The following is our submission for the Scholarly Forum here at the University of North Dakota.
Design of an In-Situ Mesospheric Sampling Sounding Rocket Payload
The mesosphere is a portion of the atmosphere that is difficult to sample. The RockSAT project, coordinated by the Colorado Space Grant Consortium, will allow the Balloon and Rocket Atmospheric Sampling and Sensing (BRASS) team at the University of North Dakota to fly a mesospheric sampling payload onboard a NASA sounding rocket.
The goal of the project is to design a mesospheric sampling payload. This payload is to be flown in a NASA sounding rocket out of Wallops Flight Facility. The payload will measure the concentrations of H2, O2, CH4 and O3 in the mesosphere. The sampling of the mesosphere will occur as the rocket descends through the atmosphere between 90 km and 50 km in altitude. In order to draw in the atmospheric gasses, six vessels will be evacuated at 138 km, the moment of apogee, creating a vacuum environment. These vessels will be opened on descent using solenoid valves to sample the atmosphere at discreet altitudes.
Nanocrystalline oxide semiconductors with different types of catalytic layers and stimulators will be calibrated in a lab. When these sensors come in contact with the gas they are stimulated for, the resistance across the sensor will change depending on the concentration of the gas in the vessel. These changes in resistance will be monitored through a Wheatstone bridge system. The changes in resistance of each individual sensor will be recorded to flash memory through a PIC microcontroller. In addition, pressure and temperature sensors will be placed in the vessels to give additional information when the data is analyzed.
A small optical particle counter will be used to measure the concentration of aerosols. The particle counter uses light scattering to size particles into six size bins ranging from 0.3 µm to 10 µm.
The RockSAT project is a collaboration between the Atmospheric Sciences, Engineering, Physics and Space Studies departments here at UND with the department of Chemistry & Physics at the University of North Florida.
posted on February 8th 2009.
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One of the projects I’m leading is “RockSAT”. Basically, it’s a chance for students to create payloads to fly into space, for a low cost. RockSAT is put on by Colorado Space Grant, and we are taking part in it’s first years operation. The following are bits taken from our Preliminary and Critical Design Reviews:
The Objective
The altitude of the mesosphere is from 50 km to approximately 90 km. It is poorly studied since it is too high for aircraft or balloons and too low for the orbiting spacecraft.
To measure concentrations of Hydrogen, Oxygen, methane, and carbon monoxide in the mesosphere in nearly real-time using nanocrystalline oxide semiconductor sensor arrays.
Additionally, two payloads are in consideration of being placed onboard. One to measure the number of particulates in the air using a particle counter and the second to inspect the “hardiness” of cellular material when exposed to rapid decompression and an extreme vacuum.
To Prove
Capability of in-situ atmospheric measurements on sounding rockets which has already been proven successful on high altitude balloons.
To Discover
The relative amounts of H2, O2, CH4, CO, and possibly N2O gasses in the mesosphere.
Magnetic field strength over the change in altitude.
Gain a particle count for the
New Insight
Better data of H2, O2, CH4, CO , and possibly N2O gaseous composition in the mesosphere, an area often ‘ignored’ and not taken into account ie. atmospheric models. Also the use of nanocrystalline sensors arrays for the detection of gases in mesosphere.
Also the use of nanocrystalline sensors arrays for the detection of gases in the mesosphere.
The particle counter can count the particulates (i.e.. Metal oxides, specifically aluminum oxides)
Additional information from the bio payload.
Related Research
Nanocrystalline solid state gas sensor arrays developed and fabricated by Dr. Nirmal Patel at University of North Florida (U.S. patent pending) had three balloon flights so far:
2007 in Florida (telemetry issues)
2008 in North Dakota (telemetry issues)
2008 HASP – successful flight and data obtained
The theory of the payload
Nanocrystalline Oxide semiconductors such as Indium-tin oxide solid state sensor arrays with different types of catalytic layers and stimulators for the detection of specific gases. Sensors will be calibrated in the lab. Also, a selectivity algorithm will be determined.
Change in the electrical resistance with change in the concentration of gas gives the electrical signal for the sensors
Resistance values will be recorded using flash memory. After data recovery and analysis, the concentration of different gases will be determined using the calibrated plots and selectivity algorithm.
The magnetic field strength can be measured with a simple magnetometer
The particle counter will measure particles sized between 0.3 microns and 10 micron. 1-60 seconds count rate
Some of the particulate will be collected on the adhesive surface of tape. The morphology of particulate will be examined using scanning electron microscope (SEM), while chemical composition will be determined using energy dispersive analysis of x-rays (EDAX)
The bio payload will undergo an extreme change in physical.
The theory of the data
The data can assist atmospheric models of our current atmosphere
The magnetometer data will give field strength as a function of altitude
The surface morphology of sensors before launch and after recovery will be examined using SEM, while EDAX will be used to check the chemical composition of the surface of sensors.
Biological Payload Information
Lettuce: 2 small plants of the Waldman’s Green species.
Soil matrix: light weight artificial matrix containing water and microbes.
Sample will be contained in a petre-dish and secured as proscribed for level 3 bio-hazards. This plant and all associated microbes are non-pathogens, the specimen container will be secured in this manner to prevent the escape of contents in flight.
Total sample mass will not exceed 500 grams
Preflight procedure
Several plants will be grown 3-6 weeks prior to launch date. 2 will be selected for flight. The others will remain in the UND Space Studies Life Sciences lab as controls.
Various samples will be taken before launch and stored for comparison with samples taken post-flight.
Post-Flight procedure
Plants and supporting microbes will be analyzed and compared with samples taken earlier and plants in the control group.
The life sciences team will consult with other team leaders to collect any supporting data (radiation counts, particle interaction, atmospheric pressure, etc.) necessary for this analysis.
More to come on this as we finish up our Critical Design Review on December 16th…. As well as properly editing this huge mess. 
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