CRC-SEM a New Horizon of Australian Space Tracking Research

Transcription

1 CRC-SEM a New Horizon of Australian Space Tracking Research Professor Kefei Zhang School of Mathematical and Geospatial Sciences RMIT University, Australia 1 st workshop on Laser Solutions for Orbital Space Debris, Paris 2015

2 CRC-SEM Australian Cooporative Research Centre Scheme To enhance Australia's industrial, commercial and economic growth through the development of sustained, user-driven, cooperative public-private research centres. Encourage and built upon long-term collaborations among government, universities and industries The participants leverage synergies from CRC programme started in 1990 and 60+ CRCs established international research efforts and embed links CRC for Space Environment Management to users for outcomes adoption and Also called Space Environment Research Centre (SERC) commercialisation Partnership Essential: RMIT University, EOS, ANU Other: Lockheed Martin Corp., Optus, National Inst. of Info and Comms Techn [NICT]/Japan Affiliates: NASA, ESA, Japanese Space Agency [JAXA] Funding - A$60M for 5 years (cash + in-kind) Website May-15 Kefei Zhang 2

3 Introduction 1. Background 2. The Problem 3. Research 4. Remote Manoeuvre 5. Summary 11-May-15 Kefei Zhang 3

4 What is space debris? All man-made, non-functional bodies Rocket bodies Fragmentation debris Break-up of satellites Deterioration products Mission related debris Refuse from human missions Objects released from spacecraft Deployment and operation Derelict spacecraft 11-May-15 Kefei Zhang 4

5 History of the debris environment Since the Sputnik launched in 1957 Approximately ~28,000 payloads, rocket bodies, and mission related objects have deployed via ~ 4,500 launches About 66% of launched mass has reentered the Earth s atmosphere 201 known break up events E.g. explosions, collisions, etc. Current environment 19,000+ objects >10 cm 500,000 objects >1 cm Tens of millions of objects <1 cm In-orbit mass: 5,900 tons Vanguard-1, the oldest known piece of space debris (launched in 1958) 11-May-15 Kefei Zhang 5

6 Space is getting polluted 11-May-15 Kefei Zhang 6

7 Space is getting polluted 11-May-15 Kefei Zhang 7

8 Space is getting polluted 11-May-15 Kefei Zhang 8

9 Space is getting polluted 11-May-15 Kefei Zhang 9

10 Space is getting polluted 11-May-15 Kefei Zhang 10

11 Space is getting polluted 11-May-15 Kefei Zhang 11

12 Space is getting polluted 11-May-15 Kefei Zhang 12

13 Introduction 1. Background 2. The Problem 3. Research 4. Remote Manoeuvre 5. Conclusion 11-May-15 Kefei Zhang 13

14 The Problem 3,000+ operational satellites in orbit around Earth Worth about $1 trillion and growing 500,000+ space debris objects, greater than 1 cm across, and tens of millions of smaller objects A collision between one piece of debris and a satellite could cause severe damage or destruction and creates more debris ISS had six+ undetected emergency evacuations in 2012/3 Space has been a very difficult environment dangerous, no way to control, delicate/fragile and expensive to reach Space may be unusable within years (Kessler syndrome) 11-May-15 Kefei Zhang 14

15 The Problem Large debris objects in Low Earth Orbit (LEO) Iridium-Cosmos collision Chinese ASAT Debris is now increasing through collisions in space 11-May-15 Kefei Zhang 15

16 Iridium 33 Cosmos 2251 Collision Analytical Graphics, Inc. (AGI) 11-May-15 Kefei Zhang 16

17 Chinese ASAT Test 11-May-15 Kefei Zhang 17

18 Collisional Cascading: The Kessler Syndrome Collisions become the dominant source of new objects! Collisional cascading NASA LEGEND Model Prediction 11-May-15 Kefei Zhang 18

19 Our dependence on space Modern societies depends on space capabilities for: Navigation Time Law Enforcement Weather monitoring Emergency and Rescue Communications Resource Management Border Protection Climate Change Defence Recognising this, Australian Government Policy defines the following single national goal in space: Achieve on-going, cost-effective access to the space capabilities on which we rely. The economic and social impact of a loss of access to space capabilities would be catastrophic 11-May-15 Kefei Zhang 19

20 Our dependence on space Modern societies now fundamentally depend on assured and secure access to space assets for MOST basic requirements Space debris presents a devastating societal threat and a significant commercial opportunity 11-May-15 Kefei Zhang 20

