Perseverance, nicknamed Percy, is a car-sized Mars rover designed to explore the Jezero crater on Mars as part of NASA's Mars 2020 mission. It was manufactured by the Jet Propulsion Laboratory and launched on 30 July 2020, at 11:50 UTC. Confirmation that the rover successfully landed on Mars was received on 18 February 2021, at 20:55 UTC. As of 26 May 2022, Perseverance has been active on Mars for 449 sols (462 Earth days) since its landing. Following the rover's arrival, NASA named the landing site Octavia E. Butler Landing.
|Part of Mars 2020|
|Manufacturer||Jet Propulsion Laboratory|
|Dimensions||2.9 m × 2.7 m × 2.2 m|
(9 ft 6 in × 8 ft 10 in × 7 ft 3 in)
|Dry mass||1,025 kilograms (2,260 lb)|
|Power||MMRTG; 110 watt|
|Rocket||Atlas V 541|
|Location||Jezero crater, Mars|
|Travelled||10.27 km (6.38 mi) as of 3 May 2022[update] |
|NASA Mars rovers|
The rover also carried the mini-helicopter Ingenuity to Mars, an experimental aircraft and technology testbed that made the first powered flight on another planet on 19 April 2021. As of April 21, 2022, it has made 26 successful flights. Ingenuity's 25th successful flight, which occurred on April 8, 2022, saw the helicopter set new records for highest speed and distance traveled during a single flight.
The rover's goals include identifying ancient Martian environments capable of supporting life, seeking out evidence of former microbial life existing in those environments, collecting rock and soil samples to store on the Martian surface, and testing oxygen production from the Martian atmosphere to prepare for future crewed missions.
In the first science campaign Perseverance performs an arching drive southward from its landing site to the Séítah unit to perform a "toe dip" into the unit to collect remote-sensing measurements of geologic targets. After that it will return to the Crater Floor Fractured Rough to collect the first core sample there. Passing by the Octavia B. Butler landing site concludes the first science campaign.
The second campaign will include several months of travel towards the "Three Forks" where Perseverance can access geologic locations at the base of the ancient delta of Neretva river, as well as ascend the delta by driving up a valley wall to the northwest.
Despite the high-profile success of the Curiosity rover landing in August 2012, NASA's Mars Exploration Program was in a state of uncertainty in the early 2010s. Budget cuts forced NASA to pull out of a planned collaboration with the European Space Agency which included a rover mission. By the summer of 2012, a program that had been launching a mission to Mars every two years suddenly found itself with no missions approved after 2013.
In 2011, the Planetary Science Decadal Survey, a report from the National Academies of Sciences, Engineering, and Medicine containing an influential set of recommendations made by the planetary science community, stated that the top priority of NASA's planetary exploration program in the decade between 2013 and 2022 should be to begin a Mars Sample Return campaign, a four-mission project to cache, retrieve, launch, and safely return samples of the Martian surface to Earth. The report stated that NASA should invest in a sample-caching rover as the first step in this effort, with the goal of keeping costs under US$2.5 billion.
After the success of the Curiosity rover and in response to the recommendations of the decadal survey, NASA announced its intent to launch a new Mars rover mission by 2020 at the American Geophysical Union conference in December 2012.
Though initially hesitant to commit to an ambitious sample-caching capability (and subsequent follow-on missions), a NASA-convened science definition team for the Mars 2020 project released a report in July 2013 that the mission should "select and store a compelling suite of samples in a returnable cache."
