CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jul. 31, 2023	Apr. 30, 2023	Jul. 31, 2022	Apr. 30, 2022
Current assets:
Cash and cash equivalents	$ 24,898	$ 38,542	$ 115,137	$ 126,166
Accounts receivable, net	16,209	18,298
Contract assets	14,454	9,609
Inventory	40,866	43,908
Prepaid expenses and other current assets	1,892	2,094
Total current assets	98,319	112,451
Property and equipment, net	182,835	177,770
Operating lease right-of-use assets	42,374	42,772
Deferred tax assets	114,371	113,751
Other assets	4,757	4,473
Restricted cash	350	350	350	350
Total assets	443,006	451,567
Current liabilities:
Accounts payable	22,813	24,593
Accrued compensation and benefits	4,667	8,780
Contract liabilities	33,019	37,352
Convertible senior notes, net	140,888	140,623
Current portion of operating lease liabilities	1,262	1,358
Other current liabilities	3,295	2,440
Total current liabilities	205,944	215,146
Operating lease liabilities, less current portion	45,370	45,690
Finance lease liabilities, less current portion	1,424	1,562
Total liabilities	252,738	262,398
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value; 5,000 shares authorized; no shares issued and outstanding at respective dates	0	0
Common stock, $0.001 par value; 150,000 shares authorized; 63,111 and 62,692 shares issued and outstanding at respective dates	63	63
Additional paid-in capital	623,445	620,224
Accumulated deficit	(433,240)	(431,118)
Total stockholders’ equity	190,268	189,169	$ 178,796	$ 174,526
Total liabilities and stockholders’ equity	$ 443,006	$ 451,567