United Launch Alliance is preparing to fly its first mission of 2026 with the USSF-87 mission from Cape Canaveral Space Force Station in Florida. Vulcan Centaur V-005, with four solid rocket boosters in the VC4S configuration, is set to launch on Thursday, Feb. 12, at 3:30 AM EST (08:30 UTC) from Space Launch Complex 41.
USSF-87’s launch window lasts two hours, ending at 5:30 AM EST (10:30 UTC). The launch forecast for Thursday is favorable, with a 90% chance of acceptable weather for the flight. The launch readiness review was completed on Monday, Feb. 9, and a signed launch readiness certificate was issued.
USSF-87 will take an eastward trajectory from the Cape, with the payloads deployed to geosynchronous orbit. Vulcan’s two Blue Origin BE-4 engines, using liquid methane and liquid oxygen as propellants, along with four Northrop Grumman GEM-63XL solid rocket boosters, will propel the VC4S from the pad with 13.3 mN of thrust. After reaching maximum dynamic pressure at T+01:02 minutes, the four GEM-63XLs will separate from the core stage at T+01:37 minutes and be expended into the ocean.
The core stage, known as the booster in ULA parlance, will cut off its BE-4 engines at the T+04:57 minutes, followed by the Centaur V stage separating at T+05:03 minutes. While the booster falls away, the Centaur V, using liquid hydrogen and liquid oxygen as propellants and two L3Harris (formerly Aerojet Rocketdyne) RL-10C-1-1A engines, will propel the USSF-87 payloads into an initial parking orbit.
The USSF-87 payloads encapsulated into their fairing before integration onto the Vulcan VC4S. (Credit: United Launch Alliance)
After the fairing, which measures over five meters in diameter, separates at T+05:21 minutes, United Launch Alliance (ULA) will end its launch coverage at the request of the customer, the U.S. Space Force (USSF). The USSF-87 mission will continue for nearly 10 hours, becoming the longest mission ever flown by a Vulcan. The USSF-87 mission also marks the second national security mission Vulcan has flown since its first flight on Jan. 8, 2024.
The Centaur V and its two engines, each capable of up to 106 kN of thrust, will propel USSF-87’s two Geosynchronous Space Situational Awareness Program (GSSAP) satellites and a propulsive EELV Secondary Payload Adapter (ESPA) ring directly into geosynchronous orbit 35,000 km above Earth. This is unlike launches that inject satellites into a highly elliptical geostationary transfer orbit, which require the spacecraft to circularize the orbit using onboard propulsion, thereby reducing the spacecraft’s potential lifetime.
The GSSAP 7 and 8 satellites, also known as Hornet 7 and 8, were built by Northrop Grumman. They are the latest in a series of spacecraft designed to track and characterize satellite activity and hazards near geosynchronous orbit, helping protect national security assets and prevent collisions in space.
Artist’s rendering of GSSAP satellites in orbit. (Credit: U.S. Space Force)
The GSSAP spacecraft will be better equipped to observe other spacecraft and activities due to its position in geosynchronous orbit. Ground-based tracking assets must view spacecraft targets through distortions caused by Earth’s atmosphere. In addition, the GSSAP satellites are capable of rendezvous and proximity operations to maneuver toward and to characterize an object of interest.
The first GSSAP mission flew in 2014, and another flew in 2016, both aboard Delta IV rockets, before the USSF was formed as a separate service from the U.S. Air Force. The last GSSAP launch was in 2022 aboard an Atlas V, and all GSSAP missions to date have been flown by ULA.
The ESPA ring will also be released during the USSF-87 mission. The ESPA ring, also manufactured by Northrop Grumman, contains several payloads that the USSF will use for research, development, and training. USSF personnel, known as Guardians, will use the ESPA ring to refine tactics, techniques, and procedures for precision on-orbit maneuvers. These activities will help the USSF validate resiliency and protection techniques in the space near geosynchronous orbit.
Rendering of Northrop Grumman’s ESPAStar ring. (Credit: Northrop Grumman)
ULA, currently under interim CEO John Elbon after longtime CEO Tory Bruno left to join Blue Origin, plans to fly more Vulcan missions this year, increasing the cadence after addressing initial problems on its first three flights. Most notably, one of these issues included a nozzle blowout on a GEM-63XL booster during the second flight, though Vulcan’s third flight demonstrated a successful resolution of that situation.
The company plans to start west coast operations for Vulcan this year from Space Launch Complex-3E, formerly used by the Atlas V, while also launching other national security payloads from both coasts. Amazon Leo satellites for broadband internet, competing with SpaceX’s Starlink, are also on the manifest. Vulcan is scheduled to fly the first flight of the DreamChaser cargo spacecraft this year as well, though DreamChaser’s readiness remains in question.
(Lead image: The USSF-87 Vulcan stands atop SLC-41 at the Cape. Credit: Tyler Gray for NSF)
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