At a launch event in London, the team confirmed it has won its race to make it to Melbourne thanks to the personal investment of Stephen Fitzpatrick, who heads the British electricity company Ovo Energy.
British newspapers say he is putting in about $45 million, with the rest of the budget coming from 2014 prize-money that is expected to arrive later this month.
Fitzpatrick told reporters he invited Justin King to buy half the team, but the former Sainsbury's boss has instead been appointed interim chairman and advisor.
"We are not expecting to win any races," joked 37-year-old Fitzpatrick, "at least not until halfway through the season."
Manor has scrambled to modify Marussia's 2014 car to comply with this year's rules, but the team said a fully 2015 car will be debuted "later in the season".
Fitzpatrick said the situation at Manor had appeared initially "hopeless".
"It has been a challenging period for all of us but we've come through it and now we just want to go racing again," continuing team president Graeme Lowdon said.
It is believed the modified 2014 car will be crash-tested on Thursday, while Manor said Will Stevens' teammate will be appointed "soon".