The end of the Space Age

At the moment, we feel kind of connected to many places off-Earth. We have active experiments, orbiters and rovers on the Moon and Mars. Japan's Akatsuki is in orbit around Venus. New Horizons has whizzed past Pluto and into the Kuiper Belt.

But just imagine if we couldn't send anything more into space. This situation might arise if the density of space junk becomes too great and the exponential cascade of collisions causes the Kessler Syndrome. Objects launched from Earth would not escape fatal damage from these hypervelocity collisions.

Gradually, one by one, orbiters would crash onto planetary surfaces as their fuel ran out. Batteries would fail, materials would decay. One by one, the little spacecraft voices that come to the antennas of Earth would fall silent.

The great antennas set to listen to the human sounds of space would cease their turning like sunflowers to catch the signal; they in their turn would become useless monuments to the Space Age.

Dr Space Junk throws down the gauntlet to the Australian space community on orbital debris

Well, I exaggerate a little.

Last week the National Council of Research in the US released a report calling on NASA to get serious about orbital debris.

Ashley Hall, a journalist from ABC's PM current affairs programme, called me for comment.  You can listen to the interview here.  He also talks to orbital debris guru Donald Kessler.

At the end of the interview, I make a case that Australia should become more than a passive observer to the efforts of the space agencies and the Inter-Agency Space Debris Coordination Committee.

There are a number of reasons why this makes perfect sense:

1.  Australia has a number of non-operational and functioning assets in space:  FedSat, Australis Oscar V, and the Aussat/Optus telecommunications satellites.  We rely very heavily on satellite services.  Orbital debris is a problem for us as much as anyone.

2.  Orbital debris often re-enters over Australia - a function of our large landmass and location.

3.  Because of both the above factors, not to mention plenty of radio-quiet space and political stability, Australia is ideally suited to host tracking and surveillance facilities (which we have done, and still do, a lot of).

4. We have a great track record in tracking expertise, and have local industries developing innovative capabilities in this field (eg EOS).

5. Recently we have signed a couple of agreements with the USA to increase collaboration on Space Situational Awareness.

6.  We are located in a global navigation satellite systems "hotspot" - in a decade we will have access to over 40 such systems (apparently).

7.  In the past (ie before the Howard era), Australia had a good reputation in middle power diplomacy.

8. Now that we are starting to take space seriously, with the Space Policy Unit and a new space policy on the way, and funding for space research, it is important to build our credibility.

9. Australia has a (rarely used) place on the UN Committee on the Peaceful Uses of Outer Space.

You see my drift?  If I hadn't managed to fill up my sabbatical with other writing obligations, I would write a paper about this for the Monthly or something like that.  Perhaps I still will.  Anyone want to collaborate on it with me?

Space Junk Mess Getting Messier in Orbit

By Leonard David
SPACE.com’s Space Insider Columnist posted: 23 February 2010
09:20 am ET

BRECKENRIDGE, Colo. — The already untidy mass of orbital debris that litters low Earth orbit nearly got nastier last month. A head-on collision was averted between a spent upper stage from a Chinese rocket and the European Space Agency's (ESA) huge Envisat Earth remote-sensing spacecraft. Space junk tracking information supplied by the U.S. military, as well as confirming German radar data, showed that the two space objects would speed by each other at a nail-biting distance of roughly 160 feet (50 meters).


ESA's Envisat tips the scales at 8 tons, with China's discarded rocket body weighing some 3.8 tons. A couple of tweaks of maneuvering propellant were used to nudge the large ESA spacecraft to a more comfortable miss distance. But what if the two objects had tangled? 

Such a space collision would have caused mayhem in the heavens, adding clutter to an orbit altitude where there are big problems already, said Heiner Klinkrad, head of the European Space Agency's Space Debris Office in Darmstadt, Germany. It turns out, Klinkrad told SPACE.com, that 50 percent of all the close conjunctions that Envisat faces are due to the lethal leftovers from China's January 2007 anti-satellite test, as well as chunks of junk resulting from last year's smashup between an active U.S. Iridium satellite and a defunct Russian Cosmos spacecraft.

Klinkrad joined several orbital debris experts that took part in the 33rd Annual Guidance and Control Conference organized by the Rocky Mountain Section of the American Astronautical Society. The five-day meeting began Feb. 5.

Avoidance maneuvers
Significant progress has been made by the U.S. and the international aerospace communities in recognizing the hazards of orbital debris, reported Nicholas Johnson, chief scientist for orbital debris at the NASA Johnson Space Center in Houston, Texas. Johnson added that steps are being taken to reduce or eliminate the potential for the creation of new debris. However, "the future environment is expected to worsen without additional corrective measures," he noted.

