The United States' Space Force successfully launched its first mission aboard the United Launch Alliance's Atlas V rocket on Thursday: it is due to deploy the final Advanced Extremely High Frequency (AEHF) satellite shortly. The AEHF satellite is designed to serve as a secure communications platform for the U.S. military and its allies, according to NASASpaceFlight.com.
The launch was scheduled for 2:35 PM EDT, but was delayed until 4:18 PM EDT from Cape Canaveral, following ground-based hydraulics issues that were later corrected.
UPDATE March 26, 4:50 PM EDT: First-ever US Space Force orbital mission successfully launches, entering five-hour coast
The first-ever U.S. Space Force orbital mission successfully launched from Cape Canaveral at 4:18 PM EDT. Following the launch, the President and CEO of United Launch Alliance, manufacturer of the Atlas V rocket, said:
"I wanted to say congratulations to the newly-formed United States Space Force, and to say how excited we are to fly the very first mission for the Space Force," said Bruno, during the broadcast. "And I think it's just so apropos that it is the advanced AEHF 6 spacecraft [that will] provide secure military communications around the globe."
He went on to voice support for the U.S. Space Force's mission to work toward "keeping the peace" both on Earth, and in space.
UPDATE March 26, 4:18 PM EDT: First-ever US Space Force orbital mission via Atlas V rocket successfully completes first stage of launch
The first-ever U.S. Space Force orbital mission successfully completed the first phase of its launch aboard an Atlas V rocket at 4:18 PM EDT. As of writing, the mission is in the first of three Centaur rocket burns.
UPDATE March 26, 4:10 PM EDT: Atlas mission control determines new launch time at 4:18 PM EDT, after delays
The Atlas Mission Control has reset its launch system and scheduled to launch at 4:18 PM EDT, after delays occurred from hydraulics issues that have since been corrected.
UPDATE March 26, 4:07 PM EDT: First-ever US Space Forces launch delayed, issue corrected with trouble-shooting test, standing by for new launch time
Following a hold, the launch team completed procedures to back out of a partially-completed launch countdown. The team corrected a ground-based hydraulics issue and is presently working to set a new launch time. The launch window extends until 4:57 PM EDT.
UPDATE March 26, 3:55 PM EDT: Atlas mission control resetting anomalous system, will reset countdown to T-Minus 4 minutes if successful
Atlas Mission Control reset the system that was anomalous and caused a delay in the U.S. Space Force's first-ever orbital mission aboard the Atlas V rocket. If successful, mission control will reset the countdown to launch at T-Minus four minutes. The launch window extends until 4:57 PM EDT.
UPDATE March 26, 3:50 PM EDT: Bad amplifier card on ground-based hydraulic pump caused delay, team working on solution to launch before 4:57 PM EDT
The delay in launching the U.S. Space Force's first-ever orbital mission aboard an Atlas V rocket "seems to have been caused by a bad amplifier card on a ground system hydraulic pump controller," according to launch control. The team is currently working on the issue to solve the problem before the launch window closes, at 4:57 PM EDT.
UPDATE March 26, 3:40 PM EDT: Hydraulics issue identified, to be corrected, launch window open until 4:57 PM EDT
The team at Cape Canaveral has identified and understands the cause of the hydraulics issue that led to a temporary delay in the launch of the U.S. Space Force's first orbital mission aboard the Atlas V rocket — the team is currently working to correct this issue. The window for launch extends until 4:57 PM EDT.
UPDATE March 26, 3:10 PM EDT: Recycle of Atlas V rocket launch systems complete
Mission Control at Cape Canaveral has completed recycling the launch system of the Atlas V, following an earlier hold less than one minute before planned launch. The rocket is carrying the first-ever orbital mission of the newly-formed U.S. Space Force. The cause of the initial hold is currently under review.
UPDATE March 26, 3:00 PM EDT: Flight Delayed temporarily and reset to T-Minus 4 Minutes
The Atlas V launch of the first U.S. Space Forces mission to orbit was delayed temporarily due to an unscheduled hold call "LC Switch not ready." Mission Control at Cape Canaveral is assessing the issue and returning the rocket to full launch-readiness before resuming the countdown at T-Minus four minutes.
Space Force Mission Zero Launches on Atlas 5
The U.S. Space Force will launch its first mission aboard ULA's Atlas 5 rocket — a 60-meter (197-foot) rocket, propelled by an RD-180 main engine and five solid rocket boosters — during a two-hour launch window on Thursday, March 26, which opens at 2:57 PM EDT.
Officially designated the AEHF 5 mission, this launch will mark the 83rd flight of an Atlas 5 rocket and the second of 2020.
The Atlas 5 sequence (launch procedure) will last 5 hours, 40 minutes, from liftoff, and last until the AEHF 6 spacecraft is deployed. ULA added extra hardware and maneuvering fuel to the Centaur upper stage of this mission, in a bid to help the launcher deliver the AEHF 6 satellite to its intended orbit, more than 36,000 kilometers (22,000 miles) above the Earth's equator.
Lockheed Martin's AEHF 6 satellite
Lockheed Martin manufactured the AEHF 6 satellite slated to join five earlier satellites in the AEHF constellation, also carried on Atlas 5 rockets in 2010, 2012, 2013, 2018, and 2019. The initial four AEHF satellites — currently in orbit — have given the U.S. Air Force's new generation of video and data relay for nuclear security a world-spanning network, and the addition of two extra AEHF geostationary relay satellites will provide greater capacity and resiliency to the network, according to NASASpaceFlight.com.
The AEHF 6 satellite will separate in orbit at a perigee — or low point — several thousand miles higher than usual, thanks to a GSO kit, added to the Atlas 5 rocket last August, which enhances the performance of the Centaur upper stage rocket, allowing it to coast two extra hours before firing for a third time. The spacecraft separation is scheduled for T+plus 5 hours, 40 minutes.
Editor's Note: This article has been updated to reflect ongoing developments of the U.S. Space Force's first orbital mission: the AEHF 6 satellite. Initially scheduled for March 26, 2:35 PM EDT, the launch was delayed following ground-based hydraulics issues that were later corrected. The Atlas V rocket successfully launched later that day, at 4:18 PM EDT.