The  ESA-­‐SSA  programme:  the  NEO  and  SST  segments  

Fabrizio  Bernardi  

The  ESA-­‐SSA  Programme  

•  SSA  stands  for  Space  Situa9onal  Awareness  •  “The  objec<ve  of  the  Space  Situa<onal  Awareness  (SSA)  ini<a<ve  is  

to  support  the  European  independent  u<lisa<on  of  and  access  to  space  for  research  or  services,  through  providing  <mely  and  quality  data,  informa<on,  services  and  knowledge  regarding  the  environment,  the  threats  and  the  sustainable  exploita<on  of  the  outer  space.”  

From the SSA Programme Declaration, ESA/C/SSA-PP(2008)2 Translated: We will provide a service to inform the customers

(governments, disaster management, scientists, the public/press…) about the situation of natural and artificial objects in space. This will allow us to better protect our satellites and our planet.

Where  SSA  is  in  the  ESA  plan  

Mandatory  Op<onal  

Science   General  Studies  Programme  (GSP)   Microgravity  

research  

Interna<onal  Space  Sta<on  

Telecommu-­‐nica<ons  Earth  Observa<on  

Space  Situa<onal  Awareness  All others…

studies on future projects, technology research, shared technical investments, information systems and training programmes

Pay based on Gross Domestic Product (GDP)

Pay based on interest

(From: http://www.esa.int/spaceinimages/Images/2015/01/ESA_Budget_2015_by_domain)

SSA  phases  

–  Preparatory phase (2009 – 2012) approved at ESA’s council meeting on ministerial level in Nov 2008 (50 M€) as an optional programme

–  After confirmation at ESA’s council meeting on ministerial level in Nov 2012: Phase – 46 M€

Preparatory Phase 2009 - 2012

Phase 2 2013 - 2016

Operational Phase 2017 - ???

time

SSA  segments  

•  The  SSA  programme  is  divided  into  three  segments:  

Space  Situa<onal  Awareness  

Space Weather segment Surveillance and Tracking

segment (man-made objects) Near-Earth object

segment

SSA  in  the  ESA  framework  

Director General

ESA SSA Core Team

ESA Technical Staff

Programme Board

advises

directs

directs

supports

report

Director of HSO

directs

User Group

Contractors (Industry, institutes)

HSO  =  Directorate  of  Human  Spaceflight  and  Opera<ons  

Advisory Group

for D/HSO

advises

ESA-­‐SSA  core  team  and  management  

•  Director of the Human Spaceflight and Operations directorate (HSO): Thomas Reiter

•  ESA Core Team –  Programme Manager SSA: Nicolas

Bobrinsky –  SSA-SWE Segment Manager: Juha-

Pekka Luntama (‘Jussi’) –  SSA-NEO Segment Managers:

Detlef Koschny, Gerhard Drolshagen

–  SSA-SST Segment Manager: Emmet Fletcher

–  Ground Segment Manager: Gian Maria Pinna

–  Public Relations: Daniel Scuka –  Project Controller: Andreas

Ottenbacher

TR NB

JPL

DVK

GD

EF GMP

DS AO

SSA  yearly  procurement  

Segment   2013   2014   2015  

SW   12260k€   2650k€   2420k€  

NEO   2320k€   8500k€   720k€  

SST   2050k€   1300k€   510k€  

COMMON   3900k€   700k€   640k€  

NEOs:  What  was  there  before  2008  

•  NEOs  surveys:  mostly  American,  they  had  mandate  from  the  US  congress  to  discover  at  least  90%  of  killer  asteroids  within  2008  (D>1km,1998),  extended  since  2005  to  D>140m  un<l  2020  

•  USA  invested  a  lot  of  resources  for  the  NEO  problem:  –  Ini<ally  4  M$/year  –  Now  20M$/year  and  increasing  –  Several  American  NEOs  surveys  operated  since  early  1990s:  

