Call For A Sustainable Future In Space

On 18-21 April ESA's Space Operations Centre in Darmstadt, Germany hosted The 7th European Conference on Space Debris - the largest ever conference on space debris. The event brought together over 350 leading scientists, engineers, managers, space operators, industry, academia and policy-makers from all major spacefaring nations.

Today, around 750 000 objects larger than 1 cm are orbiting Earth. At average speeds of 40 000 km/h, impacts on space hardware would deliver roughly the energy equivalent to the explosion of a hand grenade. Consequences for our operational satellites could be severe.

About 18 000 of these pieces of debris are large enough to be regularly monitored by powerful surveillance systems. Such monitoring data are used by space agencies such as ESA to avoid collisions. The majority of these objects have been generated by more than 250 explosions.

With the increase in the number of objects in space, experts believe that collisions among these objects, some of which have already occurred, might become the primary source for new fragments in orbit.

The latest results of debris research were featured, especially the safe disposal of retired satellites and rocket stages and the still uncertain challenges posed by satellite megaconstellations being considered by commercial operators.

“Only about 60% of the satellites that should be disposed of at the end of their missions under current guidelines are, in fact, properly managed,” noted Holger Krag, head of ESA’s debris office.

Researchers also confirmed there is now a critical need to remove defunct satellites from orbit before they disintegrate and generate even more debris.

“This means urgently developing the means for actively removing debris, targeting about 10 large defunct satellites from orbit each year, beginning as soon as possible – starting later will not be nearly as effective,” said Dr Krag.

Inconvenient truths

Since 1957, more than 5250 launches have led to a population today of more than 23 000 tracked debris objects in orbit. Only about 1200 are working satellites – the rest are debris and no longer serve any useful purpose.

Many derelict craft have exploded or broken up, generating an estimated 750 000 pieces larger than 1 cm and a staggering 166 million larger than 1 mm.

“In orbit, these objects have tremendous relative velocities, faster than a bullet, and can damage or destroy functioning space infrastructure, like economically vital telecom, weather, navigation, broadcast and climate-monitoring satellites,” said Dr Krag.

Working for the future

Launched in 2009, SSA is developing software, technologies and precursor systems to test a fully European surveillance network that will ensure independent data on space infrastructure.

Additionally, the Agency is developing new technologies under the Clean Space initiative that promise a significant reduction in the creation of space pollution at all stages of space activities.

“Space debris threaten all working satellites, including Europe’s Sentinels and the Galileo navigation constellation, and any loss of space infrastructure would severely affect modern society,” noted Dr Krag.

“The sustainable use of space has been persuasively shown to be at risk, and the status quo is obviously no longer acceptable. We must now start removing dead satellites.”