  The ongoing push to send humans back to the Moon and to Mars is giving rise
to a wide range of novel technical solutions in support of prospective
astronaut expeditions. Against this backdrop, the European Space Agency (ESA)
has recently launched an investigation into unobtrusive interface technologies
as a potential answer to such challenges. Three particular technologies have
shown promise in this regard: EEG-based brain-computer interfaces (BCI) provide
a non-invasive method of utilizing recorded electrical activity of a user's
brain, electromyography (EMG) enables monitoring of electrical signals
generated by the user's muscle contractions, and finally, eye tracking enables,
for instance, the tracking of user's gaze direction via camera recordings to
convey commands. Beyond simply improving the usability of prospective technical
solutions, our findings indicate that EMG, EEG, and eye-tracking could also
serve to monitor and assess a variety of cognitive states, including attention,
cognitive load, and mental fatigue of the user, while EMG could furthermore
also be utilized to monitor the physical state of the astronaut. In this paper,
we elaborate on the key strengths and challenges of these three enabling
technologies, and in light of ESA's latest findings, we reflect on their
applicability in the context of human space flight. Furthermore, a timeline of
technological readiness is provided. In so doing, this paper feeds into the
growing discourse on emerging technology and its role in paving the way for a
human return to the Moon and expeditions beyond the Earth's orbit.
