Senior government ministers acknowledged an expansion of US military intelligence operations at Pine Gap would see them accused of "weaponising space" and walking away from an anti-ballistic missiles treaty.

Key points: Senior ministers wanted complete oversight of US intelligence operations

Senior ministers wanted complete oversight of US intelligence operations Cabinet demanded it be briefed on any US military operation that used Pine Gap data

Cabinet demanded it be briefed on any US military operation that used Pine Gap data These demands were the basis for Australian approval for the new station

Cabinet documents from 1997 marked "for Australian eyes only" reveal the pre-conditions for establishing the Relay Ground Station, which has become the foundation of the US missile launch detection system.

In years to come, Defence officials repeatedly refused to widely share details about the secretive and remote base near Alice Springs, with members of a federal parliamentary committee denied entry.

Large sections of documents released today remain classified, but they make the Australian Government's conditions and some of its concerns clear.

The Howard government's National Security Committee wanted Australia to be fully briefed on any US military operation based on intelligence acquired at Pine Gap.

It also wanted Australian officials to have direct access to the data and for the station to be used for Australian military interests when appropriate.

"It would be established and run in accordance with the principles of our full knowledge and concurrence to the operation and to the wider mission of which it plays a part, and our right to access the data that passes through the site," Defence Minister Ian McLachlan said in a submission to cabinet.

"The capabilities of the system supported by the Relay Ground Station would be available, subject to agreed tasking priorities, to support ADF operations.

"Access to the raw data derived through the Relay Ground Station is potentially of interest to Australia's direct security interests."

Mr McLachlan told the National Security Committee that the head of US Space Command had agreed these measures were "acceptable".

The US also agreed, in principle, for Australians to work in "central mission control" overseas to ensure full knowledge of Pine Gap's capabilities.

Cabinet warned of 'isolated' protest

Before agreeing to the expansion, cabinet met to discuss how it would be announced and how any public concerns would be dealt with.

Protests at Pine Gap were common during the 1980s and would continue in the early 2000s once the Relay Ground Station was operational during the Afghanistan and Iraq wars.

"Given the minor nature of the proposed changes at Pine Gap, and the general level of community support for a US presence, we do not anticipate criticism locally," Mr McLachlan said.

"On the national scale, some criticism by issue-motivated groups opposed to a US presence in Australia, or to co-operation with the United States in ballistic missile early warning, may eventuate.

"In particular, we anticipate isolated criticism that Australia is following the US down a path that leads to withdrawal from the ABM treated and to deployment of weapons in space.

"However, the very high levels of public support for the alliance are grounds for confidence that, properly handled, the new arrangements would be well accepted."