coders are working on an early use version of M-Code software, which may be ready by 2020.
But one last hurdle remains. Every piece of equipment that uses global positioning sats needs a receiver that is capable of handling the M-code. The effort to develop these receiver cards has been hampered by the lack of operational testing, since no sats had been launched.
“The military services were unlikely to have sufficient knowledge to make informed procurement decisions starting in fiscal year 2018, because operational testing that provides valuable information about Military GPS User Equipment (MGUE) performance would not be complete until fiscal year 2019,” the GAO notes.
A Bright GPS Future…Delayed
So when can the military expect for the new GPS III to provide its promised battlefield advantages?
It could be a while, the GAO warns: “Full M-code capability—which includes both the ability to broadcast a signal via satellites and a ground system and user equipment to receive the signal—will take at least a decade once the services are able to deploy MGUE receivers in sufficient numbers.”
In any situation, the delays and cost overruns would make an observer’s head spin. But unfortunately for the Pentagon, the need to protect sats has never been greater. As more nation’s militaries become increasingly capable in space, the U.S. finds itself on the defensive in orbit. A nation that projects power across the world can be hobbled with an attack on vulnerable space navigation systems.
This changing landscape has prompted big changes in the Pentagon, with the creation of a Space Command and a future debate over the wisdom of forming a whole new branch of the military (the Space Force) to focus on operations in orbit. As this pressure grows, the beleaguered program will certainly receive sharp attention.
So while the launch of this first GPS III satellite is a big milestone, it’s still got a long and bumpy road ahead.