Shortlisted Mars One astronaut: venture has taken one giant leap backwards

Astrophysicist Joseph Roche says selection process for one-way mission is not vigorous enough, Dutch organisers are naive and project is unlikely to happen

He is not the first person to express scepticism about Mars One, a vastly ambitious private mission aiming to settle humans on Mars from 2025. But Joseph Roche is different to most critics: he's on the shortlist to be one of the astronauts.

Roche, an astrophysicist at Trinity College Dublin who was announced last month as among the 100 people in line for the mission, has written for the Guardian expressing his grave doubts about the viability of Mars One.

Related: I'm on list to be a Mars One astronaut -but I won't see the red planet | Joseph Roche

All of a sudden it changed from being a proper regional interview over several days to being a 10-minute Skype call

Related: Mars One shortlist: the top 10 hopefuls

Related: Houston, we have a lot of problems: is Mars One too good to be true?