spacegrant.colorado.edu · web viewafter recovery of the satellite, data recorded in the flash rom...

16 September 2010 Payload Proposal

Colorado Space Grant Consortium

GATEWAY TO SPACE

FALL 2010

BALLOON PAYLOAD PROPOSAL

Team KhufuMembers: Henry Shennan, Chelsea Donaldson, Graham Risch, Jennifer Nill, and

Jonathan Lupkin

16 September 2010

Revision 0

Chris Koehler, 09/22/10,

Some parts of your proposal are good and some need some work. My biggest concerns are with the understanding of how your mission ties together with your measurements and the HOW section of your proposal is lacking. See comments below.


1: Mission Overview

This satellite will be equipped with a magnetometer, as well as thin solar films attached to a data collector. The purpose of the magnetometer is to measure how magnetic fields change as elevation increases. We expect to find a change in magnetism as the balloonSat rises through the atmosphere. Just as the different levels of the atmosphere affect temperature, we are going to measure the effects of the levels of the troposphere on the magnetic field around the satellite. If we consider the earth as a point charge, and the satellite as another, then the data we can expect to collect will follow Coulomb’s law, which states that the electromagnetic force will decrease in an inverse square relationship as elevation increases.

The solar panels placed outside of the satellite will convert solar energy to electrical energy, which will then be measured in watts. We can use this data to analyze how solar energy varies in each layer of the atmosphere. Because of money and technological restraints, we will utilize photovoltaic solar cells, which use a silicon phosphorous material in which easily moveable electrons create an electric current when struck by photons from the sun. The atmosphere is known to refract light, which can affect the energy output of a solar cell. Measuring the solar intensity throughout the atmosphere will allow us to locate the optimum altitude for solar energy collection.

In conjunction with the solar panels, we will also measure UV radiation through the use of photodiodes. The photodiodes will measure UV radiation in the form of watts as well. The ozone has been proven to block some UV rays, and by comparing where the UV radiation is strongest with the electrical output of the solar cells, we can determine the role ultraviolet light has in solar energy collection. It stands to reason that the more photons there are, the more energy is radiated by the sun. We aim to prove the correlation, if there is any, between atmospheric conditions and different forms of electromagnetic waves. By conducting these experiments simultaneously, we will be able to isolate which variable is affecting our data, since there are many factors-- such as temperature and weather-- that can alter the mission’s results. This mission will allow us to perform a comparative analysis of electromagnetics in the atmosphere.

In addition, we will use a HOBO data collector to measure temperature inside and outside the satellite and relative humidity. This will allow us to record how climate changes throughout the atmosphere. A camera will also be mounted on the satellite to track our flight path visually. One adjustment that will need to be accounted for is the effect of extreme temperature on the solar panel and UV photodiode. Temperature affects the resistance of materials, and therefore modifications must be made to ensure the accuracy of the data collected. We can monitor just how much the temperature is affecting our results by plotting how the temperature changes throughout the flight.

Using all of the data collected, we can form a correlation between temperature, altitude and atmospheric conditions and UV, magnetic and solar strength.


Might want to rethink this statement.


Only if you are measuring the temperature of the cells directly, which you should attempt to do.


This is for the most part the climate changes inside your box.


This entire statement should be re-worded. I am left with the question of how can you isolate any variable if there are others you are not measuring (temp and weather).


Should be more specific on this. (clouds, humidity, what?


Really? I would expect that to volts.


Perhaps you could consider using different types of solar cells as part of your experiment. You should also have a control case (i.e. cells measuring on the ground while cells are in the air).


This means to me that you understand that you will need a load between cell and measuring device.


You should ask an expert about this. I am not sure 30 km is high enough to do this but I could be wrong. I applaud your initiative but make sure this is a reasonable experiment.


It is not technically the levels of atmosphere that affect temperature. Temperature changes as direct result of 1. pressure which is related to altitude and 2 the constituents in the air as function of altitude.


Are these two missions related in anyway?


This section is not bad. It is the right length but is lacking a little bit of connection. Solar cell experiment mixed with UV is a natural connection but magnetometer is not. I am not saying don’t do it but I am saying consider the best way to justify or connect it to the solar cell experiment. Maybe it’s entirely separate.


2: Design and Technical Overview

2.0: Design Description

The structure of will consist of a triangular box constructed from 0.125” foam board, reinforced along the exterior edges with Aluminium tape, and insulated with 0.25” foam insulation. Structural joints will be made by bonding the foam board with hot melt adhesive. The balloon tether line will be run through a PVC tube along the center of gravity of the craft and will be fixed in place through the use of knots at either end of the tube and protected using rubber bushings.

