Six astronauts, six nights underground: CAVES expedition day 1 report and more astounding photos on the blog: http://blogs.esa.int/caves/2016/07/03/caves-day-1-report/
Six astronauts, six nights underground: CAVES expedition day 1 report and more astounding photos on the blog: http://blogs.esa.int/caves/2016/07/03/caves-day-1-report/