COLORADO SPRINGS, Colo. — The successful qualification of the second stage of Rocket Lab’s Electron rocket keeps the small launch vehicle on track to carry out a series of test flights later this year, the company announced April 13.

Rocket Lab said it had completed qualification testing of the second stage, powered by the company’s Rutherford engine, clearing it for flight. The company will soon begin qualification tests of the vehicle’s first stage, which uses nine Rutherford engines.

In an interview during the 32nd Space Symposium here April 13, Rocket Lab Chief Executive Peter Beck said the company remains on schedule to begin test flights of Electron from the company’s launch site on New Zealand’s North Island starting around the middle of this year.

“We have a minimum campaign of three test flights,” he said. “We’ll do the test flights and, if we have some anomalies, we’ll keep rolling them out.” Those test flights will carry instrumentation but no satellite payloads, he said.

The company is completing construction of its launch site, which Beck said should be ready by the end of May. Rocket Lab had announced last year it planned to develop a launch site on New Zealand’s South Island, near the city of Christchurch. However, Beck said difficulty in getting environmental approvals led them to shift their plans to the new location.

The new site, located on the remote Mahia Peninsula, does allow Rocket Lab to launch to a wider range of orbits than it could from its original site. “We get from sun-synchronous orbit to 38 degrees inclination out of that site,” he said. That is important, he said, since the company is hearing from potential customers who want to go to a variety of orbits.

“Traditionally the smallsat guys would want to go to sun-synchronous because there’s a lot of rides there if you’re ridesharing,” he said. “But when you given them the opportunity to choose their orbital plane, they want to go to all sorts of planes, which is very interesting.”

The new launch site has received its local environmental approvals, Beck said. Rocket Lab, with its headquarters in the United States but with most of its staff in New Zealand, is working with the U.S. Federal Aviation Administration for a spaceport license for the site, as well as a commercial launch license for Electron. Both U.S. and New Zealand authorities are working together on issues like clearing airspace for launches, he added.

If the Electron test program is successful, Rocket Lab plans to start commercial launches in early 2017. Beck said the company is planning one launch a month through 2018, with most of those launches already sold. That includes a launch NASA awarded to Rocket Lab in October 2015 under its Venture Class Launch Services program, which Beck said is currently scheduled for July 2017.

“We really have to make that schedule, because we have a lot of customers now that we need to fly,” he said. “So we can’t have that test program roll out too long.”

Beck also hinted that Rocket Lab has plans to expand in the U.S. The company currently has more than 100 employees, primarily in New Zealand, and is hiring about two people a week, but is running into growth issues. “There are challenges with not being able to scale fast enough in New Zealand,” he said. “We need to be able to scale much faster.”

“Growth in the U.S. is a big focus for us,” he said, adding that the company planned announcements in the next several weeks about some related initiatives in the United States.