Nuclear weapons, have, let's face it, a rather bad press. But nukes can be thought of as cute, cuddly and useful if they save mankind (and yes womankind) as we know them. Nukes, to their credit may save us by stopping Asteroids, bent on destroying Earth.
A Hypervelocity Asteroid Intercept Vehicle (HAIV) is a spacecraft being developed by NASA to deflect dangerous Near Earth Objects (NEOs) such as comets and asteroids that threaten colliding with Earth. HAIVs focus on utilizing powerful explosives, such as nuclear bombs, to achieve deflection by detonating on the surface of the NEO to change its trajectory away from Earth. This method of asteroid impact avoidance is intended to be used on dangerous NEOs detected within a short time frame (less than 5 years) before a possible impact event with Earth. The idea came about when asteroid detection became accurate and since then, scientists and engineers have come up with a well thought out design for an HAIV.
Even a meteor of only 30 meters in diameter (but weighing an estimated 13,000 tonnes) caused major damage in Chelyabinsk .
After detecting many of the asteroids within our solar system and observing their composition through meteorite remains, NASA has identified multiple large asteroids that may collide with Earth. To combat these NEOs, NASA has come up with the following design for an HAIV.
The vehicle is split into two major parts; the leader craft and the follower craft. These can be boosted into space by a Delta IV M+ "Heavy" booster rocket.
The leader craft is initially attached to the follower craft, but before impact the two crafts are spread out by an extendable pillar known as the AstroMast Boom. Furthermore, it contains the primary guidance systems including normal cameras and Lidar (light based radar). The purpose of this craft is to make an initial crater in the target NEO where the follower craft may detonate in. Doing this helps direct the explosive energy of the follower craft, hopefully applying enough force to change the orbit of the NEO.
The follower craft contains the following:
· Solar panels and batteries to power both the follower and leader craft.
· A large antenna and communication electronics to relay information back to Earth.
· A camera to check on the status of the leader craft.
· The NED (Nuclear Explosive Device) which detonate upon impact with the NEO.
· Thrusters and fuel tanks to help the vehicle to travel towards the target NEO.
· Other support systems and fail safes in the case of a malfunction.
Once the leader craft impacts the NEO and makes a crater, the follower craft detonates its NED soon after. It also relays back whether the detonation was a success or failure which can be confirmed by observation from the Earth.
There are numerous factors that have slowed the development of the HAIV. These include but aren't limited to budget, law, and irregular NEOs.
Initial test missions have cost between $600 million to $1.8 billion and these were to test the feasibility of the guidance. A full mission may cost much more than this amount, especially in the case of a NEO detected with a short time till collision with Earth. With recent cuts to NASA's funding, it is unsure whether an HAIV mission will ever occur.
The use of nuclear explosive devices is an international issue and will need to be addressed by the United Nations Committee on the Peaceful Uses of Outer Space. The 1996 Comprehensive Nuclear-Test-Ban Treaty technically bans nuclear weapons in space. But saving the Earth looks like a "peaceful" use...more see."