National Aeronautics and Space Administration Orbital Debris Quarterly News Volume 19, Issue 1 January 2015 International Space Station Performs Inside... Fourth and Fifth Debris Avoidance Iridium Anomalous Maneuvers of 2014 Debris Events 2 On 27 October 2014, the International Space was posed by mission-related debris (2001-066G, DRAGONS to Fly Station (ISS) performed a maneuver to avoid the SSN# 39372), from Yaogan 12, launched by the on the ISS 2 close approach of debris from the 2009 collision of People’s Republic of China. The debris is estimated UKIRT Extends OD Iridium 33 and Cosmos 2251. In this case, Cosmos to be approximately 14 cm in diameter. This PDAM Observations into the 2251 debris (International Designator 1993-036ACU, had the added benefit of obviating a pre-planned Infrared Regime 3 U.S. Strategic Command [USSTRATCOM] Space ISS orbit reboost to have been performed by the Korean Aerospace Surveillance Network [SSN] catalog number 34881) ATV-5 later that day. Research Institute was identified as passing within approximately 4 km The PDAM capability allows ground teams Joins IADC 4 of the ISS, with a time of closest approach (TCA) to implement a generic, 0.5 m/s debris avoidance of 20:13 UTC. The small fragment displays an maneuver as late as TCA – 3 hours, depending upon Fiftieth Anniversary average characteristic diameter of approximately continued on page 2 of First Intentional 8 cm. Fragmentation Event 5 The maneuver burn Solar Cycle Sensitivity was performed by the 6 Study of Breakup European Space Agency Events in LEO 6 (ESA) Automated Transfer Vehicle no. 5 (ATV-5), 5 Conference and Georges Lemaître. Ground Workshop Reports 8 teams commanded a pre- 4 Space Missions and determined debris avoidance Satellite Box Score 10 maneuver (PDAM) and the ATV-5 performed a 4-minute 3 thrust at 17:42 UTC, with a total Δv of 0.5 m/s, 2 sufficient to raise the ISS by 1 km and thereby avoid the conjunction. 1 The ATV-5 executed a second PDAM on 0 12 November 2014 at 12:20 UTC to eliminate 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 a repeating conjunction A publication of This figure depicts the occurrences of debris avoidance maneuvers since the launch concern, the TCA of of the first module, Zarya, in 1998. The reader is cautioned that the number of the NASA Orbital most concern being at maneuvers per year does not lend itself to a single, simple interpretation; rather, the Debris Program Office 14:40 UTC. The threat number depends upon Poisson statistical, environmental, and operational factors. Orbital Debris Quarterly News Avoidance Maneuvers continued from page 1 ISS configurations. In this case, the maneuver used, and provided redundancy to using either of 2014. would commence at TCA – 140 minutes the ISS Zvezda module’s onboard thrusters Note: The ATV-5 is named after ± 15 minutes. Mission analysts verify that or docked Russian Progress vehicles for ISS Professor Georges Lemaître (1894-1966), the the PDAM does not inadvertently increase maneuvers. The ATV-5, the heaviest Ariane 5 Belgian physicist regarded as the father of the collision risk subsequent to a maneuver. The launch to date, is the last ESA supply vehicle. Big Bang theory. ♦ capability of performing an ATV PDAM was These maneuvers were the 20th and 21st introduced on ATV-4 Albert Einstein but not overall since 1999 and the fourth and fifth Iridium Anomalous Debris Events The year 2014 saw two puzzling debris- Strategic Command [USSTRATCOM] Space in the figure, some of these pieces were created producing events involving Iridium satellites. Surveillance Network [SSN] catalog number with considerable delta-velocity – in one case Neither produced a large number of debris, 25106, launched 20 December 1997). On exceeding 80 meters per second. According but both illustrate how mysterious many of the 7 June 2014, this spacecraft produced to Iridium Communications Inc., the parent debris phenomena in Earth orbit still remain. 10 pieces of debris that are currently tracked spacecraft continued to function normally and The first event was a breakup of Iridium 47 and catalogued by the U.S. Joint Space did not show any obvious changes in its orbit at (International Designator 1997-082C, U.S. Operations Center (JSpOC). As can be seen the time of breakup. The second breakup was of Iridium 91 (2002-005A, #27372, launched 11 February 2002). On 30 November 2014, the spacecraft 1200 produced four pieces of debris that are currently tracked and catalogued by JSpOC. 