Sunday, April 23, 2017

3D Video Shows Thousands of Pieces Of Space Junk Orbiting Earth

The European Space Agency released a stunning 3D video animation of man-made space debris orbiting the Earth and other planets that could catastrophically collide with future spacecraft.

Since 1957, more than 5,250 launches have led to more than 23,000 tracked debris objects in orbit. Only about 1,200 are working satellites - the rest are debris and no longer serve any useful purpose often referred to as 'space junk.'

Two major contributors of the space debris were the Chinese Feng Yun-1C anti-satellite test in 2007 that created more than 3400 tracked fragments; and the first-ever accidental collision between two satellites, Iridium-33 and Cosmos-2251, which created 2300 tracked fragments in 2009.

Scientists are now calling for coordinated international action to mitigate space pollution to ensure the long-term sustainability of spaceflight.

The call for international action came on the final day of the European Conference on Space Debris, a gathering of over 350 participants from science, academia, industry and space agencies worldwide held at ESA’s mission control center, where the ESA Space Debris Office and the SSA effort are based.

During the conference, ESA Director General Jan Woerner made an appeal to keep Earth’s orbital environment as clean as possible. “In order to enable innovative services for citizens and future developments in space, we must cooperate now to guarantee economically vital spaceflight. We must sustain the dream of future exploration,” he said.

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

“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.

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

“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.

“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.”

Image and video credit: ESA

Thursday, May 7, 2015

International Space Station May Use Laser Cannon To Shoot Space Junk

CAPE CANAVERAL, Florida -- Scientists have come up with a solution to get rid of space junk in low Earth orbit by detecting it with a telescope and then shooting the debris with a laser cannon mounted on the International Space Station (ISS).

But don't look forward to any laser-induced explosions is space. After locating a piece of floating space junk with a super-wide field-of-view telescope, scientists propose shooting the debris with a laser pulse to slow down its orbit; thereby causing the space junk to fall back into Earth's atmosphere.

Space junk is made up of artificial objects orbiting the Earth as a result of human activities. The number of objects have nearly doubled from 2000 to 2014 and pose a hazard to present and future space activities. Recent estimates place the total mass of space junk to be about 3,000 tons.  Because the debris exists in different orbits, it is difficult to find and capture. 

The EUSO telescope, which would be used to find the space junk, was originally planned to detect ultraviolet light emitted from air showers produced by ultra-high energy cosmic rays entering the atmosphere at night. “We realized,” says Toshikazu Ebisuzaki, who led the research effort, “that we could put it to another use. During twilight, thanks to EUSO’s wide field of view and powerful optics, we could adapt it to the new mission of detecting high-velocity debris in orbit near the ISS.”

The second part of the experiment, the CAN laser, was originally developed to power particle accelerators. It consists of bundles of optical fibers that act in concert to efficiently produce powerful laser pulses. It achieves both high power and a high repetition rate.

Scientists say that these two instruments would be capable of tracking down and de-orbiting the most dangerous space debris, around the size of one centimeter. The intense laser beam focused on the debris will produce high-velocity plasma ablation, and the reaction force will reduce its orbital velocity, leading to its reentry into the earth's atmosphere.

The group plans to deploy a small proof-of-concept experiment on the ISS, with a small, 20-centimeter version of the EUSO telescope and a laser with 100 fibers. “If that goes well,” says Ebisuzaki, “we plan to install a full-scale version on the ISS, incorporating a three-meter telescope and a laser with 10,000 fibers, giving it the ability to deorbit debris with a range of approximately 100 kilometers. Looking further to the future, we could create a free-flyer mission and put it into a polar orbit at an altitude near 800 kilometers, where the greatest concentration of debris is found.”

“Our proposal is radically different from the more conventional approach that is ground based, and we believe it is a more manageable approach that will be accurate, fast, and cheap," said Ebisuzaki. "We may finally have a way to stop the headache of rapidly growing space debris that endangers space activities. We believe that this dedicated system could remove most of the centimeter-sized debris within five years of operation.”

The scientific team's research and proposal was published in the most recent edition of Acta Astronautica.

