Release No. 96-13
For Release: March 1996
STS-76 Mir Environmental Effects Payload (MEEP)
Understanding the Effects of Space Debris on Space Station
What Are The Objectives Of MEEP?
MEEP will be attached to the outside of the Russian
space station Mir to study the effects of impacts from space
debris. MEEP, made up of four separate experiments, will study the
frequency and effects of space debris striking the station. MEEP
will study both human-made and natural space debris, capturing some
debris for later study. MEEP will also expose selected and proposed
international Space Station materials to the effects of space and
How Will MEEP Be Attached To Mir?
MEEP will be attached to the Mir shuttle docking module during a
spacewalk by mission specialists Linda M. Godwin and Michael (Rich)
Clifford. After the four MEEP experiment containers are attached to
Mir, Godwin and Clifford will open the containers to expose the
experiment materials to space and orbital debris.
Why Fly MEEP Aboard Mir?
The international Space Station will be placed in approximately
the same Earth orbit as Mir. Flying MEEP aboard Mir will give
researchers an opportunity to test materials for the international
Space Station in a comparable orbital position. MEEP will remain
attached to Mir until late 1997, when the four experiment
containers will be retrieved by another space shuttle crew (STS-86)
and returned to Earth for study.
How Will MEEP Study Orbital Debris?
The NASA Langley Research Center's Polished Plate Micrometeroid
and Debris (PPMD) experiment is designed to study how often space
debris hit the station, the sizes of these debris, the source of
the debris, and the damage the debris would do if it hit the
station. The PPMD is made up of gold, zinc and aluminum plates. The
NASA Johnson Space Center's Orbital Debris Collector (ODC)
experiment is designed to capture orbital debris and return them to
Earth to determine what the debris are made of and their possible
origins. The ODC uses a material called aerogel, developed by the
Jet Propulsion Laboratory, which is a silicon dioxide compound. The
aerogel will capture debris and hold them in place until the
experiment is recovered.
How Will MEEP Study International Space Station
The Passive Optical Sample Assembly (POSA) I and II experiments,
from the NASA Marshall Space Flight Center and the Boeing Defense
and Space Group in Seattle, Wash. respectively, consist of various
materials that are intended for use on the international Space
Station. These materials include paint samples, glass coatings,
multi-layer insulation and a variety of metallic samples.
How Will the MEEP Data be Used?
The debris which is brought back to Earth, after approximately a
year and a half of being on orbit, will be analyzed using several
techniques. These techniques include a scanning electron microscope
and spectroscopy to determine what the debris are made of and their
relative sizes. The data will be studied to determine what kind of
debris hit the space station and how those contaminants can
actually collect on some of the different surfaces of a space
station, affecting its surfaces and long-term performance. After
the data from all four MEEP experiments is analyzed, the data will
be placed into an electronic archive which will be accessible via
What Hardware Components Make Up MEEP?
The four MEEP experiments are contained in four separate Passive
Experiment Carriers (PEC). Each PEC consists of a sidewall carrier
for attachment to the payload bay of Atlantis (STS-76), a handrail
clamp for attachment to the Mir shuttle docking module, and the
experiment container to house the individual experiment. The four
PEC handrail clamps will be stored in a Spacehab locker aboard
Atlantis and will be used to orient the MEEP experiments during the
spacewalk. The PECs were designed and built at NASA Langley
Research Center. NASA Langley, which manages the MEEP project, was
also responsible for ensuring that the MEEP experiment was properly
integrated aboard both the Space Shuttle Atlantis (STS-76) and
- end -
For more information on MEEP, please contact the NASA Langley
Office of Public Affairs at (757) 864-6123. Photos of the MEEP
Passive Optical Sample Assembly II experiment (L-95-6412) and
astronaut Godwin testing the MEEP attachment hardware (
L-95-6370) are available. Video of the MEEP hardware
being examined and tested by astronauts at NASA Langley and in the
Johnson Space Center Weightless Environment Training Facility is
also available, as is an interview with the MEEP Project
text-only version of this release