All space projects push the frontiers of technology and are drivers of innovation.

I recall a lecture by John Glenn, the first American to go into orbit. When asked what went through his mind while he was crouched in the rocket nose-cone, awaiting blast-off, he replied, "I was thinking that the rocket has 20,000 components, and each was made by the lowest bidder."

Collective human actions are transforming, even ravaging, the biosphere - perhaps irreversibly - through global warming and loss of biodiversity.

I hope that by 2050 the entire solar system will have been explored and mapped by flotillas of tiny robotic craft.

One of the computer models for a four degree temperature rise would give rise to a 10 degree temperature rise in Africa. And bear in mind also that in the depth of an ice age the mean temperature drop compared to the present was five degrees.

I think all countries need to aim to cut the CO2 emissions per person, taking account of externalities like imports and exports.

Cosmology does, I think, affect the way that we perceive humanity's role in nature. One thing we've learnt from astronomy is that the future lying ahead is more prolonged than the past. Even our sun is less than halfway through its life.