Enter GPS III. The long-awaited navigation payload for the next-generation satellite pulled into its new temporary home over the September 13 weekend, the Lockheed Martin Space Systems facility in Littleton, Colorado. Lockheed is the U.S. Air Force’s prime contractor for the first batch of eight GPS III satellites.
Exelis Geospatial Systems has committed to delivering the payloads for the second, third, and fourth GPS III satellites “right on the heels” of the first, according to Gen. John Hyten, commander of Air Force Space Command. “If that’s the case, in the not-too-distant future GPS III will be in good shape,” he added. The first GPS III launch is now scheduled for 2016.
Exelis has built GPS payloads since the beginning of the program, but found new challenges over the last two years posed by advanced features of the modernized version. “First-time development and integration issues, including design changes to eliminate signal crosstalk” have set back the schedule.
According to reports, Lockheed Martin has a group of initial platforms readied on its production line to take the incoming payloads.
Still ahead, completion of acceptance testing following integration with the first satellite platform.
Earlier this year, Lockheed Martin issued a request for information on alternate payload providers, and received responses from five companies. In June, the Air Force issued a call for contractors interested in building the next batch of GPS IIIs. Northrop Grumman and Boeing have responded.
The seventh GPS-IIF satellite, SVN-68/PRN-09, launched on August 2, was set to healthy and usable Sunday night, according to Rick Hamilton, CGSIC executive secretariat of the USCG Navigation Center. The change brings the number of satellites transmitting the L2C signal to 13, and those transmitting the L5 signal to seven.
The next GPS-IIF satellite, IIF-8/SVN-69, is tentatively scheduled for launch on October 29.
Below is the full text of the Notice Advisory to Navstar Users (NANU).
NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2014071
SUBJ: SVN68 (PRN09) USABLE JDAY 260/2026
1. NANU TYPE: USABINIT
NANU NUMBER: 2014071
NANU DTG: 172024Z SEP 2014
REFERENCE NANU: N/A
REF NANU DTG: N/A
SVN: 68
PRN: 09
START JDAY: 260
START TIME ZULU: 2026
START CALENDAR DATE: 17 SEP 2014
STOP JDAY: N/A
STOP TIME ZULU: N/A
STOP CALENDAR DATE: N/A
2. CONDITION: GPS SATELLITE SVN68 (PRN09) WAS USABLE AS OF JDAY 260
Two U.S. Air Force officers provided a GPS program update at Tuesday morning’s Civil GPS Service Interface Committee meeting plenary session at the ION GNSS+ 2014 conference in Tampa, Florida. Here are some key points from the presentations by Colonel Matthew Smitham, deputy director, GPS Directorate, and Lieutenant Colonel Todd Benson, Commander, Second Space Operations Squadron:
31 primary satellites on orbit, 7 satellites in residual status, 1 satellite in test status
best weekly URE of 58.7 cm during week of 18 August 2014
newer satellites typically perform better than older ones
anticipate URE dropping to about 30 cm in a few years as more modern satellites come on line
60-70 navigation data uploads to the satellites are performed each day; average of about two per satellite per day
IIFs:
SV 3 and SVs 5-12 have improved rubidium clocks; one of the IIFs is running on a cesium clock
14 SVs are currently broadcasting L2C (set healthy); 7 SVs are broadcasting L5 (set unhealthy)
CNAV:
Data uploads are currently being done about twice per week to each satellite; daily updates expected by December 2014
average UREs currently about 1.4 m (data ages quickly with few uploads per week); expect CNAV URE to be marginally better than LNAV (Legacy NAV) when daily uploads begin
Continued progress in bringing M-code on line; expect early use by 2017
GPS III:
satellites will use three improved rubidium clocks
although the program is behind schedule, SV 1 will be available for launch starting in January 2016
the Block 0 version of the OCX (Next Generation Operational Control System), currently under test, will be needed to support the GPS III satellites
The U.S. Air Force’s fleet of GPS Block IIR and IIR-M satellites, manufactured by Lockheed Martin, have reached 200 collective years of operational life. The 20 satellites make up about two thirds of the current GPS constellation.
