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Avalanche Risk Assessment Final Presentation
- 2. Mission Objectives ● The current approach to avalanche prediction, using meteorological data, is inaccurate because snow depth on mountains is very uneven. ● This mission will measure the snow depth and land slope at millions of points to more accurately predict avalanches. ● An avalanche only needs to form at one point before starting. ● Prevention from prediction
- 3. Why do we need better accuracy?
- 4. Why are spacecraft needed?
- 5. Mission Implementation ● Orbit description ● Three spacecraft for better coverage
- 8. Flight System ● Payload / Payload Accommodations ● Electrical ● Thermal ● Propulsion ● Attitude ● Telecommunications ● Navigation ● Data Handling ● Flight Software ● Structures
- 9. Payload Description ● Laser Altimeter System ●Sensor 1: Visible Light bounces off snow ●Sensor 2: Microwaves goes through snow and bounces off ground ●Difference in height of two sensors determines snow depth. ●Micro-Pulse Multi-Beam Approach ● Laser system fixed in satellite ● Turns off over zero-risk areas
- 10. Attitude Determination and Control ● Attitude Determination ● Rate Gyro ● Sun Sensor ● Star Tracker ● Attitude Control ● 3-axis Control Techniques ● Thruster Control ● Reaction Wheel Control
- 11. Telecommunications ● Omni-directional Antenna to prevent interference with sensor pointing. ● White Sands, New Mexico Ground Satellites Antenna Network ● Other Ground Stations could be added ● Transceiver frequency: 27GHz (Ka-band) ● Data Acquisition Rate: 150 kB/s or 1200 kbit/s ● Maximum estimated data per orbit: 231.5 MB ● Acquired by assuming constant data acquisition across Rocky Mountain and Andes Mountain ranges. ● Downlink Rate: 5 Mbps or 0.625 MB/s ● Determined with use of average downlink window of seven minutes ● Received EbNo: 12.13 dB
- 12. CAD Model
- 13. Mass Budget ● Overall mass <1200 kg ● Payload by far the most massive component ● Laser Altimeter 2 less massive than 1 due to parts overlap ● Fuel somewhat low due to direct orbit injection by launch vehicle
- 14. Launch Vehicle ● Need a site in USA with access to 55 degree inclination ● Cape Canaveral (CCAFS) ● Wallops Island (WFF) ● From launch vehicles that launch there, Minotaur IV and Delta II are in our size range ● ~1200 kg ● Minotaur IV is best fit ● Size and cost
- 15. Risk Identification and Mitigation 1. Launch Failure 2. Orbit Insertion Failure 3. Reaction Wheel Failure 4. Orbital Debris 5. Promptness/Response Time Likelihood 5 1 4 2 3 2 5 1 4,3 1 2 3 4 5 Severity
- 16. Cost/Benefit Analysis ● Cost (Fiscal Year 2016): ● $1,246,478,092 ± $147,838,485 (USCM8) ● With launch costs: $1.40 B ● 30% cost overrun: $1.77 B ● Prevents: ● Lives lost per year: 122 ● People affected per year: 2,401 ● Property damage: $27,844,000 per year ● Legal: ● Litigation: estimated $27,844,000 ● Court Settlement: undisclosed, estimated $250,000,000 ● Rescues, response: $1,000,000 ● Ski Resort Revenue: $6.9 billion per year in North America, estimated $20 billion globally; 1% closures ● Total: $506 million, 122 lives per year
- 17. Bibliography ● (2003, December). Retrieved April 18, 2016, from http://www.pbs.org/wgbh/nova/education/programs/2418_avalanch.html ● Annual Information Form for the Fiscal Year Ended September 30, 2015. (2015, December 11). Retrieved from http://www.whistlerblackcomb.com/~/media/Files/Investor-Relations/AIF-2015.ashx?la=en ● Avalanche - Data and statistics. (2009). Retrieved April 15, 2016, from http://www.preventionweb.net/english/hazards/statistics/?hid=67 ● Avalanche Danger Scale. (n.d.). Retrieved April 18, 2016, from https://utahavalanchecenter.org/avalanche-danger-scale ● Avalanche Problem Defintions. (2013). Retrieved April 18, 2016, from http://www.sierraavalanchecenter.org/avalanche-problems ● Kramer, H. J. (2015). ICESat-2. Retrieved April 18, 2016, from https://directory.eoportal.org/web/eoportal/satellite- missions/i/icesat-2 ● Orbital ATK. (n.d.). Minotaur Launch Vehicles. Retrieved April 10, 2016, from https://www.orbitalatk.com/flight-systems/space- launch-vehicles/minotaur/ ● Temper, B. (2014, November 12). 