Mars is a planet that’s been attracting a lot of attention lately. The Red Planet has been home to many robotic spacecraft, including NASA’s Opportunity and Spirit rovers.
Those rovers found signs that water once flowed on the Martian surface. Scientists are still trying to determine if that means there was life on the Red Planet in the past.
The Curiosity Rover
The Curiosity rover, which has been on Mars for over a decade now, was launched from Cape Canaveral, Florida, on 26 November 2011, and landed in Gale crater on 6 August 2012. It has spent the past year investigating past Martian climate conditions and searching for signs of ancient life.
One of the rover’s most remarkable discoveries is that it has found evidence of ancient rivers and lakes in Gale Crater. The rover has uncovered more than 1,000 vertical feet of rock that formed in a series of shallow lakes and rivers.
These sedimentary rocks are now being analyzed using Curiosity’s chemistry and mineralogy instrument, CheMin. Researchers will look for traces of organics in the blocks and see whether they are present in the same place that they were when the water was flowing.
To do this, Curiosity will drill into each of the blocks and place a sample in its oven. It will then run its chemistry and mineralogy instrument to determine the composition of the material.
The rover has a suite of instruments that are designed to help it answer key questions about Mars’s geology and climate. It also has a radiation detector that tracks the amount of radiation on the surface and in the atmosphere.
The Perseverance Rover
The Perseverance rover will be a key part of NASA’s mission to Mars. It’ll search for signs of ancient microbial life on the Red Planet, and will cache a collection of rocks that future NASA missions will send back to Earth to be studied.
The rover’s cameras and sensors will take pictures in high resolution, with a wide field of view, to make the data easier for scientists on Earth to interpret. The rover’s Mastcam-Z camera, for example, has a 20-megapixel image sensor and can capture images of large areas at once.
It’s also able to take stereoscopic pictures that allow the viewer to see three different viewpoints in one shot. This is a big help for planning future drives and finding hazards, and it’ll reduce motion blur while the rover is moving.
Other instruments on board will help the rover hunt for signs of past water on the Martian surface, like SHERLOC, which is a microscopic camera and spectrometer that can get close to a rock for detailed analysis. It will look for organic molecules, which could be an indicator of microbial life on the planet.
Another experiment aboard Perseverance, MOXIE, will try to extract oxygen from the Martian atmosphere. If it succeeds, humans may be able to use it for breathing and as fuel in future human spaceflight missions to Mars.
To help the rover reach its destination, it also contains a small autonomous helicopter called Ingenuity that will demonstrate powered flight on the Martian surface. It’s not a fully functioning helicopter, but it will be attached to the rover’s belly to test whether it can fly in the Red Planet’s thin atmosphere.
The MOXIE Experiment
MOXIE’s mission is to test the technology that will help future missions “live off the land.” It produces oxygen from the arid, CO2-rich Martian atmosphere.
To do so, MOXIE draws in Martian air and filters it of dust and grit. It then presses the air through a solid oxide electrolyzer (SOXE) that electrochemically splits carbon dioxide into oxygen ions and carbon monoxide. The resulting breathable oxygen, which is measured for purity and quantity, is then released back into the air.
By the end of 2021, MOXIE was producing oxygen at an average rate of six grams per hour. That’s enough to sustain an astronaut on Mars, and fuel a rocket that would bring them back home.
But it’s a huge challenge to make this happen in a thin, oxygen-starved atmosphere like Mars. NASA estimates that a human-sized expedition to the Red Planet would use around 25 metric tons of oxygen, and it would be extremely costly to transport the necessary hardware from Earth.
To combat this challenge, researchers are working to scale up the device, so it can produce oxygen at a much higher rate. The larger MOXIE could one day be the size of a cubic metre, which would be enough to sustain astronauts on Mars, as well as to fuel a rocket for return. But a major challenge will be insulating the unit so it maintains its temperature.
The Sojourner Rover
Sojourner landed on Mars in 1997, the first time a robotic rover made a successful landing. It was part of NASA’s Mars Pathfinder mission.
A tiny spacecraft, it landed on the Red Planet with air bags to make it safe for a bouncy landing. Once on the surface, it rolled out and walked around, snapping pictures and taking measurements.
It also sampled rocks and sent them back to Earth. One of the most exciting discoveries was a plain that was formed by ancient floods, like those found along the Columbia River.
These floods were formed by major groundwater eruptions, which happened a long time ago on the planet. This was a huge leap forward for scientists who believed the Red Planet was dry and devoid of water.
This discovery paved the way for future rovers, like Curiosity and Perseverance. They will carry powerful instruments that search for evidence of life on Mars and take samples back to Earth.
The rover is controlled by an engineering team at NASA’s Jet Propulsion Laboratory in Pasadena, California. The team will use a computer program called “Rover Control Workstation” to create a sequence of commands that will tell Sojourner what to do and when to do it.
Sojourner’s main scientific payload is an alpha proton X-ray spectrometer, which uses energy from a beam of alpha particles to produce X-rays. This enables Sojourner to measure the composition of rocks, a crucial tool for scientists.
The Pathfinder Rover
The Mars Pathfinder Rover was launched on December 4, 1996 and landed on Mars’ Ares Vallis on July 4. It was designed as a technology demonstration of a new way to deliver an instrumented lander and a free-ranging rover.
The mission was designed to answer a number of questions about the red planet, including its ancient history. It also wanted to learn more about the chemical composition of Mars’ rocks and soil, and how they may have changed over time.
To help with these challenges, the team had to design a rover that was strong enough to handle the Martian landscape and its many hazards. It needed a powerful camera to snap pictures of the landscape and take measurements of chemicals and atmospheric conditions on the surface, as well as a rover that could be operated safely under its own power.
After 83 days on the Martian surface, the Pathfinder rover — named Sojourner — is winding down its mission. During the last week of its trek, Sojourner has studied a rock nicknamed Chimp with its alpha proton X-ray spectrometer.
The rover has taken more than 9,669 tantalizing photos of the landscape so far, with 1.2 gigabits of data. It has also analyzed the composition of rocks and measured the weather on Mars. And, most important of all, it has returned more data about the planet than its engineers expected.
The Mars Climate Orbiter
The Mars Climate Orbiter was the first spacecraft to study the climate of another planet. It was launched on December 11, 1998 atop a Delta II launch vehicle from Cape Canaveral Air Station in Florida.
The satellite was designed to monitor the weather, dust, water vapor and temperature on Mars, as well as take pictures of the surface to build a map of the Martian climate over time. It also was to act as a relay for signals from the Mars Polar Lander that was due to reach the red planet on December 3, 1999.
After its launch, the orbiter performed several angular momentum desaturations, or AMDs, to correct its path as it passed through the solar wind (the stream of particles from the Sun that can agitate and eject photons). It then used hydrazine thrusters to adjust its path in the martian atmosphere, reaching its final near-circular Sun-synchronous mapping orbit on September 23, 1999.
Following the loss of the Mars Climate Orbiter, NASA officials have taken wide-ranging managerial and technical actions at JPL. These include a new senior management leader, fresh work plans, detailed fault tree analyses for pending mission events, daily telecons to evaluate technical progress and plan work yet to be done, and an independent peer review of all operational and contingency procedures.