After years of waiting and after the squeezing of the minds of thousands of engineers, designers, computer scientists, and technicians, the world observed the SLS (Space Launch System), being launched from Cape Canaveral LC-39B on Nov. 16. This launch officially kicks off the Artemis program to return mankind to our natural satellite, this time to stay there. The SLS, the heir sign of the legendary Saturn V, took off after 2 attempts: the first launch was postponed on Aug. 28 due to a leak in the cryogenic propellant, while the second time the rocket had to deal with Nicole storm.
Artemis program: an overview
Artemis program is composed of a series of Moon exploration missions, with the purpose to come back to the Satellite for the first time since the Apollo 17 Mission, after more than 50 years. If successful, the first woman and the first person of color will land on the Moon, and a lot of new technologies for future exploration will be demonstrated. The program is intended to be the most diverse international human space exploration coalition in history. Artemis I is led by NASA with the cooperation of the European Space Agency (ESA), the Italian Space Agency (ASI), the Israelian Space Agency (ISA), and the Japan Aerospace Exploration Agency (JAXA).
Static and ground tests
Neil Armstrong declared that the percentage of landing safely on the Moon’s surface of the Apollo 11 mission was around 50%. This is why NASA waited all these years to try to come back: failures are not admitted this time. A series of ground tests have been conducted before the launch to verify if all the systems were working properly. The most important static test was surely the Wet Dress Rehearsal. Just like in a theatrical show, all the systems are tested most comprehensively, starting from the onboard systems of the launcher to the Orion capsule (which still smells like a new car), without the rocket leaving the pad.
This 45-hour test has been conducted successfully on the ground on June 20, and NASA was able to determine the testing campaign completed. In the next illustration, you can find all the principal objectives demonstrated through this test.
NASA’s primary goal is to show first that all the infrastructures of the deep space exploration system work, which is divided between the Rocket, the Orion capsule, and the ground systems at the Kennedy space center in Florida.
The Space Launch System will carry also 10 Cubesats to test innovative ideas along with an uncrewed Orion spacecraft. Initially, the CubeSats were 13, but 3 of them were not ready for the deadline.
“The 13 CubeSats that will fly to deep space as secondary payloads aboard SLS on EM-1 showcase the intersection of science and technology, and advance our journey to Mars”NASA Deputy Administrator Dava Newman
These small satellites’ secondary payloads will carry science and technology investigations to help pave the way for future human exploration in deep space, including the journey to Mars.
The journey to the Moon will last 25 days, 11 hours, and 36 minutes, during which the spacecraft will travel for 2.1 million kilometers (1.3 million miles). During the whole mission, there will be a very heated activity on the ground to test all the onboard systems making sure that everything works properly.
Orion will fly about 97 kilometers (60 miles) above the surface of the Moon at its closest approach, during its flybys the capsule will exploit the gravitational force of the moon to mark an incredible record, traveling about 64,000 kilometers (40,000 miles) past the Moon.
This distance is 48,000 kilometers (30,000 miles) farther than the previous record set during Apollo 13 and the farthest in space any spacecraft built for humans has flown. Then it will proceed with the maneuvers that will bring it back to its planet of origin.
The mission will end with perhaps one of the most important tests, namely, to prove Orion’s ability to successfully re-enter the Earth’s atmosphere and make a landing in the Pacific Ocean where numerous teams will be waiting for it for recovery. The return will be traumatic: Orion will enter Earth’s atmosphere traveling at about 40,000 km/h (25,000 mph).
Earth’s atmosphere will slow the spacecraft down to a speed of about 480 km/h (300 mph), producing temperatures of approximately 3000K and testing the heat shield’s performance. With the recovery of the capsule, the mission can be said to be accomplished and we can advance toward the next milestone at full power with Artemis II.
SLS and Orion Spacecraft
With 111m in height and 4 million kg (8.8 million lbs) of thrust, the Space Launch System is the most powerful rocket in the world. This rocket is classified as a super heavy-launcher because it is designed to go beyond the Earth’s orbit. The SLS program development started many years ago, in 2011, and was supposed to be launched for the first time in 2016.
Two solid rocket boosters, which burn approximately six tons of solid propellant each second, and four RS-25 rocket engines accelerate the rocket to more than 23,000 km/h (17,000 mph) during the first 8 minutes of flight. Thanks to supercool propellants and hot combustion gases, these rocket engines withstand temperatures ranging from 20 K to more than 3500 K. As far as propellant and oxidizer SLS uses liquid hydrogen and liquid oxygen respectively, stored in two huge tanks.
On top of the first stage, it is possible to find the second stage which will have the task of ferrying the capsule on the long journey to the moon, hosting thirteen special missions, or CubeSats that various space agencies and universities have built to take the opportunity to study the cosmos more closely.
The service module was built by ESA (European Space Agency) with the participation of ASI (Italian space agency) as regards the development of the solar panels.
Finally, there is the Orion capsule, which will host the 4 crew members. Above the capsule, there is a special tower called Launch Abort System that will have the task of saving astronauts by tearing the capsule from the rocket in case of failure, the system’s powerful abort motor can accelerate from 0 to 800km/h (500 mph) in two seconds if needed during an emergency.