The fifth GPS III satellite is now set healthy for initial operational use, according to the U.S. Coast Guard Navigation Center (NAVCEN). GPS III 05 (SVN-78/PRN-11) was launched June 17, 2021, from Space Launch Complex-40 at Cape Canaveral Air Force Station, Florida.
Constellation Changes
The U.S. Space Force Second Space Operations Squadron (2 SOPS) indicates that GPSIII 05 replaced SVN-61/PRN-28 in the D plane at slot D1.
SVN-61 is being rephased to optimize its position in the D plane, and is expected to complete its journey on or about July 14.
SVN-44/PRN-28 was moved to GLAN 31.64 to optimize its position within B plane.
GPS III space vehicle 05 (GPS III-SV05) launched in June 2021 from Cape Canaveral Space Force Base, Florida, aboard a SpaceX Falcon 9 launch vehicle. (Photo: SpaceX)
By Michael J. Dunn, Space Systems Command, Capability Area Integrator for Positioning, Navigation and Timing
The Global Positioning System is the premier positioning, navigation and timing (PNT) source for more than six billion users worldwide. It is vital to the function of all 16 of the United States’ essential critical infrastructure components. Life as we know it relies on the essential services that GPS provides.
The United States Space Force (USSF) is committed to maintaining a healthy GPS constellation that continues to deliver the “gold standard” of PNT availability and reliability throughout the world. Continuous improvements in equipment and performance have been a hallmark of the enterprise since its inception. 2021 was no exception, with a continued record-setting delivery of new capabilities.
Space Systems Command (SSC) at Los Angeles Air Force Base in El Segundo, California, is laser-focused on delivering the most important modernization in GPS history. The government and industry team are committed to bringing major upgrades to the space, control and user-equipment segments. It is an exhilarating time for the GPS enterprise. The specific updates within each segment cement the continued evolution in GPS and the USSF commitment to delivering advanced capabilities to the nation and the world.
Space Segment
Currently, 37 GPS satellites are on orbit, with 29 satellites set healthy. The baseline constellation requirement is 24 satellites. The system continues to perform in stellar fashion, providing an average 48-centimeter position accuracy throughout 2021.
Orbital systems modernization is focused on the GPS III satellite fleet, and the program continues to deliver peerless capabilities. GPS III space vehicles (SV) 1–4 were all operationally accepted in 2020. In 2021, the most notable event was the launch of GPS III SV05 in June. The satellite successfully achieved operational acceptance and mission-capable status for USSF in just under two weeks: a new record. SVs 6–8 are available for launch and are awaiting their launch windows. SV09 system-level testing is in progress. SV10 component deliveries continue. GPS III provides up to eight times better anti-jam and a new L1C signal to improve user connectivity.
For the GPS IIIF program, the long-range picture remains bright as the contract for GPS IIIF SVs 15–17 was awarded in October 2021. The delivery of the first GPS IIIF is expected early in 2026. GPS IIIF will build upon the tremendous increase in capability provided by GPS III with the addition of a search-and-rescue payload, a laser retroreflector array for precise ranging, a fully digital navigation payload, and a Regional Military Protect capability that will provide 60 times greater anti-jam for operations in electromagnetically hostile environments.
GPS III space vehicle 05 (GPS III-SV05) launched in June 2021 from Cape Canaveral Space Force Base, Florida, aboard a SpaceX Falcon 9 launch vehicle. (Photo: SpaceX)
Control Segment
The next-generation Operational Control System (OCX) continues to execute within its program baseline. OCX will provide enhanced command and control capabilities, modernized architecture, robust information assurance and cyber security.
OCX’s incremental development approach began with OCX Block 0, which is the launch and checkout system (LCS) for GPS III. The LCS successfully supported the launch and checkout of GPS III SV 01–05. OCX Blocks 1 and 2 will control all legacy GPS III satellites and both legacy and modernized signals.
Despite barriers presented by the global COVID-19 pandemic, all 17 global OCX monitoring station installations were completed in July 2021. Most of the remaining equipment was fielded throughout December 2021. System integration and verification continues with transition to operations scheduled for early 2023.
