Scientists seek special shaft to conduct space’ experiments

There’s an air of expectation at the Atomic Energy Canada Ltd. (AECL) research labs at Whiteshell, Man. The scientists there are keeping their fingers crossed hoping that the provincial and federal governments will come through and finance a new shaft facility.

But it will be no ordinary shaft. Mining companies view shafts as expensive conduits needed for servicing a mine and bringing the ore to the light of day. The scientists at Whiteshell see otherwise — they want to use the shaft for dropping experimental canisters.

If this should sound a little odd, it has nevertheless been headline news for the last while, albeit in a different form. The link is astronaut Roberta Bondar, who carried out a total of 42 experiments to discover the effects of weightlessness, or zero-gravity, on a variety of plants, biological materials and the human frame. She did this on her recent trip in the Skylab of the Discovery space shuttle.

Needless to say, experimental work using the space shuttle is extraordinarily expensive. But scientists have found they can mimic zero-gravity by dropping their tests from a great height. In the U.S., France, Germany and Japan there are “drop towers,” skyscraper high, from which experimental canisters are dropped. Depending on the height of the tower, 3-10 seconds of zero-gravity conditions can be obtained and this is satisfactory for many research projects. Tests cost $3,000-4,000 per drop and there is a long waiting list. A total of “$300 million is spent on this kind of research annually,” AECL says. “There is a good possibility of capturing part of the business with a facility at Whiteshell.” The Canadian Space Agency has been asked to fund a feasibility study to determine the business that could be attracted. The facility itself would centre around a 420-metre shaft at a cost estimated by AECL of up to $2 million plus an additional $15-30 million depending on the equipment and instrumentation that will be installed. The 420-metre shaft will permit 7-9 seconds of zero-gravity, making it one of the foremost research centres on earth.

AECL already has a 443-metre shaft, where a variety of geotechnical studies have been under way since 1989. The new zero-gravity shaft will be located about 50 metres distant and raise-bored in two or more lifts. It will be 2-3 metres in diameter (final plans are still in the preparatory phase), and equipped with a track to allow the test canisters to be accelerated. Acceleration is necessary to overcome the effects of air friction. This will be done using a “drag shield” conveyance powered either by compressed air or by electromagnetic induction. The same conveyance will also allow the canister to come to a controlled stop at the end of its run. The answer to the immediate question — why doesn’t AECL use the shaft it already has? — is that the present shaft is in continuous use and there is not the space for all the new equipment and instrumentation that is needed. So what kind of tests will be done at zero-gravity? For a 7-9 second drop shaft, practically all the test work will be of a purely scientific nature. If satisfactory results are returned, much larger, commercial-scale work will be forwarded to Skylab and eventually to the much heavier payloads envisaged on the “permanent” station-in-space.

This type of work will include the growing of pure, perfect crystals for computers, lasers and other electronic-optical devices; the preparation of high-strength, temperature resistant glasses and ceramics at levels of purity that cannot be duplicated on earth; the separation of the macro-molecules of proteins and enzymes; and numerous other applications requiring a weightless environment for their completion.

It is interesting to note that a neutrino laboratory is being established at the Creighton mine at Sudbury at a depth of 2,100 metres and is expected to be completed in 1995 at a cost of $50 million.

Also, there are research centres at Chalk River and Elliot Lake, both in Ontario, a particle accelerator in British Columbia, and a host of other centres across Canada financed all or in part by the federal government.