By Helen Briggs
BBC News science reporter
British astronomers are seeking your views on the merits of sending humans to visit the Moon or Mars.
Man last set foot on the Moon in the '70s
The Royal Astronomical Society has set up a commission to investigate whether the UK should break with tradition by funding human spaceflight.
The panel of three independent experts wants to hear the opinions of BBC News website readers.
Britain must decide in December its commitment to European proposals for future space missions.
The European Space Agency (Esa) has floated ambitious plans to send robotic spacecraft to Mars ahead of a possible human journey in 2033. But the UK has always been against costly human spaceflight, preferring to send robots to do the work instead.
The UK will have to invest millions of pounds in the Aurora programme if it is to play a leading role.
HAVE YOUR SAY
We belong in the cosmos and need to explore what is out there
Chair of the commission, Professor Frank Close, a particle physicist at Oxford University, says a human Mars mission would be very costly.
"It's clear the [UK] scientific budget alone would never fund a human mission to Mars," he told BBC News.
"Everyone's fascinated by space and science fiction but turning it into fact is a very expensive business. If it were to happen, public opinion would be a very important factor indeed."
Man last set foot on the Moon in 1972, escaping the gravity of the Earth and using technology that had a fraction of the computing power found in even today's home devices.
While astronauts have been into space since then, they have largely been confined to the Earth's near orbit, carrying out relatively mundane work such as on the International Space Station.
When President Bush spoke last year of a new vision for the US space programme, sending astronauts to the Moon and even Mars, he revived dreams of venturing back out into the Solar System.
Mars may have frozen reserves of water
These have been echoed in Europe, which now hopes to build on the success of its Mars Express spacecraft with a series of missions to the Red Planet and beyond.
However, the issue of human spaceflight has always divided the scientific community.
Some believe only human spaceflight can truly capture the imagination of the general public, and have the adaptability to take missions that extra mile.
Others would prefer to channel money into the sort of science that can be done by machines.
"Space scientists will be at best lukewarm [to the idea of funding human spaceflight]," says panel member Professor Ken Pounds, an astrophysicist at the University of Leicester.
"We are very conscious of the fact that if we do anything involving humans in space, the costs rocket by at least a factor of 10 and maybe more.
"What do the general public feel about it? They are going to be paying the bill."
The third "wise man" on the panel is Dr John Dudeney, of the British Antarctic Survey in Cambridge.
Having spent long periods cooped up on research stations in Antarctica he is well placed to comment on what life might be like for astronauts spending long periods on the Moon or Mars with only each other for company.
"There are some parallels you can draw," he says.
Research on the frozen continent has involved a mixture of both man and machines, as it might do one day on Mars.
Dr Dudeney says it is important to consider what robots are capable of doing now, then think forward to what they might be able to do in 10 or 15 years' time.