Late last night an unarmed test of the Air Force’s new Mk 21A intercontinental ballistic missile (ICBM) reentry vehicle quickly ended with an explosion 11 seconds after launch at Vandenberg Space Force base in California. Nobody was injured, but the failure is a setback for the LGM-35A Sentinel ICBM program that is intended to replace the aging LGM-30 Minuteman III.
According to a press release, the Minotaur II+ rocket launch was supposed to be centered around “demonstrating preliminary design concepts and relevant payload technologies in operationally realistic environments” for the U.S. Air Force’s new Mk 21A reentry vehicle engineered to be carried on the LGM-35A Sentinel ICBM. The explosion caused by the failed launch occurred at 11:01 p.m. on Wednesday, July 6. An additional release goes on to state that the debris was contained in the immediate vicinity of the launch pad, and the San Luis Obispo Tribune reported that the blast caused a fire to break out on the base which the Vandenberg Fire Department responded to and extinguished by about 1 a.m.
“We always have emergency response teams on standby prior to every launch,” said Col. Kris Barcomb, Space Launch Delta 30 vice commander and launch decision authority for this launch. “Safety is our priority at all times.”
Northrop Grumman’s LGM-35A Sentinel ICBM was previously known as Ground-Based Strategic Deterrent and is being developed to take the place of Boeing’s LGM-30 Minuteman-III beginning in 2029. The Mk 21A reentry vehicle is the product of a joint development effort between the Air Force Nuclear Weapons Center and Lockheed Martin that dates back to 2019.
“It is essential that Lockheed Martin continue our long-standing ICBM partnership with the Air Force to provide them with advanced solutions,” said John Snyder, vice president of Advanced Strategic Programs for Lockheed Martin in a 2019 press release following the contract award. “We will continue to demonstrate, through this TMRR [Technology Maturation and Risk Reduction], cutting-edge engineering to defeat rogue nation threats.”
Vandenberg SFB says that an investigative review board has been established to determine the cause of the explosion. However, The War Zone reached out to the Space Launch Delta 30 Public Affairs office to follow up, and no further details regarding the pending investigation or the potential cause of the explosion could be provided at this time. It is also worth noting that Vandenberg’s initial announcement of the test stated that it would be carried out on Thursday morning. Why it was instead conducted late Wednesday night has yet to be elucidated.
The Mk 21A will hold an improved W87-1 warhead, as opposed to the W87 thermonuclear warhead carried by its predecessors, the Mk 21. As reported by Inside Defense, Lockheed Martin is in the process of developing a second Mk 21A prototype as part of the vendor’s contract. Two flight tests were scheduled for the reentry vehicle prototypes, the first being the one that failed last night with the second slated to occur in the second quarter of the fiscal year 2023.
Whether or not the failure of last night’s launch will influence the second prototype’s test scheduled for next year is unclear at present, but The War Zone reached out to Lockheed Martin through phone and email for comment and have yet to hear back. Being that the incident is still developing, we will continue to supplement this report with any updates as they become available.
Contact the author: Emma@thewarzone.com