Gateway to Space ASEN/ASTR 2500Fall 2011

Gateway to Space ASEN/ASTR 2500Fall 2011

Colorado Space Grant Consortium

Gateway to Space

Fall 2011

Design Document

R3D3

Written by:

Tyler Smith

Marisa Antuna

Kate Kennedy

Nicole Ela

Greg McQuie

Devon Campbell

Henk Wolda

12/03/11

Revision D

Table of Contents

1.0 MissionOverview

2.0 RequirementsFlowDown

MissionObjectives

ObjectiveRequirements

SystemRequirements

Structures

Thermal

DataRecordingandHandling

Power

3.0 Design

4.0 Management

TeamMembers

Schedule

5.0 Budget

CostmanagementforR3D3

6.0 TestPlanandResults

TestPlan

TestResults

WhipTest

DropTest

ColdTest

PropellerTest

SolarPanelTest

CameraTest

ComprehensiveTest

7.0 ExpectedResults

8.0 LaunchPlan

Launch

Recovery

9.0 Results, Analysis, andConclusions

FailureAnalysis

SDFailure

PropellerFailure

CameraFailure

ThermalFailure

Results

FlightPictures

Post-FlightData

10.0 ReadyForFlight

11.0 ConclusionandLessonsLearned

12.0 MessagetoNextSemester

1.0 Mission Overview

The mission is to design, build and launch a BalloonSat which will test and compare two types of energy generation systems. For the science component, the first system will involve solar panels harnessing light energy at various altitudes and measuring the power output. This will provide data on the effectiveness of solar panels on BalloonSats and other near-space crafts. We will then compare this data to the power generated by a propeller connected to a DC generator and mounted on the side of the BalloonSat. The data from the propeller will demonstrate the viability of utilizing wind power on aircraft that remain within Earth’s atmosphere. A comparison of the two data sets will also allow for an analysis of overall efficiency of the systems.

According to the European Space Agency, “The sun is a very powerful, clean and convenient source of power, specifically for satellites”1that first came into usage in space with the 1958 Vanguard satellite. However, “the solar arrays needed by an average-sized satellite are quite large, due to the rather low efficiency of the individual solar cells.”2 Due to the small size and surface area of a BalloonSat, a power system based off of solar panels may not represent the most effective method. Furthermore, according to the U.S. Energy Information Administration, wind power is the fastest growing source of power.3 While on a normal satellite wind is not a viable source of power, due to lack of atmosphere, a propeller is a possibility for a BalloonSat. During the BalloonSat’s movement through the lower atmospheric layers, there will be enough air to spin the propeller thereby generating energy. Our team proposes to do a comparison of these two types of power systems in order to determine the most effective technique for use on subsequent BalloonSats and potentially other near-Earth satellites.

Current and voltage data will be collected at various altitudes so that a comprehensive comparison of the two systems can be conducted. Essentially, the energy gathered over the period of the flight by both systems will be charted against the altitude. This will determine in what environments the systems are most effective. Furthermore looking at the systems’ charts together will allow us to discover whether the solar system or propeller system is most efficient overall. We shall also be able to discover which power generation type puts out more power at various altitudes. This may provide evidence that both systems could be used at different times during a flight, instead of just relying on one throughout the entire flight. In this final comparison, we will also attempt to take into account other environmental factors and their effects on each system. For example, the presence of clouds could have an effect on the solar panels, and it is also important to consider varying sun angles both at different altitudes and at different times of day. This would allow future engineers to design their power systems with consideration to predicted environmental conditions in order to achieve more efficient power generation in their crafts.

Our mission’s purpose is to learn about solar and propeller power generation and better understand these systems and how to properly utilize them. The number of BalloonSat programs is increasing, and according to NASA, these programs help “attract and retain students in the areas of science, technology, engineering and mathematics.”4 Due to budget cuts NASA is not able to fund such projects without knowing the risks and rewards. As BalloonSats grow in popularity, the need for more efficient power systems will grow as well. Our experiment is designed to benefit future missions.

Sources:1

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at_prt.htm

2.0 Requirements Flow Down

Mission Objectives

Requirement #: / Requirement:
1 / Build and fly a retrievable BalloonSat.
2 / Collect and measure solar energy during a typical BalloonSat flight.
3 / Collect and measure wind energy from the ascent and descent of a typical BalloonSat flight.
4 / Compare wind and solar power generation.
5 / Collect other essential flight data of a BalloonSat such as temperature, humidity, and ascent/descent rates of the string
6 / Take pictures for the duration of a BalloonSat flight

