22,500 miles GEOSYNCHRONOUS ORBIT
Satellites used for communication and television broadcasts
Taking Aim at Space Junk
Wayward Satellite Is Just One Piece in an Orbiting Trash Heap
20,000
MILES
NASA tracks debris
with computer
images, such as the
one shown here.
President Bush has ordered the Navy to try to shoot
down a falling spy satellite that lost contact with Earth
right after its launch in December 2006. The bus-size
satellite is carrying 1,000 pounds of highly toxic fuel
that some scientists say could endanger lives if the tank
survived reentry into Earth’s atmosphere.
There is a short time in which to attempt hitting
the wayward satellite with a heat-seeking missile. The
earliest possibility was last night (after KidsPost went
to press).
The fuel tank, which is a little more than three feet
long, is the only piece of the satellite not expected to
break up naturally during reentry. The Navy’s goal: to
destroy it 150 miles above Earth, which would also
cause more than half of the pieces of the satellite to burn
up quickly. If it isn’t shot down, it will probably fall on
its own in early March.
Since the world’s first satellite, Sputnik, was launched
in 1957, humans have lobbed more than 28,000 objects
into space. Of the more than 10,000 now in orbit, only
800 or so still function. The rest have become space
junk, according to Alan Jenkin, a space debris expert at
Aerospace Corp., a private company that works with the
Defense Department.
What is space junk? Everything from large rocket parts
and broken satellites to explosion fragments such as tiny
paint chips.
In most cases, what goes up must come down. But in
space, what goes up can stay up — forever if it’s high
enough, or for centuries until gravity slowly pulls it back
to Earth.
At least one piece of space debris has fallen to Earth
each day on average for the past 40 years. Usually, it
happens without incident.
There is only one confirmed case of a person being hit
by manmade space debris: In 1997 an Oklahoma woman
was struck in the shoulder by a 4-by-5-inch piece of
blackened metallic material from the fuel tank of a rocket
launched the year before. She was not injured.
— Brenna Maloney
NASA replaces space shuttle
windows often because objects
as small as a flake of paint can
damage them, as shown at right.
15,000 MILES
Size and Amount of Debris
What’s Up There?
1 millimeter
Percent of debris that is . . .
Rocket bodies
12,500
miles
Global
positioning
satellites
Trash from
manned
missions,
objects
released from
spacecraft
17%
42%
19%
22%
Debris (dead
batteries, paint
flakes, etc.)
from satellites
breaking up or
wearing out
Old or broken
spacecraft
0.1 centimeter
Diameter of pencil lead
Millions of objects this size
Most are not tracked;
cannot be shielded against
or maneuvered around.
Tracked by the U.S. Space
Surveillance Network using radar
and optical systems; spacecraft
can be maneuvered around these
objects to prevent damage.
Can damage spacecraft
Can damage spacecraft. Running
into a piece this size at low-Earth
orbit would be like being hit by a
bowling ball that is going more
than 300 miles per hour.
A piece this size has the
damage potential of 25 sticks
of dynamite.
The higher the object, the longer it will remain above.
10,000 MILES
it could remain in orbit for . . .
22,369 miles or more
forever
497 miles to 22,369 miles
centuries
373 miles to 497 miles
decades
124 miles to 373 miles
a few years
124 miles or less
a few days
SOURCES: Center for Orbital and Reentry Debris Studies, NASA Orbital Debris Program
Office; Graphic by Bill Webster — The Washington Post
LOW-EARTH ORBIT: Where most debris is found
1,240 MILES
Debris is traveling about 18,000 miles per hour
1 in 1 trillion
The odds that a person will be injured
by a piece of space debris
1 in 1.4 million
The risk that someone in the United
States will be hit by lightning
Space Jams
ª The oldest debris still in orbit is the
second U.S. satellite, Vanguard I,
launched in March 1958.
ª In 1965, during the first U.S.
spacewalk, astronaut Edward White lost
a glove that briefly orbited at 17,398
miles an hour before burning up.
990
Peak areas of debris
840
5,000 MILES
620
Peak areas of debris
470
ª The first confirmed space-junk
collision was in 1996 and involved two
French satellites. A piece the size of a
suitcase from one satellite hit the other.
Incroyable!
ª The largest space-debris incident
happened last year. The Chinese
destroyed one of their satellites 530
miles above Earth, creating an estimated
2,300 pieces of debris the size of a golf
ball or larger, and more than 1 million
smaller pieces.
375
Most space shuttle flights
250
International space station
150
1,240 miles
LOW-EARTH ORBIT
0
Altitude of satellite Navy will try to shoot down
EARTH’S SURFACE
PHOTOS COURTESY NASA
0 MILES (EARTH’S SURFACE)
10 centimeters
Diameter of a grapefruit
More than 11,000 objects
Too small to be tracked
How Long Does Debris Stay in Orbit?
If altitude is . . .
1 centimeter
Diameter of a nickel
More than 100,000 objects
This stainless-steel rocket fuel tank landed in
Texas in 1997. It weighed more than 500 pounds.