HOW much do you love your wife or husband? Could you spend 501 days with them in a confined space on a return trip to Mars?
It's a scenario that would test any relationship, regardless of tolerance and compatibility.
A US financial tycoon and his wife are offering a no-frills flight that would take the husband-and-wife astronauts as close as 160km to the planet, but it would also mean being cooped up for 16 months in a cramped space capsule.
The private project, called Inspiration Mars, will get initial money from investment consultant Dennis Tito, the first space tourist.
The flight is expected to cost more than $1 billion.
NASA will not be involved but the project's backers intend to use a private rocket and space capsule and some kind of habitat that might be inflatable.
There's no stops along the way so talk of a moon walk is out of the question.
The pair chosen will need to take minimal food and clothing and their urine and sweat will be recycled into drinking water.
The project's organisers want a married couple, pointing out they need someone who has been through a lot together.
They are keen to test the limits of human behaviour as well record a whole lot of scientific information along the way.
The timing of the project is very tight.
It aims to capitalise on the once-in-a-generation close approach of the two planets' orbits.
The 501-day mission calls for a launch on January 5, 2018, a Mars fly by on August 20, 2018, and a return to Earth on May 21, 2019.
What would cause the most pain for you and your partner?
This poll ended on 08 March 2013.
The confined space
Sharing sweat and urine
Eating asparagus and then sharing sweat and urine
Leaving the toilet seat up
Having one remote for the spacecraft
This is not a scientific poll. The results reflect only the opinions of those who chose to participate.
Update your news preferences and get the latest news delivered to your inbox.