UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Cash flows used in operating activities:
Net loss		$ (15,712)	$ (15,849)	$ (43,510)	$ (46,891)
Adjustments to reconcile net loss for the period to net cash used in operating activities:
Non-cash portion of interest expense – Note 9				9,096	10,129
(Gain) loss on fair value adjustment for warrant liabilities – Notes 13 and 20		(1)	(1,133)	(182)	482
Gain on settlement of accrued liability – Note 8		0	0	(1,151)	0
Depreciation and amortization – Notes 2 and 5				2,155	2,577
Stock-based compensation – Note 16				2,200	1,750
Accretion – Note 12		186	102	558	306
Gain (loss) on sale of equipment, net of commissions	[1]	(456)	725	(541)	123
Changes in operating assets and liabilities:
Accounts receivable				2,771	(978)
Interest receivable				(59)	(294)
Production-related inventories				0	8,632
Materials and supplies inventories, net – Note 4				(4)	235
Prepaids – Note 3				(1,392)	(1,880)
Accounts payable and accrued expenses – Note 8				(1,416)	(3,835)
Contract liabilities – Note 10				100	6,682
Other liabilities – Note 11				(556)	(1,401)
Net cash used in operating activities				(31,931)	(24,363)
Cash flows (used in) provided by investing activities:
Additions to property, plant, and equipment				(851)	(913)
Proceeds from sale of equipment				559	2,007
Proceeds from assets held for sale				0	439
Net cash (used in) provided by investing activities				(292)	1,533
Cash flows (used in) provided by financing activities:
Principal payments on debt				(1,650)	(25,506)
Principal payments on notes payable				(95)	(94)
Proceeds from issuance of common stock and warrants, net of issuance costs – Note 14				0	188,860
Net cash (used in) provided by financing activities				(1,745)	163,260
Net (decrease) increase in cash, cash equivalents, and restricted cash				(33,968)	140,430
Cash, cash equivalents, and restricted cash, beginning of period				175,966	46,635
Cash, cash equivalents, and restricted cash, end of period		141,998	187,065	141,998	187,065
Reconciliation of cash, cash equivalents, and restricted cash:
Cash and cash equivalents		106,911	153,403	106,911	153,403
Restricted cash		35,087	33,662	35,087	33,662
Total cash, cash equivalents, and restricted cash		$ 141,998	$ 187,065	$ 141,998	$ 187,065

[1] Certain items from prior years were reclassified in the financial statements to conform with the current year presentation.