The Perseverance design evolved from its predecessor, the Curiosity rover. The two rovers share a similar body plan, landing system, cruise stage, and power system, but the design was improved in several ways for Perseverance. Engineers designed the rover wheels to be more robust than Curiosity's wheels, which have sustained some damage. Perseverance has thicker, more durable aluminum wheels, with reduced width and a greater diameter, 52.5 cm (20.7 in), than Curiosity's 50 cm (20 in) wheels. The aluminum wheels are covered with cleats for traction and curved titanium spokes for springy support. The heat shield for the rover was made out of phenolic-impregnated carbon ablator (PICA), to allow it to withstand up to 2,400 °F (1,320 °C) of heat. Like Curiosity, the rover includes a robotic arm, although Perseverance's arm is longer and stronger, measuring 2.1 m (6 ft 11 in). The arm hosts an elaborate rock-coring and sampling mechanism to store geologic samples from the Martian surface in sterile caching tubes. There is also a secondary arm hidden below the rover that helps store the chalk-sized samples. This arm is known as the Sample Handling Assembly (SHA), and is responsible for moving the soil samples to various stations within the Adaptive Caching Assembly (ACA) on the underside of the rover. These stations include volume assessment, imaging, seal dispensing, and hermetic seal station, among others. Owing to the small space in which the SHA must operate, as well as load requirements during sealing activities, the Sample Caching System "is the most complicated, most sophisticated mechanism that we have ever built, tested and readied for spaceflight."
The combination of larger instruments, new sampling and caching system, and modified wheels makes Perseverance heavier, weighing 1,025 kg (2,260 lb) compared to Curiosity at 899 kg (1,982 lb)—a 14% increase.
The rover's radioisotope thermoelectric power generator (MMRTG) has a mass of 45 kg (99 lb) and uses 4.8 kg (11 lb) of Plutonium-238 oxide as its power source. The natural decay of plutonium-238, which has a half-life of 87.7 years, gives off heat which is converted to electricity—approximately 110 watts at launch. This will decrease over time as its power source decays. The MMRTG charges two lithium-ion rechargeable batteries which power the rover's activities, and must be recharged periodically. Unlike solar panels, the MMRTG provides engineers with significant flexibility in operating the rover's instruments even at night, during dust storms, and through winter.
The rover's computer uses the BAE Systems RAD750 radiation-hardened single board computer based on a ruggedized PowerPC G3 microprocessor (PowerPC 750). The computer contains 128 megabytes of volatile DRAM, and runs at 133 MHz. The flight software runs on the VxWorks Operating System, is written in C and is able to access 4 gigabytes of NAND non-volatile memory on a separate card. Perseverance relies on three antennas for telemetry, all of which are relayed through craft currently in orbit around Mars. The primary UHF antenna can send data from the rover at a maximum rate of two megabits per second. Two slower X-band antennas provide communications redundancy.
JPL built a copy of the Perseverance; a twin rover used for testing and problem solving, OPTIMISM (Operational Perseverance Twin for Integration of Mechanisms and Instruments Sent to Mars), a vehicle system test bed (VSTB). It is housed at the JPL Mars Yard and is used to test operational procedures and to aid in problem solving should any issues arise with Perseverance.
The Ingenuity helicopter, powered by solar-charged batteries, was sent to Mars in the same bundle with Perseverance. With a mass of 1.8 kg (4.0 lb), it demonstrated the realility of flight in the rarefied Martian atmosphere and the potential usefulness of aerial scouting for rover missions. Its pre-launch experimental test plan was 3 flights in 45 days. As of April 21, 2022, it has made 26 successful flights. Ingenuity's 25th successful flight, which occurred on April 8, 2022, saw the helicopter set new records for highest speed and distance traveled during a single flight. It carries two cameras but no scientific instruments and communicates with Earth via a base station onboard Perseverance. The first takeoff was attempted on 19 April 2021 at 07:15 UTC, with livestreaming three hours later at 10:15 UTC confirming the flight. It was the first powered flight by an aircraft on another planet. Ingenuity made additional incrementally more ambitious flights, several of which were recorded by Perseverance's cameras.
Associate Administrator of NASA's Science Mission Directorate, Thomas Zurbuchen selected the name Perseverance following a nationwide K-12 student "name the rover" contest that attracted more than 28,000 proposals. A seventh-grade student, Alexander Mather from Lake Braddock Secondary School in Burke, Virginia, submitted the winning entry at the Jet Propulsion Laboratory. In addition to the honor of naming the rover, Mather and his family were invited to NASA's Kennedy Space Center to watch the rover's July 2020 launch from Cape Canaveral Air Force Station (CCAFS) in Florida.
