Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 68,278	$ 13,994
Short-term investments	99,985	54,981
Accounts receivable	4,357	2,865
Inventories	9,442	8,288
Prepaid and other current assets	4,274	1,372
Total current assets	186,336	81,500
Property and equipment, net	11,991	13,287
Operating leases right-of-use assets	4,561	5,319
Restricted cash	561	461
Other assets	287	110
Total assets	203,736	100,677
Current liabilities:
Accounts payable	1,691	1,134
Accrued expenses and other current liabilities	6,016	4,174
Warrant liability	0	5,018
Lease liabilities	1,469	1,274
Total current liabilities	9,176	11,600
Long-term warrant liability	0	3,828
Long-term lease liabilities	4,033	5,079
Term loan, net	39,636	24,399
Total liabilities	52,845	44,906
Commitments and contingencies (Note 12)
Redeemable common stock:
Common stock, $0.001 par value, no shares authorized, issued or outstanding as of September 30, 2021 and 24,545,966 shares authorized, 3,813,450 shares issued and outstanding as of December 31, 2020	0	80,780
Notes receivable for common stock issued	0	(803)
Redeemable stock options	0	53,085
Stockholders' deficit:
Common stock, value	27	0
Preferred stock, $0.001 par value, 100,000,000 shares authorized, no shares issued and outstanding as of September 30, 2021	0	0
Additional paid-in capital	614,418	0
Accumulated other comprehensive loss	(11)	(3)
Accumulated deficit	(463,543)	(430,588)
Total stockholders' deficit	150,891	(430,591)
Total liabilities, redeemable common stock, stock options, convertible preferred stock and stockholders' deficit	203,736	100,677
Convertible Preferred Stock
Convertible preferred stock:
Preferred stock, $0.001 par value, no shares authorized, issued or outstanding as of September 30, 2021 and 16,572,792 shares authorized, 14,376,272 shares issued and outstanding as of December 31, 2020 (redeemable)	0	353,300
Series G Common Stock [Member]
Stockholders' deficit:
Common stock, value	0	0
Series W Common Stock [Member]
Stockholders' deficit:
Common stock, value	$ 0	$ 0