•  Spacewatch,  NEAT,  LINEAR,  LONEOS,  CSS  –  Catalina,  Pan-­‐STARRS  –  They  discovered  most  of  the  more  than  12,000  NEOs  discovered  so  far  

(but  also  most  of  the  550,000  asteroids:  MBs,  Trojans,  KBOs…)  •  Europe  and  the  rest  of  the  world  did  quite  lille  for  the  surveying  

ac<vi<es:  –  Few  NEOs  surveys  and  with  lille  resources  

NEOs:  What  was  there  before  2008  

•  NEODyS:  Near  Earth  Objects  Dynamic  Site  à  performs  Impact  Monitoring  ac<vi<es  on  a  daily  basis  since  1999  hlp://newton.dm.unipi.it/neodys2.  This  is  in  Pisa  (Univ.  of  Pisa,  prof.  Andrea  Milani)          The  other  similar  service  in  the  world  is  Sentry  @JPL-­‐NASA  

•  EARN  DB:  Database  of  physical  proper<es  of  NEOs,  hosted  by  DLR  

•  Europe  did  a  lot  of  work  for  the  physical  characteriza9on  of  NEOs  (spectroscopy,  photometry  and  light  curves,  polarimetry  …)    

•  Don  Quijote  phase  A  study:  performed  early  2000  for  ESA,  for  a  deflec<on  experiment  mission  

NEOs:  SSA  program  purposes  

•  Federate  exis<ng  assets  •  Provide  surveying  and  follow-­‐up  capabili<es  •  Be  an  authorita<ve    en<ty  providing  informa<on  to:  

–  Decision  makers  –  Scien<sts    –  General  public  

•  Provide  services:  –  Impact  monitoring  –  Orbits  DB  –  Physical  parameters  DB  

A two-tier approach  

Exis<ng  assets  

Mission  requirements  

User  requirements  

System  requirements  

Precursor  system  

Final  system  

Top-down

Bottom-up

SSA-­‐NEO  Development  approach  

Customer Requirements

System requirements Architecture

Precursor Service

Agreements w/ data centres

Agreements w/ telescopes

2010 Definition of final service

Studies related to SSA paid by other ESA programmes

TIME

Policy, interfaces to other related

activities (UN…)

2011 2012-14

SSA-­‐NEO  setup  -­‐  context  

SSA-­‐NEO  situa<on  and  major  assets  

•  The  NEO  Coordina9on  Centre:  –  Is  actually  the  PRECURSOR  SERVICE  that  federates  several  exis<ng  European  Assets:  NEODyS/AstDyS,  EARN,  Priority  List  

–  Located  in  ESRIN,  Frasca<,  Italy,  near  Rome  –  The  personnel  allocated:  

•  Two  Front  Desk  Operators  (Micheli  &  Borgia)  •  ESA  staff:  Koschny  and  Drolshagen  à  NEO  managers  •  Scien<fic  coordina<on  and  consultancy:  Perozzi  (DEIMOS),  myself  (SpaceDyS),  Milani  (UniPi),  Valsecchi  (IASF-­‐INAF)  and  others  

SSA-­‐NEO  situa<on  and  major  assets  

•  The  NEO  Coordina9on  Centre:  –  Provides:  

•  Web  portal  hlp://neo.ssa.esa.int    –  NEODyS:  NEO  orbits  and  Impact  Risk  tables  –  AstDyS:  all  numbered  and  mul<-­‐opp  asteroids  orbits  –  Comets  orbits  –  EARN  data  for  NEO  physical  proper<es  –  DB  query  –  Image  DB  (OGS  and  La  Sagra)  –  Close  approaches  –  Priority  List  –  Orbit  visualizer  

•  Interface  with  decision  makers  (ESA,  ONU,  governments,…)  •  NEO  follow-­‐up  ac<vi<es  (ESA-­‐OGS,  VLT,  BLT,  Faulkes  …)  •  Coordina<on  of  NEO  observa<ons  between  astronomers  and  amateurs  •  Monthly  newslelers  •  Outreach  and  informa<on  (mass  media,  schools,  …)  

