Nationals from several countries as Australia, Canada, Japan, South Korea, Unites States, UK and most European Union nations do not require a visa to visit Chile and can stay up to 90 days. You must have a passport, in good condition and valid for the period of stay. Australians are required to pay a reciprocity fee (US$ 117 at the airport).
Please, check the following link to verify if you require of a tourist visa click here. Visa applications are processed by the Ministry of Foreign Affairs, through the network of Consulates of Chile in the world .
If you need an invitation letter to attend APC1SS, this could be sent after you paid in full for your registration. Please, contact the registration office of APC1SS early enough considering the days required for the whole procedure.