An AMADEE-18 analog astronaut heads out to conduct experiments in Oman's Dhofar region.
AMADEE-18 is run by the Austrian Space Forum (OeWF) and aims to trial technologies that could be used on a future Mars mission.
Organizers say the Dhofar region was chosen to host AMADEE-18 because of its remoteness as well as its striking visual similarity to Mars.
The AMADEE-18 field crew is composed of 15 OeWF members, but a further 150 specialists from universities and research institutions around the world have contributed to the project.
Radio communication between the astronauts and mission control in Austria has been delayed to mimic the the 10 minutes it would take for a signal to travel between Mars and Earth.
Members of the AMADEE-18 Mars simulation mission conduct scientific experiments during an analog field simulation in Oman's Dhofar region.
OeWF field commander, Gernot Groemer, said AMADEE-18 is about road-testing technologies and becoming familiar with the workflows the first human visitors to Mars will experience.
A soil assessment rover -- an autonomous robot that maps terrain -- and geophone devices which search for underground water sources are among the devices to be tested.
The mental and physical stresses on crew members have also been closely monitored.
An increasing number of national space agencies and private sector companies are now part of the race to Mars.