During 2009, Johnson reported, five different NASA robotic spacecraft carried out collision avoidance maneuvers: a Tracking and Data Relay Satellite (TDRS-3), Cloudsat, Earth Observing Mission 1, Aqua, and Landsat 7. Also, the space shuttle and the International Space Station took collision avoidance actions, he said.

The worst thing that could happen, according to ESA's Klinkrad, is the International Space Station (ISS) receiving a fatal hit. The space station is currently home to five astronauts representing the U.S., Russia and Japan.
"A penetrating object hitting the ISS, and possibly causing a casualty onboard . . . I think that would be the most dramatic case we could have," Klinkrad suggested. Such an incident might turn public opinion against human spaceflight, he said.

Collaboration on the increase
One bit of good news in all this orbital riff-raff. Due to last year's satellite crash between the Iridium and Cosmos spacecraft, Johnson explained that the Joint Space Operations Center (JSpOC) of the U.S. Strategic Command now conducts conjunction assessments for all operational spacecraft in Earth orbit, regardless of ownership nationality. "To be honest, a year ago, we couldn't even have hoped to have done this," Johnson told SPACE.com.
"It's really a consequence of the collision last year. People have been talking about this for years. But now we've made the commitment . . . that this is something that needs to be done and can be done relatively easily," Johnson said. Klinkrad concurred. "The collaboration is getting even closer now," he said.

Duck or pluck?
Playing dodge ball with high-speed space debris is one tactic. But there is also a growing interest in removing the most troublesome objects — perhaps an annual quota of some sort. Targeted would be specific inclination bands and altitude regimes, Klinkrad said. But prior to implementing debris remediation measures on a global scale, technical, operational, legal and economic problems must be overcome. 

Klinkrad and NASA's Johnson provided a wearisome appraisal of the future. Even with an immediate halt of launch activities, spacefaring nations will be dealing with an unstable low-Earth orbit environment in some altitude and inclination bands. This would be a consequence of about 20 catastrophic collisions within the next 200 years, the two orbital debris experts explained. Some orbit altitudes already have critical mass concentrations that will trigger "collisional cascading" within a few decades, unless debris environment remediation measures are introduced.

The Kessler Syndrome
The idea of debris creating debris was put in motion by Donald Kessler, along with fellow NASA researcher, Burton Cour-Palais, back in 1978. Their research suggested that, as the number of artificial satellites in Earth orbit increases, the probability of collisions between satellites also increases. Satellite collisions would produce orbiting fragments, each of which would increase the probability of further collisions, leading to the growth of a belt of debris around the Earth. Now, decades later, that prophecy has been dubbed the Kessler Syndrome.

Kessler told SPACE.com that the disorder fits into much more complex natural laws that include the evolution of the solar system, as well as meteoroids, meteorites, and climate-changing asteroids. Kessler is now an orbital debris and meteoroid consultant in Asheville, North Carolina. "There is nothing complex about what is called the 'Kessler Syndrome' . . . it is just the way nature may have converted a disorderly group of orbiting rocks into an orderly solar system . . . although nature reminds us with a large asteroid or comet collision every few million years that it isn't quite finished yet. 

"In the case of orbital debris, this collision process is just starting," Kessler explained.  Consequently, nobody should be surprised that as orbital debris models became more complex — and as more data is obtained — the same conclusion holds, Kessler said. "The future debris environment will be dominated by fragments resulting from random collisions between objects in orbit, and that environment will continue to increase, even if we do not launch any new objects into orbit," Kessler concluded.

• Some of the Worst Space Debris Moments in History
• India Developing Anti-Satellite Spacecraft
• Video — The Expanding Danger of Space Junk

Leonard David has been reporting on the space industry for more than five decades. He is past editor-in-chief of the National Space Society's Ad Astra and Space World magazines and has written for SPACE.com since 1999.

The Chinese rocket and space junk - radio interview

Last week I did an interview on The Current, on CBC Radio, Toronto. The subject of the show was China's recent destruction of a satellite by missile, and the effect on the growth of orbital debris. Other guests included Don Kessler (formerly of NASA's Orbital Debris Office), Geoff Forden (MIT) and David Wright (Union of Concerned Scientists). Some of the show is available online at the following link:

http://www.cbc.ca/thecurrent/2007/200702/20070207.html

The interview took place at about a quarter past midnight, Australian time. I was very sleepy and may not have made as much sense as I'd like ....