Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Operating activities:
Net loss	$ (13,461)	$ (15,971)
Adjustments to reconcile net loss to net cash used in operating activities:
Bad debt expense	56	8
Inventory reserve	896	33
Depreciation and amortization	3,262	2,427
Stock-based compensation	2,140	2,080
Deferred taxes	(44)	(4)
Amortization of debt financing costs	188	210
Non-cash lease expense	94	31
Long-lived assets impairment	0	2,195
Loss on disposal of property, plant, and equipment	49	0
Changes in operating assets and liabilities:
Accounts receivable	(705)	(319)
Contract assets	0	(1,050)
Inventories	(289)	196
Prepaid expenses and other current assets	413	1,042
Other non-current assets	206	222
Accounts payable	(389)	(1,362)
Accrued liabilities	(1,764)	(1,234)
Other	(48)	(44)
Cash used in operating activities	(9,396)	(11,540)
Investing activities:
Proceeds from sale of property, plant, and equipment	125	0
Purchases of property, plant, and equipment	(227)	(6,650)
Cash used in investing activities	(102)	(6,650)
Financing activities:
Proceeds from equity financing, net	(37)	0
Repayment of financed insurance premiums	(409)	0
Payment of debt issuance costs	(25)	(24)
Payment of at-the-market facility costs	0	(395)
Proceeds from exercise of stock options	0	76
Proceeds from issuance of common stock under employee stock purchase plan	81	138
Cash used in financing activities	(390)	(205)
Change in cash, cash equivalents, and restricted cash	(9,888)	(18,395)
Cash, cash equivalents, and restricted cash at beginning of period	28,484	42,236
Cash, cash equivalents, and restricted cash at end of period	18,596	23,841
Supplemental cash flow disclosures:
Income taxes paid	0	0
Interest paid, net of amounts capitalized	770	630
Capitalized property, plant, and equipment included in accounts payable and accrued liabilities	99	920
Issuance of common stock warrants	132	0
Recognition of operating right-of-use lease asset	1,293	(1,137)
Recognition of operating lease liabilities	$ 1,306	$ (1,193)