RESULTS
Preliminary DAFT results showed the P-Trak Ultrafine Particle Counter (a device that counts
ultra-fine dust particles in a microgravity environment) could be successfully built into the
Smoke and Aerosol Measurement Experiment (SAME) payload and established the optimal
ranges for particle detection using this instrument. The data collected also indicate very low-
particulate levels in the ISS environment relative to that previously measured on the space
shuttle. This low particulate level was not surprising due to the small crew size on ISS (2 or 3 vs
7 on space shuttle) and the High-Efficiency Particular Accumulator (HEPA) filtration system on
ISS. The particulate level was expected to rise with the larger ISS 6 person crew. In later
experiment runs, DAFT showed
the average size of the particles
was larger on orbit than on
Earth. These results could be
due to the inefficiency of the
large particle filter. Once the
average particulate level
throughout ISS is known, it can
be used to design future smoke
detectors that accurately
distinguish normal dust from
the presence of dangerous
smoke particles. A series of
events (malfunction of the
electronic data transmitted,
crew time limits, and an
alcohol wick that did not open)
shortened the overall experiment, but adequate data was collected to label the demonstration
successful (Urban 2005).
PUBLICATION(S)
Ruff GA, Urban DL, King MK. A research plan for fire prevention, detection, and suppression in
crewed exploration systems. 43rd Aerospace Sciences Meeting and Exhibit, Reno, NV; 2005.
Urban D, Griffin D, Ruff G, et al. Detection of smoke from microgravity fires, SAE International
Journal of Aerospace, 2005- 01 -2930, 2005.
This investigation is complete; however no publications are expected.
Expedition 13 science officer Jeffrey N. Williams works with DAFT in the
US Laboratory of the ISS.