Thread by @megsylhydrazine

This is what happens to aluminum when hit by a 1/2 oz (~14g) piece of plastic going 15,000 mph (~24000 km/h) in space 💥

#Hypervelocity

👆 shows the violence a little piece of orbiting space debris can wreak on a spacecraft 🛰

#Hypervelocity

That’s the great thing about Kinetic Energy (KE):

KE = ½mv^2

Velocity is *far* more important than mass. Doesn’t matter how light something is...if it’s moving really fast, it can pack a serious punch!

#Hypervelocity

For quick reference:

a high-powered rifle bullet goes about 1500 mph

(wayyy slower than that 15000 mph plastic space debris!)

#Hypervelocity

So how do we protect spacecraft against this orbital shooting range?

🛡Advanced Shields🛡

There are various concepts that have been developed and tested, and now help to protect spacecraft like the @Space_Station 🛰

Here are some different types...

#Hypervelocity

This is a “Monolithic Shield” 🛡

It’s your 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 the impact.

#Hypervelocity

This is a “Whipple Shield”🛡

It’s the first spacecraft shield ever implemented. Introduced by Fred Whipple in the 1940’s, it’s still used today.

It uses a sacrificial bumper -usually aluminum- in front of the spacecraft, allowing it to absorb the initial impact.

#Hypervelocity

This is a “Stuffed Whipple” Shield 🛡

It’s a variation of the simple Whipple.

Layers of Nextel and Kevlar are inserted between the bumper and rear wall to shock and pulverize the debris cloud even more 💪

#Hypervelocity

This is a “Multi Shock Shield” 🛡

🏆This is a popular design

It staggers layers of Nextel at specified standoff distances. The multiple layers repeatedly shock that debris until the remaining fragments are harmless against the rear wall.

#Hypervelocity

This is a “Honeycomb Panel”🛡

Many spacecraft are designed using Aluminum honeycomb sandwich panel structures (what’s with all the food refs?).

These panels are tested and evaluated for their MMOD shielding capabilities.

MMOD = MicroMeteoroid and Orbital Debris

#Hypervelocity

This is a “Foam Panel” 🛡

Metallic foam sandwich panels provide structural support - they’re similar to honeycomb panels, but have improved MMOD shielding capabilities.

Metallic foam panels are being tested and evaluated for future spacecraft designs.

#Hypervelocity

Lastly, this is a “Transhab Shield”🛡

This shield is a prototype developed for a future human-rated mission to Mars, and consists of layers of Mylar, Nextel, Kevlar, & Foam (cored out).

Foam is used because it’s desired that shielding be compressible for launch.

#Hypervelocity

For more information on shield development and hypervelocity impact technologies:

@Astromaterials 💥

hvit.jsc.nasa.gov/shield-develop…

#Hypervelocity

...and then I found the videos...

#Hypervelocity

This is an impact test for the @Space_Station lab module shielding💥

Purpose: generate damage representative of potential impacts on the ISS

Video: a ~0.4 inch (10 mm) aluminum sphere “micrometeoroid” impacting an orbital debris shield @ 12300 mph (~19800 km/hr)

#Hypervelocity

For any fans of shooting/marksmanship *and* space sciences, I think I found your perfect job:

High Velocity Impact Testing and Advanced Spacecraft Shielding Materials.

👉 hvit.jsc.nasa.gov/hypervelocity-…

#Hypervelocity #Engineering