By Shashank Singhal
Aviation has been a favourite target for terrorist groups over the last three decades. Apart from the use of bombs as in September 2008 when 270 people were killed by a blast in the luggage bay of a flight in Scotland, terrorists have also resorted to other means. These include the use of a shoe bomb in December 2001, lethal liquids in August 2006; an underwear implant bomb in December 2009; packed printer cartridges in October 2010; and the insulated lining of beverage containers in December 2010. Some of the above were foiled by flight attendants while others were prevented by passengers or intelligence services. This commentary is focused on one particular method in which the aviation sector could be targeted in future; namely, suicide bombers carrying surgically implanted bombs in their body and blowing up airliners in mid-air. US intelligence has reported that the al Qaeda in the Arabian Peninsula may be considering the use of this method.1
Many advances have been made in detection devices such as full body scans that complement metal detectors. However, new technologies are being developed not only by scientists but also by terrorists. One of the new terrorist innovations could be surgically implanted bombs in the body of a terrorist travelling by air. This is not really new given that smugglers of contraband have been known to adopt this method. Nevertheless, the fact remains that such a bomb cannot be detected even by advanced detectors. The implant of a bomb in the body of a terrorist would be similar to a breast implant; only, instead of silicon, explosives like PETN would be filled in the abdomen, buttocks or even near the heart where pacemakers are placed. The detonator can be electronically managed like a pacemaker, or injected into place, or even mechanically compressed by pressing the breast downwards if planted there. Implants are so common that they are not noticed by security personnel.2 Depending upon the amount of explosive used, a plane can even be destroyed.
Governments will now have to consider ways of detecting the carriers of surgically implanted bombs. One way is to use lasers, which have been used to trigger PETN explosions. A pulse with a duration of 25 nanoseconds and 0.5-4.2 joules of energy Q-switched ruby laser can initiate the detonation of a PETN surface coated with a 100nm thick aluminium foil in less than half a microsecond.3 But if the laser were to be passed through the human body instead of aluminium foil at the same speed and energy it will not explode. Instead, it will heat up the body and this can be measured in an infrared radiation chamber. Thus, the provision of an infrared chamber is essential before and after the administration of the laser. Administering such a laser pulse to the human body is thus likely to help in detecting implanted explosives. Experiments need to be undertaken in this regard to identify the particular duration and energy that would be required to illuminate different parts of the body given the differing thicknesses of each part.
What of the infrastructure necessary for detecting surgically implanted bombs in the human body? A passenger will have to pass through first an infrared chamber, then a chamber where the laser will be administered and finally another infrared chamber. Laser and infrared chambers will be administered electronically through computers. During this process, a body containing explosives will heat up. Images from the two infrared chambers before and after the laser was administered will show observable changes if the body in question contains explosives.
This particular method is also useful to detect persons carrying explosives outside their bodies. In such a case, the bomb will be clearly visible in the infrared chamber.
At worst, using this technology may result in a bomb explosion. However, this can be eliminated by controlling the on-off time of the laser. The whole set-up can check a person in less than five seconds. As of now, there are no known side-effects from the use of lasers. But research must be carried out to clearly establish this.
1. Keith Johnson and Siobhan Gorman, “Bomb Implants Emerge as Airline Terror Threat,” The Wall Street Journal, July 7, 2011.
2. Shirley S. Wang, “I could train someone to do it within a few hours,” The Wall Street Journal, July 7, 2011.
3. Tarzhanov, V. I.; Zinchenko, A.D.; Sdobnov, V.I.(1996). “Laser initiation of PETN”. Combustion, Explosion and Shock Waves 32:454. Doi: 10.1007/BF01998499 (http://dx.doi.org/10.1007%2FBF01998499).
Originally published by Institute for Defence Studies and Analyses (www.idsa.in) at http://www.idsa.in/idsacomments/DetectingSurgicallyImplantedBombs_ssinghal_180711