March 13, 2015 – NASA’s Space Launch System (SLS) is an advanced, heavy-lift launch vehicle that provides an entirely new capability for science and human space exploration beyond low-Earth orbit.
SLS will be the most powerful rocket in history, and is designed to be flexible and evolvable, to meet a variety of crew and cargo mission needs. SLS utilizes Orbital ATK’s five-segment boosters to propel the rocket off of the launch pad and for the first two minutes of flight.
Here are some quick facts about the SLS:
Twin solid rocket boosters were first introduced for human spaceflight missions on the first launch of the space shuttle April 12, 1981.
Each five-segment SLS booster burns 1,385,000 pounds of propellant in two minutes. That is an average of 5.5 tons of propellant every second.
The SLS booster generates 20% greater average thrust than the Space Shuttle booster and 24% greater total impulse.
Each booster produces 3,600,000 pounds of maximum thrust – greater than fourteen 4-engine Boeing 747’s at full take-off power.
During operation, the temperature of the five-segment booster motor chamber gases reach 5,600° F. At this temperature, steel does not melt – it boils.
The stacked booster is 177 feet tall, or as tall as a 17-story building, or taller than the Statue of Liberty from base to torch.
Once assembled, each booster will weigh more than 1.6 million pounds, or as much as four blue whales combined.
The primary components of the SLS booster contain the motor, forward structures and aft structures. These components combine for a total weight of 1.6 million pounds.
A 600-gallon bread mixer is used to blend the propellant materials together before being cured. The propellant is mixed in bowls and it takes about 45 bowls to make the necessary amount of propellant.
It takes 5 hours total from mix to cast, and only 3-4 bowls can be mixed at a time, so this is an around-the-clock process until it’s complete.
When the propellant is mixed, it resembles play-dough. After the propellant is cured, it has the appearance and texture of a pencil eraser.
Each of the five booster segments is filled with 280,000 pounds of propellant.
The two boosters could supply enough power for over 92,000 homes for a full day.
After the hot test on March 11, the booster was roughly 3,000° F. It was cooled by water for at least three hours and 31 tons of Carbon Dioxide was pumped into the booster core through a nozzle to preserve the data from the test.
The core stage towers more than 200 feet tall and holds 196,000 gallons of liquid oxygen and 537,000 gallons of liquid hydrogen.
Measuring 27.6 feet in diameter, the core stage is the same size as a giant sequoia tree.
The SLS uses four RS-25 engines which are 14 feet tall, 8 feet in diameter and weigh 7,775 pounds each.
The power generated by 4 RS-25 engines is equivalent to the output of 16 Hoover Dams.
If 4 RS-25 engines pumped water, rather than fuel, they would drain a family-sized swimming pool in 20 seconds.
4 RS-25 engines generate power equivalent to 3,386,364 miles of residential street lights. That’s a street long enough to go to the moon and back 7 times, then circle the earth 1/2 times.
To fit NASA’s future needs for deep-space missions, there will be several versions of the rocket, beginning with a 70-metric-ton (77 ton) lift capability to one of 130 metric tons (143 tons).
The 70-metric-ton configuration will provide 10% more thrust at launch than the Saturn V rocket and carry more than three times the payload of the space shuttle. It will produce 8.4 millions pounds of thrust at liftoff, the equivalent of 13,400 locomotive engines.
The first SLS mission – Exploration Mission 1 – will launch an uncrewed Orion spacecraft to a stable orbit beyond the moon and bring it back to Earth to demonstrate the integrated system performance of the SLS rocket and Orion spacecraft.
The second SLS mission – Exploration Mission 2 – will launch Orion with a crew of up to four astronauts farther into space than humans have ever ventured.