The Next Generation OCX 3F contract was awarded in April 2021. The program will modify OCX to launch and control GPS IIIF satellites with enhanced capabilities. Acquisition Milestone B is expected in 2022, and operational acceptance is planned for 2027.
MGUE: The future warfighter’s battlespace edge. (Image: Space Systems Command Production Corps)
User Equipment Segment
Millions of GPS receivers are fielded, but very few of them can use the military code (M-code) signal that is being broadcast by 24 GPS SVs. To keep our competitive advantage against the adversary, the GPS enterprise is focused on developing modernized GPS user equipment (MGUE) that takes advantage of these signals. The MGUE program is a joint service program developing modernized, M-code-capable military GPS receivers. The program is broken into two increments (Inc 1 and Inc 2). Both are designed to deliver secure PNT performance, allow navigation warfare operations, enhance anti-jam, anti-spoof and anti-tamper, and enable Blue Force Electronic Attack.
MGUE Inc 1 achieved a major milestone in September 2021 with successful testing on the Marine Corps Joint Light Tactical Vehicle (JLTV). The event took place in an electromagnetically degraded GPS environment at White Sands Missile Range, New Mexico. The JLTV is a pathfinder lead platform for the MGUE program. Lead platforms for the other services, the Army Stryker combat vehicle, Air Force B-2 bomber, and Navy Arleigh-Burke Class Guided Missile Destroyer, will commence integration testing in FY23 and FY24.
MGUE Inc 2 development continues to make progress in maturing the next generation ASIC technology required for all weapon-system platforms to provide functionality and backward compatibility. It will deliver a miniature serial interface card in CY26 to support handheld and ground applications. Eventually, MGUE receiver cards will be loaded onto hundreds of Department of Defense (DOD) weapon systems.
GPS III SV04 in Highbay (Photo: Lockheed Martin)
Partner Community
The GPS enterprise is committed to cooperation on a global basis. It works closely with the DOD, the armed services, the U.S. Coast Guard, other federal agencies, the International Civil Aviation Organization and all the other global and regional navigation satellite systems toward the development of PNT in the global commons.
A highlight of this cooperative work is GPS enterprise involvement in the National Executive Committee for Space-Based PNT (PNT EXCOM), which supports the interests of the various federal bodies, especially the Department of Transportation (DOT) and the Federal Aviation Administration (FAA). The PNT EXCOM is applying GPS technology to a broad variety of governmental activities, including the development of the Next Generation Air Transportation System and intelligent transportation systems.
The GPS enterprise commitment to international partners is unwavering. Our support to the North Atlantic Treaty Organization (NATO) is ongoing with support to the Capability Panel 2 for Navigation working toward the integration of MGUE and compatibility arrangements with Europe’s Galileo system. A highlight this year was the first delivery of MGUE loan equipment to the United Kingdom, Canada, Germany, and the Republic of Korea. Germany is the first country to purchase MGUE equipment.
Conclusion
GPS is the foundation of global PNT and a cornerstone of modern life. Improvements to the enterprise are continual. As the nation moves into the complex and dynamic world of the coming decades, the dedicated military, civilian and industry professionals that provide this world-changing capability will continue their challenging and rewarding work. Semper Supra!
The “encapsulation” of a GPS satellite. (Photo: U.S. Department of Defense)
GPS III SV05 (nicknamed Armstrong) was launched on June 17. (Photo: U.S. Space Force)
The U.S. Space Force’s Space and Missile Systems Center (SMC) transferred Satellite Control Authority of the GPS III SV05 to the 2nd Space Operations Squadron at Schriever (2 SOPS) Air Force Base on June 28. The fifth GPS III satellite — nicknamed Armstrong —was launched into space on June 17.
On June 29, GPS III SV05 received Operational Acceptance approval, marking the first GPS III SV to receive SCA handover and Operational Acceptance within 24 hours and decreasing the time from launch to on-orbit operational capability by 97 percent.
