Update 8:04 p.m. EDT: Added comments following the announcement of a successful launch.
Northrop Grumman launched its first flight of a Minotaur rocket from California in nearly 14 years. Onboard the four-stage Minotaur 4 rocket was the NROL-174 mission for the National Reconnaissance Office.
Liftoff from Space Launch Complex 8 (SLC-8) happened at 12:33 p.m. PDT (3:33 p.m. EDT, 1933 UTC). The NRO gave no indication prior to launch that it would facilitate a livestream of the mission’s countdown or liftoff, however, a camera controlled by University of California (UC) San Diego’s ALERTCalifornia program caught the ascent into a layer of clouds.
As is typical with NRO missions, little is known about what is being sent into orbit. In a prelaunch press kit, the intelligence-gathering agency said the NROL-174 consists of “multiple national security payloads designed, built, and operated by the NRO.”
“This launch is a testament to what the national security launch enterprise is able to achieve,” said Laura Robinson, Deputy Director, NRO Office of Space Launch, and NROL-174 Mission Director, in a post-launch statement. “The NROL-174 Minotaur IV rocket was once a Peacekeeper ICBM that sat watch 24/7 in support of our nation’s nuclear deterrent. Now modified for space launch, it completed its final mission of placing a national security payload on orbit, a credit to the decades-long dedication of those who were part of the missile’s early development, maintenance and operations, and innovative conversion into the Minotaur IV rocket. It was truly a team effort.”
The first three stage of the Minotaur 4 rocket consist of solid rocket motors from decommissioned Peacekeeper intercontinental ballistic missiles (ICBMs) and the fourth stage is a commercial, solid rocket upper stage. The rocket is capable of launching up to 1,730 kg (3,814 lbs) of payload mass to low Earth orbit.
The first Minotaur 4 rocket launched on April 22, 2010, from SLC-8, and there have been three Minotaur 4 rockets launched from there, most recently NROL-66 on Feb. 6, 2011, back when the rocket was managed by Orbital Science Corporation.
That company merged with the defense and aerospace sectors of Alliant Techsystems to become Orbital ATK on April 29, 2014. Northrop Grumman announced its intention to acquire Orbital ATK for $9.2 billion in September 2017, with the deal being approved by the Federal Trade Commission in December 2018.
The Minotaur 4 rocket was procured for the NROL-174 mission under the Rocket Systems Launch Program (RSLP). That program is under the Orbital/Suborbital Program-3 contract, which is managed by the U.S. Space Force’s Space Systems Command (SSC).
“RSLP is the small launch counterpart to SSC’s National Security Space Launch program and focuses on the small launch market,” the NRO wrote in a prelaunch press kit. “RSLP primarily launches more risk-tolerant experimental, research and development, responsive space and operational missions.”
The OSP-3 contract was established in late 2012 and finished awarding missions in November 2019, which was a month after the OSP-4 contract was established.
The OSP-3 contract established an indefinite delivery, indefinite quantity for launch capability with a cap of $900 million. Launch are dolled out using firm-fixed price contracts for each mission.
“Superb launch. This was our third Minotaur launch for the NRO since July 2020 and just like then, this mission was textbook…truly outstanding,” said Lt. Col. Steve Hendershot, SSC’s Materiel Leader for RSLP. “We have a great relationship with our partners at the NRO, and watching today’s launch you saw our teamwork, discipline, and trust pay off strong.”
Around the country and back again
One of the unique aspects to the Minotaur rocket program is that the vehicle is agnostic to location.
After making its suborbital debut in a Minotaur 4 Lite configuration on April 22, 2010, Orbital Science Corporation launched a Minotaur 4 from SLC-8 at Vandenberg that September.
That was followed by the Department of Defense’s Space Test Program’s S26 (STP-S-26) mission at the Kodiak Launch Complex on Nov. 19, 2010. It used a Minotaur 4 rocket.
Another suborbital flight followed at SLC-8 using a Minotaur 4 Lite on Aug. 11, 2011, and then the TacSat-4 mission featured the debut of the Minotaur 4+ configuration when it launched from Kodiak on Sep. 27, 2011.
Nearly six years went by before the next Minotaur 4 launch on Aug. 26, 2017. That was the first launch of the rocket from what was then Cape Canaveral Air Force Station and its pad, Space Launch Complex 46 (most recently used by Astra Space’s Rocket 3).
The last time a Minotaur 4 rocket took flight was up at Mid-Atlantic Regional Spaceport at the southern tip of NASA’s Wallops Flight Facility in Virginia. That mission, NROL-129, launched on July 15, 2020.
There are at least two more launches of Minotaur rockets on the books following the NROL-174 mission. The vehicle was tasked with the launches of STP-29A, which was originally scheduled to fly in September 2024, and USSF-261S-A, which had a target launch date of May 2025.
Spaceflight Now has asked SSC what the timeline for those missions looks like and is waiting to hear back.
