Nasa Satellite UARS Falling to the Earth

Nasa Satellite Falling to the Earth
NASA scientists are doing their best to
tell us where a plummeting six -ton
satellite will fall later this week . It ’s just
that if they’re off a little bit, it could
mean the difference between hitting
Florida or landing on New York . Or ,
say , Iran or India .
According to Space.com ,
atmosphere re-entry specialists are
predicting that 26 different
components from UARS will survive
the satellite’s return to Earth . The
remnants will weigh somewhere
around 1 ,170 pounds and be made of
titanium , aluminum , steel and
beryllium .
But exactly where the UARS spacecraft
will fall is still unknown .
NASA expects at least 26 large pieces
of the massive satellite to survive the
scorching temperatures of re-entry
and reach Earth ’s surface . Titanium
pieces and onboard tanks could be
among that debris, but the UARS
satellite carries no toxic propellant
( NASA used up all the fuel in 2005) .
The debris is expected to fall over a
swath of Earth about 500 miles ( 804
kilometers ) long , NASA officials
WHAT HAPPENS WHEN A
SATELLITE FALLS TO EARTH?
Astronomer Dr Ian Griffin, from the
UK Association of Science and
Discovery Centres, says the Earth ’s
atmosphere slows down falling
satellites a great deal.
He explained that what remains of
UARS will hit the ground relatively
slowly and ‘certainly not at orbital
velocity of 17,500 mph ’.
Much of any satellite crashing to Earth
will be disintegrated by heat, caused
by friction with the atmosphere. It ’s
the reason we get shooting stars –
created by meteors burning up in the
upper atmosphere. UARS is large
enough, though , that up to half a ton
will strike the ground. It will probably
not be in one piece , however : space
vehicles experience incredible stress
on re-entry . The load can be as much
as 10Gs. An F1 car experiences
around 5 Gs with maximum braking
from high speed.
The reason why the location of the
crash site is so hard to predict is
because the density of the
atmosphere varies so greatly higher
up , producing different amounts of
drag .
A prediction that was wrong by even a
few minutes would mean the satellite
landing a huge distance away , owing
to its speed.