In 2020, the GPS enterprise launched two GPS III SVs in the midst of a global pandemic. According to Los Angeles Air Force Base, home of SMC, the delivery time from launch to Operational Acceptance approval has continued to shrink, with innovation and teamwork across the GPS enterprise enhancing rapid identification and elimination of redundant on-orbit verification steps.
Launch of SV05 was the first National Security Space Launch on a previously flown Falcon 9 booster, reusing the same booster that delivered GPS III SV04 to orbit in November 2020.
GPS III SV05 joins a constellation of 31 operational satellites. “The inclusion of GPS III SV05 into the operational constellation marks another significant milestone for the enterprise with 24 M-code capable satellites,” said Colonel Heather J. Anderson, transition director.
The Lockheed Martin-built GPS III SVs provide improved accuracy, advanced anti-jam capabilities, and increased resiliency for the GPS constellation and 4 billion users worldwide. GPS III SV05 will be set healthy to all global users in September, following the completion of on-orbit testing.
SpaceX launched into orbit for the U.S. Space Force the fifth GPS III satellite (SV05) on June 17.
Photo: U.S. Space Force
GPS III SV05 eventually will replace one of the legacy GPS IIR satellites. Once GPS III SV05 is operational, about 16% of the 31-satellite constellation will be modernized with GPS III’s new capabilities.
M-Code Requirement Met
GPS III SV05 is the 24th M-code satellite on orbit, completing the constellation’s baseline requirement to provide U.S. military forces a more-secure, harder-to-jam and spoof GPS signal.
GPS III SV05 is the fifth Lockheed Martin-built, next-generation GPS III space vehicle. The SpaceX Falcon 9 rocket is the first U.S. Space Force mission to reuse a previously-flown booster, the company said.
The U.S. Space Force contracted Lockheed Martin to design and build GPS III/GPS IIIF satellites to help modernize today’s GPS satellite constellation with new technology and advanced capabilities. Lockheed Martin said the GPS III provides three-times greater accuracy, eight times improved anti-jamming capability for U.S. military forces; a new L1C civil signal to the constellation that is compatible with other GNSS; and a new modular design that allows new technology and capabilities to be added in the future to better address changing mission needs and emerging threats.
Future GPS III Satellites
GPS III Space Vehicles 06, 07 and 08 already are complete and waiting to be called up for their launch dates, which are to be determined.
In addition, GPS III SV09 was core-mated, meaning it reached a major production milestone in which two major satellite components — the mission module and the propulsion core — are paired to form one space vehicle. The GPS III SV10 currently is in the component build up stage.
Lockheed Martin has been contracted to design and build up to 22 additional GPS III Follow On – or GPS IIIF – satellites (SV11-32), with even more capabilities. Contract options for the first four GPS IIIFs, SV11-14, have been exercised so far.
The U.S. Space Force contracted Lockheed Martin to design and build GPS III/GPS IIIF to help modernize today’s GPS satellite constellation. Photo: Lockheed Martin
By Col. Ryan Colburn Director, Spectrum Warfare Divisionand Portfolio Architect, Space and Missile Systems Center
The United States’ Global Positioning System is used now more than ever before. With an estimated four billion users worldwide, industries of all kinds continue to leverage the precise and consistent data streaming from the GPS satellites. The universal use of GPS signals permeates our lives and creates positive impacts around the globe.
We continue to deliver on our decades-long commitment to provide precise positioning and timing data to the civil, commercial and scientific communities. To support the evolving use of this global utility, the government and industry GPS Enterprise team has embarked on major investments to modernize GPS capabilities for our stakeholders. These efforts are occurring across all of our segments and combine to deliver incremental capabilities and improvements over time.
Colonel Ryan Colburn leads the team dedicated to modernizing the GPS constellation to meet tomorrow’s needs. (Photo: U.S. Space Force)
GPS ENTERPRISE ROADMAP
The GPS Enterprise Roadmap is an overview of the many programs we have in execution or planning stages. These efforts will enable us to deliver new and improved positioning, navigation and timing (PNT) capabilities across all segments. We are upgrading each of the three GPS segments (space, control, and user equipment) to deploy modernized capabilities while continually replenishing the GPS constellation; ensuring we have 24 or more operational satellites available at least 95% of the time.