Objective Requirements

Requirement #: / Requirement:
1.1 / Build a retrievable BalloonSat that will be able attached to a flight string of multiple BalloonSats for a launch to an altitude of approximately 30km in November 2011.
1.2 / Build the BalloonSat such that it will be able to withstand the forces and energies of the entire BalloonSat flight.
1.3 / Have an indicator to know upon landing that the BalloonSat is still functional
2.1 / The BalloonSat will have eight solar panels, two to a side, attached to the exterior of the satellite which will gather energy from the sun.
2.2 / The voltage and current of this solar energy will be measured, recorded, and stored for the duration of the flight
3.1 / The BalloonSat will have a propeller attached to the top of the structure which will be attached to a generator and gather energy from the ascent and descent.
3.2 / The voltage and current of this energy will be measured, recorded, and stored for the duration of the flight
4.1 / Each voltage and current sensor will be interfaced to a flight computer which will interpret the readings from the sensors.
4.2 / The data from the flight computer will be digitally recorded while the BalloonSat is flying
4.3 / The data must be retrievable from the flight computer via a wired connection after the flight is over.
5.1 / Measure humidity of the inside of the BalloonSat throughout the flight
5.2 / Measure both internal and extremal temperature of the BalloonSat throughout the flight.
5.3 / Acquire ascent and descent rates of the flight string
6.1 / Take pictures of the earth every few seconds for the duration of the flight

System Requirements

Structures

Requirement #: / Requirement:
1.1.1 / The BalloonSat must not weigh more than 850 grams
1.1.2 / The main structure of the BalloonSat will be constructed from foam core and aluminum tape.
1.1.3 / The BalloonSat will have a tube running through the center of the structure through which the flight string will run.
1.1.4 / The BalloonSat will have contact information and a USA flag painted on the exterior.
1.2.1 / The BalloonSat must be able to withstand the forces of ascent, burst, descent, landing, and the motion of the flight string.
1.3.1 / There will be holes in the side of the BalloonSat for LEDs that will indicate that the BalloonSat is functional.
2.1.1 / The solar panels will be attached with hot glue to the exterior of the BalloonSat.
2.1.2 / The solar panels will be evenly spaced on each side of the BalloonSat to ensure the most even amount of power collected.
3.1.1 / The propeller will be made entirely out of lightweight materials and strong enough to endure the high speeds of descent.
3.1.2 / The propeller will be attached to the side of the BalloonSat
3.1.3 / The propeller will be attached to a generator which will spin with the propeller and harness energy from the motion of the BalloonSat.
5.2.1 / A hole will be made in the structure of the BalloonSat through which a temperature probe will be inserted.
6.1.1 / A hole will be made in the structure of the BalloonSat through which the lens of a camera will be pointed.

Thermal

Requirement #: / Requirement:
1.2.3 / The BalloonSat must be insulated from the thermal extremes of Earth's atmosphere and space.
1.2.4 / The BalloonSat must be actively heated to ensure the temperature does not drop below -10º Celsius.

Data Recording and Handling

Requirement #: / Requirement:
1.3.2 / There must be a status LED on the exterior of the BalloonSat that will show upon landing that the flight computer is still functional.
2.2.1 / The power from the solar panels will be measured with a preassembled circuit that will give an analog reading of voltage and current.
3.2.1 / The power from the propeller system will be measured with a preassembled circuit that will give an analog reading of the voltage and current.
4.1.1 / The analog data from the two power sensors will be fed into an Arduino Uno which will convert it to digital information.
4.2.1 / The digital information from each respective sensor will be will be timestamped and recorded on the flight computer.
4.3.1 / The data will be then retrieved upon landing via USB cable.
4.3.2 / This data then will be tabulated and graphed by a team member.
5.1.1 / The humidity will be measured by a sensor attached to a HOBO datalogger during the flight.
5.2.2 / The internal and external temperatures will be measured by sensors attached to a HOBO datalogger during the flight.
5.3.1 / The digital altitude data will be extrapolated from temperature readings from the HOBO
5.3.2 / This data then will be timestamped and recorded on the flight computer.
6.1.2 / The pictures from the camera will be stored on a Secure Digital(SD) card as they are taken.
6.1.3 / The pictures on the SD card will be transferred to a computer by a team member.

Power

Requirement #: / Requirement:
1.2.5 / The BalloonSat must have adequate stored energy to power an active heater for the duration of the flight.
1.3.3 / The indicator will be powered directly from the Arduino Uno board.
4.1.2 / The flight computer will be powered by the BalloonSat's batteries for the entire duration of the flight
5.1.2 / The humidity sensor will be powered by the HOBO data logger which will be powered by its own internal batteries.
5.2.3 / The temperature probes will be powered by the HOBO data logger which will be powered by its own internal batteries.
6.1.4 / The digital camera will be powered by its own internal batteries

3.0 Design

We are using two different systems to complete our mission of comparing methods of power generation. Our general systems include power generation systems through the propeller and solar panels, and the command and data handling system that interfaces with those two systems. The solar panels were purchased from Solarhome.org, and are self-contained units of solar cells. These will be wired to three 9-volt batteries, which will store the power generated by the solar panels. One of the Attopilot Voltage and Current Sense breakout modules will measure the voltage and current coming from the solar panels, and will interface with the Arduino board to record the data. Both of these products come from Sparkfun, and will interface through a solder connection.

