Commitments and Contingencies Thales Alenia Space In June 2010, the Company executed a primarily fixed-price full-scale development contract ("FSD") with Thales Alenia Space for the design and build of satellites for its Iridium NEXT satellites. The total price under the FSD is approximately $2.3 billion , and the Company expects payment obligations under the FSD to extend into the second quarter of 2019. As of December 31, 2018 , the Company had made aggregate payments of $2.2 billion to Thales Alenia Space, which are capitalized as construction-in-progress within property and equipment, net, in the accompanying consolidated balance sheet, of which $1.5 billion were financed from borrowings under the Credit Facility. On March 9, 2018, the Company and Thales Alenia Space entered into an amendment to the FSD, pursuant to which the Company and Thales Alenia Space unwound the prior changes that allowed for the deferral of certain milestone payments totaling $100.0 million through the issuance of bills of exchange. The March 2018 amendment to the FSD became effective on March 21, 2018, upon the Company's receipt of proceeds from a senior unsecured notes offering (see Note 7 ). The Company utilized a portion of the proceeds from the senior unsecured notes to prepay in full the $59.9 million of amounts due under outstanding bills of exchange, replenish the DSRA under the Credit Facility to $189.0 million , and to pay approximately $44.4 million in Thales Alenia Space milestones previously expected to be satisfied by the issuance of additional bills of exchange. In connection with the prepayment of the Thales Alenia Space bills of exchange, for the year ended December 31, 2018, the Company recorded a $4.0 million loss on extinguishment of debt, included within interest expense, representing premiums paid and the write-off of unamortized debt issuance costs. The Company had no loss on extinguishment of debt recorded for the year ended December 31, 2017. SpaceX In March 2010, the Company entered into an agreement with Space Exploration Technologies Corp. (SpaceX) to secure SpaceX as the primary launch services provider for Iridium NEXT (as amended to date, the SpaceX Agreement). The total price under the SpaceX Agreement for seven launches and a reflight option in the event of launch failure is $448.9 million . The SpaceX Falcon 9 rocket was configured to carry ten Iridium NEXT satellites to orbit for each of the initial seven launches. In November 2016, the Company entered into an agreement for an eighth launch with SpaceX to launch five additional satellites and to share the launch services with GFZ German Research Centre for Geosciences (GFZ). This launch took place in May 2018. The total price under the SpaceX Agreement for the eighth launch was $61.9 million . GFZ paid the Company $29.8 million to include the launch of NASAs two Gravity Recovery and Climate Experiment Follow-On satellites. As of December 31, 2018 , the Company had made aggregate payments of $498.9 million to SpaceX, which were capitalized as construction-in-progress within property and equipment, net in the accompanying consolidated balance sheets. The Company expects payments to SpaceX to continue into the first quarter of 2019. Kosmotras In June 2011, the Company entered into an agreement with Kosmotras as a supplemental launch services provider for Iridium NEXT. The original cost under the Kosmotras agreement was $51.8 million . Kosmotras to date has been unable to obtain the permits or authorizations to launch the Company's satellites on a Dnepr rocket as planned, and Kosmotras has proposed no satisfactory alternative launch plan. As a result, the Company wrote-off the full amount previously paid to Kosmotras, by recording accelerated depreciation expense of $36.8 million , in the fourth quarter of 2017. Iridium NEXT Launch and In-Orbit Insurance The Company was required, pursuant to its Credit Facility, to obtain insurance covering the launch and first 12 months of operation of the Iridium NEXT satellites. The launch and in-orbit insurance the Company obtained contains elements, consistent with the terms of the Credit Facility, of self-insurance and deductibles, providing reimbursement only after a specified number of satellite failures. As a result, a failure of one or more of the Companys satellites, or the occurrence of equipment failures and other related problems, could constitute an uninsured loss or require the payment of additional premiums and could harm the Companys financial condition. Furthermore, launch and in-orbit insurance does not cover lost revenue. The total premium for the company's current launch and in-orbit insurance is $120.7 million , which was paid in full as of December 31, 2018 . Due to various contractual requirements with Motorola, the prior operator of the Company's first-generation satellite constellation, the Company is required to maintain a third-party liability in-orbit insurance policy on its first-generation satellites with a de-orbiting endorsement to cover potential claims relating to operating or de-orbiting the satellite constellation or individual satellites. The current policy has a renewable one-year term, which is scheduled to expire on December 8, 2019. The policy coverage is separated into Sections A, B, and C. Section A coverage is currently in effect and covers product liability over Motorolas position as manufacturer of the first-generation satellites. Liability limits for claims under Section A are $1.0 billion per occurrence and in the aggregate. There is no deductible for claims. Section B coverage is currently in effect and covers risks in connection with in-orbit satellites and for the de-orbit of individual satellites. Liability limits for claims under Section B are $500 million per occurrence and in the aggregate for space vehicle liability and $500 million and $1.0 billion per occurrence and in the aggregate, respectively, with respect to de-orbiting. The balance of the unamortized premium payment for Sections A and B coverage as of December 31, 2018 is included in prepaid expenses and other current assets in the accompanying consolidated balance sheet. The deductible for claims under Section B is $250,000 per occurrence. Section C coverage is effective once requested by the Company and covers risks in connection with a mass decommissioning of the first-generation satellites. Liability limits for claims under Section C are $500 million and $1.0 billion per occurrence and in the aggregate, respectively. As of December 31, 2018 , the Company had not requested Section C coverage since no mass decommissioning activities are currently anticipated. The deductible for claims under Section C is $250,000 per occurrence. Unconditional Purchase Obligations The Company has a manufacturing agreement with Benchmark. Pursuant to the agreement, the Company may be required to purchase certain materials if the materials are not used in production within the periods specified in the agreement. Benchmark will then repurchase such materials from the Company at the same price paid by the Company, as required for the production of the devices. As of December 31, 2018 and 2017 , the Company had $2.5 million and $4.0 million , respectively, of such materials, and the amounts were included in inventory on the accompanying consolidated balance sheets. As of December 31, 2018 , the aggregate unconditional purchase obligations were $39.1 million , which includes the Companys commitments with Boeing and Benchmark as well as $7.2 million of open purchase orders executed with other vendors. The Boeing obligations (see Note 8 ) represent the take-or-pay commitment with the execution of the Development Services Agreement (DSA). The Company's obligation to Benchmark for the year ending December 31, 2019 is $13.9 million . Operating Leases The Company leases land, office space, and office and computer equipment under noncancelable operating lease agreements. The Company adopted ASC 842, the new lease accounting standard, effective January 1, 2019 (see Note 2 ). Most of the leases contain renewal options of 1 to 10 years. The Companys obligations under the current terms of these leases extend through 2030 . Additionally, several of the Companys leases contain clauses for rent escalation including, but not limited to, a pro-rata share of increased operating and real estate tax expenses. Rent expense is recognized on a straight-line basis over the lease term. Future minimum lease payments, by year and in the aggregate, under noncancelable operating leases at December 31, 2018 , are as follows: Year ending December 31, Operating Leases (In thousands) 2019 $ 3,692 2020 3,734 2021 3,827 2022 3,402 2023 3,359 Thereafter 12,926 Total $ 30,940 Rent expense for the years ended December 31, 2018 , 2017 and 2016 was $3.3 million , $3.2 million and $3.1 million , respectively. Contingencies From time to time, in the normal course of business, the Company is party to various pending legal claims and lawsuits. The Company is not aware of any actions that it expects to have a material adverse impact on its business, financial results or financial condition.