The document discusses space debris and active debris removal techniques. It states that space debris poses a threat to satellites and future space activities. It then describes various active debris removal concepts and technologies that could be used to remove debris from low Earth orbit (LEO) and geosynchronous orbit (GEO), such as solar sails, drag augmentation devices, electrodynamic tethers, and laser systems. Challenges to implementing effective active debris removal include the technical difficulties and high costs associated with the technologies.

2. SPACE DEBRIS

3. THE PRESENTATION MAINLY STATES THE PRESENT SPACE
DEBRIS SITUATION AND DISCUSSES THE ACTIVE DEBRIS
REMOVAL TECHNIQUES.
1. INTRODUCTION TO SPACE DEBRIS
2. ACTIVE DEBRIS REMOVAL CONCEPT
3. ACTIVE DEBRIS REMOVAL TECHNIQUES
4. CHALLENGES IN INSTITUTING EFFECTIVE SPACE DEBRIS
REMOVAL

4. o Space debris also known as orbital debris, space junk or space waste, is the
collection of defunct objects in orbit around the Earth.
o This includes everything from spent rocket stages , old satellites , fragments
from disintegration , erosion and collision.
o Debris poses a growing threat to satellites and could prevent the use of valuable
orbits in the future.
o Many pieces of debris are too small to monitor but too large to shield satellites
against.

5. DISTRIBUTION OF CATALOGUED
OBJECTS IN SPACE .
CLOSE-UP OF THE LEO REGION
DISTRIBUTION OF CATALOGUED
OBJECTS IN SPACE .
GLOBAL VIEW

6. CATEGORISATION OF DEBRIS
6
❑ The source of space debris could be expired satellites, spent rocket
upper stages, fragments from explosions and collisions, paint flakes,
chunks of slag from solid rocket motors, remnants of old science
experiments and a variety of small particles.
❑ Three categories of space debris, depending on their size:
▪ Category I (<1cm)
• make significant damage to vulnerable parts of a satellite
▪ Category II (1-10 cm)
• seriously damage or destroy a satellite in a collision
▪ Category III (>10cm)
• destroy a satellite in a collision, can be tracked

7. SPACE SURVEILLANCE NETWORK (SSN) 7
⚫ Currently more than 15,000 objects are tracked and kept in
a catalog by SSN
⚫ Space debris number is much more than catalog
ESTIMATED AMOUNT OF ORBITAL DEBRIS BY
SIZE.
.
Debris Size 0.1-1cm 1-10cm >10cm
Total Number at all
altitudes
150 million 780,000 23,000
Debris in Low-Earth
Orbit
20 million 400,000 15,000

8. DISTRIBUTION OF LEO
8
The distribution of low earth orbit (LEO) debris as a function of altitude anddeclination
(Data from Space Situation Report of August 25th 2008)

9. GRAPHIC EVOLUTION OF TRACKABLE LEO ORBIT OBJECT 9
Graphic evolution of total trackable Low-Earth Obit (LEO) object population since 1994
The number of space debris increases very quickly:

10. COLLISION OF
IRIDIUM33 &
COSMOS2251
10
❑ In an unprecedented space collision, a commercial
communications satellite (IRIDIUM 33) and a defunct
Russian satellite (COSMOS 2251) impacted each other
on February 9th, 2009 above Northern Siberia, creating
a cloud of debris.
❑ Till now, over 1719 large fragments have been
observed.
IRIDIUM 33
Космос 2251

11. ACTIVE DEBRIS REMOVAL CONCEPT 11
The debris population, non-mitigation and ADR with no PMD 2020/5: Five objects removed annually beginning in 2020 2020/10:
Ten objects removed annually beginning in 2020 2020/20: Twenty objects removed annually beginning in 2020
ADR would be an effective way of stabilizing the space environment

12. ACTIVE DEBRIS REMOVAL TECHNIQUES 12
Removing debris from LEO can make the LEO environment safe for the future space activities.And
clearing GEO will keep the GEO orbit resources available.
Catalog I
(Size < 1cm)
Catalog II (Size
1cm~10cm)
Catalog III (Size >10cm)
LEO
orbit
Space-based Magnetic
Field Generator
Ground-/Air-
/Space-based
Laser
Drag AugmentationDevice
Magnetic Sail Momentum Tethers
160km-
2,000km
Sweeping/Retarding
Surface Electrodynamic Tethers
Space-based Laser Capture/Orbital Transfer Vehicle (Space Shutter)
GEO
orbit Solar Sail Momentum Tethers
About
35,000km
Capture/Orbital Transfer Vehicle (Using Net or
Tentacles )

