CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jul. 31, 2019	Apr. 30, 2019
CURRENT ASSETS:
Cash and cash equivalents	$ 28,944	$ 32,351
Accounts receivable	8,223	7,374
Contract assets	5,589	4,327
Inventory	8,031	6,557
Prepaid expenses and other current assets	777	709
Total current assets	51,564	51,318
Property and equipment, net	26,453	25,625
Operating lease right-of-use assets	22,601	0
Restricted cash	1,150	1,150
Other assets	302	302
TOTAL ASSETS	102,070	78,395
CURRENT LIABILITIES:
Accounts payable	5,458	4,352
Accrued payroll and related costs	3,230	3,540
Contract liabilities	18,104	14,651
Operating lease liabilities	1,382	0
Other current liabilities	761	619
Total current liabilities	28,935	23,162
Operating lease liabilities, less current portion	23,451	0
Deferred rent, less current portion	0	2,072
Other long-term liabilities	0	93
Commitments and contingencies
STOCKHOLDERS' EQUITY:
Preferred stock, $0.001 par value; 5,000 shares authorized; 1,648 shares issued and outstanding at July 31, 2019 and April 30, 2019, respectively	2	2
Common stock, $0.001 par value; 150,000 shares authorized; 56,238 and 56,136 shares issued and outstanding at July 31, 2019 and April 30, 2019, respectively	56	56
Additional paid-in-capital	613,395	613,615
Accumulated deficit	(563,769)	(560,605)
Total stockholders' equity	49,684	53,068
Total liabilities and stockholders' equity	$ 102,070	$ 78,395