1100 Like Iridium 47, the operators of the spacecraft report that the spacecraft continues to function normally, and did not show any obvious changes 1000 in its orbit at the breakup time. In contrast to the previous Iridium breakup, however, these 900 pieces were produced with minimal delta [km] velocity and remained in the vicinity to the parent spacecraft for some time. 800 Altitude Either or both of these events could have been due to collisions with small debris 700 – collisions that did not result in noticeable momentum transfer. The Iridium 91 event could have simply been a sloughing off of 600 insulation material that has been seen in other types of satellites before. The Iridium 47 event, 500 however, clearly was due to some sort of high- 97 98 99 100 101 102 103 104 105 energy event. In the absence of evidence of an Period [minutes] explosion on board the spacecraft, a collision with a piece of untracked debris is the most A Gabbard diagram of the Iridium 47 breakup. Hollow symbols indicate payload orbit. In this Gabbard likely culprit. ♦ diagram, red and blue symbols denote a given object's apogee and perigee altitudes, respectively. DRAGONS to Fly on the ISS On 28 October 2014, the International impact sensor designed to directly measure the observation techniques to measure the size, Space Station (ISS) Program approved ISS orbital debris environment for 2 to 3 years. speed, direction, time, and energy of small development of the Debris Resistive Acoustic Grid The sensor will have about 1 m2 of debris impacting the sensor. The front layer Orbital Navy-NASA Sensor (DRAGONS) as an detection area mounted at an external payload of DRAGONS is a thin film of Kapton with experiment to fly on the ISS, possibly as early as site facing the velocity vector to maximize October 2016. The DRAGONS is a calibrated detections. As shown in Figure 1, it combines continued on page 3 2 www.orbitaldebris.jsc.nasa.gov DRAGONS continued from page 2 acoustic sensors and a grid of resistive wires. energy in the collision. With energy (E) and future missions at higher altitudes where risks These acoustic sensors will measure the time velocity (v), we can solve for mass (m) in the from debris to spacecraft can be greater than at and location of a penetrating impact, while a equation: E = ½ m * v2. Finally, the density of the ISS altitude. change in resistance on the grid when lines are the object can be estimated if we assume that The decision by the ISS Program to fund broken will provide a size estimate of the hole. the object volume is about the same as a sphere and fly DRAGONS marks a major milestone The relationship between object size and hole with a diameter determined from the hole in the history of the project. The DRAGONS size will be determined by hypervelocity testing size. Density is an important feature of debris team includes the NASA Orbital Debris under controlled conditions at the White because an object made of steel (7.9 g/cc) will Program Office, the NASA Hypervelocity Sands Test Facility in New Mexico and at the do more damage than a similarly sized piece of Impact Technology group, the NASA/JSC University of Kent at Canterbury, UK. aluminum (2.8 g/cc). Engineering Directorate, Jacobs, the United Located 15 cm behind the first layer is The DRAGONS should be able to detect States Naval Academy, the Naval Research Lab, a second thin layer of Kapton with acoustic debris as small as 50 microns and will collect Virginia Tech, and the University of Kent. See sensors to measure the time and location of the statistics on objects below 1 mm, illustrated our previous article on DRAGONS in ODQN, second penetration. Velocity is determined by in Figure 2. Results from this experiment will vol. 16, issue 3, July 2012, pp. 2-3 <http:// dividing the distance travelled between the first update information previously obtained by orbitaldebris.jsc.nasa.gov/newsletter/pdfs/ and second impact points by the time it took to inspecting hardware returned from space by the ODQNv16i3.pdf>. ♦ travel that distance. An instrumented back layer Space Shuttle. This flight demonstration will will stop the debris and measure the amount of also prove the viability of the technology for Incoming MMOD Acoustic Sensors Impact time & location Resistive Grids Damage/Size Dual-layer Films Time of flight Backstop Impact Energy Figure 1. The DRAGONS will use observation techniques, acoustic sensors, and a grid of resistive Figure 2. A preliminary concept drawing of the sensor, which illustrates how debris as small as 50 microns wires to directly measure the ISS OD environment. will pass through. The ISS DRAGONS will collect statistics on objects below 1 mm. UKIRT Extends OD Observations into the Infrared Regime In 2014, NASA’s Orbital Debris Program premier astronomical sites due to its altitude, Using UKIRT’s five available instruments, Office (ODPO) gained access to the United exceptionally dry air (often 5-10% humidity or the ODPO’s spectral coverage extends into the Kingdom Infrared Telescope (UKIRT) for lower) and distance from light pollution.