It’s been 19 months since the launch of the original Galaxy Zoo. That week was ridiculous – my main memory is of incredulous laughter as the number of users and classifications climbed and climbed and I, and the rest of the team, realised what we had on our hands.

Since then, we’ve made a lot of use of the results, but I’ve also spent a lot of time talking to all sorts of people and plotting to expand the project way beyond its original scope. Real people are now employed to make this happen, and Galaxy Zoo 2 which launched on Tuesday is our first site to use a new, extremely flexible interface.

It’s all come together rather rapidly in the last few weeks. On Monday night, I talked to the University’s Space and Astronomy society and told them the launch was only an hour or two away. Opening my laptop and connecting to the net on the train, I saw the new site appear. By chance I’d logged on 20 seconds after the beginning. I wonder if I was the first to see it?

I stayed up for a couple of hours that night watching the forum and email to see how reactions were. People were positive, but it stayed quiet and there was no flurry of press attention to mark the end of our press release’s embargo.

I lay in bed that night wondering if we’d just lost a colossal gamble. Perhaps we didn’t understand what it was about Galaxy Zoo that attracted people. Perhaps it really was just a one-off. It still seemed quiet the next morning as I watch the first report on BBC Breakfast TV, at 6.20, but I didn’t have time to think before being picked up and whisked off to Television Centre for more interviews.

And then we were off. More breakfast tv at 7.20, upstairs to 5 Live with Annie, one of our users, for 7.55 before that got bumped. Then back downstairs for more TV at 8.20 (Annie was great!) and then, as she headed off to work upstairs again for Radio 4. Once more I was sitting opposite John Humphrys, and we had a lot of fun on Today getting more and more enthusiastic about the project.

Spat out in the corridor, I was grabbed by the World Service for a quick interview, by now working completely on automatic. Just as quickly I found myself in a cab and at Paddington, and on a train to Oxford had time to catch my breath.

The site was clearly struggling, but stayed up (which is more than we managed for Galaxy Zoo 1) which I think is a pretty impressive achievement. More importantly, we were busy which meant that people were interested, and would come back to the site. Galaxy Zoo 2 is going to work, and we are going to get the data we want. It’s an amazing feeling; a mixture of relief and excitement. Less incredulous laughter, more satisfied grinning, I suppose.

We’d scheduled a small celebration for 5pm in the department, but unfortunately Arfon our lead developer had a bright idea just as the clock ticked toward 5, and he spent the whole time typing frantically, champagne at his side.

Since then, traffic has refused to die (which is fantastic) and as I write we’re on the front page of Digg.com so that’s not going to change any time soon. Thanks for your efforts – and the more classifications you do the sooner you’ll see what we’ve got up our sleeves for our next trick.