First, determine what firmware version you are currently on. To do this, click the “Menu” button on the phone. Then select “Setup”. Then select “Phone information”. This page will show the current firmware on the phone. As of November 2011, the current firmware version is HT11001.
If you need to upgrade your firmware, you can download the Iridium 9555 firmware upgrade tool by clicking here.
You will need a USB data cable to perform the upgrade. The upgrade process can take 20-30 minutes so make sure your computer and the Iridium 9555 are connected to external power during the upgrade so that the upgrade process is NOT interrupted once it begins. Carefully follow the instructions on the PDF included with the upgrade tool.
Outfitter Satellite can perform the firmware upgrade for you for an $89 inspection charge plus shipping costs.