SSA-­‐NEO  situa<on  and  major  assets  

•  The  Fly-­‐Eye  telescope:  –  A  new  telescope  design  developed  in  Europe  by  CGS-­‐OHB  (Italy)  –  The  approach  is  different  from  the  American  surveys:  

•  Search  for  IMMINENT  IMPACTORS,  that  is  small  asteroids,  10-­‐200  m  in  diameter  range,  which  are  going  to  collide  within  few  days  or  weeks.  (US  surveys  look  in  general  for  events  occurring  in  the  next  decades)  

•  Need  wide  field  of  view  •  Goal  is  to  cover  all  the  visible  sky  from  ground  each  night!  

Fly-­‐Eye  Wide  Survey  

• Wide   survey   observes   the   full  visible   sky   from   one   sta<on  down  to  mag.  21.5  

• Having   at   least   4   or   5   sta<ons  spread  both  in  la<tude  (in  both  hemispheres)   and   longitudes,  allows   to   cover   all   the   visible  sky   from   ground   except   near  the   Sun,   the   Moon   and   the  galac<c   plane   more   than   four  <mes  a  night    

Earth  

Wide  Survey  

Deep  Survey  

•  Low  weather  correla9on  !  survey  system  capable  to  observe  many  nights  a  year  

The  Fly-­‐Eye  parameters  

FoV° 6.7°x6.7° (>44 sq. deg.)

Class Aperture Diameter 1 meter

Pixel Size 15 µm

Pixel Resolution 1.5’’ (>80% Encircled Energy in 1” radius)

Readout timeframe 3-5 s

Time accuracy for image acquisition

~ 10-3 s

A  Wide  Survey  strategy  imposes  to  observe  twice  in  one  night  ALL  the  visible  Sky  from  one  sta9on  down  to  Vmag.  =  21.5,  thus  an  extremely  large  FoV  is  required    (>44  sq.  deg.),  joined  to  1  meter  class  telescope  and  exposure  9me  of  about  40s.      To  obtain  a  good  sampling  of  typical  CCD  pixel  size,  a  fast  op9cs  architecture  is  needed    (F/#  <2)  

The  Fly-­‐EyE  optomechanical  structure  

Fly-­‐Eye  Op9cal  Architecture  

The   Fly-­‐Eye   Telescope   is   equivalent   to   16   one  meter   class   telescopes   sharing   the   same  primary  mirror.    Light   arriving   from   the   same   direc9on   is   imaged   in   a   single   pixel   therefore   each   pixel  collects  the  light  coming  from  the  whole  primary  mirror  surface  (one  meter  diameter  class)    

 

The  FoV  is  decomposed  in  16  sub  FoVs,  each  one  exploi9ng  the  full  primary  mirror  aperture    (from  different  direc9ons),  thus  allowing  reduced  op9cs  size  and  complexity  

The  Fly-­‐Eye  architecture  

•    The   Fly-­‐Eye   Telescope  detailed   architecture   can   be  d e c ompo s e d   i n t o   t h e  following  subsystems:  

–  Primary  Mirror  –  Fly  Eye  Secondary  Op9cs  –  Equatorial  mount    –  Camera  Assembly  –  Telescope  Structure  –  The  telescope    is  about  

5,5  m  high  with  an  envelope  of    about  6  m  and  weight  of  25  tons  

Fly-­‐Eye  Secondary  Op9cs    Camera  Assembly    

Fly-­‐EyE  network  architecture    

•  Goal:  observe  all  the  visible  sky  on  ground  each  night  •  Need  telescopes  in  both  hemispheres  •  Need  at  least  two  telescopes  in  different  sites  for  each  

hemisphere  to  avoid  weather  correla<on  •  Need  follow-­‐up  capabili<es  •  Forbidden  regions:  

–  Near  Sun  (less  than  40  deg  in  solar  elonga<on)  –  Near  Moon  (depending  oh  phase)  –  Near  galac<c  plane  (less  than  15  deg  in  gal-­‐lat,  TBC)  to  avoid  crowded  fields  