Mather wrote in his winning essay:
Curiosity. InSight. Spirit. Opportunity. If you think about it, all of these names of past Mars rovers are qualities we possess as humans. We are always curious, and seek opportunity. We have the spirit and insight to explore the Moon, Mars, and beyond. But, if rovers are to be the qualities of us as a race, we missed the most important thing. Perseverance. We as humans evolved as creatures who could learn to adapt to any situation, no matter how harsh. We are a species of explorers, and we will meet many setbacks on the way to Mars. However, we can persevere. We, not as a nation but as humans, will not give up. The human race will always persevere into the future.
The Perseverance rover lifted off successfully on 30 July 2020, at 11:50:00 UTC aboard a United Launch Alliance Atlas V launch vehicle from Space Launch Complex 41, at Cape Canaveral Air Force Station (CCAFS) in Florida.
After 17 May 2022, The rover will roll uphill, stopping every so often to examine rocks that look to have the best chance of retaining evidence of past life on the planet Mars. On its way back down, Perseverance will collect some of these rocks, placing the samples at the base of the delta to be retrieved by later missions. The goal is to bring this material back to Earth in the 2030s for detailed inspection.
The successful landing of Perseverance in Jezero Crater was announced at 20:55 UTC on 18 February 2021, the signal from Mars taking 11 minutes to arrive at Earth. The rover touched down at , roughly 1 km (0.62 mi) southeast of the center of its 7.7 × 6.6 km (4.8 × 4.1 mi) wide landing ellipse. It came down pointed almost directly to the southeast, with the RTG on the back of the vehicle pointing northwest. The descent stage ("sky crane"), parachute and heat shield all came to rest within 1.5 km of the rover (see satellite image). The landing was more accurate than any previous Mars landing; a feat enabled by the experience gained from Curiosity's landing and the use of new steering technology.
One such new technology is Terrain Relative Navigation (TRN), a technique in which the rover compares images of the surface taken during its descent with reference maps, allowing it to make last minute adjustments to its course. The rover also uses the images to select a safe landing site at the last minute, allowing it to land in relatively unhazardous terrain. This enables it to land much closer to its science objectives than previous missions, which all had to use a landing ellipse devoid of hazards.
The landing occurred in the late afternoon, with the first images taken at 15:53:58 on the mission clock (local mean solar time). The landing took place shortly after Mars passed through its northern vernal equinox (Ls = 5.2°), at the start of the astronomical spring, the equivalent of the end of March on Earth.
Jezero Crater is a paleolake basin. It was selected as the landing site for this mission in part because paleolake basins tend to contain perchlorates. Astrobiologist Dr. Kennda Lynch's work in analog environments on Earth suggests that the composition of the crater, including the bottomset deposits accumulated from three different sources in the area, is a likely place to discover evidence of perchlorates-reducing microbes, if such bacteria are living or were formerly living on Mars.
There are additional cameras and two audio microphones (the first working microphones on Mars), that will be used for engineering support during landing, driving, and collecting samples. For a full look at Perseverance's components see Learn About the Rover.
Perseverance is planned to visit the bottom and upper parts of the 3.4 to 3.8 billion-year-old Neretva Vallis delta, the smooth and etched parts of the Jezero Crater floor deposits interpreted as volcanic ash or aeolian airfall deposits, emplaced before the formation of the delta; the ancient shoreline covered with Transverse Aeolian Ridges (dunes) and mass wasting deposits, and finally, it is planned to climb onto the Jezero Crater rim.
In its progressive commissioning and tests, Perseverance made its first test drive on Mars on 4 March 2021. NASA released photographs of the rover's first wheel tracks on the Martian soil.
In support of the Mars sample-return mission, rock, regolith (Martian 'soil'), and atmosphere samples are being cached by Perseverance. Currently, out of 43 sample tubes, rock sample tubes cached: 8, atmosphere sample tubes cached: 1, witness tubes cached: 1, tubes due to be cached: 33. Before launch, 5 of the 43 tubes were designated “witness tubes” and filled with materials that would capture particulates in the ambient environment of Mars.
