National Aeronautics and Space Administration Orbital Debris Quarterly News Volume 16, Issue 3 July 2012 Dr. John W. Lyver, IV, Retires as NASA Inside... Program Executive for Orbital Debris Status of Three Major Dr. John W. Lyver, IV, retired from NASA’s Debris Clouds 2 Office of Safety and Mission Assurance (OSMA) Development of at the end of June this year. John had served as DRAGONS – an NASA’s Program Executive for the Micrometeoroid MMOD Impact and Orbital Debris (MMOD) program since 2005. Sensor System 2 In this role, he coordinated MMOD requirements and the project elements, budget, and interfaces 15th Annual NASA/ with NASA spaceflight programs. He also served DoD OD Working as NASA’s Manager for Nuclear Flight Safety Group Meeting 3 Assurance and managed NASA’s documents and The First NASA Orbital standards developed by the NASA Safety and Debris Workshop 4 Mission Assurance Technical Authority. John began his career with the U.S. Navy, Coring the WFPC2 graduating from the U.S. Naval Academy with Dr. John Lyver (right) is presented with a signed picture by Radiator for Impact an Engineering-Physics degree in 1978. Always Wilson Harkins (left) and the OSMA staff in recognition of his years of service with NASA and the MMOD program. Trace Residue stretching his boundaries, he recently received his Assessment 4 Ph.D. in Computational Science and Informatics In his spare time, which he now has more of, Abstracts from the from George Mason University. John is a very active Boy Scout Leader and holds the NASA Orbital Debris Working at NASA was a dream of John’s from Silver Beaver Award, the Vigil Honor, and multiple Program Office 6 the time he watched John Glenn’s Mercury flight Woodbadge beads. orbit the Earth. He joined NASA after retiring from John remains a very strong advocate for the Meeting Report 7 the Navy and worked on the Space Station Freedom MMOD program and his contributions will be Space Missions and Project in Reston, VA. sorely missed. ♦ Satellite Box Score 8 New Version of DAS Now Available A minor revision of the Debris Assessment used in the assessment of reentry casualty risk Software (DAS) 2.0 has been released. DAS 2.0.2 (Requirement 4.7-1), has been revised to improve includes some code changes as well as an updated nomenclatures. Note that old (DAS 2.0.1) projects software installer and User’s Guide. The features of that use any of the 10 corrected materials will need DAS have not changed with this release. to be updated with the new material names. The two changes most apparent to the user Other important changes include improved will be the new software installer and the corrected collision risk assessments. A publication of materials list. The new installer (NSIS) is compatible DAS 2.0.2 also includes several minor changes. the NASA Orbital with current Microsoft Windows operating systems, The orbit propagation time-step, previously set to Debris Program Office both 32- and 64-bit versions. The materials list, continued on page 2 Orbital Debris Quarterly News New Version of DAS continued from page 1 different values in different computational software installation and removal procedures, nasa.gov/mitigate/das.html. modules, has been set to a single value of and to clearly state the assumptions behind the DAS users should discontinue using 2 days. The unused input “Retraction Year” has assessment of tethers. Lastly, the solar flux data version 2.0.1 and install the new version 2.0.2. been removed from the GUI for assessment file is updated to the version of 4 April 2012. By default, the new version will install over of Collision Hazards of Space Tethers A list of the changes is in the “Release Notes” the previous version, or users may remove the (Requirement 4.8-1). The software User’s file, which is installed with DAS and is available previous version using the Windows Control Guide has been updated to include the new on the DAS web page: http://orbitaldebris.jsc. Panel “Add/Remove Software” feature. ♦ Status of Three Major Debris Clouds The U.S. Space Surveillance Network 1 July a total of more than 5500 debris had been that the debris from Fengyun-1C and Cosmos continues to catalog debris from the two most officially cataloged with these breakups, 90% of 2251 now completely encircle the planet. Since prolific events in Earth orbit: the intentional which were still in orbit about the Earth. These Iridium 33 was in a nearly polar inclination destruction of the Chinese Fengyun-1C debris represent 36% of all objects residing in (86.4 degrees), the orbital planes of its debris spacecraft in January 2007 and the accidental or passing through low Earth orbit, i.e., less are taking longer to diverge as a result of lower collision of the Russian Cosmos 2251 and the than 2000 km altitude. differential precession rates. ♦ U.S. Iridium 33 spacecraft