21 Kessler goes to Hollywood 11-May-15 Kefei Zhang 21

22 Introduction 1. Background 2. The Problem 3. Research 4. Remote Manoeuvre 5. Summary 11-May-15 Kefei Zhang 22

23 The Research Programs (RPs) This is a global problem, and much of the research required is already in progress but in programs not efficiently linked, or not linked at all Four research programs have been developed which will pull Key objectives are technology innovation, cuttingedge, critical mass, partner synergies, efficiency and affordability together strong, existing efforts from international and Australian participants to leverage synergies and logically develop critical mass to allow early demonstration of a solution to space debris. Research Program 1 (RP-I): Tracking Research Program 2 (RP-II): Orbits (Kefei Zhang) Research Program 3 (RP-III): Collisions Research Program 4 (RP-IV): Maneuver 11-May-15 Kefei Zhang 23

24 RP-I Tracking The RPs in a nutshell (1) Today about 5% of the 500,000 major space debris objects are monitored We will research accurate, low-cost opticaltracking sensors and management strategies which may enable affordable monitoring of 100% of the threat More accurate, lower cost sensors combined with improved orbit technology will reduce required RP-II Orbits infrastructure costs to facilitate affordable solutions Current technology requires daily tracking to maintain predictive capability aim is to reduce the need to look so often We will improve OP technology to extend the tracking interval to at least 2 days and reduce the future cost of debris tracking infrastructure CRC Space Laser tracking Facilities 11-May-15 Kefei Zhang 24

25 The RPs in a nutshell (2) RP-III Collisions We will improve collision avoidance prediction at least 10-fold This CRC breakthrough will make collision avoidance prediction useful for the first time RP-IV Manoeuvre We will develop a practical demonstration within 5 years, using Australian infrastructure and current research in precision telescopes and adaptive optics, to modify the orbits of space debris from Earth We can manoeuvre many satellites to avoid collisions, but we need to manoeuvre debris 11-May-15 Kefei Zhang 25

26 Research Program Relationships Tracking EOS Optus ANU NICT LMC Better Data = Better Predictions Tracking Tasking & scheduling Collisions EOS RMIT ESA Collision Predictions Better Predictions = More data Orbits RMIT NICT Optus Tracking Precision Propagation Manouver NASA LMC ANU EOS The whole is greater than the sum of parts we achieve critical mass 11-May-15 Kefei Zhang 26

27 RP-I Tracking Develop innovative techniques of active and passive object tracking to provide sufficient accuracy for OP and conjunction prediction 1.1 Active track for LEO Develop passive and active techniques to increase capacity, accuracy, size and range for space object tracking 1.2 Debris characterisation and object database Database of tracking data and signatures including brightness, light curve, spin rate, spectral and polarimetric details. The database will also allow us to monitor changes in time as objects age, aid identification of a target and correlation with previous or future tracks when tracking data becomes sparse High resolution imagery using adaptive optics to aid characterisation and identification of space objects. 1.3 Active track for GEO Higher power with AO to maintain energy concentration Adaptive optics astrometry using multiple laser guide stars to reduce PSD and improve angular resolution Develop two color laser guide star to allow determination of atmospheric tip tilt 11-May-15 Kefei Zhang 27

28 RP-II Orbits To predict future collisions between space objects, the OP that properly account for the variable space environment, e.g. the Earth s gravity field, atmospheric drag, solar and magnetic disturbances and other perturbing forces, are required Precise/Reliable Orbit Determination (POD/ROD) Will extend on current capabilities in debris OD/OP Robust techniques will be developed to maximise accuracy when only sparse data is available Introduction of geomagnetic disturbances into orbit prediction Geomagnetic storms can lead to lost satellites. Important in catalogue maintenance Establish a relationship between the volume and distribution of data with OD and OP performance Selected SVs (large objects) as targets of research for POD? 11-May-15 Kefei Zhang 28

29 RP-II Orbits Fast Orbit Propagation A semi-analytic orbit propagator suite will be developed Basically splits the problem into long and short term dynamics Trade-off between fast but inaccurate analytic method and slow but precise numerical method We will use a combination of perturbation techniques Method of multiple time-scales (i.e. multitiming) Poincare Lindstedt method (valid in limited cases) New algorithms and software will be developed the method of averaging is commonly used: Works well. Can improvements be made? Possible double-averaging required (not required in the method of multi-scale) Carry out a detailed order analysis with dimensionless governing equations An SGP4-like propagator will be developed 11-May-15 Kefei Zhang 29

30 RP-II Orbits Covariance Matrix Propagation Used in conjunction assessments When debris/satellite orbit state is propagated, the errors are not Gaussian (common assumption) Correct characterisation of the error from state propagation is needed for reliable collision assessments existing methods are exploring better statistical representations of this propagation error Our approach will use dynamic system theory Past true states will be used to parameterise the covariance matrix propagation into future states Specific debris propagation methods will be developed Emerging technology for SSA Square Kilometre Array (SKA)? 11-May-15 Kefei Zhang 30

