The BRASS Project

1
The BRASS Project
Balloon and Rocket Atmospheric Sampling and
Sensing
Conceptual Design Review

• University of North Dakota
• Matthew Voigt
• Nathan Ambler
• Ron Fevig
• John Nordlie
• Tim Young
• Nirmal Patel (University of North Florida)
• Baike Xi
• November 3rd, 2008

2

• Mission Overview
• The Objective
• The altitude of the mesosphere is from 50 km to
  about 90 km. It is a poorly studied since it is
  too high for the aircraft or balloons, and too
  low for the orbiting spacecraft.
• To measure concentrations of H2, O2, CH4, CO and
  possibly N2O in the mesosphere in nearly
  real-time using nanocrystalline oxide
  semiconductor sensor arrays and also
  simultaneously obtain information on the magnetic
  field strength.

3

• Mission Overview
• 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 H, O, CH4, CO, and N2O
  gasses in the mesosphere.
• Magnetic field strength over the change in
  altitude.
• New Insight
• Better data of H, O, CH4, CO , and 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.

4

• Mission Overview
• 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 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
  scanning electron microscope, while EDAX will be
  used to check the chemical composition of the
  surface of sensors.

5

• Mission Overview
• 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

6

• Mission Overview
• Mission Requirements
• Sense apogee and evacuate the six vessels
• Seal all six vessels
• Collect an air sample every 20km during descent
  in the 130km to 30km range. Only 5 of the 6
  vessels will be used. The 6th is a baseline
  sealed at apogee
• Record resistance of all sensors and magnetometer
  data to flash memory via a microcontroller
• Atmospheric density changes exponentially, so the
  sampling frequency of collection may be changed
• Pre-flight testing of payload as per the
  guidelines including vibration and thermal tests.

7

• Mission Overview
• Success Criteria
• Full evacuation of our six vessels
• Proper data fields acquired
• Data obtained from flash memory after recovery
• Benefits
• Local and national weather and atmospheric
  scientists will have additional data to pull from
  when reviewing improved models and experiments
• Atmosphere above 50km is not well known
• Natural pollution can enter the mesosphere (ie)
  CO2

8

• Payload Design
• Required Hardware
• 6 pressure vessels
• 6 solid state sensor boards
• 8 sensors on each board
• 4 gasses sampled twice, for redundancy
• 48 resistors
• Possibly few additional sensors as a back up and
  test resistors
• Ohm meter
• Microcontroller and circuits
• Flash memory
• Battery unit Lithium Ion pack
• G-switch

9

• Payload Design
• Required Hardware Continued
• Magnetometer
• Altimeter/timer board
• Atmospheric port manifold
• 6 valves leading to each vessel
• 6 solenoid valves
• Mounting plate
• Mounting hardware
• Remove Before Flight for safety purposes
• Nylon Harnesses for loose wires
• Thermal protections/dust protecting material

10

• Design Diagram

11

• Functional Diagram
• The microcontroller will cycle the ohm meter
  between each sensor

12

• RockSat Payload Canister User Guide Compliance
• Mass
• All of our allotted mass is required at this time
• A final mass is unknown at this time
• Volume
• All of our allotted volume is required, including
  a route to the atmospheric port
• Center of Gravity
• Our payload plate will have a CG located within a
  1 inch of the center of radius of the canister
• Payload activation
• G-switch. Proven technique in past RockOn event
• The entire system will be powerless until the
  G-switch is activated
• A remove before flight open circuit will be
  used while the safety pin is plugged in.

13

• Shared Can Logistics Plan
• Fellow Occupants of RockSat Canister
• Harding University
• Spectroscopy
• University of New Mexico
• Plan for collaboration on interfacing
• We plan to coordinate with the other Universities
  regarding location
• Harding University requires an optical port,
  while we require an atmospheric port. The
  University of New Mexico does not require a port.
• Structural interfacing
• Possibly consider RockOn structural design

14

• Team Management

15

• Schedule
• We are currently on time with the required
  schedule
• Upcoming Events
• PDR requirements to be met (11-14-08/11-28-08)
• Further in-depth review of our payload layout,
  and integration of components
• Student team member slots all filled, and
  preliminary designs begun
• Canister integration with other teams
  investigated
• CDR requirements to be met(12-12-08-prior to
  holiday s )
• Important constraints of payload reviewed and
  solved
• Canister integration planned

16

• Budget and Funding
• Funding is currently being acquired from
• North Dakota Space Grant Consortium
• Additional funding if required is under
  consideration

17

• Conclusions
• Thermal considerations
• Upper atmosphere temperatures are very low
• Low power consumption heater will possibly be
  required for vessels
• Volumes of payload vessels
• Vessels volume significantly larger then
  tubing/manifold volumes
• Vessel volumes must be exact