Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (26,912)	$ (59,344)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	80	998
(Gain) loss on sale of property and equipment, net	(12)	53
Noncash lease expense relating to operating lease right-of-use assets	905	1,058
Gain on termination of operating lease, net	(680)	0
Common stock purchase agreement costs	1,136	0
Impairment of right-of-use assets	0	47
Inventory write-downs, net of scrapped inventory	167	3,666
Change in fair value of convertible note and warrant liabilities	4	914
Realized loss on instrument-specific credit risk	0	46
Stock-based compensation	7,002	14,707
Amortization of premiums and accretion of discounts on marketable securities, net of change in accrued interest	(491)	33
Expected credit losses, net of write-off	35	0
Changes in operating assets and liabilities:
Accounts receivable, net	20	379
Inventories, current and noncurrent, net	157	(2,681)
Prepaid and other current assets	1,035	1,672
Other noncurrent assets	123	133
Accounts payable	275	1,494
Accrued expenses and other current liabilities	(3,411)	(2,571)
Operating lease liabilities	(936)	(1,143)
Contract liabilities	35	(969)
Other noncurrent liabilities	(346)	0
Net cash used in operating activities	(21,814)	(41,508)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(420)	(1,421)
Proceeds from sale of property and equipment	45	243
Purchases of marketable securities	(24,241)	(8,736)
Proceeds from redemptions and maturities of marketable securities	27,756	76,350
Net cash provided by investing activities	3,140	66,436
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from exercise of stock options	134	450
Proceeds from the issuance of convertible note	146	0
Payments for convertible note redemptions	0	(6,235)
Taxes paid related to the net share settlement of equity awards	(113)	(1,312)
Proceeds from issuance of common stock under Common Stock Purchase Agreements	5,863	136
Stock issuance costs related to Common Stock Purchase Agreements	(613)	0
Proceeds from issuance of common stock through the Employee Stock Purchase Plan	26	118
Net cash provided by (used in) financing activities	5,443	(6,843)
NET (DECREASE) INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	(13,231)	18,085
CASH, CASH EQUIVALENTS AND RESTRICTED CASH—Beginning of period	19,082	21,214
CASH, CASH EQUIVALENTS AND RESTRICTED CASH—End of period	5,851	39,299
SUPPLEMENTAL CASH FLOW INFORMATION:
Cash paid for income taxes, net of refund	(2)	16
Cash paid for interest	0	115
SUPPLEMENTAL DISCLOSURE OF NONCASH INVESTING AND FINANCING ACTIVITIES:
Purchases of property and equipment included in accounts payable and accrued liabilities	42	23
Conversion of convertible notes and accrued interest into Class A common stock	0	3,338
Operating lease liabilities extinguished upon termination of lease	16,325	0
Operating lease right-of-use asset derecognized upon termination of lease	10,371	0
Operating lease right-of-use assets obtained in exchange for lease obligations	753	0
Stock issuance costs included in accounts payable and accrued liabilities	657	3
Stock issuance costs through issuance of common stock	282	0
Taxes related to net share settlement of equity awards included in accrued liabilities	$ 0	$ 1