(13) Commitments and Contingencies Contractual Obligations The following table summarizes our contractual cash obligations as of June 30, 2012 (in thousands) : Payments due by year Less than 1 Year 1 to 2 years 2 to 3 years 3 to 4 years 4 to 5 years Thereafter Total Long-term debt obligations $ - $ - $ - $ 400,000 $ 125,000 $ - $ 525,000 Interest payments on long-term debt (1) 49,281 49,281 49,281 49,281 10,781 - 207,905 Operating lease obligations 13,989 17,938 18,266 18,677 10,811 14,017 93,698 Purchase obligations (2) 97,224 840 840 140 - - 99,044 Total contractual obligations $ 160,494 $ 68,059 $ 68,387 $ 468,098 $ 146,592 $ 14,017 $ 925,647 (1) Represents contractual interest payment obligations on the $400.0 million outstanding principal balance of our 2015 Notes, which bear interest at a rate per annum of 9.625 percent and contractual interest payment obligations on the $125.0 million outstanding principal balance of our 2016 Notes, which bear interest at a rate per annum of 8.625 percent. (2) Purchase obligations include all commitments to purchase goods or services of either a fixed or minimum quantity that are enforceable and legally binding. As of June 30, 2012, purchase obligations include EnhancedView-related commitments, ground systems and communication services. Operating Leases We have commitments for operating leases primarily relating to office and operating facilities and equipment. We lease various real properties under operating leases that generally require us to pay taxes, insurance, maintenance and minimum lease payments. These leases contain escalation provisions for increases as a result of increases in real estate taxes and operating expenses. We recognize rent expense under such leases on a straight-line basis over the term of the lease. Substantially all of these leases have lease terms ranging from three to twelve years. Some of our leases have options to renew. Total rental expense under operating leases for the three months ended June 30, 2012 and 2011 was approximately $1.2 millio