Flight has long held a fascination for people - and as long as the sky is there, the chances are man will attempt to travel by air.

The bid by balloonists Brian Jones and Bertrand Piccard to travel round the world is being hailed as the culmination of years of aeronautical experiments.

So what other attempts have there been to leave the earth behind and become air-borne? And what attempts may we see in the future?

As early as the mid-1500s, the ancient Chinese invented a hand-held toy that rose upward when spun round rapidly.

Da Vinci would have been impressed by today's helicopters

But it is Italian artist and inventor Leonardo Da Vinci who is credited with designing the first prototype for a helicopter.

His design, however, was only ever a theory and would have been impractical full-size.

For several hundred years, inventors dreamed up improvements on his idea, but they failed to design an adequate engine.

At the end of the 19th century, the invention of the internal combustion engine enabled pioneers to develop full-sized models with an adequate power source for what would later become the helicopter.

The world's earliest airship took off in 1852. Henri Giffard flew 27 kilometres (17 miles) from Paris to Trappes in France in a steam-powered coal-gas airship.

Plane sailing

But the world's first sustained airplane flight was famously achieved by Wilbur and Orville Wright in 1903. The brothers, from Ohio, USA, first made history a year earlier, when they built a glider which travelled a record 620 feet.

After more months of experimenting in the back room of their bicycle shop, they built a four-cylinder, 12-horsepower engine to power their Flyer.

On December 17, 1903, Wilbur tried to fly the machine first but stalled it on take-off. The brothers then flipped a coin to determine who would pilot the machine next. Orville won the toss. At 10.35am, he made the first heavier-than-air, machine-powered flight in history. It lasted only 12 seconds and covered just 120 feet, but it was an historic moment.

Work continued by those inventors experimenting with vertical lift. On November 13, 1907, Frenchman Paul Cornu lifted a twin-rotored helicopter into the air without assistance - for a few seconds.

As refinements to the Wright brothers' invention speeded up, man felt he was air-borne for good. World War I provided man with more chance to try out a variety of machines.

A replica of the Vickers Vimy used for the first trans-Atlantic flight

In 1919, two Britons achieved the first non-stop trans-Atlantic flight. Pilot John Alcock and navigator Arthur Whitton Brown flew a Vickers Vimy, named after a battle in World War I. They claimed the �10,000 prize for the first direct trans-Atlantic flight, set up by the Daily Mail.

Six years later, French pioneer, Etienne Oehmichen, became the first to fly a helicopter properly, covering one kilometer in a closed circuit. It was a historic flight, taking seven minutes and 40 seconds.

As the science of flight progressed, it suffered a serious setback with the Hindenburg tragedy in 1937. The German airship - larger than any other - was billed as a luxurious flying hotel, faster than any ship.

It exploded in New Jersey, USA, turning into a giant ball of fire and killing 35 of the 117 people on board. Many theories were investigated but the cause of the disaster was never unequivocally identified.

Records in the air

But man's love of the air could not be suppressed for long - and innovations in the air are continuing to this day.

The longest non-stop flight by a commercial airliner was 18,545km (10,007 nautical miles) from Auckland, New Zealand, to Paris, in 21 hours 46 minutes in June 1993, set by the Airbus Industrie A340-200.

The fastest jet on earth is the US Airforce Lockheed SE-71A. In 1976, a Lockheed achieved a speed of 3,529.56km/h (2,193.17mph).

Pilots Robert Timm and John Cook set the duration record when, in 1959, they landed in Nevada, USA, after a flight lasting 64 days and 22 hours and 19 minutes. They covered a distance equivalent to six times round the world and were refuelled without landings.

Hilda Wallace of British Colombia, Canada, became the oldest person to qualify as a pilot when she was awarded a licence in March 1989, aged 80 years and 109 days.

Richard Branson and his team were foiled in their round-the-world bid

The world record for endurance in a balloon was set by Andy Elson and Bertrand Piccard, in the Breitling Orbiter II, in January 1998. They travelled for nine days and 17 hours but their feat was blocked when they were barred from flying over China.

American balloonist Steve Fosset set a world balloon distance record - 22,975 kilometres - in August, 1998 as he made the first balloon crossing of the South Atlantic and Indian oceans.

The air challenges that lie ahead for man include: