June 18, 2015

Know How... 148: Rockets, RRoD Fix, and Gasification

42 minutes

The most powerful engine in the world, fix for the Red Ring of Death, how a Gassifier works, Hobbyking FPV kit, visualize the RF energy around you, and more.

Aerojet Rocketdyne RS-25

You've seen these before, they were known as the "SSME" or "Space Shuttle Main Engine"

It's a staged, liquid-fueled cryogenic rocket engine that was conceived of in the 60s, designed in the 70s and first flown in the 80s.

The fuel and oxidizer is first dumped into a small combustion chamber and ignited.

Those gasses are used to drive turbopumps which pressurize the fuel and oxidizer to be burned in the main combustion chamber

The exhaust from the small chamber is then dumped into the HighPressure manifold, adding to the thrust of the engine

When we were first developing our rocket engines, we couldn't make a proper 2-stage engine. They kept blowing up. It's actually VERY tricky to exhaust the gases from the primary combustion chamber into the high-pressure manifold

So we would just waste that potential thrust

We learned how to do it properly from the Russians. It burns a combination of liquid hydrogen and liquid oxygen. - The engine can product 418,000 lbs of thrust at liftoff.

Fun Fact: the SRBs on the Space Shuttle generated 2,800,000 lbs of lift (83% of total thrust at liftoff) -- But the SRBs only provide lift for the Shuttle for 2 minutes while the 3 RS-25 engines continued to burn for 8.5 minutes. -- And since solid fuel burns unevenly, it created a "rougher ride" for the Shuttle astronauts than for, say-- the Apollo Astronauts.

A total of 46 RS-25 engines were made, at a cost of $40 million each. -- They were reusable, so they would be refurbished and requalified after each flight. The exhaust from the RS-25 can reach temperatures of 3,315 degrees Celsius which is enough to BOIL iron... it would definitely destroy the nozzle

To prevent that from happening, the fuel (liquid hydrogen) is pumped through a series of small tubes in the nozzle to keep the material below melting.

The heated fuel is then released into the combustion chamber where it combines with the oxidizer (liquid O2) and products thrust.

This engine, from 50 years ago! will be the future of space travel for the US -- It's the engine for the upcoming "Space Launch System"

Hosts: Fr. Robert Ballecer, SJ and Bryan Burnett

Technical Director: Alex Gumpel

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