- William Harwood on Twitter: A very interesting update from Mike Menzel, NASA mission systems engineer: thanks to the accuracy of the Ariane 5 launch and two ultra-precise trajectory correction burns, Webb should have enough propellant, roughly speaking, to operate "around 20 years". https://twitter.com/cbs_spacenews/status/1479909293189173249?amp%3Bs=19&t=Ez7eqPHDD5mSU-F3OTgvdw 154 comments space