Elon Musk’s SpaceX’s Falcon 9 launch has been delayed again and is now scheduled for no earlier than February 21. This marks the second delay faced by the rocket, both of which were for the completion of additional checks.

The Falcon 9 rocket was originally scheduled for launch from the Vandenberg Air Force Base in the early hours of February 17. Falcon 9 was to send the Paz radar-imaging satellite into orbit on behalf of Spain, to take clear and crisp radar images of Earth. The mission was also set to launch SpaceX’s Starlink satellite into orbit.

On February 17, SpaceX announced that there would be a delay of 24 hours. This was to provide engineers additional time to check the payload faring, a clamshell-shaped nose cone that protects the payload for the duration of the rocket’s flight. Representatives took to Twitter to announce the second delay, confirming that the launch is set to occur no earlier than February 21.

SpaceX has been exploring its ability to reuse payload fairings, an effort that could save the company approximately five million dollars per launch. Newer designs are equipped with parachutes, slowing down descent and making it easier for other pieces of technology to “catch” them before they crash into the ocean.

This has been a challenge for Musk and his engineers, as the parachutes tend to become twisted as the fairing is descending. Twisted parachute cords tend to ruin the integrity of the chute, causing the fairing to crash into the ocean despite best efforts. When speaking with reporters about this concern, Musk seemed confident that a solution exists and that it could be found within the next six months. Representatives from SpaceX have not stated whether or not the delays in the launch are due to efforts at reusing this particular fairing.