X0306 4 2018-08-03 0 0001418819 Iridium Communications Inc. IRDM 0001498910 Hickey Thomas D C/O IRIDIUM COMMUNICATIONS INC. 1750 TYSONS BOULEVARD, SUITE 1400 MCLEAN VA 22102 0 1 0 0 Chief Legal Officer, Secretary Common Stock 2018-08-03 4 S 0 13455 18.86 D 125820 D The price reported is a weighted average sales price. The shares were sold in multiple transactions at prices ranging from $18.60 to $19.00, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (1) to this Form 4. /s/Brian Leaf, Attorney-in-Fact 2018-08-07