Inventories


	As Of December 31,
in thousands	2021		2020
Raw materials	$	5,775	$	649
Work in progress		941		—
Finished goods		959		—
Inventories	$	7,675	$	649

The Company’s inventories included materials which are necessary to construct the Company’s launch vehicles to provide launch services to customers. Costs related to the construction of research and development launch vehicles are recorded as research and development expenses when incurred. Under the Company’s business model, launch vehicles are manufactured to deliver customer payloads of various sizes to various locations in low-earth orbit. There were $6.7 million of inventory net realizable value write downs recorded during the year ended December 31, 2021. There were no inventory net realizable value write downs recorded during the year ended December 31, 2020 and 2019.

Property, Plant and Equipment, net

Presented in the table below are the major classes of property, plant and equipment:


	As Of December 31,
in thousands	2021			2020
Construction in progress	$	39,246		$	—
Computer and software		3,092			1,440
Leasehold improvements		14,177			13,873
Research and development equipment		8,935			4,903
Production equipment		10,442			8,174
Furniture and fixtures		1,001			466
Kodiak Spaceport		—			2,079
Total property, plant and equipment		76,893			30,935
Less: accumulated depreciation		(10,577	)		(6,866	)
Property, plant and equipment, net	$	66,316		$	24,069

Construction is progress relates mainly to the ongoing development of our manufacturing facility located in Alameda, California.

Depreciation expense is recorded within operating expenses in the Consolidated Statements of Operations and amounted to $3.7 million, $3.3 million and $2.3 million for the years ended December 31, 2021, 2020 and 2019, respectively. No impairment charges were recorded for the year ended December 31, 2021, 2020 and 2019.

On June 19, 2019, the Company entered into an agreement with Alaska Aerospace Corporation (“AAC”) to develop a commercial launch pad site (“Launch Pad”) in Kodiak, Alaska. The Launch Pad development includes construction of the Launch Pad and obtaining Federal Aviation Administration spaceport license approval for launch operations beginning in August 2019. The Launch Pad’s costs were jointly funded by AAC and the Company. Throughout the term of the agreement, the State of Alaska retains ownership of the developed Launch Pad site and the Company leases it.

The Company’s involvement in the construction of the Launch Pad, inclusive of the land, resulted in the Company being recognized as the owner of the Launch Pad during the lease term. Prior to the adoption of ASC 842, the arrangement was accounted for as a build-to-suit lease under ASC 840 — Leases. The total construction costs of $2.1 million were capitalized within property, plant and equipment, net on the Consolidated Balance Sheet, and were depreciated on a straight-line basis over the life of the lease term. AAC’s contributions of $0.8 million were recorded as a financing obligation which was included in other non-current liabilities on the Company’s Consolidated Balance Sheets to be released at the end of the lease term.

Upon adoption of ASC 842 on January 1, 2021, the Company derecognized the Kodiak Spaceport asset of $2.1 million, the accumulated depreciation of $0.4 million, and the financing obligation of $0.8 million, with an adjustment to equity for the difference. The Company also recognized a right-of-use asset of $0.9 million for the Kodiak Spaceport lease. No lease payments remained to be paid as of the transition date. As such, equity was adjusted against the right-of-use asset. See Note 10 — Leases.

Accrued Expenses and Other Current Liabilities


	As Of December 31,
in thousands	2021		2020
Employee compensation and benefits	$	9,927	$	484
Contract liabilities		10,162		—
Construction in progress related accruals		3,726		—
Accrued expenses		3,464		2,751
Other (miscellaneous)		2,620		1,155
Accrued expenses and other current liabilities	$	29,899	$	4,390

Other Non-Current Liabilities


	As Of December 31,
in thousands	2021		2020
Fair value of contingent consideration	$	13,700	$	—
Contract liabilities		149		122
Other (miscellaneous)		750		1,563
Other non-current liabilities	$	14,599	$	1,685

Other Income, Net


	For The Year Ended December 31,
in thousands	2021		2020		2019
Gain on change in fair value of public and private placement of warrants	$	25,681	$	—	$	—
Gain on forgiveness of PPP note		4,850		—		—
Gain on change in fair value of contingent consideration		4,700		—		—
Gain (loss) on mark to market derivatives		—		8,145		(464	)
Other (miscellaneous)		815		2,715		740
Other income, net	$	36,046	$	10,860	$	276