BalloonSat Stabilizer-StableSat

Team Perfect 10
BalloonSat Stabilizer Mission Proposal
StableSat
Team Perfect 10
9/20/2007

Mission Statement

Stabilizing the satellite from rotating in order to capture clear pictures of stars during daylight, to avoid damage to the satellite during flight, and to positively influence further near space exploration.

Purpose

Unstable satellites in near space challenge the abilities of being able to do science in near space. The proposed mission goal is to find a way to successfully make the satellite stable while it is connected to a balloon. Ultimately the plan is to take pictures of stars in space, from near space, during the daytime. If the satellite is stabilized, then more precise and clear pictures can be taken. Another advantage of stabilizing the satellite will be minimizing the damage to the satellite and its contents during the mission.

Plan

The mission is designed to discover that stars can be seen in the daylight when a picture is taken from near space and while stabilizing the satellite will allow for those pictures to be taken, the stabilization will also prevent damage to the satellite. The stabilization of the satellite is designed to inhibit rotation around the y-axis.

Team Perfect 10

Team Perfect 10 is a group of six Aerospace Engineering students who all share a passion for space exploration. Following is a brief description of each team member and his or her contact information (Table 1).

Table 1: Team Information

Name / Email / Phone / From
Amanda Childress / / 303.242.4704 / Jacksonville, Fl
Duane Goodfellow / / 720.280.7252 / New Castle, Canada
Paul Judiscak / / 719.671.4054 / Pueblo, CO
Tiana Miller-Jackson / / 720.621.5612 / Littleton, CO
Melissa Savage / / 719.482.8148 / Monument, CO
Dan Wawrzyniak / / 518.368.8632 / Glenville, NY

Technical Overview

StableSat will be a cube with a pointed top and square base and sides (see Figures 1, 2, 3).

Figure 1: Basic Design of StableSatFigure 2: Side View 1 of StableSat


Figure 3: Side View 2 of StableSat

Inside, the camera will be pointing out of one of the top slanted sides to maximize point of view of the camera. The cubicle shape of the satellite is projected to be the best design for making a stable object. The hardware needed for the satellite is as follows:

  • Digital camera
  • HOBO
  • Timing circuit
  • Heater
  • Batteries
  • CCD Imaging System
  • ADIS 16080 ± 80º/second Yaw Rate Gyro with SPI Interface
  • Futaba S148 Servo

Building the satellite has many requirements and procedures. The team has divided these tasks into individual subgroups where one main person is in charge (in some cases, more than one), but most of the team will be involved in all of the subgroups at some point in time. A table has been created to show how the subgroups have been distributed (see Table 2).

Table 2: Subgroup Assignments

Project Manager / Mass/Money Budget / Electrical / Structure / Experiment / Testing / Data Assessment
Amanda /  /  / 
Dan /  /  / 
Duane /  /  / 
Melissa /  / 
Paul /  /  / 
Tiana /  / 

Testing

To test the stabilization the satellite will be connected to the rope simulating the same rope that will be attached to the balloon. StableSat will be spun by the team hands and the stabilization system can be tested. During this “spin” process, the CCD Imaging System will be enabled to capture images in order to establish that the satellite is stabilized. The CCD Imaging System will also be tested at night to imitate what the sky will look like in near space. The team will capture images of the sky to determine the vividness and quality of the camera. The design of the satellite will undergo several structural tests as well which include:

  • Drop Test- Satellite will be dropped from a height of approximately 25 feet
  • Whip Test- Satellite will be attached to a rope and swung around vigorously
  • Cold Test- The satellite will be placed in an environment with extreme low temperatures (~-40ºF)
  • Stair Test- Satellite will be dropped down a long flight of stairs

The launch program for the satellite consists of several initializing tests which consist of checking the battery voltage, last-minute power on, sealing the satellite for take-off and connecting the satellite to the rest of the balloon satellites with a rope.

