Critical Design Review REV B Josh Yeaton Kevin Dinkel Chris Kopacz Conrad Schmidt Chris Warren 10.14.08.

Critical Design Review

REV B

Josh YeatonKevin DinkelChris KopaczConrad SchmidtChris Warren

10.14.08

The primary mission of Project SCREAM shall be to create a satellite in compliance with the RFP to ascend to an altitude between 25,000 and 30,000 meters to measure the difference between the audibility of sound at launch altitude and the maximum altitude achieved by the satellite.

The secondary missions of Project SCREAM shall be to acquire photos of the curvature of the Earth, measure the internal humidity of the satellite, measure internal and external temperature, and measure altitude and flight path of the satellite.

Mission Statement

We hypothesize that as our BalloonSat nears the silence of space, sound amplitude will decrease as a function of altitude. We theorize that a 261.33 Hertz middle C, played at a constant decibel level on ground, will decrease in amplitude as altitude increases and air pressure decreases.

Mission Visual Diagram

The chromatic tuner emits a sound (261.33 Hertz middle C) at set intervals through a sound chamber.

The MP3 flight file recorded on the voice recorder is then transferred to a PC .

The MP3 file is then analyzed with Audacity software. Decibel readings during every three minute interval will be examined for the emitted tone and its harmonics.

The tone is recorded by the voice recorder, found on the opposite end of the chamber, for the entirety of the flight

The information acquired by Project SCREAM can be conveyed to scientists involved in Mars exploration, who could then use this data in a number of ways. Sound, for example, is used in SONAR, which can be used to measure atmospheric disturbances and weather patterns.

This data can also be given to scientists who make weather predictions on Earth. SONAR used at high altitudes can be used to predict weather patterns on Earth; better understanding how sound behaves at higher altitudes would be helpful in obtaining better weather predictions.

Why?

LevelObjective Number

Requirement Reference

0

O1

Team SCREAM shall complete a functioning BalloonSat ready to launch on a high altitude balloon to 25,000 – 30,000 meters by 11/15/2008. The BalloonSat shall not weigh more than 1000g total or cost more than $150 dollars, minus the provided hardware. The instruments of the spacecraft shall remain intact and functional during a 90 minute ascent to an altitude of 30 km and a 45 minute descent including landing. The BalloonSat shall be configured to allow for attachment via a string, with several other satellites, connected to the balloon launch vehicle. The BalloonSat’s interior will, at all times, remain above the freezing temperature of water, 0 degrees Celsius. The design shall be in compliance with the RFP.

1.1

O2The BalloonSat shall measure the amplitude of sound in decibels as a function of altitude using a sound emitter, sound recorder, and sound chamber.

1.2

O3The BalloonSat shall measure altitude and accurate flight path using an onboard Global Positioning System.

1.1

O4The BalloonSat shall produce photographic images of the Earth’s horizon using a digital camera oriented along the horizontal axis of the BalloonSat.

1.1

O5The BalloonSat shall measure humidity using a hobo data logger.

1.1

O6The BalloonSat shall measure both inside and outside temperature using a hobo data logger for the duration of the flight.

1.1

Level Zero RequirementsRequirements Flow Down Chart

O1.1

•The mass and financial budget shall be divided among all structural and science components and shall allow for the purchasing of spare parts. The entire systems of the BalloonSat shall be completed and fully tested by 11/4/08.

•The BalloonSat shall be constructed from foam core, resulting in a rectangular box. It shall be sturdy enough to contain and keep intact all necessary hardware found inside.

•It shall be tethered through the middle by the flight string to achieve optimal balance. The BalloonSat shall be tethered for the entirety of the flight without severing the string or obstructing the functionality of other BalloonSats also attached to the balloon.

•The BalloonSat shall be functional at an exterior temperature as low as -30 degrees Celsius. The provided heater and the other electronic hardware used will act to keep the BalloonSat above 0 degrees Celsius. The heater will be located near the center of our structure so that it can be radiated in all directions equally. The most vital part of our system, the batteries, will be located closest to the heater to ensure that we have sufficient power for our flight. The other electronics will be spread out evenly throughout the rest of the box so that the heat produced from them can evenly disperse throughout the structure.

•The inside components shall not be exposed to the outside conditions, but rather kept on the inside of the foam core structure. The structure of the spacecraft and all inside components shall remain completely intact and able to launch again after striking the ground upon landing.

