Ed Campion
Headquarters, Washington, DC                June 14, 1995 
(Phone:  202/358-1778)

Lee Tune
National Research Council, Washington, DC
(Phone:  202/334-2138)

RELEASE:  95-93

NEW ORBITAL DEBRIS STUDY RELEASED

     A new report on orbital debris has determined that 
the hazard to spacecraft posed by artificial debris, though 
still low, is growing and requires international action.  
The report also concluded that the problem needs to be 
addressed while it is still manageable and that the nations 
of the world should approach the problem with a 
cooperative, multi-pronged effort.

     The report was funded by NASA and conducted by a 
committee of the National Research Council (NRC).  This 
study is part of an ongoing interagency review of orbital 
debris programs and policies presently being carried out under
the direction of the Office of Science and Technology Policy.

     The NRC's report suggests several steps in approaching 
the orbital debris problem.  First, spacefaring nations 
should work together to fill in critical gaps in the data 
on the effects of collisions between orbiting objects and 
on the amount and sources of debris in orbit to better 
estimate the current and future hazard to spacecraft.

     Other steps include spacecraft designers being made 
more aware of ways to protect spacecraft against debris - 
for example, by shielding critical components of the 
spacecraft.  At the same time, designers should develop and 
implement ways to prevent future spacecraft from adding to 
the problem.

     Assessing the danger of orbital debris accurately is 
difficult because of the inherent problem of studying 
small, dark objects that are traveling at very high speed, 
hundreds or thousands of miles above the Earth.  In low-
Earth orbit only objects larger than 4 inches (10 
centimeters) across can be tracked by ground-based sensors.  
In geostationary orbit, only objects larger than three feet 
(one meter) across can be tracked and cataloged.

     Objects much smaller than those presently cataloged 
can destroy a spacecraft in a collision.  Even collisions 
that do not destroy a spacecraft can degrade its 
performance or cause it to fail.

     According to the NRC report, removal of existing 
debris from orbit is technically and economically 
infeasible, so international efforts should focus on 
preventive measures to reduce the future hazard.  One step 
would be for leftover fuel or other energy sources to be 
dissipated from spacecraft and rockets at the end of their 
functional lives to ensure they do not explode.  Other 
steps would include minimizing the release of debris during 
launch and on-orbit operation along with maneuvering 
rockets or spacecraft at the end of their functional lifetime
either out of the low-Earth orbital region or into orbits that
will carry them back into the Earth's atmosphere.

     In their report the NRC committee suggested that an 
international group is needed to advise the space community 
about the most important questions regarding orbital debris 
and how best to answer these questions.  Pending creation 
of this group, the committee proposed a set of interim 
research priorities that includes:  carefully studying 
uncataloged objects in low-Earth orbit; gaining a better 
understanding of small debris by orbiting spacecraft that 
carry debris detection experiments; studying debris in 
geostationary orbits, through both measurements or modeling 
and improving models of debris sources and changes over 
time in the amount of debris.

     NASA agrees with the concerns reflected in the NRC 
report and has taken the initiative to work with the major 
spacefaring nations to organize an international technical 
effort to develop a common understanding of the orbital 
debris environment and to develop techniques and practices 
to mitigate the orbital debris hazard.

                            - end -

Editor's Note:  A copy of the report, "Orbital Debris:  A 
Technical Assessment" is available for review in the 
newsroom at NASA Headquarters, 300 E Street, S.W., 
Washington, DC.  News media who wish to obtain a copy of 
the report should contact the NRC Office of News and Public 
Information at (202) 334-2138.

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