CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Jan. 31, 2020	Apr. 30, 2019
CURRENT ASSETS:
Cash and cash equivalents	$ 30,687	$ 32,351
Accounts receivable	10,151	7,374
Contract assets	6,111	4,327
Inventory	9,565	6,557
Prepaid expenses and other current assets	763	709
Total current assets	57,277	51,318
Property and equipment, net	26,850	25,625
Operating lease right-of-use assets	20,437	0
Restricted cash	350	1,150
Other assets	302	302
TOTAL ASSETS	105,216	78,395
CURRENT LIABILITIES:
Accounts payable	5,332	4,352
Accrued payroll and related costs	2,985	3,540
Contract liabilities	26,355	14,651
Operating lease liabilities	1,172	0
Other current liabilities	710	619
Total current liabilities	36,554	23,162
Operating lease liabilities, less current portion	21,584	0
Deferred rent, less current portion	0	2,072
Other long-term liabilities	0	93
TOTAL LIABILITIES	58,138	25,327
Commitments and contingencies
STOCKHOLDERS' EQUITY:
Preferred stock, $0.001 par value; 5,000 shares authorized; 1,648 shares issued and outstanding at January 31, 2020 and April 30, 2019, respectively	2	2
Common stock, $0.001 par value; 150,000 shares authorized; 56,479 and 56,136 shares issued and outstanding at January 31, 2020 and April 30, 2019, respectively	56	56
Additional paid-in-capital	613,323	613,615
Accumulated deficit	(566,303)	(560,605)
Total stockholders' equity	47,078	53,068
Total liabilities and stockholders' equity	$ 105,216	$ 78,395