O1

Level One Requirements

How we plan to meet the RFP requirements:

Level One Requirements (continued)

How we plan to meet our science mission requirements:

O2.1The science experiment of the BalloonSat requires the use of a Korg CA30 Chromatic Tuner, a Sony ICDP620 Digital Voice Recorder, a sound chamber constructed of the provided insulation, and the audio analysis software Audacity.

O2

O3.1

The BalloonSat shall use a GPS system constructed by Viliam Klein of the Colorado Space Grant Consortium’s HASP Team. It consists of a GPS box mounted on a circuit board. Data is then stored onto a SD card for easy analysis from a computer.

O3

O4.1

The BalloonSat shall utilize the provided Canon A570IS Digital Camera and Memory Card to photograph the Earth’s horizon during flight. The camera will be securely mounted facing horizontally outwards from our BalloonSat. The lens will focus through a small piece of clear Plexiglas mounted in the side wall of our foam core structure.

O4

O5.1

Using the HOBO data logger, the humidity during the flight shall be measured. The HOBO will be located along the wall of our structure. If any condensation or humidity variations occur within our box, the data logger should be sufficiently accurate in giving us good insight into the internal conditions.

O5

O6.1

The outside temperature will be measured using a temperature probe connected to a HOBO data logger. It will be seen externally on our box, but will not come in contact with the structure in order to ensure accurate results. The inside probe will be mounted as far away from the heater as possible to ensure that our BalloonSat was indeed above 0 degrees Celsius throughout the entirety of our structure.

O6

Design Concept

Heater

9V Batts

Tuner

Timer

Switches

GPS

Sound Chamber

Recorder

HOBO12 V Batt

Temp Sensor

Camera

Plexiglas

All Measurements in Centimeters

•Dimensions 30 cm x 14 cm x 14 cm. •There shall be an American Flag on one of the square sides. •The camera shall be placed facing out on one of the square sides of the rectangle, with a clear Plexiglas section 5 cm x 5 cm where the lens of the camera faces the side. •A GPS shall be mounted on one of the 30 x 14 cm sides. •The HOBO sensor shall be mounted to another of the 30 x 14 cm sides. •The external temperature sensor shall be placed on the side opposite the heater, with the tip extending just outside of the satellite. •The primary science experiment of the BalloonSat requires the use of a Korg CA30 Chromatic Tuner, a Sony ICDP620 Digital Voice Recorder, a sound chamber (15 cm x 7 cm x 5 cm) constructed of the provided insulation, and the audio analysis software Audacity. •The tuner will be placed at one end of the rectangular sound chamber. •The tuner has the capability to emit a constant decibel tone at selectable frequencies. It will be soldered to a timing circuit in order to emit a 261.33 Hertz middle C tone for two seconds every one minute. This tone shall remain at a constant decibel level when there is no change in altitude or air density.

Design Description

•The sound chamber is not constructed to be air tight or to try to keep the atmosphere in, but simply to block out as much external noise as possible. At the opposite side of the tuner will be the recorder. This device will constantly record any sound emitted for the duration of the flight. •When the flight is complete, the recorder will be connected via USB to a computer to be analyzed in MP3 format. •The MP3 will be shown visually in audacity as a decibel waveform. By isolating the Middle C tone and its respective harmonics we can clearly see how the decibels of the main tone and its harmonics may drop during the flight.•With the data received from the GPS board in our BalloonSat we hope to compare the change in decibel level to the altitude recorded at any respective time. Data on the GPS is stored onto a SD card for easy analysis. It shall be analyzed via computer, using the GPS internet tracker that coincides with the device. With this data we will be able to accurately plot how sound is affected by increasing altitude. The data from the camera shall be recorded to an SD card, which can then be attached to a computer and the photographs downloaded onto the computer.

Design Description (cont)

Systems Diagram

GPS Power Source

Camera Memory

Recorder PowerRecorder Power

RecorderRecorder

GPSGPS

12 V Battery12 V Battery

SwitchSwitch

SpeakerSpeaker

Speaker PowerSpeaker Power

TimerTimer

External TempExternal Temp

HOBOHOBO


SwitchSwitch

HeaterHeater



CameraCameraCamera Power Source

Camera Power Source

Switch

Organizational Chart

Team LeaderJoshua Yeaton

Tuner and Voice Recorder Configuration

Christopher Warren

Kevin Dinkel

Conrad Schmidt

Christopher Kopacz

Budget Management

Soldering/Electrical

Structural Design and Testing

Camera Configuration

HOBO and GPS Configuration

Joshua Yeaton

Weight BudgetComponent Weight (grams)

