Up to 40 rocket launches a year could take off from Britain’s first spaceport in the Highlands – almost seven times the initial estimate.
And the size of the rockets are now potentially up to 98.4 feet high – almost double previous estimates.
An environmental impact assessment (EIA) scoping report prepared by consultants for spaceport backers, government agency Highlands and Islands Enterprise (HIE), has emerged.
The £17.3m project has attracted support from the UK Space Agency, which is also funding two launch companies that plan to set up in Sutherland, Lockheed Martin Space Systems and Orbex.
But campaigners pointed out HIE had initially said: “It is anticipated that up to six launches will be carried out annually, with the first taking place in the early 2020s.”
The development agency expects 40 high quality jobs will be created locally, part of more than 400 across the north. Orbex has already opened a new manufacturing facility in Forres.
But the potential satellite launch site at the Mhoine peninsula is next to the Caithness and Sutherland Peatlands Special Protection Area and Special Area of Conservation, and the Ben Hutig Site of Special Scientific Interest.
The report says: “The duration of each launch campaign is expected to run for approximately 4-6 weeks starting with delivery of the launch vehicle (LV) and ending with successful launch and facility clean down.
“There is potential that launch campaigns could run concurrently. It is anticipated there could be approximately 40 launches per calendar year.
John Williams, chairman of the Protect the Mhoine campaign group, said locals were shocked at what was being proposed.
He added: “This is not what what we were told. People were led to believe there would be up to six launches a year and that the rockets would be 17 metres high.
“Now we find that they will be bigger and more of them as well as now two launch pads. I think people are alarmed. Even if they start off with six, the document shows they have the potential to scale up over time.”
Local Highland Councillor Hugh Morrison said: “This is disappointing. There is a lot of difference between six launches a year and up to 40. We told HIE they had to be honest with people from the start and these figures are at odds with that and show a lack of apparent transparency.”
Scottish Natural Heritage also say “that the proposal is likely to have a significant effect on the environment”.
But Chris Larmour, CEO of Orbex , accused some locals of misleading statements, adding: “A very small group of people have publicly made a lot of very silly accusations and statements about Space Hub Sutherland.
“We welcome all sensible, serious debate about the future of A’Mhoine and its residents.”
A spokesman for HIE said: “We are currently working towards submitting a planning application before the end of 2019.”