Satellites
Satellites
n
in
orbit around the Earth
n
put in
orbit by a rocket
n
maintains
motion without rocket propulsion
n
first
satellite called Sputnik I, was launched by
the USSR on Oct. 4, 1957
Satellite Orbits
n
at
heights less than 200 mi the atmospheric friction will burn up satellites like
a meteor
n
orbits
are equatorial and polar
Equatorial and Polar
Orbits
n
an equatorial
orbit lies in the
plane of the earthÕs orbit.
n
a polar
orbit lies in the
plane passing through both the north and south poles.
Orbital Period (time of
revolution)
n
at a
height of 200 mi the period of a circular orbit is 90 min
n
at 500
mi it increases to 100 min
n
at a
height of 22,300 mi a satellite has a period of exactly 24 hr, the time it
takes the earth to rotate once on its axis; such an orbit is called
geosynchronous
n
if the
orbit is also equatorial, the satellite will remain stationary over one point
on the earthÕs surface.
Types of Satellites
n
There
are five satellite types:
n
research,
n
communications,
n
weather,
n
navigational,
and
n
applications.
International Space
Station (ISS)
n
the
ISS is a research satellite
n
it is
the largest and most complex international scientific project in history
ISS Missions
n
as of
May 2003, the seventh crew is working on the ISS
n
this
crew is studying microgravity on blood cell count and body mass
n
they
will stay in space for 6 months
Sleeping/Eating/Hygiene
n
astronauts
attach to a bed so they don't float around and bump into something
n
no
refrigeration
n
all
food items are precooked or processed and packaged
n
long
before their trip astronauts taste test and select their meals
n
a
dietician evaluates the menu and makes changes for dietary nutrition
n
the
toilet works like a vacuum and sucks everything out
Locate the ISS
n
sometimes
it can be seen from Earth