Additionally, we are always working on what’s next. We are actively researching, prototyping and planning; looking at how we will continue to evolve this architecture into one that is more robust and resilient than it is today. Our team is working to define the next set of capabilities for not only the GPS, as the backbone of our architecture, but also for ways to build off of this system and expand our ability to deliver PNT capabilities in new and useful ways.
“We continue to deliver on our decades-long commitment to provide precise positioning and timing data to the civil, commercial and scientific communities.”
2021 UPCOMING MILESTONES
Space Segment
The GPS III program is off to a great start, further enhancing military readiness and bolstering the activities and assurance of all GPS users. The program continues to push space acquisition boundaries with the first reuse of a Falcon 9 rocket for a National Security Space mission.
Slated for launch in June, SV05 will launch on a flight-proven Falcon 9 booster that was recovered after successfully launching SV04 into orbit.
SV05 will continue the GPS constellation modernization effort and will deliver users a bump in performance and accuracy. The satellite features the interoperable L1C signal, the newest civilian L5 signal and anti-jamming improvements. For the military user, SV05 will become the 24th military-code (M-code) satellite, bringing M-code utility to its Initial Operating Capability.
The GPS III SV03 satellite is encapsulated in its protective launch fairings. (Photo: U.S. Space Force)
Ground Segment
2021 will be a big year for the Next Generation Operational Control System (OCX). OCX will soon complete the installation of an entirely modernized network of 17 global monitoring stations. These stations allow OCX to monitor the full suite of legacy as well as modernized military and civil navigation signals, including L2C and L5.
In the factory, OCX will continue to use a newly accredited GPS System Simulator (GSYS) in support of mission software testing. In parallel, OCX will continue to replace mission equipment with Hewlett-Packard Enterprise hardware prior to its deployment to operational sites. Once deployed, connections to the GPS command and control antennas will begin, and interconnections to other mission systems will be established.
This includes the GPS Global Information Grid Automated Information System (GGA) subsystem, which will ensure timely dissemination of important navigation data to the public. OCX’s Launch and Checkout System (LCS) will be used to launch and initialize GPS III SV05.
OCX 3F is a modification of the OCX baseline to support GPS IIIF-specific mission requirements. OCX 3F will maintain backward compatibility with the existing systems to support the legacy GPS constellation and will integrate future GPS IIIF capabilities. For example, it will implement command and control of the Regional Military Protection (RMP) and Rapid Warfighter Effects requirements. We are on track for an OCX 3F contract award later this year.
A GPS Antenna is installed at the Diego Garcia Tracking Station, part of the Satellite Control Network operated by the Space Force. (Photo: U.S. Space Force)
User Equipment Segment
In 2021, Military GPS User Equipment (MGUE) Increment 1 will culminate its ground user form factor efforts by completing a Field User Evaluation (FUE) of M-Code GPS technology in two service-nominated lead platforms. The Army FUE will be conducted with multiple variants of Stryker vehicles.
Meanwhile, the U.S. Marine Corps will use the Joint Light Tactical Vehicle (JLTV) for their FUE. Both events will assess the performance of the enhanced GPS receivers in operationally relevant environments. Toward the end of 2021, MGUE Increment 1 will deliver the aviation/maritime form factor, which will enable Navy Guided Missile Destroyer (DDG) and USAF B-2 bomber lead platform integration in 2022.
GPS III SV03 is rolled out to the launchpad before its daytime launch on June 30, 2020.
Enterprise Integration
None of these systems are delivered in a vacuum, and we work hard to integrate them all. It is the only way we can continue to deliver on our promises outlined in our published standards. From test campaigns and requirements management, to model-based systems engineering and roadmaps; it takes a united team of government and industry partners to deliver truly integrated capabilities.
We have many exciting milestones this year and we have a world-class government and industry team working tirelessly to ensure continued delivery, maintenance, and operations of GPS Enterprise capabilities. Our motivation is simple — continuing to deliver and evolve the gold standard PNT capabilities we all rely on day in and day out.