Proposed  Fly-­‐Eye  architecture  for  NEOs  

•  4  F-­‐E  telescopes  for  survey:  2  in  the  northern  hemisphere,  2  in  the  southern  (beler  5)  

•  1  follow-­‐up  telescope  (near  equator?)  –  beler  2  •  Good  observing  sites:  high  eleva<on,  dry,  no  light  pollu<on  •  Possible  sites:  Canary  Island  (Spain),  Campo  Imperatore  

(Italy),  Cipro,  Chile,  South  Africa,  Australia,  …  •  Observed  sky  per  night  per  telescope:  ~8,000  sq.  degrees  –  

four  9mes!  •  Each  image  is  256  Mpixels  à  each  file  is  ½  Gb  •  Each  night  one  single  telescope  provides  350-­‐400  Gb  of  

images  

Consequences  of  the  F-­‐E  architecture  

•  Needs  local  (at  site)  capabili<es  for  image  processing  (through  internet  is  too  slow)  

•  Needs  a  Remote  Opera<on  Room  to  perform  remotely  the  telescope  opera<ons  and  coordinate  ac<vi<es  among  telescopes  

•  Needs  a  data  centre  to  perform  correla<on  and  orbit  determina<on  à  evolu<on  of  the  NEOCC?  

•  Each  year  such  a  system  would  roughly  produce  more  than  100  millions  astrometric  observa9ons  of  asteroids  (not  only  NEOs!)    –  Presently  there  are  120  millions  astrometric  observa<ons  for  ALL  telescopes  and  for  ALL  history  

Data  exploita<on  

•  Imminent  impactors:  need  reliable  methods  for  computa<on  of  a  possible  imminent  impact  with  very  few  observa<ons  (3-­‐4)  à  need  fast  computa<on  and  alert  

•  Huge  data  and  higher  precision  data  à  increase  the  impact  monitoring  horizon  (to  the  next  2-­‐3  centuries)  

•  More  data  to  compute  non-­‐grav.  effects,  such  as  the  Yarkovsky  effect,  rad.  pressure,  cometary  effects  (obviously,  only  for  comets)  …  à  beler  with  radar  observa<ons,  at  present  

•  Asteroid  families:  a  higher  sta<s<cs  allows  the  determina<on  of  more  and  more  families  à  Solar  System  dynamical  history  and  evolu<on,  families  ages    

•  Light  curves  with  sparse  data?  à  rota<onal  status  of  several  asteroids  

•  More  targets  for  space  missions  

SST:  the  past  in  Europe  

•  Strong  dependency  from  US  Space  Command  •  Na<onal  ini<a<ves  in  Europe,  lille  coordina<on  and  planning  •  Tracking  and  surveillance  instruments  allocated  for  SSA-­‐SST  were  a  few  •  Op<cal  sta<ons:  

–  Surveillance:  •  OLS  (E)        Loca9on:  Granada,  Spain  •  Starbrook  (UK)  &  S.  North  (UK)  Loca9on:  Troodos,  Cyprus  •  TFRM  (E)      Loca9on:  Lleida,  Spain  •  ZimSMART  (CH)      Loca9on:  Zimmerwald,  CH  

–  Tracking:  •  GRAZ  SLR  (A)      Loca9on:  Graz,  Austria  •  Matera  MLRO  (I)      Loca9on:  Matera,  Italy  •  OGS  (ESA)      Loca9on:  El  Teide,  Spain  •  Tarot  (F)  &  Tarot  S  (F)    Loca9on:  Calern,  France  /  La  Silla,  Chile  •  ZIMLAT  (CH)      Loca9on:  Zimmerwald,  CH  

SST:  Mo<va<ons  

•  It  is  es<mated  there  are  about  700,000  space  debris  poten<ally  dangerous  for  space  assets  (>  few  cm)  