Originally launched between 1997 and 2009 to add capabilities to the GPS constellation and to replace other aging satellites, the 12 GPS IIR and eight IIR-M satellites have maintained an availability record of 99.96 percent, which represents only 10 minutes of down time per satellite during all their years of operation.
The 200-year milestone will be celebrated with a brief cake-cutting “ceremony” during ION GNSS, on Wednesday at 12:30 p.m., at the Lockheed Martin booth.
“This is a tremendous GPS operations and sustainment performance milestone, and we applaud the men and women of the Second Space Operations Squadron of the Air Force’s 50th Space Wing, as well as the industry team who support them,” said Mark Stewart, vice president for Lockheed Martin’s Navigation Systems mission area. “The world relies on GPS every day for things like synchronizing global banking and investing, shipping and transportation, search and rescue operations, ATM transactions and even precision farming.”
This spring, the IIR-M satellites played a major role in the continued modernization of the GPS constellation. To help manufacturers develop and test next-generation advanced civil GPS receivers, under the direction of Air Force Space Command and in collaboration with the Department of Transportation, these satellites began early broadcasting of test civilian navigation, or CNAV, messages on a new signal planned for all future satellites.
Making these milestones even more significant is the fact that the GPS IIR and IIR-M satellites were designed to last 7.5 years, or collectively about 150 years. All 12 IIR satellites are currently operating beyond their design life with the oldest operating for more than 16.5 years. Three of eight GPS IIR-M satellites have surpassed their expected life span and all satellites will have done so in 2017.
To meet evolving GPS user demands, Lockheed Martin is developing the next-generation GPS III satellites. These satellites will deliver three times better accuracy, provide up to eight times improved anti-jamming capabilities, and include enhancements which extend spacecraft life to 15 years, 25 percent longer than the newest Block IIF satellites. GPS III will be the first generation of GPS satellite with a new L1C civil signal designed to make it interoperable with other international GNSS.
Starting Friday, September 5, GPS satellite SVN-35 will resume transmitting L-band signals using PRN03, according to a Notice Advisory to Navstar Users (NANU) issued today.
According to GPS WorldAlmanac editor Richard Langley, the resumption is being done in an effort to determine the exact status of SVN-35’s remaining clock. However, the satellite will remain unusable as the Air Force conducts its tests.
Below is the full text of the NANU.
NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2014069 NANU TYPE: GENERAL
*** GENERAL MESSAGE TO ALL GPS USERS ***
On approximately 05 Sep 2014 SVN35 will resume transmitting L-band utilizing PRN03. At L-band activation, SVN35/PRN03 will be unusable until further notice. Additionally, no broadcast almanacs will include SVN35/PRN03 until further notice.
A United Launch Alliance (ULA) Atlas V rocket carrying the seventh GPS IIF satellite for the U.S. Air Force launched at 11:23 p.m. EDT Friday, August 1 (03:23 UTC, August 2), from Space Launch Complex-41 at Cape Canaveral, Florida.
GPS IIF-7 launches into orbit. (Photo credit: United Launch Alliance)
A United Launch Alliance (ULA) Atlas V rocket carrying the seventh GPS IIF satellite for the U.S. Air Force launched at 11:23 p.m. EDT Friday, August 1 (03:23 UTC, August 2), from Space Launch Complex-41 at Cape Canaveral, Florida.The Boeing-built satellite has sent the signals to controllers that confirm it is currently operating properly within the constellation.
Boeing and the Air Force will complete the full on-orbit checkout of the satellite in August. The GPS IIFs offer improved signal accuracy, better anti-jamming capability, longer design life and the new civilian L5 signal.
“We are providing our Air Force partner and GPS users with a steady supply of advanced GPS IIFs,” said Craig Cooning, president of Boeing Network & Space Systems. “Our robust launch tempo requires vigilance and attention to detail, and mission success is our top priority. We continue to partner with the Air Force and ULA to effectively execute the launch schedule.”
