Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Revenue	$ 6,309	$ 3,424	$ 11,622	$ 7,296
Cost of sales	7,853	7,442	15,492	11,285
Gross loss	(1,544)	(4,018)	(3,870)	(3,989)
Operating expenses:
Research and development	19,913	9,708	33,923	18,116
Sales and marketing	3,507	1,232	6,142	3,075
General and administrative	19,237	4,892	29,510	9,505
Total operating expenses	42,657	15,832	69,575	30,696
Loss from operations	(44,201)	(19,850)	(73,445)	(34,685)
Change in fair value of warrant liabilities	6,928	(4,265)	(39,721)	(4,574)
Loss on extinguishment of debt	0	(866)	0	(866)
Interest expense and other	(288)	(489)	(488)	(1,021)
Interest income and other	731	35	901	130
Total other income (expense), net	7,371	(5,585)	(39,308)	(6,331)
Net loss	(36,830)	(25,435)	(112,753)	(41,016)
Net loss attributable to common stockholders	(36,830)	(25,435)	(112,753)	(41,016)
Net loss attributable to common stockholders	$ (36,830)	$ (25,435)	$ (112,753)	$ (41,016)
Net loss per share attributable to common stockholders:
Basic (in dollars per share)	$ (0.11)	$ (0.20)	$ (0.33)	$ (0.32)
Diluted (in dollars per share)	$ (0.11)	$ (0.20)	$ (0.33)	$ (0.32)
Shares used in computing net loss per share attributable to common stockholders:
Basic (in shares)	340,255,023	129,650,239	336,641,349	128,780,581
Diluted (in shares)	340,255,023	129,650,239	336,641,349	128,780,581
Comprehensive Loss:
Net loss	$ (36,830)	$ (25,435)	$ (112,753)	$ (41,016)
Net unrealized gains (losses) on available-for-sale debt securities	16	16	(27)	9
Comprehensive loss	$ (36,814)	$ (25,419)	$ (112,780)	$ (41,007)