GATEWAY TO SPACE SPRING 2006 DESIGN DOCUMENT

Transcription

1 Colorado Space Grant Consortium GATEWAY TO SPACE SPRING 2006 DESIGN DOCUMENT HKP Systems Written by: Nathan Billington Heather Houlton Paul Joos Eric Payton Kyllie Pobar Kristina Wang 18 April 2006 Revision C

2 Gateway to Space ASEN/ASTR 2500 Spring 2006 Revision Log Revision Description Date A Conceptual Design Review B Preliminary Design Review C Critical Design Review Page 2 of 16

3 Gateway to Space ASEN/ASTR 2500 Spring 2006 Table of Contents 1.0 Mission Overview Design Management Budget Test Plan and Results Expected Results Launch and Recovery Page 3 of 16

4 1.0 Mission Overview The mission of BalloonSat is to launch a small payload to 30 km above sea level, fully equipped to capture photographs of the Earth and test alkaline and Nickel Metal Hydride (NiMH) batteries (both insulated and fully exposed) at extremely low temperatures and pressure. With the acquired information regarding their performance, endurance, and overall ability to function, these batteries may be used for new applications in industry for future near-space missions. Battery performance greatly decreases in cold temperatures. Capacity and endurance are no longer optimum, and this poses a problem for satellite missions that require and rely on the use of a local power source. Standard household batteries (such as alkaline) cannot operate in the extremely low temperatures of space. For our mission, these common batteries as well as industry-standard NiMH batteries will be placed in a ventilated area within the payload, away from a heat source. One member of each set will remain exposed, while the other will be minimally insulated. In the past, batteries have been minimally insulated in such conditions, and our experiment will test this scenario accordingly. These four batteries will be placed within a circuit with a resistor and read by a voltmeter, which in turn will be recording values with a HOBO data logger. Prior to the flight of the payload, a control test will be conducted on ground using the same batteries and equipment. Data analysis will reveal which battery had the higher performance, and how minimal insulation affected the output. 2.0 Design Motives behind choosing Alkaline and NiMH batteries are simple. Alkaline batteries are widely used in household appliances, and are used on the payload to power the heating array. In comparison to similar batteries, NiMH is less sensitive to temperature changes and has a much lower operating pressure, which is what we will be experiencing at 30km. In order to test the batteries in the payload, each will be incorporated into a small circuit. The battery will run through a resistor and the voltage across will be recorded into the HOBO data logger using its additional external inputs for the voltmeters. Since there are going to be four different circuits to test four different batteries, two RH/Temp/2x External Data Logger HOBOs must be used, since each has two inputs to measure voltage. The voltmeter in the HOBO will record the decline in the batteries charge and voltage over time. Because the voltage of each battery is known, the value of the resistors was calculated to approximately 3 ohms. During the launch, flight, and retrieval of the payload, the exact same circuits will be running at ground. This will serve as a control. Data analysis will yield which of the two battery types is optimal for spaceflight, as well as the effect of light insulation. Ideally, one of the batteries will out perform the other in these extreme conditions, demonstrating the applications for this battery in future spacecraft missions. Data analysis will compare voltage output as a function of time, in Page 4 of 16

