Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
CURRENT ASSETS:
Cash and cash equivalents	$ 52,468	$ 15,275
Marketable securities	129,910	0
Accounts receivable, net	147	156
Inventories, net	4,852	2,655
Prepaid and other current assets	6,701	1,396
Total current assets	194,078	19,482
Property and equipment, net	4,835	4,865
Restricted cash	2,150	1,222
Total other noncurrent assets	169	316
Total assets	201,232	25,885
CURRENT LIABILITIES:
Accounts payable	4,039	1,807
Accrued expenses and other current liabilities	4,077	3,356
Deferred revenue (including $200 from related parties)	245	660
Convertible notes	0	29,079
Borrowings - net of issuance costs, current portion	0	2,693
Total current liabilities	8,361	37,595
Deferred rent, noncurrent	3,185	3,631
Private placement warrant liability	156	0
Borrowings - net of issuance costs, noncurrent	0	2,884
Total liabilities	11,702	44,110
COMMITMENTS AND CONTINGENCIES (Note 17)
STOCKHOLDERS’ EQUITY (DEFICIT):
Preferred stock—$0.0001 par value: 1,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock—$0.0001 par value: 300,000,000 shares authorized; 154,565,671 and 101,286,645 shares issued and outstanding at September 30, 2021 and December 31, 2020	15	10
Additional paid-in capital	316,318	68,549
Accumulated other comprehensive loss	(42)	0
Accumulated deficit	(126,761)	(86,784)
Total stockholders’ equity (deficit)	189,530	(18,225)
Total liabilities and stockholders’ equity (deficit)	$ 201,232	$ 25,885