OTTAWA - Stuck in a ratty industrial park for more than 40 years, Canada's science museum is making yet another pitch for new digs.

Museum officials have ordered a $191,000 study -- the third in six years -- in hope of joining other grand museums that have been built near Ottawa's downtown core over the last quarter century.

The study, to be presented to the museum's board of trustees later this month, follows a decisive thumb's down from the Conservative government just two years ago.

The earlier proposal, inherited from the previous Liberal administration, would have cost $808 million for a new Canada Science and Technology Museum at LeBreton Flats, west of Parliament Hill.

Officials later cut the cost in half, acknowledging it was "too rich," but even the no-frills version was nixed.

"Taxpayers cannot afford that," said then-Treasury Board president John Baird, also an Ottawa MP, shooting down a pair of museum studies that together had cost taxpayers $835,000.

Undaunted, officials are back again -- but this time they're pinning their hopes for success on the private sector.

"It may seem like we've studied it to death," said Claude Faubert, director general of the museum. "But it's quite a different beast."

The corporation that runs the museum created a charitable foundation and hired a veteran fundraiser three months ago to attract donations that could help underwrite construction costs.

"The days in which the government foots the whole bill are gone," Faubert says. "The private sector has to be present."

No final cost or location for the proposed facility has been determined. But a tendering document suggests the bill might be in the range of $100 million -- close to the $140-million price tag for the dazzling war museum at LeBreton Flats, which opened in 2005 with significant private-sector support of $16.5 million.

The foundation appears at a tough time for fundraising, as corporations such as Nortel -- long a science museum supporter -- struggle to survive in the global meltdown. But the foundation is also after individual donors, who are likely to make up the bulk of supporters.

Executive director John Bouza says there have been several significant donations since fundraising began two months ago.

"We do have some successes," he said. "I don't really want to get into the dollar figures because we haven't announced these gifts yet. Things are starting to come."

Although the foundation will support the project for a new building, no fundraising targets have yet been established, he added.

The foundation is strictly for philanthropic giving rather than corporate sponsorships for exhibitions and special projects, which the museum is also seeking.

The current facility inhabits a dreary, low-rise structure originally built as a bakery distribution centre but never used as such.

An Atlas rocket and Nova Scotia lighthouse adorn the front lawn of what is an otherwise grim backwater, far from downtown.

Officials had to build numerous pedestrian ramps to cover the spots where bakery trucks were supposed to back into internal loading docks, needlessly eating into the already inadequate 8,500 square metres of display room.

The museum's official business plan warns the current facility is "beyond the point of temporary repairs."

Its curators must collect historical objects, in addition to creating hands-on displays of science that are the sole concern of rival museums such as Toronto's Ontario Science Centre or Sudbury's Science North.

That collecting mandate is onerous considering that huge locomotives, giant hydro-electric turbines -- even a vintage nuclear reactor -- must be housed somewhere.

The result is that only about two per cent of the 40,000 artifacts in the collection can be on display. The rest are stuck in three rented warehouses nearby, rarely available for viewing.

Annual attendance has been dropping, from a peak of 700,000 in 1974 to just 325,000 last year, as tourists snub the burbs in favour of more dazzling attractions downtown.

"We do need a new home," says Faubert, a former radio-astronomer. "We feel isolated."

Museum officials look wistfully at federal investments in the National Art Gallery (1988); the National Aviation Museum (1988); the Canadian Museum of Civilization (1989); the Canadian War Museum (2005); and the Canadian Museum of Nature (renovated 2004-2010) -- with all but the aviation museum located near the downtown.

At the same time, the current Tory government has stalled the creation of a National Portrait Gallery and has ordered the Canadian Museum of Contemporary Photography out of its current home.

Heritage Minister James Moore has so far declined to comment on the science museum's aspirations.

"That is not something that has been discussed," spokeswoman Deirdra McCracken said in an e-mail response to questions.

Faubert won't say exactly what's in the new proposal, other than it will draw on private-sector resources and emphasize "green" architecture.

"There's a fair bit of updating because the environment has changed a lot," he said. "We do need a close relationship with the private sector."