DEVELOPMENT OF AN AUTONOMOUS HIGH ALTITUDE BALLOON CUTDOWN SYSTEM

1. DEVELOPMENT OF AN AUTONOMOUS HIGH ALTITUDE BALLOON CUTDOWN SYSTEM K. Ramus (kevinramus@vandals.uidaho.edu),K. Baird, C. Gonzalez, G. Wilson, W. Taresh, R. Riggs, G. Korbel, D. Atkinson, and the Idaho Near Space Engineering Team University of Idaho Abstract: Balloons are a simple and economical way to carry scientific instrumentation into the upper atmosphere and can provide a platform for atmospheric flight testing of prototype planetary mission instrumentation, reaching elevations up to and beyond 100,000 feet (30,000 m) on Earth. The University of Idaho Near Space Engineering program known as RISE (Research Involving Student Engineers) has now been launching balloons for seven years. Idaho RISE has a data acquisition system that measures atmospheric pressure and temperature as a function of altitude, and a redundant GPS tracking system that provides real time tracking of the balloon system through ascent, decent, and landing, allowing for a quick recovery of the descent package. A cutdown system has been developed by which payloads can be autonomously released based on timer, altitude, or if the balloon drifts outside of a preprogrammed latitude/longitude box. Working with NASA Ames Research Center, Idaho RISE is currently preparing for a flight of Snowflake, a miniature high-precision aerial delivery system developed by Dr. Yakimenko of the Naval Postgraduate School and Dr. Slegers of the University of Alabama at Huntsville to evaluate advanced control, communication and command concepts for autonomously guided parafoil-payload systems. To date, Snowflake has been successfully deployed over 120 times from altitudes of up to 10,000 feet. The goal of the Idaho RISE Snowflake experiments is to provide a platform to deploy Snowflake at and above 30,000 feet and investigate its performance in these conditions. The launches with Idaho entail the 3rd stage of a proposed ISS sample return capability currently under development (SPQR- Small Payload Quick Return) at Ames Research Center. Background: In the summer of 2010, Marc Murbach of NASA Ames and Oleg Yakimenko of the Naval Postgraduate School of Monterey, CA contacted the Near Space Engineering program at the University of Idaho with the opportunity to help him fly “Snowflake”, a GPS guided parafoil capable of landing at predefined coordinates. Before, Snowflake has only been dropped from helicopters, UAVs, and small planes from altitudes not exceeding 10,000 feet. Marc Murbach is interested in using Snowflake in support of the NASA Small Payload Quick Return (SPQR) system, so he wanted to continue development and test of the targeted return technology with higher altitudes tests. Idaho’s Near Space Engineering program has launched over 20 weather balloons, carrying equipment to 100,000 feet. The goal of the Snowflake flight is to carry Snowflake to an altitude of 50,000 feet, and release it from the balloon, so that it would be free to fall and steer itself in a westerly heading. Future tests will involve Snowflake aiming for a particular landing coordinates. In the April 2011 launch, Snowflake was cut away from 27,000 feet. Snowflake The Cut Away Capsule Design • The current cut down system consists of 3 subsystems. The Power Module distributes power from the battery. A status panel is affixed to the front, enabling the students to verify the status of the device before releasing the payload. The control module consists of a small microcontroller. The microcontroller currently used was the MSP430. The cut down module consisted of an electrically powered solenoid. A timer on the microcontroller would activate the solenoid. The solenoid would create a magnetic field, and quickly pull a plunger up. There are strings attached to the plunger. These strings hold up Snowflake. When the plunger is raised, the strings are forced to come off, releasing Snowflake. The string then falls away, and the parafoil is able to open. • Future Plans: • Add a GPS capability. A box of GPS coordinates will be defined, and cut away will occur when the balloon nears these boundaries. • Add an altimeter capability. Once the balloon reaches a certain altitude, the solenoid will be activated. • Add an uplink capability. From the ground, a command can be given to cut away. Cut away can then occur at any time. • Make it lighter. May move to a nichrome wire based cut down system. • The Idaho Rise team was responsible for creating the capsule that would house the following equipment: • Cut down system • Tracking equipment • Data logger recording • Pressure • internal temperature • external temperature • GPS coordinates (lat., long., and alt.) • 10 Hz sampling rate. • Still Cameras • Facing up and to the side • Pictures every 15 seconds • About Snowflake: • Developed by Dr. Yakimenko of the Naval Postgraduate School and Dr. Slegers of the University of Alabama at Huntsville as a means to precisely deliver a small package to predetermined landing coordinates. Adapted by Marc Murbach of NASA Ames for use in the SPQR system • It is a GPS guided parafoil system, capable of landing at a particular point, or heading in a certain direction. • How it works: • GPS system determines its location and heading with help from an IMU • The control board will then decide what direction to follow • Two servo motors can pull each side of the parafoil to steer the entire system. • Performance on This Flight: • Dropped Snowflake from 27,000 feet (Highest altitude that Snowflake has been dropped) • Initially the parafoil only partially inflated (Due to cut away string or lack of air) • Parafoil eventually fully inflated, and Snowflake steered due west, as desired. Snowflake’s Shadow upon landing Data Tracking SPQR Idea The data logger gathered pressure and temperature. This data shows some interesting milestones throughout the flight, such as launch, the cut away of Snowflake, the burst of the balloon, and landing. Also, an interesting change in ascent speed occurs, most likely due to a sudden change in drag coefficient. The upward facing camera on board was used to determine the diameter of the balloon throughout the flight. The Microtrak 8000FA is used to track the payloads. This uses a GPS receiver to determine its location. Then it can transmit its position at a given time interval. The position is broadcasted onto the APRS network. This network can place the positions onto the Internet. The tracking team also has radios capable of receiving packets, without having to rely on the APRS network. Marc Murbach has been developing the Small Payload Quick Return (SPQR) concept. The goal is to give astronauts the ability to put experiments or other items into a small payload. The payload can then be released from the International Space Station. The payload would slowly fall back to Earth and enter the atmosphere. After reentering, a system similar to Snowflake would then guide the payload to a specified landing point, where it could be easily recovered. The balloon diameter at ground level, then at 22,000 feet Acknowledgments The University of Idaho VAST team would like to acknowledge the support provided by Marc Murbach, Josh Benton, Kenny Boronowsky, and the NASA Ames SOAREX program, Oleg Yakimenko from the Naval Postgraduate School, and the NASA Idaho Space Grant Consortium. Summary Interested? The Rise class was responsible for developing a payload that had the capability carry Snowflake to a high altitude and release it. The Rise capsule and Snowflake were both recovered. Atmospheric data, pictures, and payload flight paths were all recovered Follow us on Twitter: @UIVAST Website: www.idahorise.com Email: kevinramus@vandals.uidaho.edu Univ. Idaho RISE Student Launch Team: O. Balemba, C. Birkinbine, C. Bond, J. Brubaker, B. Cheldelin, S. Goodwin, J. Henry, B. Kisling, I. Kooda, T. Lenberg, C. Li, J. Liddicoat, L. Litzko, S. Lynn, J. Postma, S. Suggs, S. Van Natter, J. Van Patten, K. Witkoe, M. Zarate