NASA plans to invest roughly US$2.75 billion in the project over 11 years, including US$2.2 billion for the development and building of the hardware, US$243 million for launch services, and US$291 million for 2.5 years of mission operations.
Adjusted for inflation, Perseverance is NASA's sixth-most expensive robotic planetary mission, though it is cheaper than its predecessor, Curiosity. Perseverance benefited from spare hardware and "build-to print" designs from the Curiosity mission, which helped reduce development costs and saved "probably tens of millions, if not 100 million dollars" according to Mars 2020 Deputy Chief Engineer Keith Comeaux.
NASA's "Send Your Name to Mars" campaign invited people from around the world to submit their names to travel aboard the agency's next rover to Mars. 10,932,295 names were submitted. The names were etched by an electron beam onto three fingernail-sized silicon chips, along with the essays of the 155 finalists in NASA's "Name the Rover" contest. The three chips share space on an anodized plate with a laser engraved graphic representing Earth, Mars, and the Sun. The rays emanating from the Sun contain the phrase "Explore As One" written in Morse code. The plate was then mounted on the rover on 26 March 2020.
In 2016, NASA SHERLOC co-investigator Dr. Marc Fries — with help from his son Wyatt — was inspired by Geocaching's 2008 placement of a cache on the International Space Station to set out and try something similar with the rover mission. After floating the idea around mission management, it eventually reached NASA scientist Francis McCubbin, who would join the SHERLOC instrument team as a collaborator to move the project forward. The Geocaching inclusion was scaled-down to a trackable item that players could search for from NASA camera views and then log on to the site. In a manner similar to the "Send Your Name to Mars" campaign, the geocaching trackable code was carefully printed on a one-inch, polycarbonate glass disk serving as part of the rover's calibration target. It will serve as an optical target for the WATSON imager and a spectroscopic standard for the SHERLOC instrument. The disk is made of a prototype astronaut helmet visor material that will be tested for its potential use in crewed missions to Mars. Designs were approved by the mission leads at NASA's Jet Propulsion Laboratory (JPL), NASA Public Affairs, and NASA HQ, in addition to Groundspeak Geocaching HQ.
Perseverance launched during the COVID-19 pandemic, which began to affect the mission planning in March 2020. To show appreciation for healthcare workers who helped during the pandemic, an 8 cm × 13 cm (3.1 in × 5.1 in) plate with a staff-and-serpent symbol (a Greek symbol of medicine) was placed on the rover. The project manager, Matt Wallace, said he hoped that future generations going to Mars would be able to appreciate healthcare workers during 2020.
One of the external plates of Perseverance includes a simplified representation of all previous NASA Martian rovers, Sojourner, Spirit, Opportunity, Curiosity, as well as Perseverance and Ingenuity, similar to the trend of automobile window decals used to show a family's makeup.
In December 2021, the NASA team announced a program to students who have persevered with academic challenges. Those nominated will be rewarded with a personal message beamed back from Mars by the Perseverance rover.
The orange-and-white parachute used to land the rover on Mars contained a coded message that was deciphered by Twitter users. NASA's systems engineer Ian Clark used binary code to hide the message "dare mighty things" in the parachute color pattern. The 70-foot-wide parachute consisted of 80 strips of fabric that form a hemisphere-shape canopy, and each strip consisted of four pieces. Dr. Clark thus had 320 pieces with which to encode the message. He also included the GPS coordinates for the Jet Propulsion Laboratory's headquarters in Pasadena, California (34°11’58” N 118°10’31” W). Clark said that only six people knew about the message before landing. The code was deciphered a few hours after the image was presented by Perseverance's team.
The main arm includes five electrical motors and five joints (known as the shoulder azimuth joint, shoulder elevation joint, elbow joint, wrist joint and turret joint). Measuring 7 feet (2.1 meters) long, the arm will allow the rover to work as a human geologist would: by holding and using science tools with its turret, which is essentially its hand.This article incorporates text from this source, which is in the public domain.
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