background as well. you could just reach out and touch it. can you explain why it requires such an enormous mirror? and how do you ensure that you can keep it safe as it is launching into space? >> so, the reason we require a big mirror is because we need more collecting area. the bigger the mirror, the more life you collect with the octobers that you can see. so, that's the first thing. how do we keep it safe during launch? well, on this particular telescope, it's gotten so big now in terms of the requirements astronomers have to do their science that we can't fit these telescopes into a rocket anymore when they're fully unfolded. so for webb, we've actually gone in a very new direction. we are actually folding up the whole package for launch so it will fit in the rocket faring and then at launch we'll unpack the telescope.