The U.S. Space Force’s Space and Missile Systems Center (SMC), located at the Los Angeles Air Force Base in El Segundo, California, is the center of excellence for acquiring and developing military space systems. The SMC’s portfolio includes space launch, global navigation satellite systems, military satellite communications, a meteorological satellite control network, range systems, space-based infrared systems, and space situational awareness capabilities.
The M-code-enabled SV03, shown launching in June 2020, was joined by SV04 in December. SV05, the 24th M-code-enabled satellite, is expected to launch by July 2021, completing the Initial Operating Capability of M-code. (Photo: U.S. Space Force)
Lockheed Martin Space has released the GPS-III satellite antenna phase-center data, as well as the group delay and inter-signal correction data, for SVN-76 and SVN-77 as measured at the factory, announced the U.S. Coast Guard’s Civil GPS Service Interface Committee (CGSIC).
The phase center and inter-signal bias data included in this new release provide additional information that supplements the antenna gain pattern data previously available.
Note that the GPS III satellite vehicles (SVNs) also broadcast the Inter-Signal Corrections (ISCs) in the various LNAV/CNAV messages in accordance with all the external IS/ICDs. The value that is being broadcast by the on-orbit constellation is not the factory measured ISCs but the ISCs estimated on-orbit by the Stanford Research Institute (SRI).
The U.S. Coast Guard Navigation Center has issued a notice that GPS satellite SVN-77 (PRN-14) was set healthy for initial use on Dec. 2 at 0131Z. This follows the U.S. Space Force announcement that the satellite, the fourth GPS III (SV04), received Operational Acceptance approval on Dec. 1.
SVN-77 is the 23rd satellite to broadcast L2C, the second civil GPS signal at 1227.6 MHz. L2C is not yet designated as “operational” by the U.S. Space Force.
However, the L2C signal is set to healthy, and users can utilize this signal at their own risk.
The U.S. Air Force’s Lockheed Martin-built next generation GPS III satellite on orbit. Rendering portrays GPS III Space Vehicles (SVs) 01-10. (Artist’s Rendering: Lockheed Martin)
SVN-77 is the 16th satellite to begin broadcasting the third civil GPS signal, L5, specifically designed for aviation use in an internationally protected band of spectrum designated for aeronautical navigation at 1176.45 MHz. L5 continues to broadcast an unhealthy designation.
SVN-77 is the fourth satellite broadcasting the new L1C signal at 1575.42 MHz.
The next GPS III satellite, SVN-78, initially scheduled to launch in January, will launch no earlier than July 1, 2021.
UPDATE: The U.S. Space Force, Space and Missile Systems Center (SMC) and its mission partners successfully launched the fourth GPS III satellite at 6:24 p.m. EST Nov. 5 from Space Launch Complex 40 at Cape Canaveral Air Force Station, Florida.
The Lockheed Martin-built satellite was carried to orbit aboard a Space Exploration Technologies Corporation (SpaceX) Falcon 9 launch vehicle.
“The launch of GPS III SV04 is a testament to SMC’s ability to rapidly and safely deliver new capabilities on orbit,” said Cordell DeLaPena, Air Force program executive officer for SMC’s Space Production Corps. “At SMC, we are proud to deliver our fourth GPS III satellite and will continue to operate at an accelerated pace to enhance the capabilities of the billions of users worldwide.”
“I’m proud of my team’s 83rd successful National Security Space Launch and look forward to our future missions with SpaceX,” said Col. Robert Bongiovi, SMC’s Launch Enterprise director. “Ultimately, our ability to embrace innovation with our launch providers advances warfighter’s capabilities while lowering costs to the U.S. Government and its taxpayers.”
GPS III SV04 separated from its upper stage approximately 90 minutes after launch. Engineers and operators at Lockheed Martin’s Waterton Facility will now begin on-orbit checkout and tests, which are estimated to complete in approximately one month. Operational use is expected to begin in a few months.
“The GPS III program continues to make strides in modernizing the GPS constellation for the U. S. Space Force while maintaining the gold standard for position, navigation and timing,” said Col. Edward Byrne, Medium Earth Orbit Space Systems Division chief.
