The two most recent payloads to be exposed
to the LEO environment are: ICA (Instrument Comrade
Active) and PIE (Particle Impact Experiment)
both located on the Mir
space station. PIE has been returned to Earth currently undergoing
detailed analysis, whereas ICA remains on the Spektr module of Mir.
The ICA experiment is an active payload
attached to the ESEF (European Scientific Exposure Facility) platform
on the Spektr module of the Mir space station. It was installed
as part of the ESA/Russia EUROMIR
95 mission in September 1995 via an EVA by Thomas Reiter. Data
can still be received from ICA, although due to the recent Mir power
problems and the depressurization of the Spektr module, ICA is currently
There are plans in hand to re-activate ICA
and continue it's role as the only real time environmental detector
in operation in LEO. The main objectives of ICA are:
- Hypervelocity Impact flux measurements using
- AO erosion measurement using Carbon coated
- Mir local contamintion using QCM
- Sun sensor, radiometer and temperature sensors
ICA is positioned on the ESEF platform with
an unhindered view out to space on 3 directions. In addition to
ICA, ESEF hosted experimental casettes each holding a variety on
surfaces for measuring the particulate environment and the intact
capture of particulates. The schematic below shows the realtive
positions of ICA and the casettes on ESEF:
ESEF Schematic showing ICA at the end.
The ICA is self contained and all electronics
are housed in the external unit. There is a power unit inside Spektr
that deals with the basic On/Off power to ICA and the data transmission
into the Mir system for data relay to Earth every 6 hours.
The results from ICA have been widely presented
to the Space community at conferences in the USA, Europe and Japan.
Two of the most valuable results obtained
from ICA and that are currently changing the international perspective
for the coming International Space Station are:
- High levels of contamination in the Mir vacinity
- The re-affirmation of Space Debris clouds
in LEO orbits
Contamination data as determined
from ICA, showing high contamination deposition.
Impact data as determined
by ICA showing debris clouds
The PIE experiment payload contains surfaces
to measure and capture hypervelocity impactors intact. PIE was be
retrieved via EVA May 1997 and returned to Earth via STS-84. This
payload is part of the ongoing Shuttle/Mir
program and the results of the analysis will be presented shortly.
PIE payload prior to experiment