Ever since I was a child, I have been obsessed with the question: what happens to spacesuits when they're not being used? Then in 2011, while spending nine days exploring the Yuri Gagarin Cosmonaut Training Centre in Star City near Moscow, I found out.

I had approached the European Space Agency about making a project that would be the most comprehensive artistic survey ever undertaken of a space organisation. The Gagarin centre is a compulsory stop for all ESA astronauts, and Star City is a fascinating place: a closed, self-sufficient community, a real throwback to modernist Soviet towns. There aren't any hotels, but the ESA got me into the Profilaktorium, which is where astronauts are quarantined before and after missions. The name sounds ominous, but actually I was really comfortable, although sadly there were no astronauts there at the time.

I spent a lot of time trying to get access to what I was really interested in – the back rooms where more banal activities occur, like astronaut dressing rooms. For a while, it felt hopeless, like I was just being given the official tour. They're familiar with journalists, but my way of working is different. I use large-format cameras, which are very static, and I spend a lot of time with my subjects. I have to be more or less right in front of an object, staring at it, to get a successful shot. After about five days of negotiating, people began to understand. It helped that they were fascinated by my equipment and, eventually, doors started opening.

I was taken into one room where a spacesuit was being depressurised. The first thing I saw was a table piled high with suits. Some were waiting to be repaired, others needed organising. Then I looked across the room and saw these two suits. It was so unexpected – finally, I had found out what happens to spacesuits when they're not being used! I was ecstatic. It was like Christmas and I was 10 again.

The suits have an element of theatre and performance about them. A lot of this project was about rehearsal: I'm trying to get to the bottom of how life in the extreme, hostile conditions of space is rehearsed down here on Earth. The suits show just how vulnerable you are up there: they're your home, your life support machine. They remind us that, however advanced the technology is, space exploration is still dependent on the individual human being. Of course, I was tempted to try them on, and they might have let me, but you have to show some respect.

CV

Born: Évora, Portugal, 1977.

Studied: BA in photography at the London College of Printing & Distributive Trades, and MA in photography at the Royal College of Art, London.

Influences: Playwright Alfred Jarry.

High point: "I like to think it's yet to come."

Low point: "The day I was told my beloved 8x10 Kodak film would only be available on order."

Top tip: "Remember that you're not in a race – and always carry spare batteries for your light meter."

• The Rehearsal of Space and the Poetic Impossibility to Manage the Infinite features in Opening the Shutters at Mallett, Dover Street, London W1, until 21 December. The book will appear next year.