HALIFAX - A Nova Scotia company has received environmental approval to build Canada's only commercial spaceport near the small community of Canso, N.S.

Maritime Launch Services called it a "critical milestone" Tuesday, but the provincial go-ahead comes with a list of conditions including providing a plan for "worst case scenarios" such as an aborted or failed launch.

The firm aims to launch Cyclone rockets with payloads of up to 5,000 kilograms to low Earth orbit, and up to 3,350 kilograms into higher orbits.

Greenpeace-funded scientists have said there's growing concern about launches like the ones planned in Canso, with issues including questions over what debris will fall into the oceans, what material is carried and how much excess fuel is on board the rockets.

The rockets are fuelled by highly toxic hydrazine.

The province's other conditions include the company submitting a plan for storage, handling and containment of dangerous goods, as regulated under the Environment Act.