On February 22, NASA said that in a series of recent tests, the performance of all rocket engines of the SLS core stage of the lunar landing rocket met expectations < p > in the previous test, the controller of rs-25 4 engine failed, which forced NASA to postpone the unmanned lunar mission Artemis 1 < p > the rs-25 engine manufactured by Aerojet Rocketdyne, a rocket engine supplier, is a legacy technology of the space shuttle era. The core stage of the lunar landing rocket SLS is equipped with four rs-25 engines. Earlier this month, NASA cooperated with Aerojet Rocketdyne to upgrade the core stage of the lunar rocket, and the controller performance of the four rocket engines met expectations < p > the rocket engine controller can communicate with the rest of the rocket to provide accurate control and internal health diagnosis information. NASA said in a statement that the problem of the No. 4 rocket engine controller stems from the failure of the memory chip used in the controller startup process. After the controller startup is completed, the memory chip will no longer have an effect on the controller operation < p > NASA added that engineers did not find any memory chip failure on the other three rocket engines, so there was no relevant restriction mechanism in the pre launch state cooperation training (WDR) < p > however, this failure forced NASA to postpone the launch of Artemis 1 no earlier than April this year < p > the NASA team at the Kennedy Space Center in Florida is currently conducting pre launch diagnostic tests, including testing the launch termination system and installing various instruments on the rocket booster < p > it is expected that the lunar rocket will conduct pre launch state joint training at launch pad 39B in March, in order to verify the overall condition of the lunar rocket, Orion capsule and Kennedy ground system. NASA will not confirm the launch date of Artemis 1 until the pre launch state training is successfully completed. (Chen Chen) < / P > < p >