Small Debris > Threat (3/4)

Small Debris > Threat (3/4)

Space debris damage increasing, collisions make even small particles disastrous.

The Pentagon's Space Control Center in Cheyenne Mountain in Colorado tracks more than 8,500 manmade objects and has warned NASA 12 times to move the shuttle out of the way of a potential collision. The space station has moved six times after a military warning. But an estimated 95 percent of the objects that could cause critical damage to the shuttle are not tracked by the military because they are too small. "Even something as small as a fleck of paint, when it's traveling at really high speeds, could cause significant damage," Emero said. It is possible that Columbia was struck without the crew noticing. "Sometimes the mass of the particles is so small it impacts, and nobody feels anything and has no effect on the orbiter. Other times the reaction control system would react and fire a thruster a little, but it would be hard to notice that," Emero said. But just because an impact was so small it wasn't noticed does not mean it might not be fatal. "The speeds are quite enormous, 17,000 miles per hour in relation to the Earth. So even a small object moving at that speed has a lot of energy and could cause a lot of damage," he said. And even if the initial damage appeared relatively mild, it could have serious consequences if it occurred at an especially crucial location on the shuttle. Minor damage can turn into catastrophic damage under the intense pressures of reentering Earth's atmosphere. "It might be a tiny object -- maybe an inch or so in size -- could strike the shuttle's tiles. The tiles are like an Achilles' heel for the shuttle. Perhaps it was struck by orbital debris in a vulnerable place, and that might have caused heat to leak in during reentry, which led to a cascade of events that led to structural failure of the vehicle," Lindner said. The Hubble Space Telescope, which has been orbiting Earth for a decade, has a three-quarter-inch hole in its antenna that was probably caused by debris or a small rock. "There may be millions of these objects. Because they're moving very fast, they can do serious damage," Lindner said. The National Academy of Sciences panel recommended that NASA take steps to better protect shuttles against debris, including researching possible upgrades to make them less vulnerable and inspecting shuttles for possible damage before they descend back to Earth.

Small debris causes millions of dollars of damage to shielded space objects.

Campbell, 2000 (Jonathan W., Colonel USAFR, Center for Strategy and Technology, Air University, Maxwell Air Force Base, Alabama, Using Lasers in Space, Laser Orbital Debris Removal and Asteroid Deflection, December 2000, http://www.au.af.mil/au/awc/awcgate/cst/csat20.pdf, NG)

Fragmentation generally produces large numbers of objects that are too small to he [sic] tracked reliably. High-velocity impact tests have shown that shields that are designed to protect satellites can he effective against objects that are less than about 1-2 cm in diameter. Such shielding is part of the design for the International Space Stat ion. Depending on environmental requirements, satellites and space vehicles may require shielding, or active protection from impacts with small particles, notably orbital debris and micrometeoroids. For particles that are larger than 2 cm, the cost of shielding a space vehicle is prohibitive. There have been numerous surveys of debris in the 1-10 cm diameter range. Radar and optical surveys, when used in conjunction with computer models, reveal that there is roughly 150,000 objects in orbits below 1500 kilometers. The problem is that each of these objects is quite capable of causing catastrophic damage to shielded spacecraft, and yet are too small to he tracked reliably by avoidance sensors. The likely composition of the debris was considered by the Orion study. The debris was classified into five representative groups, with objects made of aluminum, steel, sodium/potassium metal, carbon phenolic, and multi- layer insulation (MLI). 1 Based on the number of objects in low-earth orbit, and using the Iridium satellite system as an example, if we assume that the replacement cost of one of the 66 satellites in the $3.450 billion system is roughly $50 million, then the total cost to LEO satellites from orbital debris is estimated to be roughly $40 million per year. Debris-related expenses that are on the order of tens of millions of dollars per year should he compared with estimates from the Orion study for debris removal. It estimated that eliminating debris in orbits tip to 800 km in altitude within 3 years of operation would not exceed $200 million. It was for this reason that the study team has proposed a technology demonstration project as a next step, which is estimated to cost roughly $13-28 million

Small Debris > Threat (4/4)

It’s those space debris that are between one and 10 centimeters that are most dangerous to satellites.

Ansdell in 10 (Master in international Science and Technology Policy at the University’s Elliott school of International Affairs with a focus on space policy, Princeton Journal of Public and International Affairs, Space Debris Removal, http://www.princeton.edu/jpia/past-issues-1/2010/Space-Debris-Removal.pdf, AX)

The most dangerous pieces of space debris are those ranging in diameter from one to ten centimeters, of which there are roughly 300,000 in orbit. These are large enough to cause serious damage, yet current sensor networks cannot track them and there is no practical method for shielding spacecraft against them. Consequently, this class of orbital debris poses an invisible threat to operating satellites (Wright 2007, 36). Debris larger than ten centimeters, of which there are roughly 19,000 in orbit, can also incapacitate satellites but they are large enough to be tracked and thus potentially avoided. Debris smaller than one centimeter, in contrast, cannot be tracked or avoided, but can be protected against by using relatively simple shielding (Wright 2007, 36).

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