Three countries, three missions. This year, new state-of-the-art rovers and orbiters from the United States, the United Arab Emirates (UAE), and China will be on their way to Mars. Designed to search for evidence of life, map the planet’s climate, and drill into its surface, these missions will answer some of astronomers’ longest-standing questions about the red planet and set a new precedent for space exploration outside of the moon.
The journey to Mars begins with the UAE’s Hope orbiter, a spacecraft that aims to circle the red planet and investigate its atmosphere, with the goal of creating a global map of the climate across an entire year. Armed with an infrared spectrometer, an ultraviolet spectrometer, and a camera, the orbiter will give scientists their first view of the Martian atmosphere by monitoring solar wind, hydrogen, and oxygen.
Joining the UAE on the red planet will be China’s Tianwen-1. Not only does the spacecraft plan to orbit the planet, but it’s aiming to be the first Mars mission to drop a landing platform and deploy a rover. The rover will be equipped with a radar device that can detect water and ice beneath the surface, as well as a laser to track rock compositions.
While this will be the UAE’s and China’s first attempts at reaching the red planet, it will be NASA’s fifth. The Perseverance rover, expected to land in February 2021, has been the focus of the space community, and its mission is to find potential evidence of life and collect samples to return to Earth. Notably, once the rover lands, a helicopter named Ingenuity will make its debut by launching out of the rover’s belly. NASA plans to operate the helicopter within the first 90 days of the mission with the hopes of getting a new perspective of the planet’s geology.
As global space agencies prepared for these historic missions, several of the latest advances in space exploration were published in IEEE journals. We’ve highlighted some of the top studies that may be helpful in future missions.
Navigation on Mars has proven to be a complicated task. Not only do rovers have to be wary of unpredictable weather, but they can suffer from other complications when landing on difficult terrain, including craters, cliffs, boulders and rocks.
NASA’s Ingenuity copter hopes to mitigate this problem by serving as a scout for Perseverance by detecting hazardous materials in advance, in addition to providing useful information to map the rover’s path. This is illustrated in figure 1.
Figure 1: When NASA reaches Mars in February 2021, it plans to launch the Ingenuity helicopter.
A research team from the Aerospace Exploration Agency (Japan), the California Institute of Technology (Pasadena, California), and the Eindhoven University of Technology (Netherlands) recently proposed an additional solution for these navigational obstacles. The team developed a three-agent system that addresses localization uncertainty by mapping out optimal routes for a rover on a mission. Composed of a Mars rover, helicopter, and orbiter, the mapping system combines a copter’s high-resolution data with the help of a satellite or orbiter to pinpoint ideal terrain for the rover to drive on.
In the upcoming Mars 2020 mission, the team suggests that a satellite could serve as a base point by capturing an aerial view of the planet. While the use of a satellite comes with many uncertainties, including low resolution of the terrain, it provides the largest imaging of the Martian landscape. This can then be enhanced and improved by the copter, depending on the altitude range.
Figure 2 below illustrates the copter’s ability to observe and map regions of the planet in 3D. The lower the altitude, the more accurate the observation is. Additionally, after each measurement and observation, the satellite map is updated for the rover to use as it moves forward. Notably, the uncertainty the rover could face as a result of undiscovered territory decreases as the number of images captured by the copter increases, thereby enabling a smooth mission.
Figure 2: A three-part Mars mapping system involving an orbiter, helicopter and rover.
For future missions, this mapping method could reduce the uncertainty rovers typically face, including the risk of collisions, driving through keep-out zones, or damage to the tires and spacecraft.
Ultimately, space agencies aim to achieve the goal of sending the first humans to Mars. For humans to live and work in space, it’s essential that they have access to life-sustaining supplies like oxygen and water. However, in deep space, those essentials are limited, and resupplying missions are prohibitively expensive at long distances. So, it’s crucial for life-sustaining products to be generated from materials found on Mars. This process is referred to as In-Situ Resource Utilization (ISRU), a method that can also be used to extract and collect resources when humans aren’t in space.
To successfully mine for materials with little-to-no intervention from Earth, researchers from the California Institute of Technology identified how autonomous ISRU operations can be implemented by a spacecraft to not only reduce mission costs, but also to successfully make decisions that include extracting water and mining rocks. The process also entails dictating what path to take between the excavation, processing, and dump sites, as well as what preventive maintenance needs to be performed.
Design also has a significant role to play. With little human intervention, the autonomous systems are expected to perform tasks such as breaking down, scooping up, transporting, and dumping materials. These functions are laid out in Figure 3.
Figure 3: A In-Situ Resource Utilization system for mining in space.
Essentially, every element of the spacecraft will need to withstand the Martian landscape to successfully function. Paths will need to be smoothed out and stabilized with sensors put into place to simplify operations and monitor progress. Parts that can be easily worn out will need to be separated or replaced with spares without support from Earth. The ISRU system will need robust maintenance to support a successful mission with little error.
ISRU systems have also shown to be economical, especially when considering the costs of swapping out parts versus replacing failed equipment in space. Still, ISRU systems haven’t eliminated the need for human intervention just yet. Over time, researchers hope to replicate human processes and simplify autonomous robot requirements, so that a reliable system can be created for long-term missions.
Drilling on Mars
Since most Mars missions involve searching for proof of life or studying rock samples, it’s no surprise that the majority of discoveries lie beneath the surface. As space travel increases, subsurface exploration through drilling is expected to become increasingly common. However, with so many different techniques, which is the most effective for a landscape like Mars?
To answer this question, a team from the University of Surrey in the United Kingdom identified various space-drilling methods that would give explorers the ability to reach new depths at a faster pace. The team experimented with different designs of a drill inspired by a wood-wasp, as shown in Figure 4 below, to determine optimal penetration levels and drill time. They also took into account how the geometry, or design and feature of a drill, can be crucial to its performance and desired outcome.
Figure 4: The wood-wasp’s drilling technique has inspired some astronomers working to identify the best drilling methods in space.
For a planet like Mars, convex drill bits are more promising than concave, given their ability to handle and switch from soft to coarse-grain terrain. Customizable drills are also encouraged, given that they can be manufactured to fit a specific location, whether soft or hard in formation.
Figure 5: Types of drill bits investigated for the space-drilling abilities.
However, for successful drilling missions on Mars, scientists will need to continue to learn about the planet’s terrain, gravity levels, temperature, and pressure. Understanding how each of these elements work together can make the biggest difference in reaching new exploratory levels with drilling.
Disrupting space exploration
It’s been more than 50 years since the first mission to Mars. What started as a flyby in 1965 has quickly evolved to remote explorations from multiple countries. Each mission has given astronomers more information about the planet’s geology and habitability potential. While we are still years away from human missions to the Martian planet, this year’s Mars 2020 missions will take us one step closer to making that dream a reality. Understanding the complexities involved for a mission of this magnitude can pave the way for scientific breakthroughs and future explorations to other planets.