6. Satellite Network and Other Equipment

Satellite network and other equipment, net consisted of the following:

	September 30,			December 31,
	2018			2017
Land	$	381		$	381
Satellite network		195,256			193,292
Capitalized software		59,405			45,062
Computer hardware		5,558			5,189
Other		5,808			5,276
Assets under construction		16,711			16,539
		283,119			265,739
Less: accumulated depreciation and amortization		(117,943	)		(91,561	)
	$	165,176		$	174,178

During the quarters ended September 30, 2018 and 2017, the Company capitalized internal costs attributable to the design, development and enhancements of the Company’s products and services and internal-use software in the amount of $3,224 and $3,232, respectively. During the nine months ended September 30, 2018 and 2017, the Company capitalized internal costs attributable to the design, development and enhancements of the Company’s products and services and internal-use software in the amount of $9,873 and $9,840, respectively.

Depreciation and amortization expense for the quarters ended September 30, 2018 and 2017 was $8,764 and $8,850, respectively, including amortization of internal-use software of $818 and $1,602, respectively. Depreciation and amortization expense for the nine months ended September 30, 2018 and 2017 was $26,321 and $25,891, respectively, including amortization of internal-use software of $2,590 and $4,437, respectively.

For the quarters ended September 30, 2018 and 2017, 49% and 61% of depreciation and amortization expense, respectively, relate to cost of services and 8% and 8%, respectively, relate to cost of product sales, as these assets support the Company’s revenue generating activities. For the nine months ended September 30, 2018 and 2017, 49% and 63% of depreciation and amortization expense, respectively, relate to cost of services and 10% and 8%, respectively, relate to cost of product sales, as these assets support the Company’s revenue generating activities.

As of September 30, 2018 and December 31, 2017, assets under construction primarily consisted of costs associated with acquiring, developing and testing software and hardware for internal and external use that have not yet been placed into service.

Between April and July 2017, the Company lost communication with three OG2 satellites. The Company recorded a non-cash impairment charge of $31,224 to write-off the net book value of the satellites. In addition, the Company decreased satellite network and other equipment by $39,576 and associated accumulated depreciation by $8,352 to remove the assets as of September 30, 2017.