in February 2009. By The illustrations below clearly indicate Fengyun-1C debris orbits Cosmos 2251 debris orbits Iridium 33 debris orbits Development of DRAGONS – An MMOD Impact Detection Sensor System Due to the high impact speed in the low has been supporting the development of a acoustic sensors, to maximize information that Earth orbit (LEO) region, with an average of new particle impact detection system, Debris can be extracted from particle impacts. A basic 10 km/sec, orbital debris (OD) larger than Resistive/Acoustic Grid Orbital Navy Sensor RGS unit has dimensions of 25 cm by 25 cm. about 200 µm are a safety concern for human (DRAGONS), since 2007. The effort is led The surface consists of 75 µm-wide resistive space activities and robotic missions. Similar by the U.S. Naval Academy (USNA), with lines, lying in parallel and separated by 75 µm risks also come from small micrometeoroids. additional collaboration from the U.S. Naval gaps, on a 25 µm-thick Kapton thin film. Four To define the OD environment to cover the Research Laboratory (NRL), the University PVDF sensors are attached to the backside of entire spectrum of the population, different of Kent at Canterbury in Great Britain, and the thin film. A second Kapton layer, with observational approaches are needed. In-situ Virginia Tech (VT). another four PVDF sensors attached to the measurements are the best option to collect DRAGONS combines two different impact backside, is placed 10 cm below the first layer. data for particles a few millimeters and smaller. detection technologies – resistive grid sensors When a particle a few hundred micrometers or The NASA Orbital Debris Program Office (RGS) and polyvinylidene fluoride (PVDF) continued on page 3 2 www.orbitaldebris.jsc.nasa.gov DRAGONS continued from page 2 larger strikes the top layer, it will penetrate the speed and impact angle. at the USNA on 13 June. The PDR included thin film and sever some resistive lines. By The short-term goal of DRAGONS is to a project status overview by the Principal measuring the resistance increase of the layer, advance the Technology Readiness Level to 9 Investigator Professor A. Sadilek (USNA), the number of destroyed resistive lines and an and to demonstrate the system capabilities of an electronics system review by Professor C. estimate of the impacting particle’s size can be detecting and characterizing sub-millimeter Anderson (USNA), a system interface status determined. The PVDF acoustic sensors on the micrometeoroid and orbital debris (MMOD) by Professor R. Bruninga (USNA), an acoustic top film provide the impact timing and location impacts on the International Space Station. The system review by Dr. R. Corsaro (NRL), and information using the measured acoustic signal long-term goal is to deploy a large detection an RGS system review and hypervelocity arrival times at the four sensor locations. After area (>1 m2) DRAGONS to 700-1000 km impact testing at Kent by Dr. F. Giovane (VT). the particle hits the bottom film, the impact altitude to collect sufficient data for better In addition, Dr. P. Ballard from the DoD’s timing and impact location information on the environment definition of orbital debris in the Space Test Program (STP) also described a film are also provided by the acoustic sensors. 0.5-to-1-mm size regime. The DRAGONS potential STP flight opportunity to deploy The combination of acoustic data from the two project reached a major milestone when the and demonstrate a 0.5 m2 DRAGONS on the layers can then be used to estimate the impact Preliminary Design Review (PDR) was held International Space Station in 2014. ♦ 15th Annual NASA/DoD Orbital Debris Working Group Meeting The 15th meeting of the NASA/DoD slow the deployment of MCAT. length at human spaceflight altitudes. Orbital Debris Working Group (ODWG) was Dr. J.-C. Liou completed the NASA Mr. Tim Payne made two additional held on 17-18 April 2012. Although NASA’s presentations with three reports including status presentations; one on the status of a Windows Orbital Debris Program Office (ODPO) of the Debris Resistive/Acoustic Grid Orbital compatible version of SATRAK, and the was the official host of the meeting, most Navy Sensor (DRAGONS) collaboration with second on recommendations for a new satellite participation was accomplished virtually via the U.S. Naval Academy, the Mid-size Satellite catalog for the Joint Space Operations Center – telecon. The ODWG was formed based on Impact Test collaboration with the Air Force’s the Extrapolation SGP4, or eGP. recommendations by interagency panels, who Space and Missile Systems Center, and a brief Similar to the meeting format in 2011, reviewed U.S. Government orbital debris preview of the second day’s activities on Active the agenda on the second day was dedicated (OD) activities in the late 1980s and 1990s.