Property and Equipment, Net (Tables)

9 Months Ended

Sep. 30, 2021

Property Plant And Equipment [Abstract]

Property and Equipment, Net

Property and equipment, net, consisted of the following:

	Estimated	September 30,			December 31,
	Useful Life	2021			2020
Lab and test equipment	7 years	$	18,183		$	18,631
Vehicles	5 years		5,147			13,320
Equipment	3-7 years		35,099			32,177
Furniture and fixtures	7 years		2,696			2,938
Leasehold improvements	7 years		6,807			6,767
Aircraft	10 years		931			834
Building	39 years		2,975			2,975
			71,838			77,642
Land			725			725
Construction in progress			1,660			219
Less accumulated depreciation			(43,145	)		(44,187	)
Total property and equipment—    net		$	31,078		$	34,399