Before Boeing Co. launches a satellite into space or NASA lands a research craft on Mars, they’ll pay good money to know everything is going to work.

And that’s been good business for National Technical Systems Inc. in Calabasas. NTS specializes in testing for aerospace and defense as it can simulate altitude, temperature and other conditions of space.

The company’s annual report was released last month, showing net income of $4.4 million on revenue of $185 million for the year ended Jan. 31. The year before, net income was $491,000 on revenue of $155 million.

“We had the best year in our history,” said Aaron Cohen, company founder and vice chairman.

The results have jet-propelled the company’s stock. NTS shares were up 19 percent to $13.02 for the week ended May 22, making it one of the biggest gainers on the LABJ Stock Index. (See page 60.) Shares have risen 141 percent from a year earlier and hit a 52-week high of $13.03 last week.

Cohen owns about 12 percent of the 51-year-old company’s stock.

NTS has about 4,000 clients that use the company as a testing laboratory for their products. For aircraft, the company tests everything from landing gear to toilet seats. Also, carmakers contract with the company to test their safety features.

NTS bills each client depending on a variety of factors including the amount of time and personnel needed.

Sequestration is an issue, however. About 30 percent of the company’s revenue comes from the defense industry. Due in part to softness in that line of business, NTS announced in its latest earnings that it is laying off staff to realize savings between $5 million and $6 million.

Cohen would not say how many people are being let go.

Apart from that, there’s no doubt that the economy’s recovery is a tailwind for NTS, as manufacturers are spending more money on testing new designs and features. And not everything passes its first test. The company relies heavily on repeat business, Cohen said.

“The better the economy is the better our business is,” he said. “People have to redesign and retest and recertify. It’s not a one-time thank you and goodbye. It’s a first test of many to come.”