6. Satellite Network and Other Equipment

Satellite network and other equipment consisted of the following:

	March 31,			December 31,
	2017			2016
Land	$	381		$	381
Satellite network		232,228			231,782
Capitalized software		36,056			30,758
Computer hardware		4,767			4,707
Other		7,624			7,522
Assets under construction		11,888			11,284
		292,944			286,434
Less: accumulated depreciation and amortization		(78,885	)		(70,593	)
	$	214,059		$	215,841

During the three months ended March 31, 2017 and 2016, the Company capitalized internal costs attributable to the design, development and enhancements of the Company’s products and services in the amount of $3,097 and $2,188, respectively.

Depreciation and amortization expense for the three months ended March 31, 2017 and 2016 was $8,330 and $5,431, respectively, including amortization of internal-use software of $1,351 and $850, respectively.

For the three months ended March 31, 2017 and 2016, 65% and 67% of depreciation and amortization expense, respectively, relate to cost of services and 8% and 10%, respectively, relate to cost of product sales, as these assets support the Company’s revenue generating activities.

As of March 31, 2017 and December 31, 2016, assets under construction primarily consist of costs associated with acquiring, developing and testing software and hardware for internal and external use that have not yet been placed into service.

During the three months ended March 31, 2016, the Company recorded an impairment loss on one of its leased AIS satellites. The impairment loss of $466 was determined based on the net carrying value of the asset at the time of the impairment and was recorded in depreciation and amortization in the condensed consolidated statement of operations for the three months ended March 31, 2016. In addition, the Company decreased satellite network and other equipment, net and the associated accumulated depreciation on the condensed consolidated balance sheet by $2,374 and $1,908, respectively.

In August 2016, the Company lost communication with one of its OG2 satellites launched on July 14, 2014. The Company recorded a non-cash impairment charge of $10,680 to write-off the net book value of the satellite. In addition, the Company decreased satellite network and other equipment by $13,474 and associated accumulated depreciation by $2,794 to remove the asset as of September 30, 2016.

In December 2016, the Company lost communication with one of its OG1 Plane D satellites. In the year ended December 31, 2016, the Company removed $137 from satellite network and accumulated depreciation, respectively, representing the fully depreciated value of the satellite.