6. Satellite Network and Other Equipment

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

	June 30,			December 31,
	2018			2017
Land	$	381		$	381
Satellite network		194,615			193,292
Capitalized software		56,308			45,062
Computer hardware		5,195			5,189
Other		5,925			5,276
Assets under construction		15,487			16,539
		277,911			265,739
Less: accumulated depreciation and amortization		(109,187	)		(91,561	)
	$	168,724		$	174,178

During the quarters ended June 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 $3,267 and $3,374, respectively. During the six months ended June 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 $7,074 and $6,610, respectively.

Depreciation and amortization expense for the quarters ended June 30, 2018 and 2017 was $8,615 and $8,710, respectively, including amortization of internal-use software of $836 and $1,485, respectively. Depreciation and amortization expense for the six months ended June 30, 2018 and 2017 was $17,557 and $17,040, respectively, including amortization of internal-use software of $1,772 and $2,835, respectively.

For the quarters ended June 30, 2018 and 2017, 50% and 62% of depreciation and amortization expense, respectively, relate to cost of services and 9% and 8%, respectively, relate to cost of product sales, as these assets support the Company’s revenue generating activities. For the six months ended June 30, 2018 and 2017, 49% and 64% 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 June 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.