Steve Fossett's dream is over - for now at any rate. Fossett ascended on August 4th in Solo Spirit from Northam, Western Australia, in an attempt to become the first person to fly solo around the world in a hot-air balloon. He succeeded in breaking the record for the longest solo flight, being airborne for nearly 13 days, but the larger prize eluded him.
Fossett travelled eastwards across Australia, and then over the South Pacific, at an average height of 20,000 ft and an average speed of 50 m.p.h. and hoped to proceed out over the South Atlantic, passing south of Capetown, before landing in Australia again. In the event the weather defeated him: winds over South America were weaker than expected, so progress eastwards was slow and Fossett's supplies of oxygen were running out. The balloon also encountered violent and unexpected thunderstorms. The flight was reluctantly abandoned near the border between Brazil and Uruguay last Friday.
Balloons like Solo Spirit are kept aloft by a combination of helium and hot air. They have no engine, being powered solely by the wind, and the only directional control is by means of ascending or descending to avail of winds blowing fortuitously in the desired direction.
The southern hemisphere has several advantages for exploits of this kind. It is certainly less cluttered than our own. There is more sea, and less land, and correspondingly fewer political problems related to flying where such ventures are not always welcome. Given favourable winds, and if the latitude is chosen carefully, one could fly around the world in almost a straight line, without passing over any intervening land. But there are also meteorological factors which favour the Antipodes. The mid-latitude winds of the southern hemisphere are predominantly westerly. But the westerlies to the south of the equator are steadier and more consistent than their northern counterparts.
As it happens, The lack-land geography of the southern hemisphere contributes to the dependability of the westerly winds. The smooth eastward flow of the atmosphere in the northern hemisphere is distorted by a number of very large mountain ranges - the Rockies, the Alps and the Himalayas - which cause it to meander in an undulating stream. Moreover, the large temperature differences which develop also distort the flow. The Antipodes are largely free of these distorting complications - so the wind patterns are more dependable than those north of the Equator.