GPS IIF-7 is the seventh of 12 such satellites Boeing has built for the U.S. Air Force, and the third on-orbit delivery this year. GPS IIF-8, slated for launch during the fourth quarter, arrived at Cape Canaveral on July 16 to undergo final launch preparations. GPS IIF-7 will join a worldwide timing and navigation system utilizing 24 satellites in six different planes, with a minimum of four satellites per plane positioned in orbit approximately 11,000 miles above the Earth’s surface.
“Congratulations to the U.S. Air Force and all of our mission partners on the successful launch of the Atlas V carrying the GPS IIF-7 satellite,” said Jim Sponnick, ULA vice president, Atlas and Delta Programs. “ULA launch vehicles have delivered all of the current generation of GPS satellites, which are providing ever-improving capabilities for users around the world.”
This mission was launched aboard an Atlas V Evolved Expendable Launch Vehicle (EELV) 401 configuration vehicle, which includes a 4-meter-diameter payload fairing. The Atlas booster for this mission was powered by the RD AMROSS RD-180 engine, and the Centaur upper stage was powered by a single Aerojet Rocketdyne RL10A engine.
The EELV program was established by the United States Air Force to provide assured access to space for Department of Defense and other government payloads. The commercially developed EELV program supports the full range of government mission requirements, while delivering on schedule and providing significant cost savings over the heritage launch systems.
GPS IIF-7 launches into orbit. (Photo credit: United Launch Alliance)
According to Innovation editor Richard Langley, it appears that the satellite will be assigned PRN09, currently unused by the constellation.
The Initial NORAD 2-line element set indicates that the satellite has been launched into the F plane and is drifting towards its assigned orbital slot:
The GPS IIF-6 satellite was launched May 16. Photo credit: United Launch Alliance.
The Air Force is set to launch the seventh GPS IIF satellite this Friday.
An Atlas V 401 will launch the GPS IIF-7 mission for the U.S. Air Force on Friday, August 1, from Space Launch Complex (SLC)-41 at Cape Canaveral Air Force Station, Florida. The 18-minute launch window opens at 11:23 p.m. EDT.
A live webcast of the launch will begin at 11:03 p.m. EDT. To keep up to speed with updates to the launch countdown, dial the ULA launch hotline at 1-877-852-4321 or join the Facebook conversation and follow UA on Twitter using the hashtag #GPSIIF7.
GPS IIF-7 is one of the next-generation GPS satellites, incorporating various improvements to provide greater accuracy, increased signals, and enhanced performance for users.
The Air Force Second Space Operations Squadron indicates that IIF-7, SVN-68/PRN-3, will replace SVN-43 in the F plane slot 3 (F3). SVN-43 will be re-phased from F3 to the F2F slot to replace SVN-26. SVN-33 will be taken out of the operational constellation the day after SVN-68 launch and sent to Launch, Anomaly and Disposal Operations (LADO).
SVN-33 was launched on April 9, 1996, successfully serving over 17.5 years, 10.5 years beyond its design life. SVN-26 will back-up SVN-43 once it completes its re-phase journey.
At least some of the work on GPS III continues along prepared tracks, with the award of a Lockheed Martin contract to General Dynamics for two more satellites’ worth of communications hardware. General Dynamics Advanced Information Systems, a business unit of General Dynamics, was awarded a $25.4 million full-production contract from Lockheed Martin to support the GPS III Network Communications Element (NCE) for space vehicles seven and eight (SV 07-08). This commitment fills out that aspect of the current Lockheed Martin bevy of eight bought by the U.S. Air Force.
Many if not all components of the GPS III constellation beyond the Initial Eight have been called into question recently, with the U.S. Senate, the Air Force, and Lockheed itself keeping open minds about alternatives.
General Dynamics’ NCE components provide the communications functions for the GPS III satellites, including the ground-to-space command and control channel, the space-to-space inter-satellite channel and the command and telemetry communications channels within each satellite. General Dynamics is now under contract with Lockheed Martin for GPS III SV 01-08. Delivery of the NCE components for SV03 and SV04 are scheduled for this summer.
Compared to prior GPS vehicles, the Air Force’s GPS III satellites will deliver three times better accuracy, provide up to eight times more powerful anti-jamming capabilities and include enhancements that extend spacecraft life 25 percent further. GPS III-series satellites also will carry a new civil signal designed to be interoperable with other international global navigation satellite systems, enhancing civilian-user connectivity.
