Sunday, August 2, 2009

Near Space Security of Assets

Asset assurance needs to be top priority for near space security. Major manned and unmanned platforms are vulnerable to even the smallest bits of debris. Space debris is a matter of cleaning the environment for current and future usage of orbits. There are some major problems in cleaning orbits. First is identification, second is to deorbit the debris, third is protection of platforms.

Identification of debris:
There are several methods of debris identification. Some are more effective than others.
Radar is discussed as an option. There are several issues with radar that cannot be currently resolved in near space.
1. Range. The range of naval radar is no more then 100 miles. Debris travelling at 20,000 miles per hour will traverse 333 miles in a second. Any bit of debris would hit a platform before it could be identified.
2. Size of debris. Most space debris is very small. Most debris would never even show up on radar in optimal conditions.
3. Power requirements. The average power consumption of an Aegis ship based radar platform is 485 kwm^2. This would require putting a nuclear power plant in near earth orbit.
4. Effective platform. The platform required to utilize and maintain a radar platform along with its power supply would be as large as a naval frigate. This would take years to develop and deploy. It would be a project in the magnitude of deploying another International Space Station just to protect the current space station.
Ladar has similar problems as Radar. Reflectivity is the main issue. The debris must reflect the laser. This will not occur with small or poorly reflective debris.
Infrared Radhard CMOS camera would be the most effective tool currently available for detection of debris. CMOS cameras use <100 mW of power. These cameras can be placed on the current space station with little change to existing systems. They can take pictures of the sky above the space station identifying debris as it passes overhead. This can give exceptional lead time to controllers allowing for shielding or collection of debris.

Shielding: There are several methods that must be used in tandem to protect assets. These are physical protection, magnetic fields, collection, and changing orbits of larger pieces of debris.
1. Physical protection. The use of Kevlar needs to be developed by nations to protect near space assets. Kevlar encased aerogel should be used to shroud manned platforms. This provides layered protection to several hazards in space. By wrapping the spacecraft and by using shields on shock absorbing positional arms will provide excellent protection.
a. Debris
b. Thermal
c. Radiation

2. Magnetic fields. The use of magnetic fields has not been evaluated by nations as an effective form of protection. Using simple magnetic fields several thousand miles away from the platform will push most debris out of their current orbit. If done correctly, debris can be pushed into the Earth’s atmosphere. If used with identification tools, magnetic fields can be altered to match the debris’ size and speed. Small spacecraft can be deployed around the station as an effective barrier.
3. Collection vehicles. It is imperative that nations develop collection vehicles to be deployed from the station to recover debris and place it in a safe orbit.
4. Similar to collection vehicles. To remove large pieces of debris, vehicles would attach themselves to large garbage and use thrust to deorbit the junk.

In conclusion: It is imperative that nations protect space based assets. All these systems must be used in combination to provide effective protection.

I was asked to write this paper by Near Space Security for possible inclusion in March 24-25th 2010 conference in Amsterdam.
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