Planetary Defense Foundation - Films

Planetary Defense Foundation Films uses computer-generated art to visualize seven likely scenarios for deflecting asteroids or comets that threaten Earth. Based on current scientific knowledge, these scenarios illustrate how planetary space programs and the international scientific community might prevent a devastating impact. 


Chemical rockets

Chemical rockets can provide a more immediate, though potentially less efficient, means of deflecting an asteroid. Here's how a spacecraft using chemical rockets could deflect an asteroid on a collision course with Earth:

1. Kinetic Impactor

The Concept: This is the most straightforward approach. The spacecraft, essentially a high-speed projectile, would be deliberately crashed into the asteroid.  


Momentum Transfer: The impact would transfer the spacecraft's momentum to the asteroid, altering its velocity and trajectory.  


Effectiveness: The effectiveness depends on the mass and speed of the spacecraft, as well as the mass and composition of the asteroid. Larger, denser asteroids are harder to deflect.  


Recent Example: NASA's DART mission successfully demonstrated this technique by impacting the asteroid Dimorphos.
  



Chemical Rocket Propulsion:
A chemical rocket is attached to the asteroid and ignited. 


Solar Sails

Solar sails deflect asteroids by using sunlight's pressure. Photons reflecting off a large sail create a continuous, gentle push, gradually altering the asteroid's trajectory. The spacecraft intercepts the asteroid, deploys the sail, and positions itself to maximize the solar pressure. Larger sails and longer application times enable greater deflection, but large asteroids require years or decades of constant pressure. While fuel-efficient and predictable, solar sail technology faces challenges in sail size and maneuverability. They are a promising, but still developing, part of planetary defense strategies. 


Challenges

Sail Size: Building and deploying extremely large sails is a technological challenge.

Maneuverability: Precisely controlling the spacecraft and sail orientation for optimal deflection can be complex.

Time Scale: Deflecting a large asteroid significantly might take years or even decades.


Important Note: Solar sails are a promising technology for asteroid deflection, but they are still in the early stages of development. More research and testing are needed to determine their effectiveness and feasibility.

Other Deflection Techniques: Solar sails are just one of several potential asteroid deflection methods. Others include kinetic impactors, gravity tractors, and nuclear options.

Planetary Defense: Asteroid deflection is a critical part of planetary defense strategies to protect Earth from potentially devastating impacts.



- Solar Ablation: A series of mirrors and lenses focus sunlight onto the NEO, causing material on the NEO’s surface to be expelled. 

- Laser Ablation: A spacecraft focuses a high-energy laser on the NEO, causing the material on the surface of the NEO to heat up and be expelled from the surface. 

- Standoff Nuclear Detonation: A nuclear explosive device is detonated near the asteroid, causing the asteroid's outermost layers to vaporize. 

- High Isp Rocket Propulsion: A high specific impulse (Isp) rocket is attached to the asteroid and fires its engines over an extended period of time (i.e. VASIMR)

Pending Update

 

- Mass Driver: A lander with drilling equipment attaches to the asteroid, drills material out, and ejects it at high velocity. 

- Kinetic Impactor: A spacecraft traveling at high relative velocity is impacted into the asteroid. 

- Gravitational Tractor: A spacecraft is stationed very near to the asteroid such that their mutual gravitational attraction pulls the asteroid off course. 

- NEO net 

- Magnetic Flux Compression