Bill Sheredy, Project Manager for SAME (Smoke Aerosol Measurement Experiment)
- Wednesday, 03 January 2007
NTB: How could SAME-derived technology be applied on Earth?
Sheredy: SAME itself is designed for developing detectors for zero-g, space-based applications and NASA's exploration missions, so there is no direct terrestrial application. I would like to mention, however, that as part of NASA's Fire Prevention, Detection, and Suppression Program, NASA is developing smoke sensors for terrestrial applications. They could be based on either particle detection technologies or chemical detection technologies, but they would be a personal smoke detector per se. They are small in size, they will be robust, and they can be used by first-responders in emergency situations.
Two of the key diagnostics for SAME, the P-Trak and the DustTrak, are already commercially available aerosol measurement devices that are normally used on the ground in a one-g environment, such as for determining indoor air quality. They have been modified and repackaged for use with SAME and in the case of the P-Trak, one of the modifications was meant to improve its microgravity performance. Another key diagnostic, the ionization detector, is essentially a modified and repackaged "First Alert" smoke detector, literally the same device the you have in your home, but modified, so obviously it is normally meant for one-g applications. This device should not be confused with the space shuttle smoke detector that we are flying, which is also an ionization type detector.
But, to get to the heart of the question as I understand it, the anticipated results from SAME and the technologies that we have developed and modified for this experiment do not really have a direct or indirect terrestrial application. I would hope that someone who reads this will understand that the results from SAME will lead to the development of better, more advanced smoke detectors for use in NASA's exploration mission. This will result in increased safety of the astronaut crew and a higher probability of success for future microgravity missions.
NTB: What was the Dust and Aerosol Measurement Feasibility Test (DAFT) done as a part of SAME?
Sheredy: One of the devices we are flying as part of SAME is a commercial device called the P-Trak. It's made by a company called TSI, and it can count very small, individual particles in an aerosol stream. Early on, it was the only device we identified that would meet our needs for the experiment. But we had some concerns about its potential operation in microgravity because it relies upon the internal recirculation and flow is isopropyl alcohol, and as it's designed to rely upon gravity for its proper operation. After some consultation, with some of our fluid physics experts here at Glenn Research Center, we made some modification for the design of the device. We developed and flew DAFT as a risk mitigation experiment to demonstrate that the P-Trak would work properly in microgravity when we used it for SAME.
We designed and built the DAFT experiment, it went up to the ISS on two launches, the Russian Progress flight 16-P and on STS 121 this past July, it was operated by astronaut Leroy Chiao and Jeff Williams, during two successive periods of performance, and the results from DAFT demonstrated that, indeed, the P-Trak does operate normally in microgravity. Now that we know that, we'll feel more comfortable using it as one of our primary diagnostics for SAME.