As NASA organizes a push to return a human presence to the Moon for the first time since the Apollo era, the agency has made critical changes to the plan that would enable a crewed lunar landing to occur no later than 2024.
One of these modifications involved the Lunar Gateway, a modular space station that will be deployed in a seven-day near-rectilinear and elliptical orbit to function as a staging point for both robotic and crewed missions to the surface under the Artemis Moon program.
The Gateway is also being developed as a critical science outpost for Earth-based studies, as well as planetary geology and heliophysics research. In this effort, the station will demonstrate new technologies and hardware that are necessary for supporting future missions beyond Earth orbit, such as crewed missions to Mars.
NASA currently leads in the development of Gateway, with commercial and international entities serving as partners. All of NASA’s partners in the International Space Station effort – Roscosmos, the European Space Agency (ESA), the Canadian Space Agency (CSA), and the Japanese Aerospace Exploration Agency (JAXA) – will collaborate with the American agency in the assembly, servicing, and utilization of Gateway.
Illustration of future Lunar Gateway layout, showing international contributions – credit: NASA
The construction of two of the station’s mission-essential modules – the Power and Propulsion Element (PPE) and the Habitation and Logistics Outpost (HALO) – have been contracted to Maxar Technologies and Northrop Grumman Innovation Systems, respectively. Both modules are expected to launch on commercially-procured launch vehicles, with the PPE being scheduled to launch no earlier than 2022 to begin station assembly before the 2024 crewed lunar landing.
However, recent comments made by Douglas Loverro, the associate administrator of NASA’s Human Exploration and Operations Mission Directorate, seem to indicate the Gateway will no longer be required for such a mission in order to decrease risk of schedule delays and overall cost.
In a meeting with the NASA Advisory Council Science Committee on March 13, Loverro expressed that work was being done to increase focus on the necessary elements required to achieve a crewed lunar landing by 2024, and to decrease overall risk by temporarily removing certain components of the program, citing challenges in developing technologies and conducting activities that had not yet been accomplished in the environment of space.
Loverro stated in the meeting that this meant taking the Gateway off of the critical path towards the 2024 landing goal, but emphasized that NASA was still committed to building and developing the station. “By taking Gateway out of the critical path for the lunar landing in 2024, I believe what we have done is create a far better Gateway program,” he said.
Loverro also stated that these revised plans would not impact any development on the side of NASA’s international partners, saying that most agencies were not planning to add their contributions to Gateway before 2026. NASA officially informed all international partners of the updated plans on March 16.
“We can now tell them 100% positively it will be there because we’ve changed that program to a much more, what I would call, solid, accomplishable schedule,” he said. “If it gets behind schedule, no problem – you can still maintain it being there.”
Artistic render of Gateway in lunar orbit, with an Orion vehicle docked – credit: Nathan Koga for NSF/L2
Despite the removal of the lunar station from the 2024 landing infrastructure, NASA has made key scientific selections that will help Gateway astronauts observe space weather and the radiation environment.
On March 13, NASA announced that two scientific payloads had been picked to fly on Gateway, with the American agency and the European Space Agency (ESA) partaking in the development of these instruments. Launch dates for the two payloads have not yet been determined.
“Building the Gateway with our commercial and international partners is a critical component of sustainable lunar exploration and the Artemis program,” NASA Administrator Jim Bridenstine said in a statement following the announcement. “Using the Gateway as a platform for robotic and human exploration around the Moon will help inform what we do on the lunar surface as well as prepare us for our next giant leap – human exploration of Mars.”
NASA will build a space weather instrument suite, which will observe solar particles and the “solar wind” – a stream of charged particles that are released from the Sun’s upper atmosphere, or “corona”, at high speeds. Collecting data on these particles will help scientists further understand solar weather and enhance the ability to predict future solar outbursts, like coronal mass ejections or solar flares, that could affect astronauts during deep-space missions.
ESA will develop a radiation instrument package for Gateway, so as to monitor the radiation environment in and around the outpost’s unique orbit and provide further insight towards radiation protection for crewed deep-space vehicles.
Additional scientific payloads will be selected to fly on Gateway in the near future as development continues.
Along with space environment studies, ESA has also begun backing a study that envisions the possibility of using Gateway as a deployment mechanism for planetary defense missions, in the event that an asteroid intercept and deflection is required.
Schematic of NASA’s Double Asteroid Redirect Test (DART) mission plan – credit: NASA/Johns Hopkins APL
According to ESA, these missions could depart Gateway and conduct an intercept while using much lower-energy trajectories than if they were launched from Earth, and that they could be stationed in readiness with the benefit of a faster response time for increased effectiveness.
While no planetary defense missions have yet been launched, NASA’s Double Asteroid Redirect Test (DART) spacecraft will impact the smaller of the Didymos binary system of asteroids in an attempt to shift its orbit. This mission is currently slated to launch atop a SpaceX Falcon 9 rocket from Vandenberg Air Force Base no earlier than June of 2021.
The DART mission will be followed soon after by ESA’s Hera spacecraft, which will assess the effects of the impact and verify whether a deflection occurred. Hera is currently due to launch no earlier than 2024 aboard an Arianespace Ariane 6 rocket, with arrival at the Didymos system in 2026.