GPS III SV04 will join the current GPS constellation comprised of 31-operational spacecraft. GPS III, the newest generation of GPS satellites, brings new capabilities to users, including three times greater accuracy and up to eight times improved anti-jamming capabilities.
A Falcon 9 carrying GPS III SV04 lifts off from Cape Canaveral Air Force Station, Florida, Nov 5. (Photo: SpaceX via USAF)
GPS constellation status
According to the U.S. Space Force Second Space Operations Squadron (2 SOPS), the satellite is designated SVN-77/PRN-14 in the GPS almanac. GPS III SV04 (SVN-77/PRN-14) will replace SVN-44/PRN-28 in the B plane at slot 03. 2 SOPS will issue a Launch NANU after on-orbit checkout when control of SVN-77 is transferred from Lockheed Martin to 2 SOPS for insertion into the GPS control segment.
GPS III SV-2 (SVN 75), launched Aug. 22, 2019, replaced SVN 45/PRN-21 at D3 and was set healthy on April 1, 2020. As a result, SVN 45 is being re-phased from D3 to D2F replacing SVN 46/PRN 11 and will arrive sometime in November of this year. SVN 46 will be taken out of the operational constellation before the January 2021 launch of GPS III SV05 (SVN-78) and sent to Launch, Anomaly, Resolution, and Disposal Operations (LADO), making PRN-11 available.
GPS III SV-03 (SVN 76, PRN-23) launched June 30, 2020, and was set operational and healthy on October 1.
SVN-46, launched October 7, 1999, has been an “iron bird” workhorse in the D-plane and has successfully served the world’s GPS users for more than 20 years, 12 years past its designed service life. It outlasted (and in many cases, outperformed) many of its peers on-orbit, testament to quality engineering and the diligent efforts of the men and women of the U.S. Air Force.
Screenshot: SpaceX
The fourth GPS III satellite (GPS III SV04) is scheduled to launch today at 06:24 p.m. EST (~15 minute launch window) from Cape Canaveral Air Force Station, Florida, on a SpaceX Falcon 9 rocket. The new launch window follows an aborted launch with two seconds to go on Oct. 2.
Built by Lockheed Martin, GPS III satellites are designed to help the U.S. Space Force modernize the current GPS constellation with new technology and advanced capabilities. GPS III provides three times greater accuracy and up to eight times improved anti-jamming power over satellites in the current constellation. GPS III also adds a new L1C civil signal compatible with Europe’s Galileo global navigation satellite system, which will provide greater civil user connectivity in the future.
After adding GPS III SV04, the four GPS III satellites on orbit will represent about 12 percent of the 31 satellites in the GPS constellation.
GPS III SV04 is the 23rd M-code-enabled satellite in the constellation, only one short now of the 24 needed for global coverage. M-code is a more-secure, harder-to-jam or spoof signal invaluable to U.S. and allied military forces.
GPS III SV03, which lifted off from the Cape on June 30, was set operational on Oct. 1. The next satellite — GPS III SV05 — was declared “Available for Launch” in May 2020. The satellite is now waiting to be called up for a launch date in 2021. Five more GPS III satellites are in production, three of which are fully assembled and in testing.
Lockheed Martin is also under contract to build up to 22 additional GPS III Follow On (GPS IIIF) satellites, which add additional technology and advanced capabilities to this warfighting system, including a new Regional Military Protection Capability, which will increase anti-jam support in theater to ensure U.S. and allied forces cannot be denied access to GPS in hostile environments; an accuracy-enhancing laser retroreflector array; a fully digital navigation payload; and a new search and rescue payload.
In July, the Space Force declared that the GPS IIIF program had fulfilled Milestone C, which means the start of the production phase. Lockheed Martin has introduced augmented reality tools into the GPS IIIF production process to drive even-greater efficiency into the production process.
Continued investment in GPS is important. Besides the military applications, the U.S. economic benefit of GPS is estimated to be over $300 billion per year and $1.4 trillion since inception.
