Question: what is the biggest challenge you have come across in your work?

Delma Childers answered on 9 Dec 2015:

In science, we like to use the best methods and technologies we can for our experiments. Sometimes a new method or technology is developed that greatly improves the power of our experiments. On a normal experiment on Earth, I’d be free to switch to the new method. But for an ISS experiment, everything we do has to be approved by engineers and all sorts of people involved with the space station, so making these kinds of changes is very difficult (sometimes impossible) and can delay our mission. When new methods come up, we have to carefully consider if the challenge of getting the change approved is worth the time lost. Since it may be years from the time an experiment is proposed until when it is sent to space, it can be disheartening for us scientists to compromise and not send an experiment the way we’d really like to see it done.