Safety

  • During the drop and stair tests, the team will be sure to stand clear of the falling satellite
  • Gloves will be worn when handling dry ice
  • Use extra caution while using hot glue
  • During the whip test, no one will be standing near the person swinging the satellite around
  • Help will be sought out during any electrical tasks where assistance is needed in order to make sure appropriate handling and procedures are being completed

Special Features

One special feature of the design for StableSat is the slanted top. The purpose for the slanted “roof” of the satellite is to obtain a better angle for the CCD camera’s view. The images taken will not be pointed straight up with other satellites and the balloon to obscure the view. Instead, at an angle, the camera will be pointing up at space with a clearer view then if it were pointing straight up or to the side.

Table 3: Budget

Item / Mass (g) / Cost (US$)
Foamcore / 200 / -
Camera / 130 / -
HOBO / 29 / -
Timing Circuit / 20 / -
CCD Imaging System / 30 / 30
Heater / 20 / -
Gyro Chip / 5 / 35
Motor / 45 (2) / 14 (2)
Video Recorder / 100 / 100
Batteries / 150 / -

The budget will be followed closely and is not to exceed $200 (see Table 3).

Table 4: StableSat Mission Timeline

Date / Event
20 September 2007 / Proposal
25 September 2007 / Initial design
2 October 2007 / Complete design
11 October 2007 / Order/acquire hardware
16 October 2007 / Prototype
16-22 October 2007 / Testing
25 October-6 November 2007 / Finalization of testing and final modifications to satellite
7-9 November 2007 / Preparation for launch
10 November 2007 / Launch
After 10 November 2007 / Post-mission data assessment and conclusions
4 December 2007 / Final Presentation

The Mission Timeline is to be followed completely throughout the whole StableSat Mission.

A functional block diagram has been created to organize the roles of each system on the satellite(see Figure 4).

Figure 4: Functional Block Diagram

General Mission Requirements

The general requirements for the proposal will be met by the team. The additional experiment is to test a stabilization system on the balloon satellite and then take pictures with a CCD Imaging System of stars during daytime. The ideal situation will be obtaining clear pictures of the stars which will confirm that the stabilization system worked. Part of the design of the satellite includes a cylindrical tube through the center of the satellite where flight string can be threaded through to connect the BalloonSat to the actual balloon. The flight string will be secured tightly so that the BalloonSat does not interfere with other satellites or the balloon itself. It is imperative that the temperature is consistently above 0ºC. The internal temperature will be regulated by a heater in the satellite to ensure that the temperature constraints are satisfied. The BalloonSat will include a HOBO to collect temperature readings along with an external temperature cable. The satellite is designed to also contain an HP Photo Smart E427 Digital Camera. Foam core will be used as the main means of forming the actual satellite structure. A mass constraint of 800 grams exists. All the instruments and structure of the satellite will be controlled to conform to the mass budget. An itemized list of the instruments being used and their mass/cost has been created (see Table 3). Any measurements made for the satellite will be reported in metric units. The parts which are not provided should be ordered by Chris Koehler to avoid reimbursement paperwork. In the case that a team member pays for an item needed for the mission, the receipt(s) shall be accounted for and submitted to Chris Koehler within 60 days of purchase. The satellite will have an American Flag on the outside, labeling it as an American vehicle and the team contact information will be labeled on the outside of the structure as well.

Launch day is November 10th in Windsor, CO at 7:30AM. The team is expected to be on time for the transportation to Windsor which will leave promptly from Boulder at 5AM. Once at the launch site, the team will prepare StableSat for launch by securing the rope and switching the satellite “on”. One team member will hold the satellite while the balloon launches.

Afterrecovering the satellite from its landing, the team will make necessary repairs to the satellite to prepare it for re-launching. The team will gather the data from StableSat and make conclusions as to whether the stabilizing system and the CCD Imaging System were successful or not. A final report of the mission will be written after data has been collected from the mission.

Team Perfect 10 1