The first launch attempt on Oct. 2 from Cape Canaveral was halted due to an “unexpected pressure rise in the turbomachinery gas generator,” said SpaceX CEO Elon Musk on Twitter, referring to a part in the rocket’s Merlin engines.
SpaceX test-fired the Falcon 9 rocket for the GPS mission on Saturday at 7 p.m. on pad 40 at Cape Canaveral Air Force Station to verify that corrective actions have resolved the issue, according to SpaceX and reported by SpaceFlightNow. The fourth GPS III satellite was not aboard during the test.
GPS III SV04 first rolled out to Cape Canaveral’s Space Launch Complex 40 on Sept. 27. The satellite was originally scheduled for launch Sept. 30, then Oct. 1, but that launch was delayed because of a “traffic jam” at the launchpad caused by launch delays of other rockets.
The satellite was almost launched at 9:43 p.m. EDT on Oct. 2 until the launch was stopped at T– 2 seconds.
The Lockheed Martin-built GPS III SV04 will be launched aboard a SpaceX Falcon 9 rocket — the third National Security Space Launch (NSSL) mission on a Falcon 9 rocket, the second U.S. Space Force (USSF) first-stage booster recovery, and the sixth USSF launch.
A live feed will begin 20 minutes before the launch and conclude approximately 45 minutes afterward. A simulcast of the broadcast can be viewed at www.spacex.com.
GPS III SV04 will be launched to augment the current GPS constellation comprised of 31 operational spacecraft. GPS satellites operate in Medium Earth Orbit (MEO) at an altitude of approximately 20,200 km (12,550 miles) in six orbital planes. Each satellite circles the earth twice per day.
GPS III brings new capabilities to users such as the new L1C civilian signal, which opens the window for future interoperability with international satellite navigation systems.
GPS III SV04 rests atop a Falcon 9 rocket, waiting to be sent into orbit. (Photo: SpaceX)
The aborted launch of the fourth GPS III satellite has sparked an investigation into the SpaceX Falcon 9’s Merlin engine. With only two seconds before launch, SpaceX stopped the scheduled launch of the fourth GPS III satellite on Oct. 2.
Tim Dunn of NASA’s Launch Services Program said at an Oct. 16 briefing that the engines had undergone significant testing since the GPS III launch scrub, including taking the Merlin engines from that rocket back to SpaceX’s McGregor, Texas, test site for further study, reports SpaceNews.com. That investigation has involved NASA and Space Force personnel working with SpaceX.
While the GPS III launch has not been rescheduled, Dunn said that the NASA and SpaceX personnel have learned much, with implications involving the rocket hardware.
GPS III SV04 rests atop a Falcon 9 rocket, waiting to be sent into orbit. (Photo: SpaceX)
UPDATE (Oct. 5):Elon Musk, SpaceX founder and CEO, said a Falcon 9 launch was halted Friday night due to an “unexpected pressure rise in the turbomachinery gas generator,” referring to a part in the rocket’s Merlin engines, reports SpaceflightNow.
SpaceX has not yet set a new launch date. Another planned launch, for a Starlink satellite, was also aborted.
UPDATE (Oct. 3):Only two seconds before launch, SpaceX aborted the scheduled launch of the fourth GPS III satellite on Oct. 2. SpaceX has not yet announced a new launch window, or stated the reason for the cancellation.
We will need to make a lot of improvements to have a chance of completing 48 launches next year!
(Oct. 1) The U.S. Space Force’s newest GPS III satellite, Space Vehicle 04 (GPS III SV04), rolled out to Cape Canaveral’s Space Launch Complex 40 on Sept. 27. Originally scheduled for launch Sept. 30, then Oct. 1, the satellite is now slated to launch 9:43 p.m. EDT on Oct. 2 (01:43 a.m. UTC on Oct. 3).
The launch was delayed because of a “traffic jam” at the launchpad. According to Spaceflight Now, SpaceX initially rescheduled the GPS launch for Wednesday night after a Delta 4 launch was delayed to Tuesday. After the Delta 4-Heavy’s scrub Tuesday, SpaceX announced the GPS launch would be pushed back to Friday, when there is a 15-minute launch window available opening at 9:43 p.m. EDT (0143 GMT Saturday, Oct. 3).