•  Most  of  them  are  not  catalogued  yet  •  In  the  future  the  exploita<on  of  space  around  the  Earth  will  

increase  •  à  MAIN  MOTIVATION:  PROTECT  THE  INVESTMENT  •  In  fact  a  bullet  of  1-­‐2  cm  hiung  a  satellite  at  speed  of  several  

km/s  may  limit  the  func<onality  of  the  satellite  •  If  the  space  debris  is  bigger,  it  may  destroy  the  satellite  and  

create  further  sets  of  debris  •  Europe  needs  independence  (but  s<ll  cooperate  with  allies)  

ESA-­‐SST:  2013-­‐16  ac<vity  domains  

•  Evalua<on  of  the  enhancements  required  to  improve  the  systems  developed  in  the  SSA  Preparatory  Phase  

•  Development  of  SST  systems  •  Research  and  development  within  the  area  of  satellite  laser  

ranging  (SLR)  •  Research  and  development  within  the  areas  of  op<cal  

surveillance  •  Research  and  development  for  the  security  aspects  of  the  SST  

system  •  Enhancement  and  exploita<on  of  the  deployed  IT  

infrastructure  •  Technical  support  specific  to  SST  ac<vi<es  

Space  debris  distribu<on  

Density of objects as a function of altitude for three different size thresholds: objects with diameter larger than 1 mm, 1cm and 10 cm    

Low  Earth  Orbits  

 

LEO  is  by  far  the  most  crowded  zone  in  the  circumterrestrial  space    

Density  of  objects  with  diameter  larger  than  10  cm  in  LEO,  as    a  func<on  of  al<tude.  The  ver<cal  lines  mark  the  loca<on  of  the    three  known  accidental  collisions  happened  in  orbit    

The  possible  solu<on  

•  Have  a  full  independent  and  centralized  EU  SST  system  •  The  system  must  have:  

–  Survey  Sensors:  radar,  op<cal  –  Tracking  Sensors:  radar,  op<cal,  laser  ranging  –  Data  centre  for  processing  astrometric  data  –  Services:    

•  Catalogue    •  Orbit  determina<on  and  correla<on  •  Collision  warning  •  Fragmenta<on  detec<on  and  tracking  

Sensors  for  dynamical  regimes  

•  Problem  with  LEOs:  

–  The  radar  S/N  decreases  like  r4  !  the  higher  you  go  the  more  power  you  need  à  too  expensive  and  dangerous  

–  Op<cal  telescopes  sensi<vity  decreases  like  r2,  but  space  debris  very  low  are  also  too  fast  and  the  Earth  shadow  limit  the  visibility  of  space  debris    

•  There  is  a  transi<on  between  regions  observable  by  radar  and  observable  by  telescopes  –  1000-­‐1100  km  of  al<tude  of  perigee  –  Lower  the  costs,  but  need  technological  investment  

SST-­‐Survey  

•  Radar  à  1000-­‐1100  km  detect  and  track  Lower-­‐LEOs  •  Fly-­‐Eye  like  telescope  may  cover  the  Upper-­‐LEOs  from  1000  

km  and  above  •  Fly-­‐Eye  telescopes  and  other  exis<ng  EU  telescopes  may  

provide  surveying  and  tracking  capabili<es  for  MEOs,  HEOs  and  GEOs  

Space  debris  dynamics  challenge  

•  Sparse  data  à  new  methods  for  correla<on  and  OD  (several  works  from  Milani  and  Gronchi)  

•  Computa<onal  challenge  à  lot  of  data  to  process  within  a  short  <me  à  parallel  compu<ng  

•  Dynamical  model  à  high  harmonics  for  Earth,  rad.  pressure,  drag,  Earth  shadow  …  

The  Upper-­‐LEOs  challenge  

•  The  ESA-­‐SARA  study  demonstrated  the  possibility  to  use  the  F-­‐E  telescope  for  surveying  the  Upper-­‐LEOs  

•  Challenges:  –  The  telescope  must  be  fast,  VERY  FAST!  Image  processing  will  deal  with  long  trails,  several  hundreds  of  pixels  

–  Exposure  <me  of  1  s,  re-­‐poin<ng  and  read-­‐out  in  less  than  3-­‐4  s  –  Huge  quan<ty  of  images  à  they  are  processed  locally,  sent  only  astrometric  posi<on  to  data  centre  

–  Data  processing  for  correla<on  and  OD  must  deal  necessarily  with  sparse  data  (objects  re-­‐detected  few  orbits  later!)  

