Team Space JamCritical Design Review

Bridget Chase, Shane Meikle, Jamie Usherwood, Ben Azlein, Megan

Scheele, Taylor King, and Paul Guerrie

October 5, 2010

Fall 2010 R

ev A/B

10-05-10

Mission Statement• The main mission of Project Monstar shall be to build a satellite that ascends to an

altitude of 30km following the RFP. Project Monstar will test the use of a servo as a means of rotating a camera in the y plane, while the balloonsat naturally rotates in the x plane.

• The secondary mission of Project Monstar shall be to take pictures 360 degrees, to prove the use of the mechanical system. Project Monstar shall also record attitude of the camera with the use of a digital compass. It will also measure internal humidity, internal and external temperature of the balloonsat.

Hypothesis• We hypothesize that our mechanical system will operate by fully rotating 360 degrees

in the y plane, as the balloonsat ascends to a height of 30 kilometers. We believe that the ability to make a panoramic picture will prove the successful use of our design.

Mission Overview• The balloonsat Monstar will travel to an altitude of approximately 30 kilometers while taking

pictures while rotating 360 degrees in the x and the y planes. (The camera will be rotating vertically, as the balloonsat rotates horizontally) The balloonsat will also record temperature, pressure, humidity and the direction the camera is facing.

• Our mission will focus on the controlled mechanical rotation of our camera to provide a foundation that can be built upon for other scientific experiments. For example, the controlled rotation of the balloonsat could be used to record temperature in every direction. An analysis of this data could be used to find heat and temperature trends relative to position.

• Taking pictures while rotating 360 degrees in the x and y plane will serve many purposes. First and foremost a picture of the entire Earth from 30 kilometers will be obtained from the many pictures that the balloonsat takes. This picture will serve as a visual representation of data being collected in every direction relative to the balloonsat.

• The balloonsat Monstar will discover the plausibility of controlling the attitude of a balloon satellite dedicated to a scientific experiment which is heavily dependant on the position of the satellite. From analysis of our pictures we will be able to see what design improvements could be made to more efficiently control the attitude of our balloonsat.

 

Why?

• To design a platform for other scientific experiments which need directional sensitive data. Researches in the future will be able to record scientific data in all planes, so the results would be more realistic.

• Also to test a method of the attitude determination of the balloonsat.

Requirements Flow DownLevel # Detail Derived

From

Basic Requirements

 

O 1 The Balloonsat shall ascend to/descend from an altitude of 30 kilometers over a period of 2.5 hours on November 6.

MS

O 2 The Balloonsat shall not exceed a mass of 850 grams. MS

O 3 The expenses of the Balloonsat shall not exceed $300. MS

O 4 The balloonsat shall measure the interior and exterior temperature in Celsius throughout the flight.

MS

O 5 The attitude of the balloonsat shall be measured relative to the camera in degrees off of magnetic north.

MS

O 6 The inside of the balloonsat shall be kept above a temperature -10° Celsius

MS

O 7 The balloonsat shall fly a camera to take picture throughout the flight. MS

O 8 The balloonsat shall rotate the camera in the y-axis plane, to combine with the natural x-plane rotation of the flight.

MS

Level One RequirementsLevel 1

System Requirements

   

S 1 The balloonsat shall have a tube through the center to attach the 2.4mm Dacron flight string of the helium balloon.

O1

S 2 The balloonsat shall survive the severe temperatures throughout the flight, and the landing at the end of the flight.

O6

S 3 The structure shall protect all subsystems contained in the balloonsat. O1

S 4 A Digital Compass shall be used to record the orientation of the camera on the balloonsat relative to magnetic north.

O5

S 5 A HOBO data logger shall be used to record internal and external temperature of the balloonsat

O4

S 6 A mass budget and a monetary budget shall be created. O2,O3

S 7 A servo shall be programmed to rotate the camera 180◦ back and forth. O5

S 8 A system of heaters and insulation shall be used to maintain an internal temperature above -10° Celsius.

O8

S 9 The servo and the system of heaters shall be wired to a switch for easy use before launch. O7

S 10 A Canon Powershot SD780 IS camera shall be flown. O7

S 11 The balloonsat shall contain its own power for the entire flight. O1

S 12 All tests, design changes, and construction shall be completed prior to November 6 launch date

O1

S 13 The camera will be mounted outside the balloonsat for possible rotation. O8

Subsystem RequirementsLevel 2

Subsystem Requirements

 

SS 1 The balloonsat structure shall consist of foam core. S3

SS 2 All components shall be secured in the box so not to be damaged during flight/landing.

S3

SS 3 The camera will be protected by a casing attached to the tripod attachment of the camera.

S13

SS 4 The balloonsat shall bear the U.S.A. flag with contact information on the outside in case of separation from the flight string.

S3

SS 5 A system of ball bearings and the servo will be used to facilitate the smooth rotation of the camera.

S7

SS 6 A heating circuit shall be used with three 9V batteries. S8

SS 7 The balloonsat will be insulated with the provided insulation foam and Styrofoam. S8

SS 8 A Digital Compass shall be calibrated to measure the orientation of the balloonsat

S4

SS 9 A Basic Stamp II module shall control the digital compass and the servo, and store their data.

