ULA’s Vulcan rocket fails to deliver 40 Amazon Leo satellites

United Launch Alliance’s Vulcan rocket hit an anomaly 10 minutes after liftoff on Nov. 15, 2026, and failed to place 40 Amazon Leo broadband satellites into orbit after launching from Cape Canaveral Space Force Station’s Space Launch Complex 41.

The 214-foot-tall vehicle rose at 17:40 UTC, or 12:40 p.m. EST, on a northeasterly path. It generated 3.8 million pounds of thrust from twin methane-burning BE-4 engines and six solid-fuel strap-on boosters built by Northrop Grummon. Flying in VC6L configuration, it paired BE-4 main engines with a Centaur V upper stage driven by two RL10C-1-1A engines. The mission marked the first use of a shorter upper stage and a six-booster setup, changes designed to carry more satellites into low Earth orbit.

The solid rocket boosters finished burning and separated one minute and 45 seconds after liftoff, ahead of the anomaly; Spaceflight Now put booster burnout at roughly one minute and 40 seconds. About six minutes into flight, ULA reported core-stage separation, Centaur V ignition and fairing jettison while the vehicle was 95 miles high and moving faster than 11,000 mph east of Charleston, South Carolina. The first stage seemed to burn longer than planned, with separation coming later than expected, and telemetry animation captured unusual orientation adjustments by the Centaur early in its burn. The broadcast ended before confirming that the Centaur’s initial planned firing had completed its full duration.

In an update at 18:31 UTC, ULA said it did not have specific data to explain what happened. The company later acknowledged it fell short of its mission-success standard. ‘Today, we did not meet that standard,’ ULA said.

ULA stated that it will work with Amazon and other appropriate organizations to determine the cause, carry out corrective actions and resume flights as soon as possible, while keeping customers updated on the investigation.

Securities.io described the loss as reportedly the first mission failure in a 20-year history for United Launch Alliance, and Spaceflight Now called it the first outright ULA rocket failure since the company formed in 2006. Before this mission, a Vulcan rocket had flown only five times, and this was the first flight in nine months. The mission marked the first of 38 Vulcan flights under Amazon’s contract with ULA. ULA had flown eight Amazon deployment missions aboard Atlas V.

A gaseous nitrogen plant outage serving multiple launch providers forced a Friday scrub, while network problems between the rocket and ground systems caused a Saturday delay. On Sunday, controllers paused the countdown at T-minus 20 seconds over an unexplained rocket issue, and it remains unclear whether that problem played a role in the later failure.

For months, ULA addressed strap-on booster nozzle issues from two prior flights, one in 2024 and another this past February, even as the U.S. Space Force kept Vulcan national security payloads on hold pending analysis. Mark Peller, ULA’s chief executive, told Aviation Week & Space Technology that investigators had identified and mitigated three credible causes of the nozzle issue. On Sunday, the strap-on boosters seemed to perform normally.

Amazon had expected Vulcan to carry more than 1,500 first-generation Leo satellites as part of an initial constellation planned to exceed 3,000, while finishing the full constellation calls for more than 3,300 Leo satellites. Had it succeeded, the mission would have brought the total number of Amazon Leo satellites launched to date to 436.

Beyond ULA, the company has reserved 24 Leo missions aboard Blue Origin’s New Glenn, 24 on Europe’s Ariane 6 and 13 on SpaceX‘s Falcon 9 rockets. Amazon must wait for ULA’s investigation to conclude before flying on Vulcan again, and it is also waiting on Blue Origin’s return to flight for New Glenn after last May’s catastrophic on-pad explosion. The New Glenn explosion was traced to an oxygen valve problem in one of seven first-stage BE-4 engines.

Vulcan’s first stage is also powered by the BE-4, though the engines on Sunday’s vehicle had been retrofitted with a fix from Blue Origin engineers. Blue Origin created a design improvement for the BE-4 valve problem and installed it on the engines of the Vulcan Leo 1 rocket at its own facilities a couple of months before launch.

On X, NASA Administrator Jared Isaacman said the NASA team is ready to help with the investigation and remediation effort, adding, ‘Appreciate you quickly keeping the public and your partners informed.’ Melissa Wuerl, Amazon Leo’s director of launch systems, described Vulcan as the program’s main workhorse for the coming years, calling it ‘primary workhorse over the next several years.’

Amazon characterizes its mix of Arianespace, Blue Origin, SpaceX and ULA as deployment diversity that scales as vehicles become available. Ahead of the failure, Amazon’s next Arianespace flight, Leo Europe 4, was targeting no earlier than Nov. 23, 2026.

In early September 2026, the company passed the 1,000-satellite mark, with hundreds of flight-ready satellites headed for LV-01 and a goal to double its yearly launch rate before the initial service rollout. LV-01 marked ULA’s first mission to depend on Amazon-funded Cape Canaveral infrastructure, using the VIF-A vertical integration site and a mobile launch platform designed to ready two Vulcan missions simultaneously and reduce turnaround to days or weeks. Teams were already preparing LV-02 to launch within weeks of a successful LV-01, a plan that explicitly depended on the first flight going well. Securities.io characterized the failure as a setback for Amazon’s satellite broadband ambitions and for ULA’s launch record.