5 comparison to external temperature and altitude. The information from this analysis will be very beneficial to future Space Grant and Gateway to Space missions. To prevent all measurement devices and circuitry from malfunctioning at temperatures approaching -80 C, a heating array composed of ceramic resistors will maintain the operating temperature above 0 C within an isolated section of the payload. However, the Alkaline and NiMH batteries being tested will remain in a separate ventilated section of the payload to be tested against the environmental extremes. Within the heated chamber of the payload, a Canon ELPH LT film camera will reside in order to photograph the Earth. In order to prevent heat loss, the lens and other sensors of the camera will be pointed through a cut hole in the outer structure and sealed. The heating array will be mounted adjacent to the two HOBO data loggers, the camera and its batteries. In addition to photographing the Earth and testing the batteries, the payload will also measure external and internal temperatures. While the HOBO has a built-in thermometer to record internal temperatures, the external temperature (also measured by the HOBO) will be measured via a probe. The probe will be threaded through a hole in the side of the payload and attached, fully exposed to the environment. Similar to the lens of the camera, the area surrounding the probe will be sealed. Although ascent and descent rates of the payload may be acquired through the use of a barometer, this will add significantly to both the mass and cost budget. Instead, both rates can be obtained the day of the flight on the EOSS website ( The payload will be separated into two chambers by an insulating wall. To allow a durable, light structure for the payload, foam core will be used to house the internal components. The flight cable, a braided rope, will be used to attach the payload to the main balloon system by passing it through the center of the payload. A complex of washers and pins will securely fasten the payload to the cable. Page 5 of 16

6 Design Layout: Isometric View Exposed Experiment Compartment 4cm Hole for Flight cable Heated Compartment 7.5cm Ventilation Slits Experimental Batteries Timing Circuit Camera Batteries Heating Array (in background) 12cm 13cm Camera HOBO A 12cm 13cm 12cm 13cm Heating Array Batteries HOBO B Separating Wall Foam core thickness: 0.5 cm Page 6 of 16

7 Design Layout (continued) Side View Side View Front View Top View Key Camera. HOBOs A, B Heating Array... Camera Timing Circuit. Heating Array Batteries Camera Batteries... H x W x D (in cm) Based upon Front View: 5.5 x 8.5 x x 6.8 x x 2.0 x x 2.0 x x 8.0 x x 4.5 x 2.0 Page 7 of 16 Box Dimensions (in cm): Exterior: 13.0 x 13.0 x 13.0 Interior: 12.0 x 12.0 x 12.0 Heated Compartment: 12.0 x 12.0 x 7.5 Exposed Compartment: 12.0 x 12.0 x 4.0

8 Functional Block Diagram 9V Battery 1 9V Battery 2 9V Battery 3 Battery 1 Battery 2 Battery 3 Switch C Heating Array Switch H Timing Circuit ELPH Camera External Temperature Probe 1 2-Channel HOBO Battery Humidity Probe 2 Internal Temperature reader 1 4-Channel HOBO 2 Voltmeter 3 4 Resistor 1 Resistor 2 Resistor 3 Resistor 4 NiMH 1 NiMH 2 (Insulated) Alkaline 1 Alkaline 2 (Insulated) Switch 1 Switch 2 Switch 3 Switch 4 Page 8 of 16

9 Final Parts List Part Qty. Purpose Battery holder 4 Securing testing batteries in circuit Battery, 3 volt 3 Powering the camera timing circuit Battery, 9 volt 3 Powering the heating circuit Battery, AA (Alkaline) 2 In-flight testing Battery, AA (NiMH) 2 In-flight testing Battery, CR2 1 Powering the camera Canon Elph LT Camera 1 Photographing the Earth Circuit board 1 Securing testing battery circuit Film 1 Photographing the Earth Foamcore,.5cm thick (Black) 1 Building the main frame Heating Circuit 1 Maintaining internal temperature HOBO Data Logger 2 Measuring temperature and voltage Hot glue 1 Assembly Insulation 1 Maintain internal temperature Modeling clay 1 Creating insulating seals Plastic tube 1 Securing the flight rope within the box Plastic washer 4 Securing the tubing within the box Resistor 4 Draining testing batteries Super glue 1 Assembly Switch 6 Controlling internal circuits from the outside Tape, Aluminum 1 Assembly Tape, Scotch 1 Temporary Assembly Temperature Probe 1 Measuring outside temperature Timing Circuit 1 Photographing the Earth Voltmeter 4 Measurng voltage across testing batteries Wire N/A Circiutry Page 9 of 16

