For the second time in as many weeks, a satellite engineer has resigned from Canada's leading space contractor over the company's sale of its space division to an American weapons maker.

Trevor Williams told CBC News that he worked for MacDonald, Dettwiler and Associates Ltd. on the world's most advanced commercial surveillance satellite, Radarsat-2, under the premise that it would be used for civilian and environmental monitoring.

The senior engineer said he became skeptical when the Richmond, B.C.-based company announced it was selling its space division to an American military contractor, Alliant Techsystems — after the satellite was in orbit.

"When questions were asked, the stock answer was the spacecraft is for commercial purposes, it's civilian, it'll be used for Arctic surveillance. That was it," Williams said.

He said he believes the spacecraft will be used to support American military operations.

"This is one of the reasons I have regret about working on Radarsat-2, because originally, I and others thought it would be used for good."

Alliant derives more than half of its $4 billion US in annual revenue from military contracts for items including cluster bombs, depleted uranium rounds and landmines.

MDA announced Jan. 9 it was selling its satellite and space division, which developed the distinctive Canadarm space shuttle technology, to Alliant as part of a $1.325 billion cash deal.

The announcement prompted Williams to quit his job of nine years on Monday. The sale puts many of the company's 1,900 employees in a difficult position, he said.

"It makes people uncomfortable. It certainly makes me uncomfortable, and I think it's put myself and others in quite a moral dilemma," Williams said.

Paul Cottle, an optical engineer in B.C., resigned from MDA earlier this month, and has called on the federal government to block the deal between MDA and Alliant.

"ATK is a company that produces weaponry that kills people indiscriminately — soldiers and civilians alike," American-born Cottle said. "Part of the reason I came to Canada was to avoid having my tax dollars go to support companies like ATK."

MDA would not comment on the resignations Wednesday.

In an e-mail to CBC News on Tuesday, Alliant spokesman Brian Cullen said Radarsat-2 will still be used as a commercial satellite and the Canadian government will continue to have the same access to its data.

He wouldn't elaborate on what other uses the arms manufacturer may have for the spacecraft.

Some opposition MPs want a closer examination of the sale, which includes taxpayer-funded technology worth hundreds of millions of dollars.

NDP Leader Jack Layton has said his party will push for parliamentary hearings into the deal, which is slated for review by Industry Canada.

The Liberals' vice-chair of the industry committee, Dan McTeague, told CBC the engineers' concerns are legitimate and might be a good reason for parliamentarians to debate the sale.