Hazards from cosmic garbage for Hubble repair crew

Space shuttle Atlantis is currently flying in a chaotic space - where thousands of cosmic debris move very fast around the Earth at nearly 20,000 miles per hour (mph). Here astronauts see more debris of used satellites and missiles than any other place. The group had to stay for a week to fix Hubble Space Telescope. As soon as this is done, the shuttle will move to a safer area.

The telescope orbits the Earth and maintains a distance of about 350 miles, in a much more chaotic space than the shuttle's normal orbit. These debris increase the risk of permanent occurrence of a disaster at any time.

'It will be more risky when we reach this height,' said Bryan O'Connor, NASA's chief security officer, the former space shuttle. However, he added, NASA could face this adventure.

After the accident of the Columbia ship in 2003, flying to the Hubble telescope was considered too dangerous because it was synonymous with flying into an orbit other than the International Space Station. That also means that the shuttle will not be able to use the station as a shelter in an emergency.

NASA is now placing an alarm on the risk of a catastrophic collision with debris at 1/229 - a higher level than normal space station flights, but lower than its original forecast.

Next Wednesday, the crew will have access to the telescope and bring it into the cargo compartment of the ship, where astronauts conduct repairs and upgrades next week. Work will start from Thursday.

The delegation will spend the next 3 weeks to check the outside of the ship to see if there is any collision with the debris while launching; 4 small cuts were detected according to the initial observation. This is a mandatory procedure since the Columbia ship hit a small foam during the launch and smashed on its way back to Earth.

But for any shuttle, the biggest danger is still to crash or at high speed in orbit, not during takeoff. Since objects revolve around the earth at great speeds, just a small object of about one-third the size of a coin can penetrate the ship's cabin, causing serious harm, even a disaster, leading NASA's words.

Where Atlantis stopped becoming increasingly chaotic. In 2007, China destroyed one of their satellites to test weapons, leaving a lot of debris. Last February, a Russian shutdown satellite collided with an American telecommunications satellite, emitting more garbage into the high orbit.

To date, cosmic garbage monitoring devices have detected 950 debris generated from collisions during the year, and more than 2500 fragments since the 2007 explosion. There are many other debris that they have not observed. OK.

Astronaut Jonathan McDowell of Harvard University, who tracks objects in orbit, said 'People will closely monitor the operation of Atlantis. This is really a dangerous journey. '

It seems that the debris will not cause any serious problems, but McDowell predicts that Atlantis will return to Earth with some minor scratches in the windshield or grille. '

NASA's leading space garbage expert says we need to move from anxiety to optimism.

"There's nothing to lose sleep," said Nicholas Johnson, head of NASA's space debris research team. 'We take this very seriously, however, considering the actual situation, this is just a small risk.'

Computer display images provided by NASA, showing objects on Earth orbit currently being tracked. Nearly 95% of the objects on the picture are orbiting debris, not human satellites launched. Each bright dot is an object. The light dots are scaled according to the image size on the graphic to show the vision from Earth to it, this size does not scale according to the size of the Earth. From the image, we can see clearly where the largest orbital debris cluster exists. The Atlantis space shuttle is about 350 miles away from Earth, in a space where there is a lot of cosmic waste that is more dangerous than the low-range orbit where shuttles usually park at the International Space Station. (AP Photo / NASA)

However, Johnson acknowledges that the more dangerous orbit of the universe is more dangerous than the space station, only 225 miles from Earth.

'Hubble telescope operations are currently underway as usual,' Johnson said.

Initially, when Johnson and other experts at the Johnson Space Center calculated the risk of Atlantis being destroyed by debris, the ratio was approximately 1/200.

This is where NASA has to think more about the flight. Engineers have come up with ways to respond to different situations to reduce the risk of Atlantis hitting the debris, now they decide the risk ratio is 1/229. This ratio in the flight to the space station is 1/300.

In 2004, NASA canceled the Hubble glass repair task, citing the working group's inability to return to the space station in an emergency. However, the execution plan was restored after engineers found a way to deal with the damage in the flight, and the space agency outlined the emergency rescue plan when needed. Shuttle
Endeavor was on the launch pad ready to fly to rescue the Atlantis crew if the ship was badly damaged and could not return to Earth.

NASA has also found other options to limit the risk of Atlantis being destroyed. As soon as the ship completes its repair and brings Hubble back into orbit, it will quickly descend to a lower orbit, less garbage and safer. The crew will also conduct an overall inspection before returning to Earth.

In addition, Atlantis is flying in an egg-shaped trajectory, sometimes 350 miles from Hubble, but sometimes only 135 miles away. This helps the ship reduce the risk of cosmic garbage, and is easier for emergency rescue, said NASA spokesman Rob Navias.

The Air Force is tracking more than 19,000 objects in all trajectories - most of them are cosmic garbage.

The most junk point is 525 miles high, where Chinese satellites have been destroyed, and a height of 490 miles, where a collision between two satellites of Russia and the United States has occurred.

Although Hubble and Atlantis orbits are less than a hundred miles lower than those mentioned above, they are close enough to potentially pose many dangers. That's because garbage will fly to neighboring orbital areas, not just at the points, Johnson said.

The higher the trajectory of garbage, the longer the garbage will remain at that height because there is less force drawn from the atmosphere to pull them down. For example, a 4-inch object at 490 miles will be in orbit for more than a century, Johnson said.

At the Hubble telescope's height, the same object will fall after a century; In the height of the space station, it will fall after a few months.

The Air Force Headquarters tracks more than 4 inches of debris and will warn NASA and other agencies if the trash flies near the crew. Over the past year, NASA has moved the space station twice to avoid being exposed to cosmic garbage. But those are just fragments that the Air Force can track.

Objects ranging in size from 0.1 to 4 inches are enough to cause serious harm, even disaster, but we are not able to track them clearly.

'The biggest risk for crews is that the debris cannot be tracked,' Johnson said.