Artemis I: All about NASA's new SLS rocket launching to the Moon on August 29

The Artemis I mission is set to launch on August 29 after NASA gave the mission a ‘go’ following the completion of the Launch Readiness Review. The uncrewed endeavor will see the new Space Launch System (SLS) rocket liftoff for the first time from the Kennedy Space Center, kickstarting the Artemis Program.

It is worth noting that one of the objectives of this mission is to test SLS' abilities for a lunar mission with astronauts in the future. As the rocket nears its inaugural launch, let us take a look at what makes this launch vehicle special.

Decoding the SLS rocket

For the uncrewed Artemis I mission, NASA is using the Block 1 Crew configuration of the rocket which stands 322 feet tall, weighs over 26 lakh kg (5.75 million lbs), and can generate a maximum thrust of 8.8 million lbs. The SLS rocket has six different configurations for Crew and Cargo and its thrust capacity goes up to 9.5 million lbs. Besides, Block 1 is capable of carrying 38 tonnes of payload, including Orion and its crew, to deep space. 

(SLS rocket configurations; Image: NASA)

According to NASA, this new launch system has been developed using upgraded hardware from the space shuttle and Apollo programs. The engineers have also added some new parts to this rocket which makes it fit for deep space missions which require higher performance levels. Now breaking down the major components of the rocket, it consists of two twin solid rocket boosters, one core stage equipped with four RS-25 engines, a Launch Vehicle Stage Adapter, the Interim Cryogenic Propulsion Stage (ICPS), and the Orion Multi-purpose Crew Vehicle, which would consist of the Orion Crew module. 

(A breakdown of SLS rocket's components; Image: NASA)

Now when the launch window opens at 6:03 pm IST, the four RS-25 engines will burn 7,35,000 gallons of liquid propellant stored in the core stage's tanks to create two million pounds of thrust. Additionally, the twin rocket boosters will burn more than two million pounds of solid propellant to create more than seven million pounds of thrust during liftoff. In the first two minutes of the launch, the twin boosters will build momentum before separating from the core stage and crashing into the Pacific ocean. 

In the next six minutes, the core stage will ignite its engines for an uphill journey away from the Earth's gravity. This will be followed by a push from the second stage (ICPS) that will raise the Orion spacecraft, fitted onto the European Service Module (ESM) higher into orbit. Once all systems are clear for the journey ahead, the ICPS will fire again to provide Orion an escape to the Moon.

This rocket is being used to send Orion where no spacecraft has ever travelled before. After its separation from the core stage, the Orion will head toward the Moon two hours following the launch. After a roughly 3,86,000 kilometers-long journey, when the spacecraft skims around 100 km above the lunar surface, it will swing toward an orbit 61,000 kilometers beyond the Moon. In total, this will put Orion 4,50,000 kilometers from Earth, farther than any human-rated spacecraft's reach. 

Notably, the mission would not end until the Orion spacecraft splashes down into the Pacific Ocean after enduring the unforgiving atmospheric re-entry. This would give the mission teams a chance to test Orion's heat shield for crewed lunar missions ahead under the Artemis Program.