S4,S7

Design

• Design– HOW YOU ARE DOING YOUR MISSION– Parts

• What has been ordered and what has not• How long will it take to get parts.

– Drawings– Functional Block Diagram– Mass and Money Budgets (have but don’t discuss unless asked)– Schedule (have but don’t discuss unless asked)– Recommend you discuss proposal requirements and how you

plan to meet them.– The question of “How you are going to complete your mission?”

should be answered

Design• The balloon sat structure will be a cube with a small rectangular prism cut out of it. A smaller cube with

the camera inside of it will be embedded in this space so it is free to rotate with the help of two servos. The structure of both containers will be primarily foam core. They will be created with one sheet of foam core that is cut into connected squares and then folded up, thus maintaining the structural integrity of the foam core. The corners will be reinforced with hot glue and aluminum tape to preserve the structure strength and help with maintaining insulation. The two cubes will be attached to the arms of the servos.

• The smaller cube will be a cube with one open side to allow the camera to take pictures. The smaller cube will be 5.8 cm x 8.4 cm x 10.8 cm. The only thing in this cube will be the camera and insulation. The smaller cube will then be connected to the main body of the satellite by two servos on either side which will rotate the camera 180 degrees back and fourth. This will prevent our camera from taking pictures of our satellite as it rotates. We don’t want our camera taking pictures of our satellite because we are collecting data in a panoramic area around our satellite, we don’t need any of the satellite itself.

• The camera inside the smaller cube will be mounted by taking advantage of the threaded hole on the bottom of the camera meant for tripods. A screw inserted in that hole will connect to a tight fitting covering made of foam core surrounded by Styrofoam. The covering will be protection for landing, vibrations and shocks. It will also insulate the camera.

• To heat our balloon sat we will use one heater. The camera box will not have a heater in it, instead it will just be insulated tightly with Styrofoam and air tight. The heater will be in the center the satellite and will be surrounded by electrical components. The heater will essentially be placed right next to the majority of our electrical components to ensure the functionality of said components during the entirety of the mission.

Design Concept

Design Concept.114 m .114 m

23 cm

.23 m

.03 m

.14 m

.09 m

.11 m

.23 m

.17 m.23 m.14 m

.03 m

.09 m

.03 m .03 m

.11 m

Stamp/Digital Compass

HOBO

Heater

Batteries

Functional Block Diagram

2 AA Batteries Switch 1 Camera 2 GB Memory

3 9V Batteries Switch 2 Heater

Solar Panels (12)

Backup Batteries (15V)

Switch 3Basic Stamp

Servos

Digital Compass

HOBO

External Temp

Internal Temp

Humidity

Schedule

Mass Budget

• HOBO – 30g• Canon A570IS – 200g• Heater Systems (2) – 100g (each)• Solar Panels (6) – 4.54g (each)• Servo Motor (2) – 13g (each)• Digital Compass – 5g• Foam Core – 40g• Switches (3) – 5g (each)• Total – 543 g

Money Budget

Testing

• Tests:

-Whip Test

-Drop Test

-Freeze Test

-Staircase Test

-Subsystem Functional Test

Testing (cont.)• Whip Test

– A cord will be threaded through the balloon sat and then a team member will vigorously swing the satellite around on it

– This will test the integrity of the PVC pipe and opening in the balloon sat that are crucial to the satellite remaining on the balloon cord

– The rocks inside our prototype satellite will simulate our mass of our components and this test will allow us to test how our components need to be fastened

• Drop Test– Consist of dropping the balloonsat off of a balcony or second story to the ground below to test structure endurance

both generally and for landing. – This test will also allow for us to see how our components may be affected during landing, so we can make proper

adjustments to strengthen these specific areas.

• Freeze Test– Will be administered to the subsystems to check that all systems can work with the cold temperatures to be

expected. – Condensation tests will be done in accordance with the freeze tests to ensure that no condensation will prevent

electronics from working, and to make sure that the camera has a clear opening to take pictures from.  – The freeze test will also test the functionality of our servo motors. The motors are only able to operate efficiently

above -10° C.– By running our servo motors in the freeze test, our team can determine specific insulation changes that may need to

be made in order to maintain the servo motor’s functionality throughout our flight.

Testing(cont.)• Staircase Test

– The balloon sat will be rolled down a staircase. 

– By doing this test with the correct mass inside our prototype, we will be able to determine if structural reinforcements may be needed for our subsystems in order to ensure a successful retrieval of data.

• Subsystem Functional Test– The compass and motor tests will be run in order to test if the compass will receive accurate

readings and the motor will work properly in rigorous conditions.

– This test will require spinning the satellite about a rope. – The camera test will take place in order to check that the time intervals that the camera is

taking pictures and compare it to the spinning velocity of the motors to make sure we can accurately only take pictures of the environment around us instead of taking pictures of the satellite itself, which is not needed.

Team Organization Chart

Expected Results

• Panoramic pictures – full view from satellite to accurately show flight

• Used in future experiments – record direction sensitive data in 360 degrees

Biggest Worries

• Holding the servo in place, so it can be supported in the middle of the box.

• Having the servo survive the harsh temperature of near space.

• Condensation on the camera lens.

• Having the extended parts of foam core structure (that hold the camera) survive impact.