13. ACTIVE DEBRIS REMOVAL TECHNIQUES
13
SOLAR SAIL
❖ AN OPTION FOR DISPOSAL OF OBJECTS IN
VERY HIGH ORBITS
❖ REQUIRE NO PROPELLANT OR ENGINES
❖ HARD TO DEPLOYMENT AND CONTROL
DRAG AUGMENTATION DEVICE
◆ COULD BE A BALLOON DEPLOY ON
SPACE DEBRIS SUCH AS USELESS
SATELLITES
◆ NO NEED TO MAINTAIN ANY
SPECIFIC ORIENTATION
◆ DIFFICULT TO CONTROL
SOLAR SAIL

14. 14
➢ NO NEGATIVE ATMOSPHERIC EFFECTS
➢ BE ABLE TO TRACK AND TARGET DEBRIS WITH A MUCH
LARGER FIELD OF VIEW
➢ FOCUS ON TARGETS FOR LONGER PERIODS OF TIME
➢ THE COST IS MUCH LARGER TO BUILD, LUNCH AND
OPERATE
➢ CAN BE A SPACE-BASED WEAPON SYSTEM
SPACE BASED LASER

15. 15
❑ The Institute of Aerospace Technology, Japan
Aerospace Exploration Agency (JAXA), is studying a
micro-satellite system for active space debris removal
in LEO. They named it Space Debris Micro Remover
(SDMR).
❑ SDMR use a small satellite to capture a space
object and de-orbit the object by the electro-dynamic
tether (EDT) technology.
PRINCIPLE OF ELECTRO-DYNAMIC TETHER

16. 16
❑ The Robotic Geostationary Orbit Restorer, ROGER project which started in 2002 by European
Space Agency (ESA), is a new concept for an in-orbit roving debris removal system.
❑ ROGER can be tasked to approach and capture a redundant or non- operational satellite in the
Geostationary (GEO) orbit and tow it into a parking or graveyard orbit(GYO).
❑ Different configurations of the ROGER spacecraft have been identified. These differ not only in the
basic satellite bus but mainly in the means used to "capture" a targeted satellite.
ROGER Spacecraft by the ASTRIUM team
▪ This kind of Roger throw-nets to capture its
target, and it has 20 nets.

17. 17
ROGER Spacecraft (QinetiQteam)
• It uses tentacles to capture targets.
• If there is an incapacitated GEO satellite in the orbit as a
target, the ROGER spacecraft will approach the
malfunctioning satellite with its boom and deploy octopus
grasping system.
• The satellite will be captured by the fingers and then
towed away into the GYO.

18. 18
• STARTING THE PROCESS OF ACTIVE DEBRIS REMOVAL
• ADR TECHNOLOGY REQUIRE SUBSTANTIAL TIME AND MONEY TO DEVELOP
AND DEPLOY (IT COSTS AROUND $10,000 PER KILOGRAM TO LUNCH
ANYTHING INTO ORBIT)
• A LACK OF CLEAR POLICY ON INTERNATIONAL LEVEL
• THE POSSIBILITY OF CHANGING SPACE DEBRIS REMOVAL SYSTEM INTO
ANOTHER SPACEDEBRIS

19. • The space agency says our SSA will first be for low-earth orbits or LEO which have remote-
sensing spacecraft. Under NETRA, or Network for space object Tracking and Analysis, the
ISRO plans to put up many observational facilities: connected radars, telescopes; data
processing units and a control centre. They can, among others, spot, track and catalogue
objects as small as 10 cm, up to a range of 3,400 km and equal to a space orbit of around
2,000 km.
• NETRA’s eventual goal is to capture the GEO, or geostationary orbit, scene at 36,000 km
where communication satellites operate
• Currently there are 15 functional Indian communication satellites in the geostationary orbit
of 36,000 km; 13 remote sensing satellites in LEO of up to 2,000 km; and eight navigation
satellites in medium earth orbits.