The www.orbitaldebris.jsc.nasa.gov Volume 8, Issue 3 July 2004 A publication of FUSE Satellite Releases Unexpected Debris In early June 2004 NASA’s Far Ultra-violet The NASA Orbital Spectroscopic Explorer (FUSE) spacecraft Debris Program Office (International Designator 1999-035A, US Satellite Number 25791) was the source of nine debris large at enough to be detected and tracked by the US Space Johnson Space Center Surveillance Network (SSN). The 1360-kg spacecraft Houston, TX, USA was launched into a nearly circular orbit near 750 km on 24 June 1999 and continues to perform well. Early on 6 June 2004 FUSE temporarily entered a safe mode which resulted in the closure and re-opening of its four main sensor doors. Analyses by SSN person- nel indicate that the new debris separated from FUSE INSIDE… at very low velocities about the time of the door closures. A preliminary assessment suggests that the nine FCC Issues New objects might be fragments of the multi-layer insula- OD Mitigation tion which covers the majority of the spacecraft. The Regulations ..............2 effects of long-term exposure to the space environ- ment can lead to such insulation becoming brittle and PINDROP - An Acous- susceptible to spacecraft movements or small particle tic Particle Impact impacts. If the new debris are pieces of insulation, Detector ....................3 then their orbital lifetimes might be considerably shorter than typical spacecraft, rocket bodies, and other debris at that altitude. Tracking data through Utilizing the Ultra- the end of June supports this hypothesis. The investi- Sensitive Goldstone gation into this anomalous event is continuing. ♦ FUSE spacecraft being prepared for launch. Radar for Orbital De- th bris Measurements ..5 Publication of the 13 Edition of History of On- Orbital Evolution of Orbit Satellite Fragmentations GEO Debris with Very The 13th edition of History of On-Orbit Satellite page format. The first page consists of information High Area-to-Mass Fragmentations, JSC-62530, has recently been such as the physical characteristics and orbital Ratios .........................6 published. This document details the 173 known parameters of the parent object prior to the breakup, breakups and 43 anomalous events of on-orbit objects breakup event epoch, altitude and location, and from the first known breakup in June 1961 through 31 assessed cause. A general summary of the event can Mitigating Orbital December 2003. This edition of the document be found under the Comments heading. Reference Debris via Space discusses low Earth orbit and geosynchronous orbit documents on the subject breakup or on breakups of Vehicle Disposals .....8 spatial density, in-orbit and decayed object analysis by satellites of same type are listed for some events. The country of origin, and a comprehensive categorization second page consists of a Gabbard diagram for the of breakups and debris by assessed cause, year, and debris cloud (if sufficient orbit element data were parent object type. Several color graphs and tables are available). Each anomalous event is described on one included to illustrate information related to these page, with basic information about the object and Visit the NASA topics. event. Gabbard diagrams are not included for anoma- A significant update from the 12th edition was the lous events because of the typically low debris count. Orbital Debris Program re-categorization of events due to aerodynamic effects The 13th edition is available for download in Office Website at or near the time of reentry. Because these Adobe PDF format on the NASA Orbital Debris “aerodynamic” events had no effect on the environ- Program Office website, www.orbitaldebris.jsc.nasa. at ment past the very near term, they are listed separately gov. The History of On-Orbit Satellite Fragmentations www.orbitaldebris. from events of other environmentally impacting has been published regularly since 1984. ♦ causes. jsc.nasa.gov Each fragmentation event is outlined in a two 1 The Orbital Debris Quarterly News NEWS FCC Issues New Orbital Debris Mitigation Regulations The Federal Communications Commis- edocs_public/attachmatch/FCC-04-130A1. reach the Earth’s surface and estimate the sion (FCC) adopted on 9 June 2004 an doc. probability of human casualty from the extensive new set of rules concerning the In an effort to solicit more specific surviving debris. mitigation of orbital debris. The FCC issued reentry risk information from license appli- The FCC Public Notice suggests that a notice of Proposed Rulemaking in 2002 and cants, the Federal Communications Commis- applicants might find useful reentry risk subsequently received comments from sion on 16 June 2004 issued a Public Notice assessment tools developed by the NASA industry on the proposed rules which covered (DA 04-1724, Report No. SPB-208) clarify- Orbital Debris Program Office. Debris the design, operation, and disposal of space- ing existing FCC regulations in this area. Assessment Software (DAS) permits a craft subject to licensing from the FCC. The Applicants must first state whether the simple, conservative evaluation