Next summer, NASA will be sending it’s Mars 2020 rover to the Red Planet. In addition to being the second rover to go as part of the Mars Exploration Program, it will be one of eight functioning missions exploring the atmosphere and surface of the planet. These include the recently-arrived InSightlander, the Curiosityrover – Mars 2020s sister-mission – and the Opportunityrover (which NASA recently lost contact with and retired).
As the launch date gets closer and closer, NASA is busily making all the final preparations for this latest member of the Mars exploration team. In addition to selecting a name (which will be selected from an essay contest), this includes finalizing the spacecraft that will take the rover on its seven-month journey to Mars. Recently, NASA posted images of the spacecraft being inspected at NASA JPL’s Space Simulator Facility (SFF) in Pasadena, California.
For instance, NASA plans to expand on what Curiosity has accomplished by sending the Mars 2020 rover to conduct a sample-return mission. According to a recent announcement issued by NASA, this mission will also include the Mars Helicopter – a small, autonomous rotorcraft that will demonstrate the viability and potential of heavier-than-air vehicles on the Red Planet.
As NASA Administrator Jim Bridenstine declared in a recent NASA press release, this rotocraft is in keeping with NASA’s long-standing traditions of innovation. “NASA has a proud history of firsts,” she said. “The idea of a helicopter flying the skies of another planet is thrilling. The Mars Helicopter holds much promise for our future science, discovery, and exploration missions to Mars.”
U.S. Rep. John Culberson of Texas echoed Bridenstine statement. “It’s fitting that the United States of America is the first nation in history to fly the first heavier-than-air craft on another world,” he said. “This exciting and visionary achievement will inspire young people all over the United States to become scientists and engineers, paving the way for even greater discoveries in the future.”
The Mars Helicopter began as technology development project at NASA’s Jet Propulsion Laboratory (JPL), where it spent the past four years being designed, developed, tested and retested. The result of this is a football-sized rotorcraft that weights just under 1.8 kg (four pounds) and relies on two counter-rotating blades to spin at a rate of almost 3,000 rpm (10 times the rate of a helicopter here on Earth).
As Mimi Aung, the Mars Helicopter project manager at JPL, indicated:
“The altitude record for a helicopter flying here on Earth is about 40,000 feet. The atmosphere of Mars is only one percent that of Earth, so when our helicopter is on the Martian surface, it’s already at the Earth equivalent of 100,000 feet up. To make it fly at that low atmospheric density, we had to scrutinize everything, make it as light as possible while being as strong and as powerful as it can possibly be.”
This concept is ideal for navigating through Mars’ thin atmosphere, where the mean surface pressure is about 0.6% that of Earth’s at sea level (0.60 kPa compared to 101.3 kPa). This low-flying helicopter would not only be able to increase the range of a rover, it will be able to explore areas that the rover would find inaccessible. As Thomas Zurbuchen, the Associate Administrator for NASA’s Science Mission Directorate, explained:
“Exploring the Red Planet with NASA’s Mars Helicopter exemplifies a successful marriage of science and technology innovation and is a unique opportunity to advance Mars exploration for the future. After the Wright Brothers proved 117 years ago that powered, sustained, and controlled flight was possible here on Earth, another group of American pioneers may prove the same can be done on another world.”
Other capabilities that make it optimized for Mars exploration include lithium-ion batteries, solar cells to keep them charged, and heating mechanisms that will keep it warm during Martian nights – where average temperatures can get as low as 210 K (-63 °C; -82 °F) around the mid-latitudes. In addition, the helicopter is programmed to fly autonomously, since it cannot be flown in real-time (given the distances involved).
Commands will be issued from controllers on Earth, using the rover as a relay, who will instruct the helicopter to commence flight once it is ready to deploy. This will begin shortly after the rover arrives on the planet (which is expected to happen by February 2021) with the helicopter attached to its belly pan. The rover will then select a location to deploy the helicopter onto the ground.
After it is finished charging its batteries and a series of pre-flight tests are performed, controllers on Earth will relay commands to the Mars Helicopter to commence its first 30-day flight test campaign. This will include up to five flights that will take it to increasingly greater distances from the rover (up to a few hundred meters) for longer periods of time (up to 90 seconds).
On its first flight, the helicopter will make a short vertical climb to 3 meters (10 feet) where it will hover for about 30 seconds. Once these tests are complete, the Mars Helicopter will assist the rover as it conducts geological assessments and determines the habitability of its landing sight. The purpose of this will be to search for signs of ancient life on Mars and assesses the natural resources and hazards for future missions involving human explorers.
The rover will also conduct the first-ever sample-return mission from Mars, obtaining samples of rock and soil, encasing them in sealed tubes, and leaving them on the planet for future retrieval by astronauts. If all goes well, the helicopter will demonstrate that low-flying scouts and aerial vehicles can be a valuable part of any future missions. These will likely include robotic missions to Saturn’s largest moon, Titan, where researchers are hoping to explore the surface and atmosphere using helicopter (such as the Dragonfly concept).