5 New Avalanche Statistics You Need To Know:. Retrieved April 15, 2016, from http://snowbrains.com/5-new-avalanche-statistics-need-know/ ● Thompson, D. (2012, February 7). No Business Like Snow Business: The Economics of Big Ski Resorts. Retrieved April 18, 2016, from http://www.theatlantic.com/business/archive/2012/02/no-business-like-snow-business-the-economics-of-big-ski-resorts/252180/ ● Wertz, J. R., Everett, D. F., & Puschell, J. J. (2011). Space Mission Engineering: The New SMAD. Hawthorne, CA: Microcosm Press. ● C, A. B. (1990). Snow Avalanche Hazards and Mitigation in the United States. Washington, D.C.: National Academy Press.
- 19. Backup Slides
- 20. System Engineering, Risks, and Mission Operations ● Driving requirements ● Technical Resources (Mass, Propellant, Power, Communications Budget + Data Volume) ● Mission Operations ● How and why did the team decide on these specifics? ● Budget, design and the types of the components
- 21. Flight Software ● Responsibilities: ● Operating System (OS) ● Navigation Data ● Laser Pointing / Attitude Determination ● Fault Detection ● State of Health ● Data Uplink/Downlink
- 23. Thermal ● Thermal Subsystem ● Why and How? ● Challenges ● Typical Spacecraft Design Temperatures ● Conduction and Radiation ● Thermal Radiators ● Structural panels ● IR radiation
- 25. Consumption Mode % of Orbit Subsystem Component Power Consumed (W) Safe (bare minimum needed to survive) 0 C&DH Processor 13 Propulsion Thruster 1 0 Thruster 2 0 AD&C Sun Sensor 0 Star Tracker 0 Rate Gyro 0 COMM Antenna 1.5 PAY Payload 0 Total 14.5 Collecting Data 0.35 C&DH Processor 13 Propulsion 5 N Thruster 112.53 22 N Thruster 0 Attitude Sun Sensor 3 Star Tracker 6.8 Rate Gyro 30 COMM Antenna 0 PAY Payload 550 Total 715.33 Not Collecting 0.6 C&DH Processor 13 Propulsion Thruster 1 0 Thruster 2 0 Attitude Sun Sensor 3 Star Tracker 6.8 Rate Gyro 30 COMM Antenna 0 PAY Payload 0 Total: 52.8 Transmitti ng (maximum instantane ous power usage) 0.05 C&DH Processor 13 Propulsion Thruster 1 112.53 * Thruster 2 0 Attitude Sun Sensor 3 Star Tracker 6.8 Rate Gyro 30 COMM Antenna 3 PAY Payload 550 Total: 718.33 with 20% margin Maximum average energy consumption 317.962 381.5544 Generation Phase Power Generated (W) % of Orbit Sunlight 607.667463 62.79% Eclipse 0 37.21% Solar Power Density 1368 W/m² Original cell efficiency 28.80% Inherent Degradation 68.00% 10 Year Degradation 64.77% End-of-life Power 173.524737 W/m² Area needed (m³) 3.501906837 Percentage 2.36% C&DH 15.67% Propulsion 0.00% Thermal 5.54% AD&C 0.42% Communications 76.57% Payload 0.00% Structures Total Power (W) 718.33
- 26. Management Plan ● Satellites will stay in safe mode until all three are launched ● Autonomous day-to-day operations ● Small team of data analysts ● Five operations crews ● Program Schedule ●Five years to launch ●3 units increases flight unit production time ●10 year lifetime
- 27. Link Budget
Editor's Notes
- Hello everyone, thank you for coming to our presentation. I’m Eric, and these are my colleagues, *everyone introduce themselves* We’re here today to talk about an issue that really doesn’t get the attention it deserves, and a way that issue can be fixed. That issue is avalanches. Breakdown: Intro-what is the problem? (1 min) Mission concept (1 min) Justification/architecture (2 min) Flight System (4 min) Payload (2 min) Cost/benefit (1 min) Risks (1 min)
