Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities:
Net loss	$ (7,322)	$ (6,309)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock-based compensation	1,147	1,166
Depreciation and amortization	308	169
Changes in assets and liabilities:
Accounts receivable	(18)	(135)
Cost and estimated revenue in excess of billings	2	0
Inventory, net	(239)	2
Accounts payable	105	(289)
Income tax payable	(2)	0
Other assets and liabilities	(321)	232
Net cash used in operating activities	(6,340)	(5,164)
Cash flows from investing activities:
Purchase of security investments	(5,100)	0
Maturity of held-to-maturity securities	1,425
Purchases of property and equipment	(1,319)	(370)
Net cash used in investing activities	(4,994)	(370)
Cash flows from financing activities:
Purchase of treasury stock	(69)	0
Repayment of related party debt	(500)	(2,000)
Repayments on lease financing	(115)	(56)
Net cash used in financing activities	(684)	(2,056)
Net change in cash and cash equivalents	(12,018)	(7,590)
Cash and cash equivalents at beginning of period	26,453	35,936
Cash and cash equivalents at end of period	14,435	28,346
Supplemental disclosures of cash flow information:
Cash paid for interest	66	8
Acquisition of equipment through financing lease	0	394
Operating right of use assets and associated liabilities	223	0
Income taxes paid	$ 2	$ 0