The Mars 2020 mission is expected to reveal some very impressive things about the Red Planet. If the helicopter proves to be a viable part of the mission, we can expect that additional information and images will be provided from locations that a conventional rover cannot go. And in the meantime, be sure to enjoy this animation of the Mars Helicopter in action, courtesy of NASA-JPL:
When the Opportunity rover landed on Mars on January 25th, 2004, its mission was only meant to last for about 90 Earth days. But the little rover that could has exceeded all expectations by remaining in operation (as of the writing of this article) for a total of 13 years and 231 days and traveled a total of about 50 km (28 mi). Basically, Opportunity has continued to remain mobile and gather scientific data 50 times longer than its designated lifespan.
And according to a recent announcement from NASA’s Mars Exploration Program (MEP), the rover managed to survive yet another winter on Mars. Having endured the its eight Martian winter in a row, and with its solar panels in encouragingly clean condition, the rover will be in good shape for the coming dust-storm season. It also means the rover will live to see its 14th anniversary, which will take place on January 25th, 2018.
On Mars, a single year lasts the equivalent of 686.971 Earth days (or 1.88 Earth years). And since Mars’ axis is inclined 25.19° to its orbital plane (compared to Earth’s axial tilt of just over 23°), Mars also experiences seasons. However, these tend to last about twice as long as the seasons on Earth. And of course, the seasons on Mars’ are also much colder, with temperatures averaging about -63 °C (-82°F).
As Jennifer Herman, the power subsystem operations team lead for Opportunity at NASA’s Jet Propulsion Laboratory, recalled in a NASA MEP press statement:
“I didn’t start working on this project until about Sol 300, and I was told not to get too settled in because Spirit and Opportunity probably wouldn’t make it through that first Martian winter. Now, Opportunity has made it through the worst part of its eighth Martian winter.”
At present, both the Opportunity and Spirit rover are in Mars’ southern hemisphere. Here, the Sun appears in the northern sky during the fall and winter, so the rovers need to tilt their solar-arrays northward. Back in 2004, the Spirit rover had lost the use of two of its wheels, and could therefore not maneuver out of a sand trap it had become stuck in. As such, it was unable to tilt itself northward and did not survive its fourth Martian winter (in 2009).
However, Opportunity’s current position – Perseverance Valley, a fluid-carved region on the inner slope at the edge of the Endeavour Crater – meant that it was well-positioned to keep working through late fall and early winter this year. This was ensured by the stops the rover made at energy-favorable locations, where it would inspect local rocks, examine the valley’s shape and image the surrounding area, all the while absorbing ample energy from the Sun.
Five months ago, the rover entered the top of the valley, which runs eastward down the inner slope of the Endurance Crater’s western rim. Since that time, Opportunity has been conducting stops between drives at north-facing sites, which are situated along the southern edge of the channel. The rover team calls the sites “lily pads”, since these places are spots that the rover need to hop across during its mission.
This is necessary, given that Opportunity does not rely on a radioisotope thermoelectric generator like Curiosity does. While winter conditions affect the use of electrical heaters and batteries on both rovers, Opportunity is different in that it’s activities are more subject to seasonal change. Whereas Curiosity will simply allocate less energy to performing tasks in the winter, Opportunity needs to pick its routes to ensure it stays powered up.
During some of its previous winters, the Opportunity rover was not as well-situated as it currently is. During its fifth winter (2011-2012) the rover spent 19 weeks at one spot because no other places that allowed for a northward-facing tilt were available within driving distance. On the other hand, its first winter (2004-2005) was spent in the southern half of the Endurance Crater, where all grounds are favorable since they face north.
As the person who is chiefly responsible for advising other mission scientists on how much energy Opportunity has available on each Martian day (sol) for conducting activities like driving and observing – a task she performs for Curiosity as well – Herman understand the relationship between power usage and the seasons all too well. “Relying on solar energy for Opportunity keeps us constantly aware of the season on Mars and the terrain that the rover is on, more than for Curiosity,” she said.
Another factor which can influence Opportunity‘s power supply is how much dust is in the sky and how much of it gets onto the rover’s solar arrays. This is highly-dependent on prevailing wind conditions, which can both stir up dust storms and clear away dust deposits on the rover – basically, they are a real mixed blessing! During autumn and winter in the southern-hemisphere, the skies are generally clear where Opportunity operates.
Spring and summer is when the storms are most common in Mars’ southern hemisphere, though they don’t happen every year. The latest example took place in 2007, which led to a severe reduction in the amount of sunlight (and hence, solar energy) Spirit and Opportunity were able to receive. This required both rovers to enact emergency protocols and reduce the amount of operations and communications they conducted.