The majority of the work under contract will be performed at the General Dynamics Advanced Information Systems facilities in Scottsdale, Arizona, and Bloomington, Minnesota.
The sixth GPS Block IIF satellite was successfully launched Friday at 8:03 p.m. local time. Built by Boeing Space and Intelligence Systems of El Segundo, California, GPS IIF-6 launched aboard a United Launch Alliance Delta 4 rocket from Cape Canaveral Air Force Station in Florida.
The launch was originally planned for Thursday evening, but bad weather led to a 24-hour hold. One hour remained in the countdown when the launch was scrubbed.
Two more GPS IIF satellites are scheduled to launch before the end of the year.
Below is a video of the launch.
Here are launch highlights.
This patch commemorates the launch of GPS IIF-6, nicknamed Rigel.
GPS IIF-6 is nicknamed Rigel. All of the Block II-F satellites have been named after stars. Rigel is is the brightest star in the constellation Orion and the seventh brightest star in the night sky, with a visual magnitude of 0.12.
In the patch commemorating the launch, Orion is depicted with an alligator head. This is in reference to the “Night Gators,” the part of the launch team that is responsible for moving payloads to the launch pad, which has typically occurred at night.
A slideshow of photos from United Launch Alliance:
The ULA Delta 4 rocket blasts off at sunset from Cape Canaveral’s Complex 37 on a mission to deploy the GPS IIF-6 satellite. Photo credit: Spaceflight Now.
Photo credit: Spaceflight Now.
Photo credit: Spaceflight Now.
Photo credit: Spaceflight Now.
Photo credit: Spaceflight Now.
Photo credit: Spaceflight Now.
Photo credit: Spaceflight Now.
Photo credit: Spaceflight Now.
Photo credit: Spaceflight Now.
Photo credit: Spaceflight Now.
Innovation Editor Richard Langley helped compile this report.
Update: The launch of the GPS IIF-6 satellite has been delayed one day due to bad weather.
Another GPS IIF satellite is expected to lift off aboard a United Launch Alliance Delta 4 rocket from Cape Canaveral at 8:08 p.m. EDT May 15 at the opening of an 18-minute launch window.
The satellite, designated GPS IIF-6 and built by Boeing, is one of the next-generation GPS satellites, incorporating improvements to provide greater accuracy, increased signals, and enhanced performance for users. According to Boeing, each GPS IIF satellite has:
greater navigational accuracy through improvements in atomic clock technology.
a new civilian L5 signal to aid commercial aviation and search and rescue operations.
improved military signal and variable power for better resistance to jamming in hostile environments.
a 12-year design life providing long-term service and reduced operating costs.
an on-orbit, reprogrammable processor that can receive software uploads for improved system operation.
GPS IIF-6 will be the United Launch Alliance’s fifth launch of 2014 and 82nd overall. It also will mark the 26th flight of the Delta IV launch vehicle since its inaugural flight in November 2002.
A United Launch Alliance Delta IV lifts off from Space Launch Complex-37 with the Air Force’s Global Positioning System (GPS) IIF-5 satellite. This launch marked the 25th Delta IV flight since the first flight in 2002.
The latest GPS Block IIF satellite, IIF-5 or SVN64 (operating as PRN30), was launched on February 21, 2014. Typically, GPS satellites are checked out and made operational within about a month following launch. SVN64 has yet to be set healthy.
The delay is due to an extended navigation test being performed by the GPS master control station. A navigation upload for SVN64 was performed in March with ephemeris and clock data as usual streching weeks in advance. However, unlike with operational satellites, no further updated uploads have been performed. The aging ephermis and clock data gradually becomes less and less accurate as time goes by but should degrade gracefully.
Inquisitive observers will have noticed that the received navigation data from SNV64 changes infrequently. Currently, the navigation data changes once per day with an epoch of 13:00 GPS Time unlike every two hours with operational satellites. And the data fit interval is 26 hours, compared to four hours.