–  Correla<on  and  OD  of  mixed  data  (radar+op<cal)  –  Sensors  must  be  spread  over  the  world  à  geopoli<cal  issue  

Possible  SST  telescope  sites  

Possible  SST  telescope  sites  

l  Three  telescopes  per  sta<on  l  FoV  ~45  sq.  degrees  

STATION ID Geographic Coordinates

Latitude [deg] Longitude [deg] Height[m]

TEIDE (Spain) Z00 28° 18' 03.3'' N 16° 30' 42.5'' W 2393

HAO (FRance) Z01 18° 08' 45.0'' S 140° 52' 54.0'' W 6

FALKLAND ISLAND (UK) Z05 51° 42' 32.0'' S 57° 50' 27.0'' W 30

NEW NORCIA (Australia) Z08 31° 02' 54.0'' S 116° 11' 31.0'' E 245

MALARGUE (Argentina) Z09 35° 46' 24.0'' S 69° 23' 59.0'' W 1518

GRAN SASSO (Italia) Z10 42° 29' 60.0” N 13° 33' 04.0'' E 1448

PICO DE VARA, San Miguel Azzorre (Portogallo)

Z11 37° 47' 48.0'' N 25° 13' 10.0'' W 583

Major  differences  SST  and  NEO  

•  NEO  à  collabora9ve:  observa<ons  are  necessarily  shared  between  the  astronomers  and  even  amateurs  

•  SST  à  compe99ve:  there  are  military  implica<ons  

•  NEO  à  needs  very  good  observing  site:  high  eleva<on,  dry,  …  •  SST  à  the  driver  is  the  geographical  loca<on:    must  spread  

over  the  world,  must  be,  preferably  EU  land  

The  BIG  problem  of  SST  

•  The  future  of  the  SST  segment  within  ESA  is  quite  uncertain  •  Reasons:  

–  Deal  necessarily  with  classified  data  –  Military  implica<ons  à  going  under  EDA  (European  Defence  Agency)?  

–  No  common  agreement  between  EU  countries  (that’s  a  news!!)  –  In  this  period    a  possibility  is  coming  from  European  Commission  H2020  investment  for  the  cri<cal  infrastructure  security…  we’ll  see  

The  links  

Money  and  poli<cal  decisions  

Instruments  and  data  centres  

More  data  for  dynamicists!!!  

Conclusion,  synthesis  and  future    

•  SSA-­‐NEO  and  SST  programs  are  very  promising  for  the  ac<vi<es  of  dynamicists  for  the  next  decades  

•  New  challenges  to  deal  with:  efficient,  precise  and  robust  OD  algorithms  for  both  NEOs  and  SST  

•  NEOs:    –  Imminent  impactors:  determine  the  Impact  Probability  with  few  data  

–  Very  precise  orbits  à  Impact  Monitoring  dominated  by  non  grav.  Effects  à  extension  to  next  centuries  

–  Data  processing  of  huge  data  sets:  correla<on  and  OD  challenge  à  parallel  compu<ng    

Conclusion,  synthesis  and  future    

•  SSTs:    –  Sparse  data  correla<on  –  Data  processing  of  huge  data  sets:  correla<on  and  OD  challenge  

à  parallel  compu<ng  •  MAIN  UNKNOWN  FOR  BOTH  NEO  AND  SST  in  Europe:  

–  FUNDING!!!!  –  Phase  3  will  start  in  2017.  Research  EU  ministers  will  decide  late  2016  in  a  conference  

–  NEO  will  probably  con<nue  to  the  road  already  started  –  SST  depends  a  lot  on  poli<cal  and  strategic  (read  military)  issues