The amount of dust on the rover’s solar arrays going into autumn can also vary from year to year. This year, the array was dustier than in all but one of the previous Martian autumns it experienced. Luckily, as Herman explained, things worked out for the rover:
“We were worried that the dust accumulation this winter would be similar to some of the worst winters we’ve had, and that we might come out of the winter with a very dusty array, but we’ve had some recent dust cleaning that was nice to see. Now I’m more optimistic. If Opportunity’s solar arrays keep getting cleaned as they have recently, she’ll be in a good position to survive a major dust storm. It’s been more than 10 Earth years since the last one and we need to be vigilant.”
In the coming months, the Opportunity team hopes to investigate how the Perseverance Valley was cut into the rim of the Endeavor crater. As Matt Golombek, an Opportunity Project Scientist at JPL, related:
“We have not been seeing anything screamingly diagnostic, in the valley itself, about how much water was involved in the flow. We may get good diagnostic clues from the deposits at the bottom of the valley, but we don’t want to be there yet, because that’s level ground with no more lily pads.”
With its eighth winter finished and Opportunity still in good working order, we can expect the tenacious rover to keep turning up interesting finds on Mars. These include clues about Mars’ warmer, wetter past, which likely included a standing body of water in the Endeavor crater. And assuming conditions are favorable in the coming year, we can expect that Opportunity will continue to push the boundaries of both science and its own endurance!
NASA’s Mars Exploration Program has accomplished some truly spectacular things in the past few decades. Officially launched in 1992, this program has been focused on three major goals: characterizing the climate and geology of Mars, looking for signs of past life, and preparing the way for human crews to explore the planet.
And in the coming years, the Mars 2020 rover will be deployed to the Red Planet and become the latest in a long line of robotic rovers sent to the surface. In a recent press release, NASA announced that it has awarded the launch services contract for the mission to United Launch Alliance (ULA) – the makers of the Atlas V rocket.
The mission is scheduled to launch in July of 2020 aboard an Atlas V 541 rocket from Cape Canaveral in Florida, at a point when Earth and Mars are at opposition. At this time, the planets will be on the same side of the Sun and making their closest approach to each other in four years, being just 62.1 million km (38.6 million miles) part.
Following in the footsteps of the Curiosity, Opportunity andSpirit rovers, the goal of Mars 2020 mission is to determine the habitability of the Martian environment and search for signs of ancient Martian life. This will include taking samples of soil and rock to learn more about Mars’ “watery past”.
But whereas these and other members of the Mars Exploration Program were searching for evidence that Mars once had liquid water on its surface and a denser atmosphere (i.e. signs that life could have existed), the Mars 2020 mission will attempt to find actual evidence of ancient microbial life.
The design of the rover also incorporates several successful features of Curiosity. For instance, the entire landing system (which incorporates a sky crane and heat shield) and the rover’s chassis have been recreated using leftover parts that were originally intended for Curiosity.
There’s also the rover’s radioisotope thermoelectric generator – i.e. the nuclear motor – which was also originally intended as a backup part for Curiosity. But it will also have several upgraded instrument on board that allow for a new guidance and control technique. Known as “Terrain Relative Navigation”, this new landing method allows for greater maneuverability during descent.
Another new feature is the rover’s drill system, which will collect core samples and store them in sealed tubes. These tubes will then be left in a “cache” on the surface, where they will be retrieved by future missions and brought back to Earth – which will constitute the first sample-return mission from the Red Planet.
In this respect, Mars 2020 will help pave the way for a crewed mission to the Red Planet, which NASA hopes to mount sometime in the 2030s. The probe will also conduct numerous studies designed to improve landing techniques and assess the planet’s natural resources and hazards, as well as coming up with methods to allow astronauts to live off the environment.
In terms of hazards, the probe will be looking at Martian weather patterns, dust storms, and other potential environmental conditions that will affect human astronauts living and working on the surface. It will also test out a method for producing oxygen from the Martian atmosphere and identifying sources of subsurface water (as a source of drinking water, oxygen, and hydrogen fuel).
As NASA stated in their press release, the Mars 2020 mission will “offer opportunities to deploy new capabilities developed through investments by NASA’s Space Technology Program and Human Exploration and Operations Mission Directorate, as well as contributions from international partners.”
They also emphasized the opportunities to learn ho future human explorers could rely on in-situ resource utilization as a way of reducing the amount of materials needed to be shipped – which will not only cut down on launch costs but ensure that future missions to the planet are more self-reliant.
The total cost for NASA to launch Mars 2020 is approximately $243 million. This assessment includes the cost of launch services, processing costs for the spacecraft and its power source, launch vehicle integration and tracking, data and telemetry support.
The use of spare parts has also meant reduced expenditure on the overall mission. In total, the Mars 2020 rover and its launch will cost and estimated $2.1 billion USD, which represents a significant savings over previous missions like the Mars Science Laboratory – which cost a total of $2.5 billion USD.