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Dick Smith’s As this issue goes to press, Dick Smith is making final preparations to cross Australia by balloon. Providing winds are favourable, he is expected to make the attempt early this month, starting from Carnarvon in Western Australia. By LEO SIMPSON The gondola: (1) Lift webs; (2) Burner fuel line; (3) Entry hatch and observation dome; (4) Lift cables; (5) HF anten­na; (6) Satellite transmission antenna; (7) VHF antenna; (8) Landing trail rope; (9) Lockers for food, water and batteries; (10) 80-litre LPG tanks (four each side); (11) Hand holds; (12) Hollow keels, flooded in sea landing; (13) Twin LPG burners; (14) LPG 240VAC generator; (15) Sand ballast; (16) GPS antenna; (17) Strobe light; (18,19) Liquid oxygen tanks; (20) Navigation and communications, flight instruments, GPS, Inmarsat, VHF radio, radar transponder, HF transceiver, weather fax; (21) satellite data printer; (22) chart table. 6  Silicon Chip s Trans Australia Balloon Attempt T HIS IS NOT THE first time some- one has attempted to fly across Australia by balloon. There have been six previous at­tempts but all have failed. The last attempt was in November 1984 and it landed near Broken Hill. The prevailing winds across Australia are from the west and so it should be feasible to start on the west coast and drift right across the continent to the east coast. Ever the optimist, Dick Smith is making an attempt this year but he will be taking a new approach in more ways than one and will have the bene­fit of technology that could only be dreamed about in previous attempts. A new type of balloon will be used for this attempt although the concept has been around for almost as long as ballooning has been feasible. The balloon is a Rozier type, named after Frenchman Jean Pilatre Rozier who in 1785 devised a hot air/hydrogen balloon. Rozier was actually a passenger with the Gondolfier Brothers in the first ever balloon flight in 1783. Hydrogen and hot air is a dangerous combination and the original balloon using these gases was doomed to failure but the Rozier concept does have merit. Helium gas Dick Smith will not be using hydrogen but helium, in a double compartment balloon. Helium will fill the top compartment while the bottom compartment will be occupied by air, heated by the LPG burners below. This system is claimed to have substantial advantages over a standard hot air balloon or a helium gas bal­loon, for the following reasons. For a trans-Australia attempt, any hot air balloon needs to carry a lot of LPG, stored in heavy cylinders. The more LPG you need, the bigger the balloon required and so on. Once you run out of LPG, the flight must end shortly afterwards because you lose the means of maintaining buoyancy. By contrast, a helium gas balloon needs to be very large and carry a lot of ballast. During the day, the helium expands considerably due to heat from the sun. The balloon needs to be able to cope with the large increase in volume. At the same time, the gondola may need oxygen or pressurising to enable the crew to fly at extreme altitude. At night, the gas cools down and loses buoyancy and so the crew needs to shed ballast to maintain alti­tude. If the trip lasts several days, the ballast will eventually run out and again, the journey can’t be maintained for much longer after that. This is where the Rozier balloon has the advantage because the dual compartment balloon has a more constant buoyancy from night to day and will need little use of the LPG burners during the day. Dick Smith’s balloon attempt will be made at heights of between 10,000 and 18,000 feet to take advantage of the prevail­ing jetstreams. He will be constantly updated with weather in­for­ma­ tion via fax machine so that he and his navigator can adjust the altitude so that the jetstream blows them where they want to go – east! Even so, Dick admits that they could end up anywhere between Cairns and Tasmania. Suspended below the huge balloon will be an enclosed gondo­la made from fibreglass. It will have such ancillaries as cylin­ders of LPG for the burners and oxygen for the crew. Suspended above the gondola will be a 240VAC generator powered from LPG. This will run the communications equipment and charge the batteries. In addition to normal navigation This map shows the predicted paths for six flights starting on different days last June. The predicted landing point is somewhere between Tasmania & Cape York. and flight instruments, the gondola will be equipped with an Inmarsat C receiver as well as a Trimble GPS re­ ceiver. (Trim­ble Navigations Ltd is a fast rising company in the field, having supplied 10,000 GPS receivers to the US army during the Gulf War). Australian CQs Another attraction of the balloon attempt is that amateur radio operators will be able to contact Dick Smith as he drifts above. He will be using a Yaesu FT-757 transceiver on 14.146-MHz. His call sign is VK-2DIK. The flight is expected to take two to three days and could take place at any time after 31st May, depending on favourable weather conditions. Readers will be able to obtain daily progress reports on the attempt in The Australian or by phoning 0055 29060 from anywhere in Australia. Acknowledgement: our thanks to Dick Smith and the staff of Australian Geographic magazine for their assistance in the prepa­ration of this article and for permission to publish SC the accompa­nying diagrams. June 1993  7