The power system for the propeller will consist of the propeller, a gear motor, and an Attopilot Voltage and Current sensor, which will interface with the Arduino board. We will manufacture the propeller ourselves due to the special requirements of the mission. We will construct a three-blade propeller that mimics a wind turbine. The blades will have a small chord in comparison to the blade length to ensure high efficiency in capturing wind. The blades will also be tapered to reduce induced drag at the tips, which will increase the propeller’s efficiency. The propeller will be attached to the axle of the gear motor, which will spin and generate current. The gear motor will be purchased from Servocity. The second Attopilot Voltage and Current sensor will be attached to the wire coil inside the motor, and will measure the voltage and current. This sensor will interface with the Arduino Uno, which will record data.

Design Pictures

Our BalloonSat design meets all of the requirements. Our design collects science data from a propeller system and a solar panel system that we will be able to analyze after retrieval. The flight string will run through the center of the BalloonSat, and will be properly secured so that it does not pull through the BalloonSat. The design includes a heater that will be placed strategically so that the internal temperature of the BalloonSat never dips below -10 degrees Celsius. All of our component parts weigh less that the maximum of 850 grams. Our internal design will ensure that each of our required components (ie. HOBO, temperature cable, and camera) have adequate space to perform their duties effectively. An American flag will be placed on the outside of our BalloonSat to prove to random farmers that our BalloonSat is not a UFO or terrorist attack.

Requirement Two states that we will collect solar power during our BalloonSat flight. To accomplish this mission, we will have solar panels located on three of the four sides of the BalloonSat as well as two mounted on the top. To collect the energy from the solar panels, we will have a voltmeter to read the voltage output from the panels. The voltmeter will be attached to our Arduino which Greg will program to record our data.

We also must collect and measure wind energy from a typical BalloonSat flight (Requirement Three). There will be two components. The first component is the actual propeller that will spin as the BalloonSat ascends and descends. This will spin a DC motor in reverse which then will generate electricity. This electricity then will be measured with a voltage/current sensor which is interfaced to an Arduino. The Arduino will measure this data for the duration of the flight.

The fourth requirement is the comparison between our solar panel power and our propeller power. After the mission, we will compare the data between the solar panel and the propeller by taking the information from the Arduino and transferring it to a computer. With this, we will be able to provide a description of the power differences with which we can draw a conclusion about our power generation.

Requirement Five will be met with the data recorded from the HOBO and ascent and descent data acquired after flight. The HOBO datalogger measures internal and external temperature and humidity, which will allow for the team to extrapolate the cause of any failures. The HOBO is provided by Spacegrant. We will acquire altitude data from another team that measured altitude. If no other teams measured altitude, or if they are unwilling to share their data, we will extrapolate the rate of ascent and descent from the time of flight and the external temperature data.

The last requirement will be met with the camera provided by Spacegrant. The camera comes pre-programmed to take one picture every ten seconds for the duration of the flight. This will provide our team with a number of pictures taken from various altitudes during the flight.

4.0 Management

Management of the team was an important piece of the design and build process. It was split into several sections. Keeping in contact with each other was the basis for managing the team, so each team member has information about contact and responsibilities. The second section was the time schedule. While we didn’t strictly adhere to the schedule, it provided a good basis for goals to be accomplished throughout the project. The last section of management was the hardware decision making. The hardware list is located at the bottom of this section.

Team Members

Tyler - Team Leader/Integration (303-726-3159) - Crosman Room 013

Tyler will be in charge of bringing together the different pieces of the BalloonSat so that it is a functioning device.

Greg- C&DH/Software (303-681-6398) - Andrews Room E1B24

Greg will be involved in managing the data that comes in from the two power sources.

He will work with Nicole to get the programming and electronics functioning.

Marisa- Power (303-408-4533) - Williams Village North Room 407

Marisa will be in charge of helping to manage the budget and make sure that every part needed gets purchased.

Devon- Structures (303-999-8626) - Aden Room 026

Devon will be in charge of designing and making the structure of the BalloonSat. He will be the one to add walls, stability, and insulation to make the system secure.

Nicole- C&DH/Software (970-988-0567) - Smith Room E355

Nicole will be in charge of any programming that the BalloonSat needs. She will also set up any wiring that needs to be done.