Yes, interchangeable spellings.
dispatch or despatch verb (dispatched, dispatching; despatched, despatching) 1 to send (mail, a person, etc) to a place for a particular reason. 2 to finish off or deal with something quickly • dispatch a meal. 3 euphemistic to kill. noun 1 (often dispatches) an official (especially military or diplomatic) report. 2 a journalist's report sent to a newspaper. 3 the act of dispatching; the fact of being dispatched. 4 old use speed or haste. mentioned in despatches as a distinction: commended in official military dispatches for bravery, etc.
ETYMOLOGY: 16c: from French despeechier to set free.