Data collection will be carried out by three separate subsystems: the HOBO unit, which will record internal and external temperature and internal humidity; the digital camera, which will record images of the ascent, descent, and of Earth’s curvature at predefined intervals for the duration of the mission; and by the Arduino microcontroller, which will record data from the onboard sensors to flash memory. The intervals at which the camera takes photographs will be controlled by a cracked version of the camera firmware.

The primary mission payload will consist of two UV photodiodes, operational over the 20-350nm wavelength range, four photovoltaic cells, and a magnetometer. The secondary mission payload will consist of the camera and the temperature and pressure sensors onboard the HOBO. The photodiodes will be used to collect data on the intensity of incident ultraviolet radiation at various altitudes, and will be compared to data collected from the photovoltaic cells. The efficiency of the encapsulated photovoltaic cells will be tested under the varying atmospheric conditions as the balloon-sat rises through the atmosphere by measuring the power they collect. The magnetometer will be used to characterize Earth’s magnetic field and to look for minute changes in the magnetic field as a function of altitude.

2.1.1: Testing

The first round of testing will consist of tests on all of the individual components to ensure that they function properly. Components will be tested according to their manufacturer’s instructions, and will be tested in conditions consistent with what they will experience during the mission.

The second round of testing will be conducted on the subsystems. The magnetometer will be tested while in its final configuration and the results will be compared to the earlier tests in which the instrument was isolated in order to determine if onboard electronics will cause unacceptable levels of interference (above) within the instrument. The external structure of the craft will be tested for integrity by first conducting drop tests from a height of 20m, and then by being spun on a 1m cord at a minimum of 50rpm. Those tests will only consist of the structure with representative weights replacing onboard instruments. If any single component or subsystem fails a test, it will not be integrated into the larger subsystem (or craft as a whole).

The final round of testing will be tests on the entire craft complete with electronics. These tests will include, at minimum, a vibration test to simulate atmospheric buffeting, a temperature test to simulate


Great philosophy.


Maybe hard to achieve and over testing a bit.


This is good.


This section should be more detailed. How are you going to do this? How will you characterize/calibrate your UV sensors? Most manufacturers will tell you how test the components. You need to think about more of the details associated with this section and the numerous test you need to complete before you know your sensors and cells are working.


What is the wavelength of UV measured? How do you measure the wavelength you want with this sensor? Do you need more than two? One on each side of the balloonsat?


Not usually what we use. Please look up the correct material and method.


Metric?


Our stuff is a little thicker plus this is not metric.


This section is lacking a lot of the HOW I would expect. It has a little bit of the WHAT in it too. This section should describe how you will achieve you mission with more detail than you have here. Your drawing and functional block diagram should be here too.


temperatures down to 253K, and a full mission simulation. The temperature test will be achieved by packing the craft into an insulated container with 100-300g of dry ice while the electronic systems are running. Temperatures will be monitored from outside the external container using either a digital thermometer or an additional HOBO device.

2.1.2: Data Analysis

After recovery of the satellite, data recorded in the flash ROM of the Arduino microcontroller will be downloaded from that device using a USB cable to a laptop computer running the LabVIEW instrumentation suite produced by National Instruments. Data will be exported from LabVIEW to Microsoft Excel and analyzed along with data collected from the HOBO using Onset’s HOBOware software.

2.2: Requirements Met

The total mass of the craft with payload is projected to be 750g (with a mass allowance of 100g. For details, please see section 2.4), within the 850g limit set by the requirements in the RFP. Our design includes the HOBO, Canon camera, internal heater, and temperature sensors mandated by the requirements, and satisfies the requirement that the craft be constructed of foam-core board. Our budget does include a $50 lump sum for spare parts and damaged part replacement, and still meets the requirement that the total budget be under $300. The craft is designed to be reusable, and will include identification and an American flag on an exterior surface. Finally, onboard heaters will ensure that the internal temperature of the craft remains above 263K and a central PVC tube with rubber bushings will ensure that the tether is not damaged during the mission.

2.3: Safety Observations

While constructing and testing this satellite we will observe proper safety precautions as outlined by Professor Koehler and as described on the ITLL safety sheet. Work with soldering irons will take place in a well-ventilated area and diligence will be exercised to prevent burns and solder overflow and sputtering. During construction of the electronic subsystems ESD precautions will be observed; all members working on the microcontroller, sensors, and magnetometer will be required to wear antistatic bracelets properly connected to a common ground. In addition, wiring of key electronic components will be checked at least twice prior to the application of current in order to both safeguard the electronics and prevent accidents due to component malfunction and/or failure. Finally, both the drop and whip tests will be conducted in broad daylight under favorable weather conditions, and by at least two people: one to conduct the test, and the second to spot him or her. Both team members will be required to wear helmets for the duration of the tests. Finally, any tests involving dry ice will be conducted with the use of gloves and safety glasses to prevent contact burns and injuries due to fragmentation of the dry ice.

