Space junk – astroengine.com

Space Junk: It’s Not As Bad As It Looks (what?)

space-junk-geo-02

According to NASA, these new images of space junk orbiting Earth make the situation look more dire than it really is.

I suppose that would be like a store manager looking at the shop floor of Toys ‘R’ Us on the day after Thanksgiving rubbing his chin and saying, “You see, I told you it would be quiet.” In actuality, the shop would be rammed full of bargain hunters, and by the looks of things, Earth orbit (from LEO to geostationary altitudes) is rammed full of junk.

But space is big, so although it might look a little grim up there, it’s very unlikely a spaceship will collide with anything. A statement from NASA agrees:

The dots are not to scale, and space is a very big place. Collisions between large objects are fairly rare. The orbit of each piece is well known. If any debris comes into the path of an operating NASA satellite, flight controllers will maneuver the satellite out of harm’s way.

This may be the case, but I would argue that as a space-faring race, us humans have barely dipped our toes in the cosmos yet. It’s going to take a lot more rocket launches and space littering before we can have routine access to space. If it looks like this now, in the first decade of the 21st century, how much junk is going to be up there in 20, 50 or 100 years time when manned space flight is commonplace?

We’re already manoeuvring satellites, shuttles and space stations out of harms way, and occasionally satellites do collide. Unfortunately, I think space junk will be an additional man made hazard for space travel; we’ll just have to deal with it.

But for now, be sure to pack your double-glazed Whipple Shield if you intend to take a trip into low-Earth orbit…

Source: Space.com

In the Cosmos/Iridium Collision, Which Satellite Won?

When two satellites collide at 790 km above the Earth’s surface, who really cares which satellite “won”? It’s going to be a mess; chunks of metal and shards of solar panels exploding to life after their once-solid satellite structures impacted at a velocity of 11 km/s (that’s kilometres per second). Both satellites are losers, twisted, shattered remains of their former selves, cluttering Earth-orbit, causing all kinds of stress for other vehicles flying around in orbit.

However, when the Iridium communications satellite was hit by the defunct Russian Cosmos 2251 on February 10th, it turns out there was a “winner” in the satellite demolition derby (although I am using the word “winner” very loosely)…
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Another Satellite Collision Simulation

50 minutes after collision, over the South Pole (University of Southampton)

On February 10th, Iridium 33 and Cosmos 2251 became the first ever satellites to collide in orbit. The event was unprecedented. Quickly, visualization companies (such as AGI) created stunning 3D animations of the event unfolding, modelling the resultant debris. Now, there’s another animation available, this time from the University of Southampton Astronautics Research Group.

Watch the University of Southampton simulation »

I really like this version, as a) it is modelled by software called “DAMAGE”, b) you get a real sense of orbital speed vs. the vanishingly tiny chance that two satellites, of that size, could possibly collide, and c) you can almost hear the *BOOM* when contact is made (it is a fanciful *BOOM*, because in space no one can hear a satellite scream).

Let’s just hope those hundreds of pieces of debris don’t amplify the space junk problem up there…

Source: Flightglobal/Hyperbola

Target Australia: The EAS Re-Entry Location

The Early Ammonia Servicer re-entered 550 km south of Australia (Google Earth)

It looks like the Early Ammonia Servicer (EAS) re-entered pretty close to Australia in the end. The US Space Command released the co-ordinates of 48° S 151° E as the most likely EAS re-entry fireball. This is only 550 km south of the southern-most region of Australia, Tasmania. An eagle-eyed reader of the Universe Today also noted that the original location of re-entry being in the Indian Ocean was incorrect. As the Indian Ocean is separated from the Pacific Ocean at the 147° meridian, the 151° longitude is obviously well within the South Pacific.

All articles now corrected. At least the EAS didn’t drop into Sydney harbour… now that might have caused a “diplomatic incident”.

EAS Space Junk is Toast, Re-Entry Over Pacific Ocean Likely

It looks like the Early Ammonia Servicer (EAS) that has been orbiting Earth for the past 15 months had a fight with the Earth’s atmosphere… and lost. Due to re-enter at some time today (Sunday), an eagle-eyed amateur astronomer noted when the EAS was due to make an orbital pass… but the ammonia-filled space station cast-off missed its November 2nd appointment.

Thomas Dorman of Horizon City, Texas, observed the object fly overhead on November 1st. Dorman was using a low-light camera to attempt to spot the speeding debris earlier today, “but the EAS did not appear,” he said. “I think it is safe to assume EAS has reentered.”

It is most likely that the EAS disintegrated and any surviving bits either fell into an ocean (somewhere) or dropped harmlessly in a sparsely populated region. No reports of a fireball or half a refrigerator randomly dropping into someone’s back yard have surfaced, so my money is on NASA’s reckoning that the EAS would fall harmlessly into water.

Update (Nov. 3rd):
News from SpaceWeather.com as to the location of re-entry:

US Space Command reports that the Early Ammonia Servicer (EAS) probably reentered Earth’s atmosphere on Nov. 3rd at 04:51:00 GMT +/- 1 minute over the following coordinates: 48° S, 151° E. That would place the fireball over the ~~Indian Ocean~~ [Pacific Ocean] south of Tasmania where sightings are unlikely.

Update (Nov. 4th):
Refer to Target Australia: The EAS Splashdown Location…

Aside: As it’s Sunday and I’ve not been writing much, I decided to have a dabble with Photoshop and create a quick visualization of what the EAS may look like as it’s falling through the atmosphere (above). I used NASA images for the Earth atmosphere backdrop and the original 2007 space station image of the EAS tumbling in space…

Source: SpaceWeather.com

Watch Your Heads! Space Station Junk to Hit Earth Today

Somewhere, sometime today, the Early Ammonia Servicer (EAS) will drop to Earth at 100 mph.

The EAS as photographed by the ISS crew in 2007 (NASA)

A huge piece of space junk discarded from the space station in 2007 will drop through the atmosphere some time today (Sunday). The Early Ammonia Servicer, otherwise known as the EAS, was detached from the orbiting outpost as its services were no longer required. The double-refrigerator-sized piece of equipment weighs 635 kg (1400 lb) and is filled with toxic ammonia. Although NASA believes most of its mass will disintegrate during re-entry, there’s a real chance of up to 15 pieces of the EAS reaching the ground, the largest piece could weigh up to 17.5 kg (40 lb).

But here’s the funny thing, as the EAS is currently skirting along the outermost reaches of the atmosphere, we are uncertain as to when, or where, the re-entry will take place. NASA and U.S. Space Surveillance Network scientists have done well to narrow the re-entry window down to one day. Fortunately, 70% of the planet is covered in water, so we should be fine. But should any parts of the EAS find solid ground, NASA has warned that we shouldn’t approach any suspicious-looking (and probably steaming) bits of meteorite in case the EAS still has some ammonia on board…
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