The goal of project Altus is to do an in-situ investigation of Polar Mesospheric Clouds (PMCs). These clouds form around an altitude of 84 km, and only for 60 to 80 days per year, during the summer. Normally, these clouds only form in the polar regions, from around 50◦ latitude north and south. Recently, however, PMCs have been observed as low as 40◦ north. There are theories linking this change in location, and other unexpected behaviours of PMCs, to climate change. However, further research is still required to confirm these theories. As these changes are happening at a slow rate, a database of PMC measurements would be extremely beneficial to track indicator values over time. Project Altus sets out to bridge this knowledge gap by taking regular measurements of PMCs over an extended period of time.