of reentry new rules closely follow the US Government reentry will be controlled or uncontrolled. risk, is easy to use, and is available to the Orbital Debris Mitigation Standard Practices, For the former case, applicants must identify public via the NASA orbital debris website which were developed in 1997 and adopted the geographic region in which surviving (www.orbitaldebris.jsc.nasa.gov). For a in 2001. Applicants are encouraged, but not components are expected to strike the Earth more detailed, high fidelity risk assessment, required, to use the NASA safety standard on and measures to be taken to warn people who the Object Reentry Survival Assessment Tool orbital debris mitigation (NSS 1740.14) when are likely to be in the geographic region (ORSAT) is available, although the complex- assessing their debris mitigation plans and during the time of reentry. For cases in ity of this model requires operation by preparing those plans for submission to the which the reentry will be uncontrolled, the trained technical personnel. ♦ FCC. The full FCC Report and Order can be applicant must estimate the number, size, and found at http://hraunfoss.fcc.gov/ mass of components which are expected to Annual Meeting of the IADC The Inter-Agency Space Debris Coordi- presentations were given in the four perma- received from the Scientific and Technical nation Committee (IADC) held its annual nent working groups to address issues con- Subcommittee (STSC) of the United Nations’ meeting at Abano Terme, Italy, during 19-22 cerning the measurement, modeling, and Committee on the Peaceful Uses of Outer April 2004. Delegations from 10 of the 11 mitigation, through both technical and policy Space (COPUOS). The IADC guidelines IADC members were in attendance, repre- means, of orbital debris. One of the accom- were formally presented to the STSC in Feb- senting the national space agencies of the plishments of the meeting was the approval ruary 2003 and discussion of the guidelines United States, the Russian Federation, China, of the IADC Protection Manual which is de- continued at the STSC meeting in February Japan, India, France, Germany, Italy, and the voted to the effects of hypervelocity impacts 2004, where several inquiries and sugges- United Kingdom, as well as the European of small particles and which will soon be tions for the IADC arose. Space Agency. The IADC was established in available on the IADC public website (www. The next full meeting of the IADC will 1993 to promote the exchange of technical iadc-online.org). be held 21-22 April 2005 at the European information on orbital debris and to encour- The IADC Steering Group was also very Space Operations Center in Darmstadt, Ger- age its mitigation in the design and operation busy during the meeting, spending the major- many, immediately after the Fourth European of space systems. ity of its time considering comments on the Conference on Space Debris at the same lo- During the four-day meeting, dozens of IADC Space Debris Mitigation Guidelines cation during 18-20 April. ♦ PROJECT REVIEWS A Debris Avoidance Feasibility Study for Robotic Satellites J.L. FOSTER study. ver rate. Higher tasking improves the covari- Collision avoidance maneuvering is a Objects in low Earth orbits approxi- ance estimate and lowers maneuver rate. means of mitigating risk from tracked Earth mately 10 cm and larger in size are tracked The flux of tracked objects is small satellites, mainly orbital debris. Maneuver- by radar by the US Space Surveillance Net- compared with the flux of objects large ing, however, has associated costs and risks. work (SSN). From the tracking information, enough that vehicle shielding is ineffective An holistic approach to debris collision state vector and state vector covariances are but too small to be tracked. With annual col- avoidance maneuvering is required for a safe, determined for all tracked orbiting objects lision probabilities of between 10-4 and 10-7 effective process. A debris collision avoid- and conjunctions are predicted. Based on the for the relatively small robotic satellites and ance feasibility study was recently conducted conjunction predictions, debris avoidance the risks inherent in any space maneuver, any at Johnson Space Center. The orbital re- maneuvers may be performed for a satellite decision to perform debris avoidance maneu- gimes studied included satellites at 400 km of interest. From the debris flux experienced vers for robotic satellites requires careful altitude with orbital inclinations between 35° by a satellite and the distribution of debris analysis and thought. Since there is a debris and 55°, 550 km altitude near 57° inclination, covariances for conjuncting objects, risk re- avoidance system in place to support the ISS and Sun synchronous orbits near 700 km alti- duction, fractional residual risk (FRR), and and the Space Shuttle, the cost of setting up a tude. The probability-based approach devel- maneuver rate can be determined as a func- debris avoidance process is not a major fac- oped for the International Space Station (ISS) tion of a chosen maneuver threshold collision tor.