- Current avalanche models estimate avalanche likelihood based off of snow depth, land slope, temperature, wind and other factors. However, they use weather models to estimate snow depth, which is a poor method because snow doesn’t fall evenly on mountains. Snow depth is uneven and unpredictable due to high wind speeds and steep surfaces. We plan to improve upon weather models by measuring the snow depth and land slope at millions of points on mountain ranges. Avalanches only need to start at one point. Once they start, they sweep up the snow under them. Therefore, using the total snowfall for a region is a bad approach, and having many discrete points of data is much better. Now you might say, great, you can predict avalanches, but how does that prevent any damage? Well, as it turns out, 90% of avalanches in which humans are affected are set off by human activity. What that means is that merely by detecting that an area is at risk, we can warn the authorities of that area, and they can close off the area until containment methods are employed. This way, potential damages can be completely avoided.
- I want to prove to you that we really do need an improvement. If you’ll look, only high and extreme risk situations are considered “not recommended.” This means that 87% of people who die in avalanches die when activity is “recommended.” This is the North American Public Danger Scale, the standard scale used.
- This is an issue that really needs a space mission to solve because aircraft miss the most crucial time. Each one of these logos on the y-axis represents a doubling of likelihood of an avalanche. With an aircraft, you’d have to wait until stormy conditions are 100% finished. By that time, people are already back on the mountain, and facing the highest risk. In addition, aircraft would need to fly over the entire world 24/7 to match our coverage, and wouldn’t be able to see steep angles from their low altitudes. Similar missions have unusable orbits (polar) End around 2:30 %%% Persistent time scale-weeks to months Less persistent time scale-hours to days
- 3 separate satellites in repeating grounds on LEO These lasers will measure snow depth and land slope. The data will be sent to the ground stations, where it will be run through an existing model to determine if there is any risk for an avalanche. If there is any risk, the system will send a warning to the authorities of the corresponding area. This will all be done autonomously.
- The payload will be a laser altimeter system. The design will be done through analogy of the ATLAS from ICESAT-2. There will be two different lasers to measure snow depth. One laser will send visible light to measure the height from the top of the snow. The other laser will send microwaves. The microwaves will penetrate the snow and measure the height from the top of the mountain surface itself. The time difference between the two signals to return to the satellite will determine the snow depth. Each laser will acquire data at a rate of 10 khz. The Micro-Pulse Multi-Beam Approach will split one laser into six beams. The six beams will then be split into pairs. The beams will sweep across the area of interest and collect data. The beams are put in pairs in order to improve the accuracy of measurements at each location. This will provide a clearer view of the land slope and land elevation. SSN data will determine the position at which the laser will point towards. To reduce power usage and data rate, lasers will be turned off when passing over irrelevant areas of the Earth. Such areas may include oceans, land without any mountains, or where population density is low. Reaction wheels will control the attitude of the spacecraft as well as the laser beams. The intial plan was to have servo motors control the laser beams. However, for the sake of simplifying the spacecraft and the fact that servo motors still require constant attitude changes for spacecraft stabilization, the servo motors were replaced.
