NSSDCA ID: 1997-061C-01
Mission Name: HuygensThe Aerosol Collector and Pyrolyzer (ACP) is designed to collect aerosols in Titan's atmosphere for chemical composition analysis. The physical dimensions of the ACP are 220 x 200 x 206 mm. ACP's primary objectives are to: (1) determine the chemical composition of the photochemical aerosol; (2) ascertain the relative abundances of condensed organics in a column average in the lower stratosphere; and, (3) obtain the relative abundances of condensed organics in a column average in the upper troposphere. ACP, in coordination with other probe instruments, also strives to achieve several secondary objectives. They are to: (1) obtain the absolute abundance for all condensed species, averaged over both the lower stratopsphere and the upper troposphere; (2) determine the mean sizes of aerosol nucleation sites averaged over the lower stratosphere and compare it with those in the upper troposphere; and, (3) detect non-condensable species (e.g., CO) trapped in aerosols.
In order to achieve these objectives, the instrument is equipped with a deployable sampling device which will be operated twice during descent in order to collect aerosols. The first sample will be taken from 135 Km down to about 32 Km. The second sample will be taken from about 22 Km down to 17 Km.
After extension of the sampling device, a pump will draw the atmosphere and its aerosols through a filter, thus capturing the aerosols. Each sampling device can collect about 30 micrograms of material. After each sampling, the filter will be retracted into an oven where the aerosols will be heated in three different temperature steps (ambient temperature, 250 C, and 600 C) in order to conduct a step pyrolysis. The volatiles will be vaporized first, them the more complex, less volatile organic material, and finally the cores of the particles. The pyrolisis products will then be flushed to the Gas Chromatograph/Mass Spectrometer (GCMS) instrument will perform the analysis and provide spectra for each temperature step. To transfer the effluent gas and pyrolysis products to GCMS, a carrier gas (a radioactive labelled gas, Nitrogen-15) is used to avoid unwanted secondary reactions with atmospheric nitrogen.
Mass: 6.07 kg
Power (avg): 4 W
Bit rate (avg): 0.128 kbps
Questions and comments about this experiment can be directed to: Dr. Edwin V. Bell, II
Name | Role | Original Affiliation | |
---|---|---|---|
Dr. Tobias C. Owen | Co-Investigator | University of Hawaii | |
Dr. Siegfried J. Bauer | Co-Investigator | Institut fuer Weltraumforschung, Austria | |
Dr. Robert E. Samuelson | Co-Investigator | NASA Goddard Space Flight Center | |
Prof. Sushil K. Atreya | Co-Investigator | University of Michigan | atreya@engin.umich.edu |
Dr. Eric Chassefiere | Co-Investigator | Centre National de la Recherche Scientifique | |
Dr. Claire Vidal-Madjar | Co-Investigator | Centre National de la Recherche Scientifique | |
Dr. Guy M. Israel | Principal Investigator | CNRS, Service d'Aeronomie |