first deep space mission
More than 15 years ago, ESA's Giotto spacecraft made history by obtaining
the first close-up pictures of a comets black, icy nucleus. Giotto
then went on to become the first spacecraft to visit a second comet when
it carried out a flyby 200 km from Comet Grigg-Skjellerup in July 1992,
shortly before the spacecraft was switched off. This is still the closest
encounter with a comet ever experienced by a spacecraft. Knowledge gained
from the Giotto mission is currently being used to develop the Rosetta
comet chaser, which is scheduled for launch in January 2003.
the Suns big bubble
The night sky may look peaceful, but in fact it is anything but. Earth
is suspended deep inside the heliosphere, a huge bubble filled with high-energy
atoms and electrons zooming out from the Sun. Launched in 1990, the Ulysses
space probe entered its orbit over the Sun's poles in 1994 to take, for
the first time, a closer look at this invisible, but far from friendly,
phenomenon. Ulysses, which is providing the first-ever complete map of
the heliosphere, has been studying the high-speed particle streams that
burst from the Suns poles, and the slower wind that comes from near
the weather on our savage Star
Violent storms raging in the Suns atmosphere project charged particles
our way at speeds of up to 800 km/s. Earths own magnetic field deflects
most of this solar wind, but the storms can play havoc with
our electricity supplies, aircraft systems and satellite communications.
SOHO is stationed 1.5 million km from Earth, on the sunny side, where
it can stare at the Sun non-stop. Every day it sends back thrilling images
from which research scientists learn more about the Sun's nature and behaviour,
helping us predict bad space weather to come.
moon may resemble a baby Earth
The Huygens probe is now nearing its destination, Saturns moon Titan,
which it will reach in 2004 on-board NASAs Cassini spacecraft. When
it gets there, Huygens will parachute through Titans atmosphere,
penetrating for the first time the orange haze that hides its surface.
Titan is the only moon in our Solar System to have such a thick atmosphere,
which is thought to resemble that of a very young Earth. Huygens will
be uncovering more details of the atmosphere and any further similarities.
The Cluster mission, made up of four identical satellites, was launched
in 2000 to study the Suns effects on the Earth. The quartet is studying
the outer edges of Earths magnetosphere, our natural protective
bubble. Cluster has already confirmed that these edges are stretched and
pulled in different directions by big waves of the Suns
particles. Cluster data will eventually help us to predict how such dramatic
changes could affect Earth in the future.
back to the Moon using solar power
Humans may have landed on the Moon, our only natural satellite, but we
still dont know how it was created. Was it formed at the same time
as Earth, or did it come from elsewhere to be captured by the Earths
gravity? SMART-1, a technology demonstration mission due to be launched
early in 2003, hopes to answer some of these questions. The spacecraft
will be testing the effectiveness of solar-electric propulsion as a means
of travelling through space. In addition, an impressive set of instruments
on SMART-1 will allow scientists to draw up accurate 3D models of the
surface, and provide information about its make-up, its origins, and those
up close and personal with a comet
If you have ever had the nightmare where a comet collides with Earth,
then you will want to follow the progress of ESAs Rosetta mission
closely. In January 2003, Rosetta starts its 8-year journey to Comet Wirtanen.
Rosetta will be dropping a lander on the comet, to take some key measurements
of the surface and sub-surface. Comets contain raw materials left over
from the birth of the Sun and the planets, so these experiments should
provide clues to both the origin of the Earth and the origin of life itself.
Rosettas data could also be important for planning our future defences
against comet collisions with Earth.
hot, hot, hot
Around 2010, the Solar Orbiter will be launched on its mission to take
the closest look at the Sun yet. Building on the results from ESAs
SOHO and Cluster missions, the Solar Orbiter will endure powerful bursts
of atomic particles and intense sunlight to carry its telescopes to just
one-fifth of the Earths distance from the Sun. But once it has manoeuvred
into its orbit around the Sun, images from Solar Orbiter will be 10 times
sharper than anything seen before. It will also be watching storms building
up in the Suns atmosphere over several days as the orbiter hovers
over a certain point.
past the Sun to study Mercury
Mercury, the planet closest to the Sun is the destination of BepiColombo,
an ESA mission in cooperation with Japan due for launch in 2011-2012.
When it arrives at Mercury, the spacecraft will have to endure temperatures
as high as 250oC in order to provide new information about a planet we
know so little about. We need to find out more about Mercurys composition
and history, because of the light that this knowledge will throw on the
history and formation of the inner planets of the Solar System, including