NASA's SLS rocket is an engineering marvel. Here's what each major component does
The countdown is well underway to launch NASA's moon-bound Artemis I mission.
NASA is preparing to launch SLS to orbit as soon as Monday, August 29. Once there, the Orion spacecraft hitching a ride atop SLS will detach to make its way towards the moon.
The mission will kickstart NASA's Artemis launches, which will send humans back to the moon for the first time since 1972, and also pave the way for crewed missions to Mars.
A lot of hard work has gone towards the August 29 launch, culminating in the launch of SLS. The powerhouse rocket's many components were built by many organizations, each serving a vital purpose. Here is a visualization of the major components of SLS. Below we provide more information on each separate part.
If SLS does launch on August 29, as planned, these components will work in unison to send SLS skyward and Orion on towards our celestial neighbor.
The Orion spacecraft
The Orion spacecraft comprises the launch abort system, the crew module, and the European service module. The launch abort system is designed to react within milliseconds to any anomaly so that it can propel the crew module to safety if needed.
The crew module will stay empty for Artemis I, but it will house four astronauts for NASA's Artemis II mission. The European service module is the European Space Agency's (ESA's) contribution to Orion.
It is a crucial component that provides electricity, water, oxygen, and nitrogen required for propulsion and to keep systems running. It also features four seven-meter-long solar wings, each of which will have 3,750 solar cells.
The Orion stage adapter
SLS won't only send the Orion spacecraft beyond the moon and back. It will also launch 10 small CubeSats into space to carry out several scientific missions.
These include a solar sail mission called the Near-Earth Asteroid (NEA) Scout mission that will investigate a near-Earth asteroid. Another CubeSat will carry yeast into deep space to test the effects of radiation on living organisms.
Aside from connecting Orion to SLS, the Orion stage adapter will also carry and deploy these 10 satellites into orbit after the Orion spacecraft is detached.
Interim cryogenic propulsion stage (ICPS)
The ICPS, built by Boeing and United Launch Alliance, will provide in-space propulsion for Orion to send on its trajectory towards the moon and back.
Measuring 45 ft (13.7 m) tall and 16.7-foot (5.1 m) in diameter, it is a single-engine liquid hydrogen/liquid oxygen-based system that will fire up after the solid rocket boosters and core stage have served their purpose and are jettisoned. The RL10B-2 engine will produce 24,750 pounds (110kN) of thrust to power Orion towards the moon.
Launch vehicle stage adapter
The 27.5-foot-tall (8.3-meters-tall) Launch Vehicle Stage Adapter covers and protects the ICPS's RL10 engine throughout the launch. It also connects the ICPS to the core stage and serves as a separation system.
It was designed in a cone shape because it connects the 27.5-foot diameter core stage to the 16.5-foot diameter ICPS.
SLS's 212-foot-tall core stage serves the vital purpose of carrying the massive amounts of fuel required to power lift-off.
It holds 733,000 gallons of propellant to power SLS's four RS-25 engines. It features a liquid oxygen and a liquid hydrogen propellant tank. These will feed the engines approximately 1,500 gallons of propellant per second for eight minutes after launch — the time it will take SLS to reach orbit.
Solid rocket boosters
Each of SLS's two solid rocket boosters is the height of a 17-story building. Each generates 3.6 million pounds of thrust, providing 75 percent of the required power during the first two minutes of launch. After those first two minutes, their job is done.
Each solid rocket booster will burn roughly six tons of solid propellant per second to help lift during those first two minutes, helping SLS soar towards orbit.
Four RS-25 engines
As per NASA, the RS-25 engines attached to the underside of SLS's core stage are "the most efficient engines ever built". RS-25 engines were used for NASA's Space Shuttle program, and NASA uses enhanced versions of the same engine for SLS.
They will provide a total of two million pounds of thrust after launch. This, alongside the thrust provided by the solid rocket boosters, will send SLS flying into orbit at a speed of 17,000 mph (approx. 27,350 km/h). They will be fired up for the full eight minutes it will take SLS to reach orbit.
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