31 RP-II Orbits Atmospheric Mass Density Modelling The largest restrictive factor in POD/POP in LEO is accurate atmospheric mass density information We will analyse highly accurate satellite laser ranging, LEO accelerometer measurement s and POD data and calibrate existing mass density models to achieve a reduction in mass density errors to 2% Improvements will be implemented in all other work packages Reliable orbit determination and prediction Reliable conjunction assessments Laser manoeuvre Involving satellite-based measurements in orbits accelerometers Radio occultation? Alleviation/assessment of solar and magnetic storms 11-May-15 Kefei Zhang 31

32 RP-III Collisions Develop techniques, algorithms and databases to predict and avoid potential collisions 3.1 Satellite object catalogue (SOC) A core function of the CRC will be to develop a specialised satellite object catalogue. 3.2 Conjunctions analysis and threat warning The CRC will develop a conjunction analysis capability system for all objects (all-on-all conjunction analysis) in the Satellite Object Catalogue and provide alerts to subscribers. The CRC conjunction system will also distribute priority tasking to sensors in the SOC network to provide increased tracking and updating for serious potential collision prospects. The conjunction analysis and sensor tasking feedback loop will be optimised to minimise the risk of a real collision, i.e. the more likely the collisions the more intensive the tasking and tracking. 11-May-15 Kefei Zhang 32

33 RP-III Collisions Conjunction analysis EOS propagation algorithms propagate all NORAD TLE objects in an all-on-all conjunction analysis. Currently takes 8 hours run time for 7 days analysis. New accelerator hardware and algorithms will reduce this to 1 hour runtime. Currently runs daily, but after upgrade will re-run every time new orbit data becomes available. Improvement of TLE quality 11-May-15 Kefei Zhang 33

34 Typical Results Primary Secondary Date Time Distance Relative Primary Secondary Primary Secondary Object Object (km) Velocity TLE Age TLE Age Object Object ID ID (km/s) (days) (days) Name Name /04/ :46: COSMOS 952 FENGYUN 1C DEB /04/2012 9:57: COSMOS 2251 DEB FENGYUN 1C DEB /04/ :07: COSMOS 1375 DEB FENGYUN 1C DEB /04/ :07: THOR AGENA D R/B FENGYUN 1C DEB /04/ :28: FENGYUN 1C DEB FENGYUN 1C DEB /04/2012 8:56: IRIDIUM 24 IRIDIUM 33 DEB /04/2012 5:40: IRIDIUM 47 FENGYUN 1C DEB /04/2012 3:04: KYOKKO 1 DEB COSMOS /04/2012 5:16: FENGYUN 1C DEB FENGYUN 1C DEB /04/2012 5:52: OPS 1294 (DMSP 5D-2 F7) FENGYUN 1C DEB /04/ :19: METEOR 2-5 DEB FENGYUN 1C DEB /04/ :29: HJ-1A COSMOS 2251 DEB /04/ :49: SL-8 R/B COSMOS 2251 DEB /04/ :27: COSMOS 2251 DEB CZ-2C DEB /04/2012 5:23: FENGYUN 1C DEB IRIDIUM 33 DEB /04/2012 8:57: THORAD AGENA D DEB CZ-2C DEB /04/2012 0:53: METEOR 1-5 FENGYUN 1C DEB /04/ :45: ORBCOMM FM 11 IRIDIUM 33 DEB /04/ :01: ARIANE 40 R/B COSMOS 2251 DEB /04/2012 4:32: SL-12 R/B(2) FENGYUN 1C DEB /04/2012 3:00: DELTA 1 R/B COSMOS 1275 DEB * /04/2012 0:39: COSMOS 2016 FENGYUN 1C DEB /04/ :20: FENGYUN 1C DEB FENGYUN 1C DEB /04/2012 3:05: FENGYUN 1C DEB COSMOS 2251 DEB /04/ :24: COSMOS 375 DEB COSMOS /04/ :07: SL-3 R/B FENGYUN 1C DEB /04/ :09: SL-8 R/B FENGYUN 1C DEB /04/ :13: CLEMENTINE COSMOS 2251 DEB /04/2012 0:34: SL-16 DEB FENGYUN 1C DEB /04/2012 2:04: FENGYUN 1C DEB IRIDIUM 33 DEB 11-May-15 Kefei Zhang /04/ :55: COSMOS 1275 DEB DELTA 1 DEB

35 Statistics of conjunction analyses Closest Approach Number of Occurrences < 5km 42,000 per week < 1km 3,000 per week < 500m 700 per week 5km is typical or NORAD position uncertainties 500m was the predicted miss distance for Iridium/Cosmos crash Conjunction report is sorted for objects of interest (e.g. intact spacecraft) and close approaches. Output directed to scheduler for laser tracking to update catalog with precision tracks for priority objects 11-May-15 Kefei Zhang 35

