Defence contractor TP said it had been appointed as a key part of a team that had won the Skynet client support-side contract from the UK's Ministry of Defence.
The arrangement has been confirmed with the issue of first task orders, with a committed value of £1.5m to be delivered over the next 12 months.
Working with the prime contractor for CSS, PA Consulting, TP was providing technical assurance, approvals, analysis and cost estimation expertise to the project.
The full CSS contract was planned to last for 5 years and has an advertised value of £150m.
'We are very pleased to join the PA Consulting team for such a prestigious project in military satellite communications and technology,' chief executive Phil Cartmell said.
'Following the acquisition of Sapienza Consulting earlier this year, this win cements the company's role as a trusted partner to MOD in this high technology field and positions the group for other major space programme work throughout Europe.'