- Here are the sensors we have chosen to determine the attitude: Rate gyros were chosen over other types of gyroscopes due to their fast response rate and relatively low cost. In this mission, we decided to implement the Sun sensor on the satellite due to the existence of the solar panels and maneuvering the satellite to the correct direction towards the sun. Star trackers were used to track one or more stars to derive three-axis attitude information, in order to provide the precise location of the satellite. The technique that was chosen to for the attitude control was called the 3-axis control techniques, which utilizes a total of 3 reaction wheels, each representing different axises. This technique allows the satellite to perform an orbital maneuver easier while providing higher accuracy in efficiency but are also more expensive and complex. The control (counter) torques to mitigate the effect of disturbances of the satellite comes from combinations of reaction wheels and thrusters. For the thrusters, the team has chosen a types of hydrazine monopropellant rocket engines designed by Aerojet Rocketdyne. The models chosen were 8 thrusters of 5 N class and 4 thrusters of 22 N class.
- This thing can talk!
- Box to hold laser heads and receiver Octagonal frame to hold other subsystems Solar panels at angle to be perpendicular to sun at 55 degree inclination orbit
- 1- Launch Failure: Each launch has a 90% chance of success. With three launches total, the chance of failure is at 27.1%. Mitigation: If one launch fails, descope for the other two satellites. If two launches fail, transfer one satellite to 180 degrees apart. 2- Orbit Injection Failure: Failure to correctly space out the satellites relative to each other (120 degrees apart). Mitigation: Account for more fuel for orbital maneuvers. 3- Reaction Wheel Failure: Attitude and momentum control are severely compromised. Mitigation: Use thrusters for attitude and momentum control until fuel runs out. 4- Orbital Debris: Orbital debris may interfere may with satellite operations. Any orbital debris that makes contact with the spacecraft may damage the spacecraft, making it inoperable. Mitigation: NASA keeps track of orbital debris. Use thrusters to change position whenever orbital debris gets close to the spacecraft. 5- Promptness: If data takes too long to be distributed to the consumer, then the mission is a failure. Mitigation: Autonomous computer system that will automatically downlink the data, perform necessary calculations and distribute information to consumer.
- Based off USCM8, we expect this project to cost $1.26 Billion, including launch costs. Because cost overruns are common in this industry, a 30% overrun has been accounted for, and would bring the total cost to $1.26 Billion Other: An avalanche cut off aid in Afghanistan (2012), 2.9 million without food Legal costs are extrapolated from typical case study inbook “Snow Avalanche Hazards and Mitigation in the United States” http://www.unocha.org/top-stories/all-stories/afghanistan-avalanches-severely-hamper-aid-delivery; Revenue is hard to find since most ski resorts are private. Same with closures. We believe these both to be conservative estimates. We assumed 1% of ski days are closed, but there are some runs that are closed for weeks or months on end. Seeing the amount of times resorts incorrectly judged that a mountain would be safe, it is believavble that they also unnecessarily close down sometimes. If we could allow them to stay open 2 or 3 more days a year, they could save hundreds of millions. As a private space company, this is a very profitable endeavour.
- System Management Software: Fault Detection Control System Software: Attitude Determination, Laser Pointing, Navigation Data Command and Data Handling: Data Uplink/Downlink, State of Health
- Radiators generate a ton of heat and we would have the heat pipes
- Power Budget
- Other: cut off aid in Afghanistan (2012), 2.9 million without food Legal costs are extrapolated from typical case study inbook “Snow Avalanche Hazards and Mitigation in the United States” http://www.unocha.org/top-stories/all-stories/afghanistan-avalanches-severely-hamper-aid-delivery; Revenue is hard to find since most ski resorts are private. Same with closures. We believe these both to be conservative estimates. We assumed 1% of ski days are closed, but there are some runs that are closed for weeks or months on end. Seeing the amount of times resorts incorrectly judged that a mountain would be safe, it is believavble that they also unnecessarily close down sometimes. If we could allow them to stay open 2 or 3 more days a year, they could save hundreds of millions. As a private space company, this is a very profitable endeavour.