"We have not sent humans beyond the moon in more than 40 years," Mr Tito said at a press conference in Washington on Wednesday. "I've been waiting, and a lot of people my age, have been waiting. And I think it's time to put an end to that lapse（失效，流逝）".

 

The mission, a "return fly-by", in which the spacecraft would fly around Mars rather than land, would last for 500 days. It is expected to cost between $1 billion and $2 billion, which Mr Tito is hoping to fund partly through television rights and by selling data to Nasa.

 

His organisation², Inspiration Mars, is planning to select a middle-aged⁴ couple who may have already had children and would be willing to risk the potential risk to their fertility of being exposed to radiation for a prolonged period.

 

They would be forced to spend a year and a half together in a 14ft x 12 ft Dragon space craft, accompanied by supplies ranging from more than a tonne of dehydrated（脱水的） food to 28kg of lavatory⁵ paper（厕纸）.

 

As for why they were specifically seeking a couple to make the flight, "this is very symbolic⁶, and we really need it to represent humanity with a man and a woman," Taber MacCallum , chief technical officer and potential crew member told the media.

 

He said if it is a man and a woman on such a long, cramped⁷ voyage, it makes sense for them to be married so that they can give each other the emotional support that will probably need when they look out the window and see Earth get smaller and more distant, adding: "If that's not scary, I don't know what is."

 

The mission has been scheduled for 5 January, 2018, in order to take advantage of an alignment⁸ in the planets that occurs once every 15 years.

 

Mr Tito, 72, said he was determined⁹ to complete the mission because he feared not being around for the first manned mission to Mars being planned by the US government for the mid³ 2030s.

 

He said that one of the questions he hoped to help answer was: "How do humans behave when they look out and see this pale blue dot that they can barely differentiate¹⁰ from a star?"

点击收听单词发音