NASA is planning to return humans to the Moon, for the first time in over 50 years, with the Artemis program.
When Neil Armstrong landed on the Moon in 1969, one in six people across the world watched the historic event. By 1972, the last Apollo astronaut, Eugene Cernan, stepped off the lunar surface – the big budget programme and declining public interest in lunar missions meant the Apollo era had to come to an end. And whilst many years have passed with no sign of returning to the Moon, the long wait draws to a close with NASA’s Artemis Program which is set to return humans to the Moon by the mid-2020s.
Why are we going back to the Moon?
At the height of the Cold War in the 1960s, the United States and the Soviet Union were battling to land the first person on the Moon. Demonstrating the technological capability of human spaceflight to the lunar surface was the aim of the Apollo Program.
Since then, many space agencies have focused on robotic missions – to the Moon, but also to other planetary bodies. And they’ve been looking out into the wider cosmos too, for the purpose of building a better understanding of what space is like. In the case of the Moon, the exploration of its geology and resources (both on and under the surface) has been a top agenda.
The one human exploration programme that has been continuously running since the start of this millennium is crewed missions to the International Space Station (ISS). The aim of sending humans on six month-long trips to this low-earth-orbit laboratory is to investigate the impact of long-term spaceflight on the human body but also to explore ways of making living in space for long durations viable.
And so, the Artemis Program hopes to take all that we’ve learnt in the last few decades to not just return to the Moon for a few days as has been done before, but to instead pave the way for long term settlement on the Moon, which could spearhead human exploration to Mars and beyond.
As the new space era advances, it’s becoming ever more important to establish transparent rules on how we conduct ourselves when exploring space as current space law isn’t well defined.
Based on the principles outlined in the 1967 Outer Space Treaty, the Artemis Accords describe a shared vision outlining regulations on how everyone can explore and enjoy the outcomes of the scientific and commercial activities that will be brought about through exploration of the Moon and beyond.
As of March 2022, 19 countries are party to the Artemis Accords.
Space Launch System
With the Saturn V decommissioned in the 1970s, NASA needed a new launch vehicle to take humans back to the Moon. In early 2022, the long-awaited Space Launch System (SLS) rocket was unveiled. The mega rocket, which has been in development for about a decade, will be NASA’s choice vehicle to send crew and cargo to the Moon.
SLS will begin with a simple prototype (called Block 1) but will have further phases (block 1B and block 2) which will have increased capabilities. Even the SLS Block 1 will produce 15% more thrust than the Saturn V making it NASA’s most powerful rocket. It will generate 8.8 million pounds of thrust (where one pound of thrust is the amount of force required to prevent one pound, or 0.45kg, from falling due to the force of gravity on Earth.
This super heavy launch vehicle, with the crew exploration spacecraft atop, began its wet dress rehearsal in April 2022 – a series of key tests designed to show the infrastructure is ready for launch. After three failed attempts, a fourth go at a practice launch loading the rocket with fuel was successfully completed on 20 June 2022. Following a data review of the wet dress rehearsal, NASA will confirm a launch window – the earliest opportunity begins on 26 July, but it’s more likely Artemis 1 will launch in late summer.
Named Artemis after the mythological Greek goddess of the Moon and twin sister of Apollo, this crewed lunar programme from NASA will consist of a series of missions.
Artemis 1 will be an uncrewed test of the SLS and Orion capsule in a lunar orbital mission. The spacecraft will be launched on a 26-day mission that will see it spend six days orbiting around the Moon before returning to the Earth with a splashdown. During the mission, the spacecraft’s ability to operate beyond low Earth orbit will be scrutinised and the navigation and communication systems for use in deep space will be tested.
Artemis 1 is set to launch in summer 2022.
The second Artemis mission will be the first crewed mission in the programme that will take four astronauts on a lunar flyby test, but they won’t land on the Moon. This will be a crucial trial of the Orion spacecraft’s life support systems with a crew on board, and again will test critical functions and system performance. Taking a minimum of eight to ten days, but up to three weeks depending on other objectives, the mission will launch crew to the Moon on a hybrid free return trip. They’ll orbit the Earth twice to gain enough speed to propel themselves to the Moon and using its gravity, the spacecraft will slingshot back around to the Earth – no engine firing required. Their orbital path will take the crew further beyond the far side of the Moon than anyone has been before.
