It's a turn of phrase borrowed from judged sports with a jumping/dismount component, especially gymnastics. If a gymnast dismounts from a balance beam and lands without stumbling or bending the knees too much, one would say he has "stuck the landing". In the headline, OP is saying that, by virtue of the landing being near-flawless, SpaceX "stuck" the landing. This is used quite commonly in aviation/aerospace, but colloquially.