10 3.0 Management Basic Schedule: 2/16: Design Review 2/17-21: Design completed, team reviews 2/23: Meeting 6pm: Order Materials, Design Prototype: Review for construction 2/25: Begin Construction 3/9: Meeting 6pm: Structure construction 3/16: Meeting 6pm: Design Review Presentation preparation Design Revision 2 preparation Structure construction 3/18: Structure construction completed, stair test and whip test 3/23: Critical Design Review Presentations Due Design Revision 2 Due Meeting 6pm: Experiment Construction 3/25: Experiment construction completed (all construction done), systems test Contact Information for all Team Members: Nathan Billington Kristina Wang Eric Payton Paul Joos Heather Houlton Kyllie Pobar 9506 Darley South Boulder, CO (303) Crosman Hall Boulder, CO (303) Aden Hall Boulder, CO (720) Darley North Boulder, CO (719) Goss Circle E. Boulder, CO (303) Crosman Hall Boulder, CO /6: Meeting 6pm: Cold Test Design Review Design Revision 3 Preparation 4/18: Pre-Launch Inspection Bring all hardware to class 4/21: Final Weigh in, turn into Chris s Office by 430pm 4/22: Launch Day 4/28: Meeting 6pm: Data Analysis, Presentation preparation Control experiment run 5/2: Final Team Presentations All Documents due HKP Systems has resolved to meet every Thursday at 6pm, as a regular meeting. Above is a schedule with major team meetings, but a detailed version of the above schedule has been made, with additional dates as necessary. In case of absence, Kristina is the secondary leader. Paul Structures, Experiment Design, Circuitry, Testing Kyllie Imaging Systems, Structures, Testing, Circuitry Team Organization: Nathan Team Leader Testing, Structure Design, Editing. Kristina Testing, Writing/ Editing, Structures, Circuitry Heather Launch/Recovery, Budget, Hardware Eric Structures, Structure Design, Hardware, Circuitry Page 10 of 16

11 4.0 Budget Mass Budget: Equipment: Mass (g) Temperature Probe 8 Four-Channel HOBO 27 Two-Channel HOBO 25 Heating Array/connector 18 Experiment Assembly 85 timing circuit/battery holder 40 camera (no battery) switches 22 Structure: foam core/insulation/washers/cable/column/tape 98 inner matrix/wall 27 Flight Batteries: camera battery 10 2 Alkaline 48 2 Nickel Metal Hydride 58 timing circuit batteries (3) 22 Total Mass: 617 Financial Budget: Component Purpose Projected Cost HOBO A Measure voltage of batteries from experiment, upgraded from 2 channels to 4 $0, Supplied HOBO B Measure internal temp and humidity $0, Supplied Camera Capture photos of Earth $0, Supplied Heating Array Provide heat to the balloonsat $0, Supplied 9V Batteries To power heater, camera, timing circuit $0, Supplied Foam Core Interior/Exterior structure $15 4 Voltmeters Measure voltage,translate data into HOBO $0, Supplied Circuit Board To secure the tested batteries and circuits $5 Dry Ice To test all the hardware at low temps $1 per pound Extra Batteries Alkaline, Nickel-Metal Hydride for experiment $50 Others 4 Resistors, 2 additional switches, aluminum tape, aluminum foil, wires, miscellaneous supplies $40 Film Costs Extra film for testing, film development $50 Total Projected Cost $160 Page 11 of 16

