The maiden missions of the Boeing and Lockheed Martin-built Atlas V and Delta IV Evolved Expendable Launch Vehicles (EELV) have been postponed again, to 12 August and 9 October respectively.

International Launch Services says the first launch of the Lockheed Martin Atlas V booster, built under a US Air Force EELV contract but carrying Eutelsat's Hot Bird 6 communications satellite, has now been scheduled for 12 August from launch pad 41 at Cape Canaveral. The mission was first scheduled for 29 July, with the latest delay following additional umbilical retraction tests. The Atlas V was due to be rolled out to Pad 41 for a third and final countdown demonstration test on 15 July.

Boeing has delayed the maiden flight of its Delta IV EELV from late August to at least 9 October to allow further pre-launch testing. The launch was originally planned for May-June. The Delta IV Medium Plus booster version will carry the Eutelsat W5 communications satellite on a commercial flight.

Source: Flight International