GPS III SV-04 Launch

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jimh
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GPS III SV-04 Launch

Postby jimh » Sun Sep 20, 2020 9:06 am

According to NEXTSPACEFLIGHT.COM, the launch of GPS III SV-04 is now scheduled for October 1, 2020 at midnight UTC, or about 7 p.m. September 30, 2020.

The fourth GPS III satellite will be carried into orbit by a SpaceX Falcon 9 rocket.

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Re: GPS III SV-04 Launch

Postby jimh » Wed Sep 30, 2020 6:00 pm

The GPS III SV-04 launch is now scheduled for October 02, 2020 at 9:43 PM ET.

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Re: GPS III SV-04 Launch

Postby jimh » Fri Oct 09, 2020 12:26 am

The launch of GPS III SV-04 was attempted about 9:45 p.m. on Friday, October 2, 2020, but at T-minus-2-seconds there was an abort due to an overpressure condition in a rocket engine pumping system.

The FALCON9 launch vehicle has been laid over to horizontal. The recovery ships have returned to port. There is presently no launch attempt scheduled or announced. It appears that SpaceX will be investigating the problem with the FALCON9.

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Re: GPS III SV-04 Launch

Postby jimh » Mon Nov 02, 2020 5:32 pm

GPS III SV-04 launch is now scheduled to occur on November 5, 2020 at 6:24 p.m. EST.

UPDATE:
SpaceX is targeting Thursday, November 5 for a Falcon 9 launch of the United States Space Force’s GPS III Space Vehicle 04 from Space Launch Complex 40 (SLC-40) at Cape Canaveral Air Force Station in Florida. The 15-minute launch window opens at 6:24 p.m. EST, 23:24 UTC, and a backup opportunity is available on Friday, November 6 with a 15-minute backup window opening at 6:20 p.m. EST, 23:20 UTC.

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Re: GPS III SV-04 Launch

Postby jimh » Fri Nov 06, 2020 3:00 am

The GPS III SV-04 satellite was launched successfully on November 5, 2020 at the scheduled 6:24 p.m. launch window. The satellite is now in a transfer orbit to its final position in a circular orbit at an altitude of 12,500-miles above Earth.

SpaceX was able to recover the first stage rocket by an autonomous landing on their drone ship at sea.

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Re: GPS III SV-04 Launch

Postby jimh » Sun Nov 08, 2020 10:35 am

The GPS III SV-04 space vehicle is also known by the nickname Sacagawea, and as SVN-77. It is intended to rise into final orbit in GPS Plane B and Slot 03, where it will replace SVN-44, which is broadcasting with PRN-28. The new satellite SVN-77 will broadcast with PRN-14 when it comes on line in several months.

The SVN-44 space vehicle (to be replaced) was launched July 16, 2000 and is a GPS IIR type. The "R" is for replenishment or replacement. There were twelve satellites in this series successfully launched. The design life of the GPS IIR satellites was ten years. SVN-44 has been in service for 20-years, about double its design life.

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Re: GPS III SV-04 Launch

Postby jimh » Tue Dec 08, 2020 5:27 pm

Shortly after separation of the GPS III SV-04 space vehicle from its Space-X FALCON 9 Merlin vacuum engine second stage, the GPS space vehicle was in communication with ground control. The vehicle is now in the process of raising its orbit to its final circular medium-earth-orbit trajectory of 12,500-km using its on-board liquid propulsion engine. This process will take several weeks. More at

https://news.lockheedmartin.com/2020-11-05-Fourth-Lockheed-Martin-Built-GPS-III-Satellites-On-Board-Engine-Now-Propelling-It-To-Orbit

Establishing ground control after launch is an extraordinarily important step in the successful deployment of the satellite. During the orbit raising the photo-voltaic panels that produce electrical energy from sunlight are not deployed, and the satellite electrical power is obtained from batteries aboard the spacecraft. Once at final orbit height, the solar panels will be deployed. These panel then generate electrical power for on-going operation of the spacecraft during its service life, which could be 20-years or more.

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Re: GPS III SV-04 Launch

Postby jimh » Tue Feb 02, 2021 12:52 pm

Below is the text of a December 2020 press release regarding the status of GPS II SV-04 from the U.S. Space Force (USSF):

-- begin press release--

LOS ANGELES AIR FORCE BASE, Calif.--Global Positioning System III Space Vehicle (SV) 04 received United States Space Force’s Operational Acceptance approval on Dec. 1, [2020], marking [a] significant milestone for the GPS III program, Space and Missile Systems Center, and USSF. It is the fourth GPS III satellite delivered into the operational constellation in the past 12 months and the second in the past three months. Additionally, this is the first GPS III vehicle delivered to the warfighter through an expedited satellite control authority transfer process, which cuts ten days off the previous operational acceptance timeline.

“With the onset of SV04, the GPS constellation continues moving forward in next generation modernization. The 2nd Space Operations Squadron is one step closer to providing Military Code (M-Code) capability for the entire 24 satellite baseline. The highly encrypted M-Code to protect GPS signals from jamming and spoofing is currently enabled on 22 GPS satellites of various generations; 24 are needed to bring the M-Code to the next level of operational capability,” said Capt. Collin Dart, the 2 SOPS DOA Flight commander.

“SV04 brings the constellation to 23 M-Code capable vehicles. SV05 will launch no earlier than July 2021. This will add the 24th M-Code capable vehicle. SV04 also sets a new standard for handover from the contractor launch team to operational acceptance, setting the satellite healthy to the global user community approximately 30 days post launch. Moving forward with future GPS III launches, the timeline between launch and the satellite being set healthy will be at a minimum.”

SV04 was launched on a SpaceX Falcon 9 Block 5 vehicle on Nov. 5. The Air Force has been flying 31 operational satellites for years in order to ensure the United States’ commitment to have 24 operational GPS satellites available 95% of the time. GPS III SV04 joins this operational constellation of 31 GPS satellites orbiting in medium-Earth orbit. This system delivers improved accuracy, advanced anti-jam capabilities and increased resiliency for the GPS III constellation.

“The operational acceptance of GPS III SV04 is another significant milestone for GPS Modernization, delivering critical new capabilities to our Military and Civil Users. We now have a total of 23 M-Code spacecraft for our Warfighters. For our billions of civil users, it brings the count up to 23 L2C spacecraft and 16 L5 spacecraft,” said Col. Ryan Colburn, director of the SMC Portfolio Architect Office’s Spectrum Warfare Division.

“For professional users with existing dual-frequency operations, L2C enables faster signal acquisition, enhanced reliability, and greater operating range. L5 is broadcast in a radio band reserved exclusively for aviation safety services. It features higher power, greater bandwidth, and an advanced signal design. Future aircraft will use L5 in combination with L1 C/A to improve accuracy (via ionospheric correction) and robustness (via signal redundancy). The operational acceptance of this spacecraft is another display of the fantastic teamwork across SMC’s Corps, Space Delta 8, National Geospatial-Intelligence Agency, Department of Transportation, Federal Aviation Administration, our industry partners and many others who work together to make these missions possible.”

GPS satellites provide position, navigation, and timing to more than four billion military and civilian users worldwide.