Presentation Content• Space Debris – Earth to Space Threats – Space to Space Threats – Space to Earth Threats• Space Situation Awareness – SSA – The US Approach – The European Approach• A few observations
Space Debris ? Not my problem !Definition: Space debris, also known as orbital debris, space junk,and space waste, is the collection of objects in orbit around Earththat were created by humans but no longer serve any usefulpurpose. (Wikipedia) ‘Vast space, small satellites’ way of thinking ‘No disasters – Why bother ?’ Out of more than 21,000 space elements larger than 10 cm tracked during 2011, only 3500 (~16%) were live operating satellites.
From Earth to SpaceDefinition: Anti-satellite weapons (ASAT) are designed toincapacitate or destroy satellites for strategic military purposes.(Wikipedia) US and USSR experimented freely with ASAT weapons, During the 60’s and 70’s On January 11th, 2007, China destroyed an old Chinese orbiting weather satellite On February 21st, 2008, USA destroyed a malfunctioning US spy satellite USA-193
SPACE to SPACE threats – Space collisions Events of close proximity occur numerous times each day.A Passive scanning and tracking system (SOCRATES) monitors the traffic Sorting to identify those that are high risk presents a challenge. Planning an avoidance maneuver can also be challenging.
Kessler Syndrome (Donald J. Kessler) The density of objects in Earth orbit is high enough that collisions between objects could cause a cascade – each collision generating debris which increases the likelihood of further collisions.42% of all cataloged debris was the result of only 19 events
Accidents have happened before: On August 11th, 1993, the British Olympus-1 was hit by ‘something’ and left adrift. On July 24th, 1996, the French microsatellite Cerise (military use) was hit by fragments of an Ariane-1 launcher. On March 29th, 2006 the Russian Express-AM11 communications satellite span out of control due to cooler leakage, high chances it was hit by debris
Few things you should know… “The risk of collision per conjunction is one in 50 million (1:50,000,000)”… John Campbell, executive vice president of Iridium, June 2007 This was not the top predicted close approach for that report or even the top predicted close approach for any of the Iridium satellites for the coming week !!
Recent events regarding space-space threats On October 28th, 2010. a 5.37 ton satellite named EUTELSAT W3B suffered a major leak just after separation from Arianne and later on was declared a total loss. On June 28th, 2011 an emergency evacuation of the ISS was declared due to a dangerous Russian debris that was discovered at the last minute and flew less than 250 meters from the ISS. On August 18th, 2011, a 5.7 ton satellite named EXPRESS AM-4 was misplaced in orbit and now is considered a risk to GPS and GEO satellites
Reentry: Space-to-Earth Threats South Africa Australia Russia US Saudi Arabia
Recent Reentry Events• UARS – September 23rd, 2011 – Debris spread over the Pacific ocean (5.9 ton – total, mass of ~530 kg hit earth)• ROSAT – October 23rd, 2011 – Debris spread over the bay of Bengal (2.6 ton – total, mass of ~1.7 ton hit earth)• Phobos-Grunt – January 15th, 2012 – Debris spread over the pacific ocean (13.5 ton – total, mass of debris yet unknown)
Space Situation Awareness• Definition: The requisite current and predictive knowledge of the space environment and the operational environment upon which space operations (Source: Definitions.net)• The objective of the SSA is to support utilization of, and access to, space through the provision of timely and accurate information, data and services regarding the space environment, and particularly regarding hazards to infrastructure in orbit and on the ground (source: ESA).
SSA Operational Concepts – US Approach The U.S. strategy to assure freedom of access in space hinges on SSA: the ability to find and track space objects and determine their capability and intent. (source: responsive space situation awareness in 2020 – USAF) OODA – Observe, Orient, Decide, Act
SSA Operational Concept – ESA approachUnrestricted access to space and to space services is a common interestof humankind. Accordingly, the need for sustainable space services andpossibly the need to take actions to guarantee the unrestricted use ofspace are vital and recognized worldwide.
A Few Observations• There are no laws regarding space debris (only gentlemen agreements).• Current passive warning systems HAVE NOT prevented even one incident.• Active measures must be taken NOW - even if we stop all launches, the problem will only become worse.• European approach regarding SSA is commercial, US approach is strategic
Winds of change ??• ASTRIUM VP for R&T Brigitte Serreault, publically announced their interested in on-board protections against collisions at a satellite level.• The Swiss Space Center at the Swiss Federal Institute for Technology in Lausanne, announced on February 15th its plan to develop and launch a satellite to remove space debris from low-Earth orbit. The $11-million (USD) satellite, called Clean Space One