12 5.0 Test Plan and Results The following is a complete list of tests that will be completed to ensure that the Balloon Sat will operate as designed during flight: Structural Tests: Freefall, stair test, whip test. Non-Experimental Equipment Tests: Cold test, heating array functionality, camera and timing circuitry test, HOBO data collection and memory capacity. Experimental Tests: Battery endurance test, circuitry and battery compatibility, complete experiment run. The above tests are described in detail below: Freefall: This test is to ensure that our structure can survive the impact of landing, as well as testing the center of mass. The BalloonSat will be going approximately 25 to 30 mph when it hits the ground. To simulate this, we will drop our satellite off a 2 story balcony with the masses of each subsystem component simulated with bags of dirt wrapped in painter s tape. The bags will have the same mass and approximate shape as each subsystem it represents. The structure will be sealed with aluminum tape only. The Freefall test was conducted once on The Balloon Sat fell straight downward and landed flat without bouncing or rolling. Video footage capturing the test showed that the center of mass was sufficiently centered in the box to prevent it from rolling to one side during free fall. The structure remained intact and suffered negligible damage. Stair Test: The purpose of this test is to ensure that the structure can withstand the harsh rattling, bumping and thrashing that the box will have to endure upon impact. The Balloon Sat, with subsystems mass simulated as described above, will be tossed down 2 flights of stairs, at a height of two stories. The Stair Test was conducted a total of three times on After the third toss, the structure of the box suffered minimal dents to its edges and moderate damage to its corners, as expected for form core. Upon analysis, it was resolved to reinforce the edges housing nearby equipment, particularly the two HOBO loggers, with additional support beams built of form core. It was also resolved that the structure used in the freefall and stair test will also be put through the whip test. Since the design for the structure has survived both tests, a new box will be constructed in the same manner, and the current structure will remain a prototype for testing. Whip Test: To simulate the substantial forces applied to the rope-rigging device on the balloon sat, a testing rope will be attached to the rope-balloon sat interface, and the balloon sat will be swung around as fast as possible to ensure the integrity of the top and bottom panels are not significantly compromised. The test will also allow us to observe how the structure reacts to such forces, and changes to the structure will be made accordingly. Page 12 of 16

13 The Whip Test was administered on 3/23/06. After going through some rigorous jolts and whips on the string our structure also underwent some additional collisions against rigid structures. The mass simulations remained in place throughout the test and our box held completely together throughout the test with only a minor split on one of the edges. A tube and washer apparatus were also constructed to help keep the structure secured on the rope and to prevent knots from being pulled through the structure. Our design proved to be successful and will be used on the final structure. Cold Test: The equipment must be tested to run at temperatures approaching -60 C. After installing all of the equipment inside the structure, all switches will be turned on, allowing all subsystems to make a complete run. The heating array must provide sufficient enough heat to keep the internal temperature above 0 C, and will therefore be the primary subsystem tested. The cold test was run on 4/9/06. For the test, the entire functional satellite was placed in a sealed Styrofoam cooler along with five pounds of crushed dry ice placed underneath it. The test was run for the full length of the flight time.upon analyzing the results, it was determined that all the HOBOs were still collecting data up until the time that they were connected to the PC. In addition, the HOBOs recorded over the data from the cold test, and thus no results were obtained. A second cold was run on 4/13/06 after this software error was corrected. The data was offloaded successfully (Fig ). Results show that the internal temperature of the satellite stayed roughly above 0 C for the duration of the mission. The external temperature probe recorded temperatures that did not seem to be valid. It was reasoned that taping the external temperature probe to the outside of the box may have had some adverse effects on the reading. It was discovered earlier that the batteries for the camera timing circuit as well as the two-channel HOBO s batteries were low on power and were not functional during the first cold test. It was also discovered that one of the four voltmeters was not functioning. These components have been examined, repaired and retried in the second cold test. They proved to be functioning. Page 13 of 16

14 Cold Test 2 Results Cold Test Results- The figure above shows the results from the second Cold Test. In the above key, Temperature ( C) c:^3 shows the internal temperature of the heated compartment of the satellite in Celsius. The External Temperature probe is shown by Temperature ( C) c:^1 in degrees Celsius. Battery Control Test: The experimental batteries must be given a dry run on the ground, at room temperature to test how quickly the resistors drain the batteries. The resistors will be of sufficient magnitude to drain the batteries in the course of 2 hours. This test is a control test for our experiment. The battery control test proved that the resistors do an adequate job of running down the batteries in the desired amount of time. We found, however, that the heat emitted from the four resistors could potentially yield inaccurate data by heating the batteries themselves. To solve this problem, we rearranged the circuit so that the resistors located inside the heated compartment of the satellite, keeping the heat from the resistors from the batteries. A second run will be conducted on 3/18/06. Circuitry and Battery Compatibility: The circuits will be tested with the voltmeters and HOBO s to ensure this complex interface is connected properly; that is, the HOBOs are reading information from the voltmeters correctly, and the voltmeters are correctly interfaced into the circuit. This test was run on 4/9/06, before the Cold Test. It was at this time that we found one of the four voltmeters was nonfunctional. We have replaced this voltmeter and reran the cold test with it running inside the satellite. It did take data during this time, which included both the inside and outside temperatures. Page 14 of 16