The Lockheed Martin-built GPS III SV04 is scheduled to launch aboard a SpaceX Falcon 9 rocket — the third National Security Space Launch (NSSL) mission on a Falcon 9 rocket, the second U.S. Space Force (USSF) first-stage booster recovery, and the sixth USSF launch on Sept. 30. The 15-minute launch window opens at 9:51 p.m. EDT. A live feed will begin 20 minutes before the launch and conclude approximately 45 minutes afterward. A simulcast of the broadcast can be viewed at www.spacex.com.
“The GPS III program office in partnership with our contract teammates continue to push the envelope on the capabilities they deliver to users, both civil and military around the globe. Our latest GPS III satellites’ nearly 70 percent digital payload provides the U. S. Space Force with greater operational flexibility and cutting edge capabilities while continuing to support legacy users,” said Cordell DeLaPena, Air Force program executive officer for SMC’s Space Production Corps.
GPS III SV04 will be launched to augment the current GPS constellation comprised of 31 operational spacecraft. GPS satellites operate in Medium Earth Orbit (MEO) at an altitude of approximately 20,200 km (12,550 miles) in six orbital planes. Each satellite circles the earth twice per day. GPS is the premier space-based provider of positioning, navigation, and timing services for more than four billion users worldwide. This latest generation of GPS satellite boasts a 15-year design life — 25 percent longer than the previous generation of GPS satellites on orbit.
GPS III brings new capabilities to users such as the new L1C civilian signal, which opens the window for future interoperability with international satellite navigation systems.
“Our GPS III team is excited to be here once again. Less than 3 months ago, we successfully launched GPS III SV03. Since then, the team has successfully delivered the satellite to its final orbit, performed on-orbit testing and delivered the satellite to operations, while executing a mature satellite production line. I can’t be more proud of everyone involved in this mission,” said Col. Edward Byrne, Medium Earth Orbit Space Systems Division chief. “The launch of GPS III SV04 will continue to modernize our GPS constellation by increasing our capabilities with advanced features for both our civil and military users across the world.”
A Falcon 9 with GPS III SV 04 encapsulated inside the payload fairing the stands vertical on the pad at Cape Canaveral’s Space Launch Complex 40 in preparation for launch. (Photo: USAF/SpaceX)
The U.S. Space Force Space and Missile Systems Center on July 14 delivered the fourth GPS III satellite to Cape Canaveral Air Force Station, Florida. The satellite is scheduled for launch on Sept. 30.
GPS III Space Vehicle (SV) 04 was safely transported from the Lockheed Martin facility in Waterton, Colorado to Space Coast Regional Airport in Titusville, Florida. The satellite was carried aboard a C-17 Globemaster III originating from Joint Base Lewis-McChord, Washington.
The fourth GPS III satellite arrived at Cape Canaveral July 14 for launch on Sept. 30. (Photo: USAF)
The delivery of GPS III SV04 starts the clock for final testing and checkout prior to launch. The satellite will be processed at the Astrotech Space Operations facility in Florida to ensure the full functionality of the satellite, prepare the satellite for propellant loading, and encapsulate the satellite in its protective fairing. At the completion of these activities, the satellite will be horizontally integrated with the SpaceX Falcon 9 launch vehicle.
“The shipment of the fourth GPS III satellite was successfully conducted just two weeks after the launch of our GPS III-SV03 satellite. This operation is a remarkable achievement and testament to the hard work of the entire GPS team members from all across the country,” said Col. Edward Byrne, SMC’s Medium Earth Orbit Space Systems Division chief. “The delivery of SV04 marks the start of our third GPS III launch campaign on a SpaceX Falcon 9 rocket and brings us another step closer in advancing the GPS constellation with more capable satellites.”
GPS III SV04 is slated to launch in September. Once on-orbit, it will join the operational constellation of 31 GPS satellites, delivering enhanced resiliency, better accuracy, and advanced anti-jam capabilities.