Foam Core 120.00

9 volt Battery (3) 101.4012 volt Battery (1) 33.80Canon A570IS Digital Camera w/ Memory Card 220.00Timing Circuit 60.00

Hobo Temperature Data Logger 39.00GPSAluminum Tape

66.0010.00

Switches (2) 20.00Heater Circuit 30.00Korg CA30 Chromatic Tuner 66.80

Sony ICDP620 Digital Voice Recorder 50.00Insulation and Styrofoam Chamber 100.00AAA Battery (6)American FlagAttachment TubePlexiglas Window

45.602.00

10.005.00

Total 979.60

TestingImpact Test

We will kick the body of the satellite down a set of stairs as this has been confirmed as an accurate portrayal of the damage a satellite will endure by being dragged through a field after impact. The structure will also be taken to a balcony or other high place and dropped to the ground below to test whether the satellite will survive the sudden impact that will end its descent from the atmosphere. For these tests the actual internal components will not be included as these are only tests of the design of the structure. A mass replacement (weighted object) will be put inside the satellite for these tests to simulate the weight of the systems inside the satellite.

Whip Test A whip test will be preformed to ensure that the tether apparatus will

be functioning properly during the actual launch. A replacement rope will be strung through the satellite’s tether apparatus followed by repeated violent swinging of the satellite to simulate the stresses it will endure.

It is also possible that additional impact testing may take place during the whip test to indicate whether the structure will hold up to a more intense impact. Again, a mass replacement will be used to simulate the mass of the components inside the satellite.

System Test Tests to ensure that all components are functioning properly

together within the satellite and in some conditions of near space.

The satellite will be entirely put together and tested to see that the components are working.

Cold Test Following this test, the satellite will be placed into a cooler

of dry ice for a period of time that is equal to the expected duration of the actual flight (close to 3 hours) to determine whether or not the insulation and heater of the satellite do a sufficient job at keeping the batteries and other components at a working temperature.

Testing (cont)

Image TestAn image test will be performed to make sure that the camera can see through the Plexiglas and will take pictures autonomously. This component will also be included in the cold test to confirm whether or not it will take pictures at such low temperatures.

Using rocks as mass simulators, we successfully tested our satellite with the drop and stair test.After repeated drops and kicks down the stairs, all of the seams held together. We will also need to test that the actual components of the satellite are securely attached within the satellite before launch day. Failure to do so could easily ruin the purpose of our flight as well as damage ours and other satellites if something were to become dislodged.A 30 minute test was conducted with the tuner and sound recorder. The two components were turned on and placed into a box and put into a cabinet and left for 30 minutes to test whether or not the recorder would emit the note for an extended period of time and if the recorder could pick it up with its microphone. After 30 minutes, the cabinet and box were opened to find the tuner still emitting its note, and the recorder still on. Plugging the recorder into a computer proved that it had successfully recorded the note over the entire period of time and still had many more hours of empty recordable space in its memory storage.

Performed Tests

Schedule9/22-9/28 9/29-10/5 10/6-10/12 10/13-10/19 10/20-10/26

Proposal due 9/23 HW 05 due 10/02 Begin Construction DD Rev B due/ Team in-class demonstrations 10/23

Team Presentations 9/23 Order Hardware Testing: Presentations due 10/14 Complete Final Design

Complete Proposal Design Prototyping Drop Test Prep for in-class demo Electronics Into Satellite

Stair Test All Electronics work Full Mission Test - not in cold 10/21

completed

10/27-11/2 11/3-11/9 11/10-11/16 11/17-11/23

Cold Test In-class mission simulation 11/4 and 11/6 Final BalloonSat Weigh-in and TURN IN 2:00 PM 11/14 Bring raw flight data 11/18

BALLOONSAT COMPLETED LAUNCH DAY 11/15. Process Flight Data

LRR Cards due 11/6 LRR Presentations 11/11

DD Rev C due 8:00 AM 11/6 Launch Prep Prior to Launch

Launch Preparation

11/24-11/30 12/1-12/7

Fall Break DD Rev D Due 12/2

Work on Final Presentation ALL presentations due 12/2

Work on DD Rev D

Test Schedule

Acoustics in near-space could be applied very well to an atmosphere similar to Mars’, as Mars has an atmosphere approximately one percent as dense as Earth’s. By finding the ability of sound to propagate at 30,000 meters on Earth (one percent Earth’s atmosphere’s density at sea level), one could find the ability of sound to propagate on the surface of Mars.

Biggest Concerns

Time (one month to launch) Heater placement – getting heater to

keep all electronics working Sound Chamber construction Excessive ambient noise