Editing Spacecraft propulsion (section)

===Testing===
Spacecraft propulsion systems are often first statically tested on Earth's surface, within the atmosphere but many systems require a vacuum chamber to test fully.<ref>{{Cite journal |last1=Rafalskyi |first1=Dmytro |last2=Martínez |first2=Javier Martínez |last3=Habl |first3=Lui |last4=Zorzoli Rossi |first4=Elena |last5=Proynov |first5=Plamen |last6=Boré |first6=Antoine |last7=Baret |first7=Thomas |last8=Poyet |first8=Antoine |last9=Lafleur |first9=Trevor |last10=Dudin |first10=Stanislav |last11=Aanesland |first11=Ane |date=November 2021 |title=In-orbit demonstration of an iodine electric propulsion system |journal=Nature |language=en |volume=599 |issue=7885 |pages=411–415 |doi=10.1038/s41586-021-04015-y |pmid=34789903 |issn=1476-4687|pmc=8599014 |bibcode=2021Natur.599..411R }}</ref> Rockets are usually tested at a [[rocket engine test facility]] well away from habitation and other buildings for safety reasons. [[Ion drive]]s are far less dangerous and require much less stringent safety, usually only a moderately large vacuum chamber is needed.{{Citation needed|date=April 2024}} Static firing of engines are done at [[Rocket engine test facility#Rocket ground test facilities|ground test facilities]], and systems which cannot be adequately tested on the ground and require launches may be employed at a [[rocket launch site|launch site]].