In December 2020 , NASA announced its Artemis team – a gender balanced, diversely experienced group of 18 astronauts picked from its corps who will fly on the first Artemis missions. Whilst the crew are yet to be announced, one of Canada’s four active astronauts will join three NASA astronauts on Artemis 2. They will become the first Canadian to travel beyond low Earth orbit and it would make Canada just the second country to have an astronaut fly around our lunar neighbour.
Artemis 2 is planned to launch no later than May 2024.
In between the three prime missions, there will be a number of Artemis support missions delivering scientific instruments and robotic rovers to the lunar surface – ready for the arrival of crew landing on the Moon’s south pole with Artemis 3.
Artemis 3 will have the first female and first person of colour stepping foot onto our lunar neighbour in a mission expected to last several weeks, with crew exploring the lunar surface for roughly one week. This will be the first time humans have stepped foot on the Moon since 1972 and will no doubt be a momentous occasion in 21st century space exploration.
Originally planned to make use of the Gateway (a multi-purpose outpost orbiting the Moon alike to the International Space Station), astronauts will now transfer from the Orion spacecraft (in which they launch) to the Human Landing System (HLS) in lunar orbit, before descending to the Moon’s service.
The HLS for Artemis 3 will be SpaceX’s lunar variant of the Starship vehicle. After SpaceX has successfully conducted uncrewed test flights to the lunar surface with Starship, it will be ready to deliver as part of Artemis 3.
Starship will begin by launching into Earth orbit where it will be refuelled by multiple Starship tankers before boosting itself into lunar orbit. There it will await a rendezvous with the Orion spacecraft that will be carrying the crew of Artemis 3. Once the crew have transferred over, it will shuttle them down to the lunar service in Starship leaving the Orion spacecraft to orbit the Moon. Starship will act like the Lunar Module used in the Apollo program.
Although SpaceX have been chosen to land NASA’s Artemis 3 astronauts on the Moon, the space administration is looking to appoint another private company to supply a HLS vehicle by early 2023 to make sure it has redundancy for future missions and drive the different private companies through competition.
Artemis 3 is targeted for no earlier than 2025.
The Lunar Gateway or more simply Gateway is a planned orbiting station around the Moon which will be crucial for missions beyond Artemis 3 to establish long term, sustainable presence on the Moon with a surface outpost by 2028.
Made up of different modules similar to the ISS, but about one sixth of its size, Gateway will provide living quarters for astronauts to stay for up to three months with occasional trips down to the lunar surface to help setup a base or conduct research. Beyond that, it will have laboratory facilities to analyse samples collected from the Moon.
An initial station with power, propulsion and habitation provisions being built by US companies Maxar Technologies and Northrop Grumman, is due to launch in November 2024. From thereon, other modules will be added including parts made here in the UK.
The ESPRIT module of the Gateway will consist of two parts: the Lunar Communications System and the Refuelling module. Thales Alenia Space in the UK will be constructing the chemical refuelling station at its three sites in Bristol, Belfast, and Oxfordshire. The ESPRIT module is set to launch in 2027 with Artemis 5.
Other UK companies will also be included in the building of the Service and Habitation modules of the Gateway known as I-Hab which will be launched with Artemis 4.
Gateway will be positioned in a near-rectilinear halo orbit meaning it will sit in a highly eccentric orbit around the Moon, kept in a relatively stable path due to being trapped by the gravity of the Earth and Moon. The orbit will rotate together with the Moon, so will appear a little like a lunar halo as seen from Earth. As a result, it will be able to maintain high communication with the Earth unlike the Apollo missions that would lose contact each time they passed around the far side of the Moon.
Future Crewed Exploration
We’ve been to the Moon before and while Artemis 3 will be a major achievement in the new era of space travel, it’s far from the end goal.
Artemis 4 will be the second crewed mission but will not travel to the lunar surface – instead, it will take astronauts to lunar orbit. Their main mission objective will be to deliver and dock the I-Hab habitat module to the first Gateway elements of the power, propulsion and habitation provisions that will have been sent on a previous mission. Artemis 4 is targeted for 2026.
From Artemis 5 onwards, missions are set to land astronauts on the Moon’s surface where the crew will be able to make use of the growing infrastructure including habitats, rovers, resource extraction equipment, and scientific instruments that’ll be landed by support missions. It will mark the first time since Apollo 17, that a Moon landing mission will make use of an unpressurised lunar rover to explore and travel further across the surface. Artemis 5 will also deliver ESA’s ESPRIT refuelling and communications module and a robotic arm system built by Canada.
About the author: Dhara Patel is a Space Expert at the National Space Centre.