Giovanna Tinetti, a planetary scientist at University College London, learned in February that her team's proposal to lead the £400-million (US$642-million) Exoplanet Characterisation Observatory (EChO) mission to search for life on other planets will be backed by the European Space Agency (ESA).

You started off as a theoretical particle physicist. How did you make the leap to searching for life on exoplanets?

I was pursuing my PhD in theoretical physics at the University of Turin in Italy, yet I was increasingly interested in working on something for which experiments were the driving force. So I started to look at other possibilities. In 1998, NASA started a virtual Astrobiology Institute to prepare ambitious experiments looking for life and habitable planets in the Universe. As I learned more, I decided that it was a great move for me. I was intrigued by ideas about Gaia and the notion that abiotic planets and living organisms grow together. I began my adventure with exoplanets as a postdoc at NASA's Jet Propulsion Laboratory in Pasadena, California.

Characterize your early career choices.

I made a series of decisions not to follow the 'safe' route. First, I turned down a well-paying job, instead choosing to finish my PhD. And just deciding to begin this search for exoplanets meant making a big bet with my career. Back then, only a few extrasolar planets had been discovered, and nobody knew whether they would prove viable for life. Several people told me that this could be a path that leads nowhere. I just felt that I had one life, and if I didn't try, I would regret it. Luckily, the field has been successful, so I made the right choices.

How have your past experiences shaped how you approached this space mission?

During my postdoc, a number of extrasolar planets were discovered, and attention shifted to a dedicated experiment to probe exoplanet atmospheres. It ultimately became a joint project, combining NASA's Terrestrial Planet Finder (TPF) and ESA's Darwin. But technological challenges and budget hurdles kept pushing the launch date further and further back. At the same time, we discovered that we could look for atmospheres that signalled potentially habitable worlds by monitoring planets as they move in front of their stars. This 'transit spectroscopy' technique proved successful, and we started to think that, rather than pursuing a big experiment, we should use the technique with existing telescopes, such as Hubble or Spitzer. So the TPF/Darwin mission was shelved. But the process of preparing for a big experiment was informative.

Did that help you achieve success with EChO?

Absolutely. Using the transit technique and existing technology, we can now make the most of a dedicated exoplanet mission. The most important technology — including a 1.2-metre telescope and spectrograph — already exists. That was important when submitting a proposal for a launch in 2020.

Are you confident EChO will launch in 2020?

I plan to work hard to ensure its success. It looks like a long lead time but it's really not. We have to go through ESA's assessment phase, to judge whether the project is doable — so we have to be ready to answer any question relating to the science.

Are you taking steps to safeguard your career in case EChO is derailed?

The preparation for EChO relates to my everyday research. My team continues to work hard on observing planets from the ground and from the Hubble and Spitzer telescopes. When you are involved in a space mission, you can't bet on its success until you see the satellite in orbit. That said, we are doing our best to create a mission that benefits extrasolar-planet research.

What is the most important thing you've done for your career?

I can say that it was a good idea to spend one year of my life pursuing this space mission because, in the end, we were selected. You have to believe in something — unfortunately, that doesn't necessarily mean it will happen.