Image Credit: NASA (laser added by Brevard Times).

Wednesday, April 29, 2015

Russian Re-Supply Spacecraft To Fall Back To Earth

CAPE CANAVERAL, Florida -- Russian flight controllers have abandoned future attempts to recover an unmanned Russian re-supply spacecraft carrying more than 6,000 pounds of food, fuel, and supplies for the International Space Station that continues to spin out of control in low Earth orbit.  The spacecraft is expected to fall back to Earth within the next few days.

The Russian Progress 59 cargo spacecraft launched at 3:09 a.m. EDT on Tuesday from the Baikonur Cosmodrome in Kazakhstan. Once in orbit over 200 miles above the Earth, the spacecraft began to spin uncontrollably Tuesday morning.

As of 9:50 a.m. EDT on Wednesday, Russian flight controllers were still unable to communicate commands through the telemetry system onboard the spacecraft as it made passes over Russian ground stations.

The International Space Station Expedition 43 crew was notified on Wednesday that docking with the International Space Station has been called off for the Progress 59 spacecraft. Meanwhile, the crew continued their work today with a variety of research and technology demonstration activities.

According to NASA, both the Russian and USOS segments of the station continue to operate normally and are adequately supplied well beyond the next planned resupply flight on June 19th from Cape Canaveral, Florida.

Video released by NASA shows images of the Earth, followed by space, followed by the Earth again, which was captured by a camera onboard Progress 59 as the spacecraft spun wildly.

Image and Video Credit: NASA

Sunday, November 10, 2013

GOCE Space Junk Satellite Fell To Earth

GOCE Satellite.  Image Credit: ESA

UPDATE:  GOCE Has Fallen To Earth

Around 7:00 PM EST on Sunday, November 10, 2013, ESA’s GOCE satellite reentered Earth’s atmosphere on a descending orbit pass that extended across Siberia, the western Pacific Ocean, the eastern Indian Ocean and Antarctica.

The European Space Agency estimates that a satellite weighing 2,425 pounds (1,100 kilograms) will fall somewhere on Earth anytime between 5:50 p.m. and 7:50 p.m. Eastern Standard Time in an uncontrolled descent from an orbital height of less than 74 miles (120 kilometers). 

According to the latest GOCE satellite status update at 5:50 p.m. on Sunday, November 10, 2013, last contact was made with the satellite at 5:42 EST by Antarctica’s Troll station.  Based on data collected by the last contact, ESA scientists now calculate that the most probable re-entry area lies on a descending orbit pass that mainly runs across the Pacific and the Indian Ocean.

If GOCE has not yet fallen over Antartica by 7 PM EST, the satellite's path then goes over mostly Argentina and northwest Brazil in South America, then the Caribbean, followed by a pass along the east coast of the United States in North America by 8 p.m.

The satellite's central computer temperature was at 80ºC and the battery is at 84ºC.  At an altitude of less than 120 km, the spacecraft is - against ESA expectations - still functional.

The ESA cautioned that, while most of the satellite will disintegrate in the atmosphere, several parts might reach Earth’s surface.  Exactly when and where the space junk debris will crash cannot yet be predicted, but the affected area excludes Europe and is likely to encompass oceans and the polar regions of Earth.

Because two-thirds of Earth is covered by oceans and vast land areas are thinly populated, the ESA reasoned that danger to life or property is very low.  An international campaign is monitoring the descent, which includes the Inter-Agency Space Debris Coordination Committee.  The situation is being continuously watched by ESA’s Space Debris Office, which will issue reentry predictions and risk assessments.  The ESA will also keep its Member States and the relevant safety authorities permanently updated.

The satellite, named Gravity field and steady-state Ocean Circulation Explorer or "GOCE", has spent more than four years mapping Earth’s gravity.  To accomplish this scientific task, GOCE has been orbiting Earth since March 2009 at the lowest altitude of any research satellite.

Dubbed the ‘Ferrari of space’ because of its sleek, aerodynamic design to minimize atmospheric drag, GOCE has mapped variations in Earth’s gravity with extreme detail.