Solution

Opening the calendar in a ics-reading-program (such as Google Calendar) will give you loads of weird events. By grouping events by day and searching for all event descriptions on that day together, you'll find out that some groups of events are missions at a planet in the game Ratchet And Clank (2002). For instance, "Search the laboratories" and "Traverse the wilderness" are done on the planet Orxon, resulting in the letter O. Taking the first name of each planet, with planets ordered by date of the events, you will get the answer organ.