RS-25
The RS-25 engines
are the most powerful engines in the world. Also they will be the first
reusable engines in history. They were used 30 years ago on another mission,
but now they know that they are the right ones to carry with this mission.
These engines are 200 feet long and have a diameter of 275.6 feet of diameter.
They will be the main engines powering the SLS. They will also be the only ones
to function on all of the missions while the astronauts are in space.
The RS-25 will
function with hydrogen and liquid oxygen fuel. These engines are already in
Florida for trials and they are installing new technology like new hardware and
a new battery.
Each engine will be equipped with a Main Engine Controller, an
integrated computer that controls all of the engine's functions and monitors
its performance.
These engines
are very sophisticated because they have 50,000 parts. The engines produce a specific
impulse for 453 seconds in a vacuum, or 363
seconds at sea level, consuming
1,340 L of propellant per second. They have a mass of approximately 3.5
tones and are capable of throttling between 67% and 111% of its rated power
level in one percent increments. The RS-25 operates at extreme temperatures,
with the liquid hydrogen fuel being stored at 250 °C while the temperature
in the combustion chamber reaches 3,315 °C
After 135
missions and more than 280 hours of trials, 100% of missions succeeded. So
before using this huge engine, that is referred to with the nickname of “Clark
Kent”, they will make further trials to show this is not only the best engine in
history but also the right one for the mission. So these engines will allow the SLS to push 73 times faster than an Indi-500
race car.
Here are some
examples that NASA gives us on their official page to know how powerful these
engines are:
The fuel turbine that is on the RS-25 is so powerful that if it were
spinning an electrical generator instead of a pump, it could power 11
locomotives; 1,315 Toyota Prius cars; 1,231,519 iPads; lighting for 430 Major
League baseball stadiums; or 9,844 miles of residential street lights -- all
the street lights in Chicago, Los Angeles or New York City.
Pressure in the RS-25 is equivalent to the pressure of submarine
experiences three miles beneath the ocean.
The RS-25 engines will be
starting their final trials after they
finish testing the J-2X, at the end of November 2014.