Most spacecraft shielding solutions involve a combination of standard spacecraft shielding materials. A handful of proven and prototype shields are briefly discussed and illustrated below.
This Monolithic Shield is the brute force approach and does not win any points for ingenuity. It's simply a slab of aluminum capable of absorbing the entire force of an impact. This shielding method is mostly relevant as a comparison to equivalent mass advanced shields. Also, the monolithic shield can be used to represent the "default shielding" (a simple aluminum wall) against meteoroid and debris impacts.
The Whipple Shield is the first spacecraft shield ever implemented. It was introduced by Fred Whipple back in the 1940s, and is still in use today. Simply, it consists of placing a sacrificial bumper, usually aluminum, in front of the spacecraft, thus allowing it to absorb the initial impact. The Whipple bumper shocks the projectile and creates a debris cloud containing smaller, less lethal, bumper and projectile fragments. The full force of the debris cloud is diluted over a larger area on the spacecraft rearwall.
This is what the Debris Cloud looks likes like on the rearwall of a Whipple shield. The debris has caused damage to a wide area of the rearwall, but did not perforate it.
Stuffed Whipple Shield
The Stuffed Whipple Shield is a variation of the simple Whipple shield. Layers of Nextel and Kevlar are inserted in between the bumper and the rearwall. These additional layers further shock and pulverize the debris cloud such that any fragments reaching the rearwall are benign.
Mars Module Shield
The Mars Module Shield is a prototype shield developed for a future manned mission to Mars. The shield consists of layers of Mylar, Nextel, Kevlar, and foam. The foam is cored out inside in order to reduce mass. The foam design is used because it is desired that the shielding be compressible for launch (the entire Mars Transhab spacecraft must fit within the Space Shuttle). The shield will expand once the spacecraft is deployed in space.
Mesh Double Bumper Shield
The Mesh Double Bumper Shield consists of a double layer bumper of aluminum mesh, followed by an aluminum rearwall.
The Multi-Shock Shield is a popular shielding design. It consists of staggering layers of Nextel at specified standoff distances. The multiple layers of Nextel repeatibly shock the projectile and debris cloud until the remaining fragments are too harmless to breach the rearwall.
Beta Cloth Shield
The Beta Cloth Shield was tested as a possible shielding design for the ISS Common Berthing Module (CBM) shield. It consists of multiple layers of beta cloth placed in front of a rearwall.