36 Introduction 1. Background 2. The Problem 3. Research 4. Remote Manoeuvre 5. Summary 11-May-15 Kefei Zhang 36

37 What Can We Do? Reliable debris orbit determination Radar tracking High accuracy tracking High accuracy catalogue Laser tracking Adaptive optics Laser manoeuvre Atmospheric mass density calibration Optical (CCD) Fast orbit propagation Reliable conjunction assessments 11-May-15 Kefei Zhang 37

38 Debris de-orbit There are lots of ideas around for debris de-orbit Balloons, drag sails, electrostatic tethers, rendezvous missions, laser ablation But none have demonstrated affordability $150M -$500M per object removed, plus technology issues None have an effect on current debris population We propose debris avoidance rather than removal Practical and affordable 11-May-15 Kefei Zhang 38

39 Collision avoidance vs removal Collision avoidance Two objects at orbital velocities (7.5 km/s) spend <100 µs in the same 3D space. If we can shift the point in time that one object reaches an intersection point by 100 µs (1m in along-track) a collision could be avoided. In reality it s a bit more complex than that because our predictions aren t as good as 100 µs (1m). Avoidance vs removal Avoidance reduces the rate at which collisions occur potentially stops collisions Avoidance may need to be repeated a number of times for the same targets It s a temporary solution, but it buys us time while more permanent (more costly solutions) are implemented. 11-May-15 Kefei Zhang 39

40 Photon pressure (nudging) Photons carry momentum which can be transferred to a target 11-May-15 Kefei Zhang 40

41 Can it fill a useful role/niche? Collision types Small on Small Common but not much damage Small on Large Common with significant damage Large on Large Rare but significant damage Realistically, photon pressure can only move (nudge) relatively small objects Demo system < 20 cm (in size) Full system ~ 50 cm (TBD) 11-May-15 Kefei Zhang 41

42 How much is enough? We are talking about using light pressure to manouver a space debris object. Photon pressure is weak, so we only want to make the smallest change necessary to have an effect So it comes to a balance between 1. how accurately we can measure the position and 2. how accurately we can propagate the orbit 3. how far is it practical to move an object using lasers from the ground 11-May-15 Kefei Zhang 42

43 Key technologies concerned Accurate laser tracking Adaptive optics to concentrate the energy High power laser and beam delivery system Demo system being developed at EOS Mt Stromlo debris tracking station. Adding AO Add 10kW laser 11-May-15 Kefei Zhang 43

44 Remote manoeuvre summary We think remote maneuver using photon pressure is feasible, practical and affordable We intend to prove that it can work within the next 5 years (CRC term, ) When successful, we will plan to build an operational network for collision avoidance 11-May-15 Kefei Zhang 44

45 Legal/international implications Is it a laser weapon? Requires near conjunction already so vey difficult to apply to a target of choice except coincidentally Same order as solar radiation pressure Only works on small (low mass objects), but not satellites Precision tracking and orbit propagation needed to ensure the object is not pushed into something else, but this is standard space navigation. 11-May-15 Kefei Zhang 45

46 Summary Introduced the recently awarded CRC-SEM/SERC Built upon ASPR success and further extended Access to space is critical to our way of life in modern societies, Australia in particular. In the next years we could lose our access to important orbit slots (Kessler Syndrome) Everybody loses if space becomes unusable Debris de-orbit is too expensive to be feasible (for now) Collision avoidance can stop the problem getting worse, and may even be a solution, at an affordable cost. A global problem needing global solutions Significant boost for Australian space tracking research 11-May-15 Kefei Zhang 46

47 Where are we now? Major milestones June lodged Feb announcement of outcomes July - SERC created ( Dec 2014 formal launch of CRC-SEM April 2015 NASA membership under way Significant training/employment/research opportunities Recruitments started at the end of 2014 Young, bright, committed, outstanding, Post-doctoral, PhD and Masters Upto 30 students scholarships Further information 11-May-15 Kefei Zhang 47

48 Acknowledgements Australian government Cooperative Research Centre for Space Environment Management (CRC-SEM) The Australian Space Environment ResearchCentre (SERC) Australia Research Council (ARC) Craig Smith EOS Jizhang Sang Wuhan University James Bennett RMIT/SERC 1 st workshop on Laser Solutions for Orbital Space Debris, Paris

49 Thank you Professor Kefei Zhang Director, Satellite Positioning for Atmosphere, Climate and Environment Research Centre School of Mathematical and GeoSpatial Sciences, RMIT University Tel: , 1 st workshop on Laser Solutions for Orbital Space Debris, Paris