Planetary Attack Atomic Rockets. Traditionally, spacecraft attacking targets on a planetary surface are assumed to have a high ground advantage, referred to by Heinlein as the gravity gauge. This assumption, like many about space warfare is wrong for several reasons. Firstly, a spacecraft in orbit is very vulnerable to ground launched kinetics, which only need to intercept it to do lethal damage, as described in Section 8. Second, the ground based defenders are able to use the clutter of the planetary surface to hide their actions, while the attackers are clearly visible. Lastly, the planet itself offers advantages in the construction of defenses that serve as a very powerful force multiplier for the defender. The thought experiment that underlies the gravity gauge is two men, one at the bottom of a well, the other at the top, having a fight with rocks. The man at the top has an obvious advantage. However, like many analogies, this one has deep flaws. The largest is a misunderstanding of orbital mechanics. Php Code To Convert Html To Pdf. Bomb Detection Robot Project Pdf' title='Bomb Detection Robot Project Pdf' />Because of the motion of the orbital craft, any projectiles that it launches must slow down before they can leave orbit, and in low orbit, the delta V requirement can be significantly higher than is required for a defenders projectile to reach the attacker. The requirement depends heavily on the geometry of the situation, but it is outside the scope of this section. For more details, see Section 1. A consideration for this If warfare is about causing the maximum destruction, these space siege scenarios make sense. If warfare is about achieving political. As Cassinis tour of Saturn comes to a close, NASAs getting a bit nostalgic. Yesterday, the space agency released a photo of Saturns North pole the doomed. Tabtight professional, free when you need it, VPN service. A flurry of reports claim that bomb shelter sales have skyrocketed recently. Ron Hubbard, president of Atlas Survival Shelters, told a California Fox affiliate that. ISSN 2278 1323 International Journal of Advanced Research in Computer Engineering Technology IJARCET Volume 2, Issue 1, January 2013 47. INTRODUCTION This ebook contains 100 transistor circuits. The second part of this ebook will contain a further 100 circuits. Most of them can be made with. Bomb disposal is the process by which hazardous explosive devices are rendered safe. Bomb disposal is an allencompassing term to describe the separate, but. The V1 flying bomb German Vergeltungswaffe 1 Vengeance Weapon 1also known to the Allies as the buzz bomb, or doodlebug, and in Germany as Kirschkern. Get the latest science news and technology news, read tech reviews and more at ABC News. Space Weapons, Earth Wars. A warhead is unnecessary for the defenders weapons, as the targets orbital velocity provides all the kinetic energy required for the job. Another issue is that the rocket necessary for this type of mission is quite small. An R 1. 7 Scud B can reach a maximum altitude of approximately 1. Another version, the Scud C, is capable of reaching about 2. The MGM 3. 1A Pershing has an apogee of about 3. All of these missiles date back to the 1. Their warheads are rather heavier than would be optimal for engaging orbiting vessels, and lighter warheads could result in somewhat higher altitudes. For higher orbit engagements, something like the Pershing II altitude 8. Above that, the various ICBM type systems would take over, with apogees in the range of 5,0. Note that all of these missiles have warheads which are far heavier than are required for direct hit kill on any practical spacecraft. There are two ways this fact can be exploited. First, the warhead could be replaced by another stage carrying a smaller warhead and achieving a greater altitude. This should be good for another few hundred kilometers altitude, depending on the size of the warhead available and the previous burnout velocity. Second, the unitary warhead could be replaced by a bursting warhead, as described in Section 8. A detailed treatment of this concept with regards to planetary defense can be found in the Appendix to Section 1. Physics of Space Security. The two extant missiles that most closely approximate what would be required of a low altitude surface to orbit missile SOM are the THAAD Terminal High Altitude Area Defense and the SM 3. The current model of THAAD, the block 4, has a launch weight of 6. Later and presumably heavier models could improve the maximum altitude to as much as 5. The SM 3, which is currently ship launched, has a launch weight of 1. Later versions are reported to be capable of 1. Both missiles use the same sensor system, which is reportedly able to acquire targets presumably ballistic missile warheads at ranges above 3. The above missiles are listed to demonstrate that the basic physical requirements for an SOM are quite simple, and well within the grasp of current technology. All of the listed missiles are fired off of trucks of some sort or another with the exception of the SM 3, which does have a fixed land based version. THAAD itself is launched from a vehicle the size of a semi. If a system was designed explicitly for the SOM role, it should be very easy to conceal the missiles in trucks until the time of launch, preventing the attackers from detecting and destroying them. Even if the attackers can see everything clearly, if the trailer is self contained and built to look like an ordinary semi trailer, the attacker wont be able to tell it apart from the millions of others in use. Extensive tracking and control stations will be unnecessary, as the ship in question will be moving in a more or less predictable orbit, and the missile will have enough homing capability to compensate for the imprecision. Orbit determination is a well established science. All that is needed are a few measurements of time, observers position, and target bearing. These sensors are even easier to hide then the missiles themselves, as they could be as simple as a sextant at dusk or dawn. At night, it should be possible to detect the vessel, probably through radiator glow. Illinois State Police Patch. During the day, it is somewhat more difficult. This suggests that a sun synchronous orbit might be ideal for an attacking spacecraft, as dawn and dusk occur over the poles which are presumably largely uninhabited. However, the same could be said of any polar orbit, and other conditions are likely to play a large part in attack orbit selection. The advantage of a sun synchronous orbit is that the illumination angle beneath the spacecraft is nearly constant, but for a long period orbit, the inclination is likely to be fairly low, potentially placing dawn over an inhabited area. Geographical conditions are as likely to dictate the orbit as astrodynamical conditions, although the astrodynamic effects of attacking a non Earth planet should not be discounted. In some cases a sun synchronous orbit will place the attacker over territory that he would rather avoid. For example, a 2. North America will spend a large amount of time over South America, a situation that is hardly idea. For optimal results, attacks would be made in daylight, which gives the best conditions for the attackers sensors and the worst for those of the defender. The obvious counter to the visibility of spacecraft is for the spacecraft to maneuver regularly, hopefully spoiling any shots the defender may take. A burn of approximately 3 ms in the prograde or retrograde direction in a 1. Earth orbit will change the period of the orbit by 2 seconds and the semi major axis by about 5 km. What this means is that the spacecraft will arrive on the opposite side of the orbit either a second late or early respectively, and will be either 1. However, this is unlikely to be enough to spoil the attack. If the missile seeker locks on 3. V would be sufficient to compensate for the divergence, and it is quite likely that SOMs will be designed to frustrate such tactics. So long as the change remains relatively small, the results above can be linearized, with a 1. V producing a 4 second change in arrival time, and a 4. Note that the divergence in position only occurs in the orbital plane. The plane itself can be changed by a burn half an orbit away, but the spacecraft will still pass through a point opposite the location of the burn. For out of plane dodging, it is best to burn a quarter orbit away three quarters of an orbit will produce identical results. Moving the ground track 1. Earth reference orbit will require 1. V, significantly more than an equivalent amount of in plane dodging. To a first approximation, the dodge delta V for a quarter orbit burn will be approximately twice that required for a half orbit burn.