A satellite launch scheduled for later this week to carry the Air Force’s latest Advanced EHF (AEHF) system into orbit has been delayed until early-to-mid July, the service said June 23.

The delay is due to a vehicle battery failure on the United Launch Alliance (ULA)-built Atlas V rocket that was discovered during final processing, and the launch is now targeted for July 9 at the earliest, the Air Force Space and Missile Systems Center (AFSMC) said in a Sunday release. ULA – a joint launch venture between Boeing [BA] and Lockheed Martin [LMT] – confirmed the issue on Monday. The launch was originally scheduled for June 27 at Cape Canaveral Air Force Station, Florida.

A launch of an Atlas V rocket. Photo: United Launch Alliance

The latest AEHF satellite would be the fifth of six planned systems in the Air Force’s protected tactical satellite communications constellation, which is expected to replace the legacy, lower capability Milstar constellation first launched between 1994 and 2003. Lockheed Martin and Northrop Grumman [NOC] are the prime manufacturers for advanced EHF.

Meanwhile, the Air Force has prepared for the scheduled June 24 launch of the Space Test Program-2 (STP-2) mission aboard a Space X Falcon Heavy rocket from Cape Canaveral. The launch window is scheduled to open at 11:30 p.m. Eastern Time and will remain open for four hours, according to AFSMC. The launch includes 24 research-and-development payloads from the Air Force, NASA, NOAA and other partners, and will allow the service to assess the feasibility of launching the Falcon Heavy with two previously used side boosters (Defense Daily, June 7).