Star Trek is almost here with a new project, Clarissa, that NASA has been working on. An article on TrekToday says:
NASA will soon be installing a new voice-activated computer system on the International Space Station that bears a striking resemblance to Star Trek's computer system.
Clarissa will be able to understand 75 individual commands and have a vocabulary of around 260 words. Users will not need to prefix their request with a specific word, such as "Computer', in order for the system to listen to them. It's meant to be always on and as such will try to distinguish between voice commands that require a response and speech directed at other people.
You can view the actual project page at NASA here