2.4: Necessary Components

Part Dimensions Supplier Cost


Good ventilation is recommended.


Try to have two team members always working together during tests and build and always use common sense.


Good.


Good section and summary. What about accent and descent rates?


Great.


Make sure your balloonsat is running or in a mission simulation mode during cold test.


Why the switch to Kelvin?


Arduino Nano 10x18x45mm, 10g SparkFun Electronics $18.95HOBO H08-004-02 68x48x19mm, 30g GTS -Canon A570IS digital camera 45x75x90mm, 220g GTS -Heating circuit 10x50x50mm, 100g GTS -9V Batteries and 5V regulator <35g GTS -Foam Board and Foam insulation See section 3.5, 150g GTS -Camera Timing Circuit Replaced by camera firmware, N/AExternal switches (x3) 5x5x20mm, 15g total GTS -PVC pipe with rubber bushings 10x350mm, 15g McGuckin’s Hardware $3.55Low Cost–High Output Encapsulated Solar Cells (x4)

26x45x7mm, 80g total Edmund Scientifics $15.80

UV Photodiodes 20-350nm (x4) 5x5x5mm, 20g total Boston Electronics $80.00MicroMag 3-Axis Magnetometer 25x25x19mm, 10g SparkFun Electronics $59.95

2.5: Craft Design

Figure 1: Satellite, exploded view

Figure 2: Satellite, flight configuration


Another good drawing.


Good drawing but labels and dimensions are a little small. Overall though, great drawing.


Do these work with Arduino?


Why even mention it?


Not provided by GTS.


How many?


2.6: Functional Block diagrams

Microcontroller:Arduino Pro Mini 328- 5V/16MHz

Batteries: (9V with 5V regulator)

Camera: Includes power source (AA batteries) and data storage (flash memory)

HOBO Internal Temperature

External Temperature

Humidity

switch

switch

Timing Circuit

switch

IR PhotodiodesPhotovoltaic Cells

Magnetometer

Flash ROM

Heater


No timing circuit.Hard to see all of the HOBO section.


3.0: Proposed Project Schedule

design complete 9/16/2010

acquire all hardware 9/28/2010Magnetometer sensor test 9/30/2010prototyping design complete 10/4/2010

DD Rev A/B and CDR presentation 10/5/2010

cold test complete 10/12/2010Drop test 10/12/2010Whip test 10/12/2010

testing final design complete 10/26/2010mission simulation 10/28/2010

LLR presentation and DD Rev C 11/2/2010Weigh In 11/5/2010

final presentations due 11/30/2010

design document Rev D due 12/4/2010design Expo 12/4/2010Hardware Turn in 12/7/2010


You need much more detail on the schedule. This is like your task list/plan for the project. You should have more milestones of you design and build. More testing details too. What about your team meetings? Schedule should be ~1 page for Design Document Rev A/B.


3.1: Team Organizational Chart

3.2: Team Member Descriptions

Name Duty Skills Phone numberChelseaDonaldson Team Leader

Leadership and good imagination

970-331-6409

Jennifer Nill Testing and Design Troubleshooting Woodshop Skills

303-241-7143

Jonathan Lumpkin Structural Design, Payload Assembly

good listener and innovative ideas

970-669-8776

HenryShennan

Systems Integration and Programming

Technical and computer skills

303-564-7575

GrahamRisch

Structural design, Budgetary Management

Organization and building skills 678-463-1374

3.3: Budget

Graham will be in charge of ordering components and ensuring that the project remains within the stated maximum budget of $300.

Component ExpensesPart Supplier CostArduino Nano SparkFun Electronics $18.95PVC pipe with rubber bushings McGuckin’s Hardware $3.55

Low Cost–High Output Encapsulated Solar Cells (x4) Edmund Scientifics $15.80UV Photodiodes (x4) Boston Electronics $80.00MicroMag 3-Axis Magnetometer SparkFun Electronics $59.95Testing ExpensesDry Ice Safeway Grocery $10.00Batteries: 9V McGuckin’s Hardware $20.00Allowance for spare parts and damaged part replacement - $50.00Total Expenses $258.25


What about data storage?


Please include the process/procedure Graham will follow.


Consider having some overlap between team members, especially with a team of five.

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