It is 2021-sunrise on Mars, and a reddish-tinged haze surrounds the Perseverance Rover. As the robotic geologist surveys the landscape of jagged rocks and dust devils, the walls of Jezero Crater beckon for its long traverse across the plain of Isidis Planitia.
Overhead, the two-kilogram Ingenuity helicopter buzzes as its cameras survey the landscape once a day. As the rover moves at a methodical pace to its next interrogation spot, it looks back towards home with its medium gain antenna. The rover transmits data back to its human operators in Mission Control in California twice a day via X-band radio frequency, a microwave portion of the electromagnetic spectrum used for communication between spacecraft and Earth.
The signal takes up to 14 minutes over a distance of more than 400 million kilometres.
What we have learned from Sojourner, Spirit, Opportunity, and Curiosity rovers over the past 25 years has laid the scientific and technological foundations for the human beings who will follow.
I have often wondered whether I will ever set foot on the sands of Mars. In 2012 a part of me did with the landing of the Curiosity Rover while working as a member of the entry, descent and landing engineering team.
Curiosity
Back on Earth, I am preparing a lecture for my graduate class Entry and Landing Systems for Planetary Exploration. As I compile the specifications of a Mars landing system so my students can do their own calculations, I ponder how best to train them for a mission to Mars.
Ever since I was a child, I have wondered if there was sentient life out there, perhaps not in our solar system, but surely in another solar system, even within the Milky Way Galaxy.
After two decades working for the space programme as a student researcher and engineer I know what it will take to get us there this century. For that, let’s take a journey through time from Earth to Mars.
Ingenuity
It is 2040 and the first human explorers reach Mars orbit after the seven-month interplanetary cruise. The crew descend to the surface inside an entry capsule just like several rovers did on missions before them, only larger and significantly heavier.
To protect the crew from the extreme heat during entry, the capsule is made from a carbon composite construction with an inflatable heat-shield. Descending rapidly through the upper atmosphere, aerodynamic drag dissipates most of the kinetic energy, slowing the vehicle from hypersonic to supersonic speeds. Because the atmosphere of Mars is very thin compared to Earth, supersonic retro-rockets are fired. This provides thrust in the opposite direction and further slows the capsule making the landing a soft touch-down on a pad of sintered Mars soil bricks that robots have laid down in the past five years.
After landing, the crew inspect the supplies and equipment which were sent by prior robotic missions and await their arrival. Redundancy, planning, and backups are a necessity when you are the first explorers to a new world 400 million kilometres from home. They begin setting up a permanent Mars basecamp.
Perseverance
It is 2050 and the fifth Mars Expedition prepare themselves mentally for the two-year stay. After landing, the crew suit up, disembark and enter a pressurised and environmentally controlled habitat to protect themselves from the thin 95% carbon dioxide atmosphere and temperatures as low as -70 degrees Celsius. Their habitat is partially subterranean for radiation protection. As Mars does not have a strong magnetic field, radiation levels are higher than humans can withstand for extended periods of time.
The mission relies on the principles of In Situ Resource Utilisation (ISRU) or living off the land: Solar panels generate electricity and subsurface water is extracted to use in greenhouses pressurised with atmospheric CO2. The crew grow plants for sustenance and natural oxygen production. The atmospheric carbon dioxide and reclaimed water are electrolysed to produce methane, a type of rocket fuel, for the trip back home in two years’ time.
Opportunity
It is 2020 and as I write this, I find it both ironic and transformative that sustainability will be the key to survival and the Martian way of life. Let us take those lessons to heart and implement them here on Earth. Only then can Earthlings become Martians.
Image credit: NASA-Langley.