15 This shows us that all of our components in the circuitry are working together accurately. Camera and Timing Circuitry: The camera-timing circuit system will be given an entire dry run to ensure the maximum amount of in-flight pictures taken over the ascent time. We have been troubleshooting and calibrating the camera-system s functionality at almost every meeting since 3/9/06. The timing circuit has been calibrated to take photos on only the ascent time interval, taking pictures every 3.5 minutes. On 4/9/06 the camera system was found to be nonfunctional prior to the administration of the Cold Test but has since been fixed and is now fully functional. Although it was presumed that there was a problem with the timing circuit, the problem was found to be due to dead timing circuit batteries. The batteries have since been replaced and the circuit is now functioning properly. HOBO Memory Capacity: To ensure that some of the data isn t lost or erased during flight, the HOBO software must be calibrated to sample data at a sufficient set of time intervals to collect the most data over the entire time span of the flight. The two-channel HOBO would not properly connect to the computer program and we were unable to tell it was recording data. Upon examination it was determined that the HOBO s battery was dead. The battery has since been replaced and the HOBO s functionality was verified during the second cold test. It displayed data of both the inside and outside temperatures. 6.0 Expected Results We will obtain several clear pictures of the Earth s horizon as well as obtain the inside and outside temperatures. As for the experiment, we will have recorded the voltage output of the two tested battery types as a function of time. Post flight analysis of the data will reveal a relation between the voltage of each battery type over time, approximate altitude and external temperature. This data will be compared to a control run at room temperature and normal atmospheric pressure. This wealth of information will be extremely beneficial to future Space Grant and Gateway to Space missions. We expect the Nickel Metal Hydride batteries to out-perform the Alkaline batteries significantly at the peak of the flight. As such, we also predict that the voltage output of all the batteries will steadily decrease as the surrounding temperature drops to around -60 C. 7.0 Launch and Recovery The launch will take place on April 22 nd, 2006 at Windsor, Colorado. Teams will leave Boulder at 5:15am to arrive in Windsor, ready for launch by 7:00am. To ensure smooth operations of the payload, one member, Paul Joos, will hold the spacecraft while the balloon is released and, as gently as possible, release the payload as it ascends to the sky. Page 15 of 16

16 Before launch, all external switches controlling the heating system, camera timer, and circuits will be activated. Kristina Wang will be responsible for this task. Eric Payton will provide the computer and data analysis software for after-flight measurements. Nathan Billington and Heather Houlton will organize the team during the events of launch day, as well as provide transportation for retrieval. All members of HKP Systems will be present for retrieval. Kyllie Pobar is responsible for the visual documentation of the launch, as well as safety. It will take the BallonSat about 90 minutes to reach the peak altitude (where the balloon ruptures), and 45 minutes for the system to descend back down to Earth. To help reduce impact from falling to Earth, the balloon is equipped with a moderately sized parachute. The 1200 gram latex balloon will be filled with helium gas. With a tracking device (GPS) attached to the end of the rope connecting all of the payloads, the teams will be able to recover the satellites and retrieve data. Nathan and Heather will drive separate vehicles to the landing site, with Kristina and Kyllie navigating the respective cars. Eric and Paul will recover the payload, and all members will fully participate in the post-flight data analysis. Page 16 of 16