One hundred years ago today, at Kitty Hawk, North Carolina, USA, Orville Wright
made the world’s first manned, powered and controlled flight by a
heavier-than-air vehicle. His fourth flight of the day lasted fifty-nine seconds
and he flew 259 metres.
On 17 December 2003, as Europe’s Mars Express nears arrival at the Red Planet,
it has made the one of the fastest ever trips from Earth to another planet. Mars
is 150 million kilometres from Earth and the journey has taken only 205 days.
We have seen a lot in the first hundred years of powered aviation and it is
wonderful to celebrate how far we come in this short time, with many
achievements by European pioneers, such as Bleriot’s first crossing of the
English Channel and Frank Whittle’s development of the jet engine.
However, ESA’s Mars Express and the US Mars missions find their roots in a
completely different pioneering heritage. The technologies of aviation and
‘astronautics’, the science of space travel, actually share little common
history. Astronautics is based on the science of ballistics — how an object
leaves the ground, travels up in an arc, then downwards to land — and this
story starts a long time before 1903.
By about 200 BC, the Chinese had mastered the mixing and use of charcoal,
saltpetre and sulphur (gunpowder) to be the primary ingredient of the first true
ballistic rockets. In 994 AD, the Chinese used fire arrows in battle. Fire
arrows were traditional feathered arrows propelled by ignited gunpowder in a
tube tied to the arrow.
In 1258, the Mongols were reported to have used gunpowder-propelled fire arrows
in their effort to capture Baghdad. Use of these weapons quickly spread
throughout Asia and Europe, and scientific papers on the preparation of
gunpowder were being published in Europe.
In 1379, an Italian named Muratori used the word ‘rochetta’ when he described
types of gunpowder-propelled fire arrows used in medieval times. This is
believed to be the first use of the word later translated in English as
‘rocket’. Several hundred years of experimentation had to pass before Robert
Goddard launched the first liquid-fuelled rocket in 1926.
Another subject covered by astronautics is ‘orbital mechanics’, which deals with
how objects such as planets and spacecraft travel in space.
The first real understanding of orbital mechanics came in 1530, when Nicolas
Copernicus, the founder of modern astronomy, completed his great work De
Revolutionibus. He said that the planets, including Earth and Mars, travel
around the Sun: a fantastic concept for the times.
A succession of European astronomers then studied the Solar System, making many
important findings about Mars. Tycho Brahe was the first to accurately map the
motions of Mars in the sky. Johannes Kepler first worked out the orbit of Mars.
Galileo Galilei was the first to observe Mars through a telescope.
Perhaps the most far reaching development in rocketry and orbital mechanics, if
not in all of science, occurred in 1687 when Sir Isaac Newton published what
became known as the ‘Universal Laws Of Motion’.
Newton’s Third Law stated ‘For every action there is an equal and opposite
reaction’, the fundamental principle behind rocket propulsion.
These are the basic ingredients for a trip to Mars, or to any other planetary
body. All that is then needed is the human spirit to make the journey. So far,
Europe has never sent its own spacecraft to Mars — until now.
The Mars Express orbiter and its Beagle 2 lander carry this spirit and will play
key roles in an international exploration programme spanning the next two decades.
More about …
* Europe goes to Mars
http://www.esa.int/SPECIALS/Mars_Express/index.html
* Mars Express overview
http://www.esa.int/esaSC/120379_index_0_m.html
Related articles
* Isaac Newton and our XMM mission
http://www.esa.int/esaSC/SEMIT1T1VED_people_0.html
* Interplanetary trajectories
http://www.esa.int/esaSC/SEM8USS1VED_index_0.html
* Types of orbit
http://www.esa.int/esaSC/SEMU4QS1VED_index_0.html
* Let gravity assist you …
http://www.esa.int/esaCP/SEMXLE0P4HD_Expanding_0.html
Related links
* Beagle 2 lander homepage
http://www.beagle2.com
[NOTE: Images supporting this release are available at
http://www.esa.int/export/SPECIALS/Mars_Express/SEM1WR274OD_1.html ]
