Space Debris Affirmative
Brink: Kessler Syndrome (1/3)
Download 394.08 Kb.
|
- Navigate this page:
- Brink: Kessler Syndrome (2/3)
Brink: Kessler Syndrome (1/3)Only way to prevent Kessler syndrome is through removing debris now- stalling would increases risks to active satellites. Kessler 09 (Donald J. Kessler, Donald J. Kessler is an American astrophysicist and former NASA scientist known for his studies regarding space debris. Kessler worked at the Johnson Space Center in Houston, Texas, as part of NASA's Environmental Effects Project Office. Kessler first published his ideas in 1978, in an academic paper titled "Collision Frequency of Artificial Satellites: The Creation of a Debris Belt."[2] The paper established Kessler's reputation, and NASA subsequently made him the head of the newly-created Orbital Debris Program Office to study the issue and issue guidelines to slow the accumulation of space debris.[1] , The Kessler Syndrome, March 8, 2009 http://webpages.charter.net/dkessler/files/KesSym.html, rn) We are entering a new era of debris control….an era that will be dominated by a slowly increasing number of random catastrophic collisions. These collisions will continue in the 800 km to 1000 km altitude regions, but will eventually spread to other regions. The control of future debris requires, at a minimum, that we not leave future payloads and rocket bodies in orbit after their useful life and might require that we plan launches to return some objects already in orbit. These control measures will significantly increase the cost of debris control measures; but if we do not do them, we will increase the cost of future space activities even more. We might be tempted to put increasing amounts of shielding on all spacecraft to protect them and increase their life, or we might just accept shorter lifetimes for all spacecraft. However, neither option is acceptable: More shielding not only increases cost, but it also increases both the frequency of catastrophic collisions and the amount of debris generated when such a collision occurs. Accepting a shorter lifetime also increases cost, because it means that satellites must be replaced more often….with the failed satellites again increasing the catastrophic collision rate and producing larger amounts of debris. Aggressive space activities without adequate safeguards could significantly shorten the time between collisions and produce an intolerable hazard to future spacecraft. Some of the most environmentally dangerous activities in space include large constellations such as those initially proposed by the Strategic Defense Initiative in the mid-1980s, large structures such as those considered in the late-1970s for building solar power stations in Earth orbit, and anti-satellite warfare using systems tested by the USSR, the U.S., and China over the past 30 years. Such aggressive activities could set up a situation where a single satellite failure could lead to cascading failures of many satellites in a period of time much shorter than years. As is true for many environmental problems, the control of the orbital debris environment may initially be expensive, but failure to control leads to disaster in the long-term. Catastrophic collisions between catalogued objects in low Earth orbit are now an important environmental issue that will dominate the debris hazard to future spacecraft. Kessler Syndrome on the brink-debris removal needed now. David 10 (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., Space.com, Space Junk Mess Getting Messier in Orbit, http://www.space.com/7956-space-junk-mess-messier-orbit.html, 2/23/10, rn) 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 Brink: Kessler Syndrome (2/3)(continued) 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. Kessler prediction fulfilled so far; soon, debris will be insurmountable Kessler 09 (Donald J., Former head of the Orbital Debris Program Office, The Kessler Syndrome; As discussed by Donald J. Kessler, 3/8/09, http://webpages.charter.net/dkessler/files/KesSym.html, M.S.) The lower growth rate of 320 objects per year in the 1978 paper predicted two collisions by 2009, both catastrophic. Although the actual number of collisions is too few to be statistically meaningful, they may indicate that the actual collision rate could be higher than predicted, but fewer are catastrophic. This higher collision rate would be consistent with the uncertainty in spacecraft area subject to collisions, as was noted in 1978. In 1991 and 2000 publications, the collision area was shown to be about 2.5 times greater than adopted in 1978. The 2000 publication also concluded that not all cataloged fragments were massive enough to cause a catastrophic collision…this would be especially true if the colliding fragment hit an antenna, stabilizer boom, or solar panel, or if the target were the empty tank of an upper stage. The presences of antennae, solar wings, and stabilizer booms were ignored in 1978, and obviously hitting one of these areas will only transfer a fraction of the impact energy to the entire spacecraft structure, reducing the likelihood of a catastrophic breakup. Also an impact into the empty fuel tank of an upper rocket stage may not transfer all the impact energy to the rocket body structure….again not causing a catastrophic breakup. We may have been lucky that only one of the four collisions since 1991 was catastrophic…or it may be that only one out of four of the collisions between catalogued objects will be catastrophic. The 1978 prediction of collision frequency becomes more consistent with the actual collision frequency by simply assuming that the area used in 1978 is the average catastrophic collision area, which was the intent of the paper. However, a more accurate understanding of both the non-catastrophic and catastrophic collision frequency is achieved by using data generated since 1978 in more accurate models currently used by the Orbital Debris Program Office. Despite the absence of random catastrophic collisions, the predicted fluxes of smaller debris in 1990 and beyond in the JGR paper are not too different from what has been measured as a result of the orbital debris program. Accidental explosions and a few intentional collisions almost certainly (continued) contributed to the similarity…. and possibly some non-catastrophic collisions involving an un-catalogued object also contributed. However, the major contributors were a number of small debris sources that were discovered since 1978. Even though these sources have produced a debris environment in the past that is about the same as predicted from collisions, past debris sources are fundamentally different from future random collisions between catalogued objects. The past sources produce debris at a rate that is proportional to the number of objects in orbit, while the future frequency of collisions will produce debris at a rate that is proportional to the square of the number of objects in orbit. For example, if one were to double the number of upper stages and payloads in orbit, each having a probability that they would explode, then the rate that debris is generated by explosions would also double. However the rate that debris is generated by collisions between these objects would increase by a factor of four. The 1978 prediction of a catastrophic collision between catalogued objects of 0.013 per year was based Directory: files files -> Answer True False 2 points Question 2 files -> Integer programming and game theory files -> 4 Integer Programming files -> Bpa vehicle Window Repair Scenario #1 task: Procure vehicle window relacement. Objective files -> Pop Warner History files -> North Carolina Inclusion Initiative Mapping Where Children with ieps are Being Served Purpose files -> Fall 2013 Spring 2014 Program Data: Standard 1 Exhibit 4d files -> Hanban – asia society confucius classrooms network 2010 request for proposal files -> Northern England’s set-jetting locations Download 394.08 Kb. Share with your friends:
|