This blog will expose readers to many facets of scientific investigation and discovery. Recent news in science will be shown and expanded on to teach far more. Biographies of scientists will give a deeper insight than what you may have read in textbooks. I hope that the posts will help improve scientific literacy, expand your interest in many fields of science, and inform you about some important scientists.
Friday, August 11, 2023
What's Up With Mars?
People have been looking at Mars for millennia. In 1609, Galileo was the first to look at it with a telescope. Italian priest and astronomer Angelo Secchi was among the first to draw pictures of its surface in 1858. He drew what he called canale (plural canali), which just mean "channels" to him. Another Italian astronomer Giovanni Schiaparelli also made sketches of the canali and even gave names to various geographical structures that he saw in 1877. The word was misinterpreted by American Percival Lowell as "canals" when he made his own observations in 1894, and this was the first time the notion of irrigation structures by intelligent alien life was proposed. We've come a long way since then.
Astronomers around the world had an active interest in studying Mars, but it was only in 1954 that the International Mars Committee was formed to coordinate observatories around the world in their studies. Three years later, the Soviet Union put Sputnik 1 into orbit around the Earth as the first artificial satellite, and in 1959 it landed the first manmade object Luna 2 on the Moon to measure radiation, magnetic fields, and the solar wind. It was the United States, though, that successfully sent the first exploration vehicle to Mars.
You can read about all successful and failed attempts to visit Mars by all countries at this link. The rest of this blog article will deal only with the 21 successes and what we have learned. Yes, that many! Get ready to read about Russia, the U.S., India, China, the United Arab Emirates, and the European Union.
1 - NASA's Mariner 4 (launched November 28, 1964) reached Mars on July 15, 1965 and performed a flyby to gather data and take photos.
2 - Mariner 6 and 7 were the next successful flights, and both were flybys, too, in February & March of 1969. They flew over the Martian equator and south pole to examine the atmosphere and the surface features. Their pictures of the dark areas confirmed that there were no canals.
3 - NASA's Mariner 9 orbiter arrived on November 14, 1971, becoming the first spacecraft to orbit another planet. It paused for 2 months to allow a planet-wide dust storm to settle, then took photos and measurements. After almost a year, it had monitored 85% of the surface.
4 - Two weeks later, on November 27, 1971, the Soviet Union managed to get its Mars 2 orbiter, lander, and rover to the fourth planet. Sort of. The orbiter made 362 orbits and sent back data on gravity and magnetic fields plus 60 photos, but the lander with its attached lander crashed. Its twin Mars 3 arrived in December, 1971, and the orbiter lasted for 20 orbits. The landing package was the first to soft land on Mars, but the lander lost communications in less than 2 minutes, so the rover was unable to be deployed.
5 - The Soviet Mars 4 failed to orbit and could only fly by, sending back some pictures in February, 1974. The Mars 5 orbiter arrived also in February, 1974 and remained in orbit where it measured gamma rays and surface temperatures for 16 days out of the planned 3 months. The next two attempts were scheduled as flybys, Mars 6 and Mars 7. The Mars 6 flew by, but its lander crashed. Mars 7 took solar measurements, but its lander misfired and is now in orbit around the sun.
6 - The U.S. made the first actual successful landing with Viking 1 on July 20, 1976 which operated for over 6 years. Its orbiter relayed 57,000 pictures to Earth, and the lander conducted 3 experiments on soil samples to test for life. Results: inconclusive. The Viking 2 spacecraft arrived on August 7, 1976 and deployed its lander on September 3. The orbiter made close approaches to the moon Deimos and was turned off on July 25, 1978. The lander performed elemental analyses of the soil and similar tests for life until its batteries died on April 12, 1980.
7 - The last successful Soviet explorer was Phobos 2, which was intended to examine the moon Phobos more than Mars itself. Computer failure allowed it to make only 3 passes by the moon, but it took 37 pictures covering 80% of it. It arrived on 29 January 1989, and the attempt to put 2 landers on the moon failed when communications were lost on 27 March 1989.
8 - On 11 September 1997, the U.S. placed into orbit the Mars Global Surveyor, which lasted for 10 years in orbit. To achieve that, it was the first spacecraft to use aerobraking, where it made several passes through the atmosphere to slow it down. The MGS took many pictures (including the famous "face") and was the radio relay to Earth for future landers Spirit and Opportunity until 2006.
9 - The Pathfinder was America's next step in Mars exploration in 1997. It was built cheaper by virtue of its landing process. A capsule descended on a parachute until a certain point, then its heat shield was ejected from below to allow for a lander/rover package to unwind on a cord. Before hitting the ground, the capsule fired retro rockets to slow it down even more. A series of balloons surrounding the lander/rover were inflated, and then its cord to the capsule was released. The lander/rover was protected inside the cushioning effect of the balloons until it stopped bouncing. After the balloons deflated, arms on the lander peeled them away, and its radio and camera unfolded. Inside, the rover Sojourner then rolled out to explore as the first rover on Mars. Watch the animation below showing this landing.
Sojourner contained instruments that let it analyze mechanical, geochemical, and evolutionary history of the land, and it had 3 types of cameras. It roamed about 100 m (330 ft) in total, less than 12 m (39 ft) from the Pathfinder station itself, and in its 83 days of operation, it relayed 550 photographs to Earth. The lander made over eight million measurements of the atmospheric pressure, temperature and wind speed as well as analyzed the airborne dust particles.
10 - Four years after Pathfinder, the U.S. placed another spacecraft, Odyssey, into orbit on October 24, 2001. After aerobraking for 76 days, it was ready to work on February 19, 2002. Its thermal imagers and light sensors located bulk water ice under the surface at the equator. It is still in service feeding data for future programs, and it is expected to run until 2025.
11 - The European Space Agency placed its orbiter Mars Express around the red planet on December 20, 2003. It contained the Express orbiter and the Beagle 2 lander made it to the surface but failed to open its solar panels, so communication with it were lost. The orbiter found ice in the south pole that was 85% carbon dioxide ice and 15% water ice. It also has found various important compounds in rocks and the air. It should remain operational until 2035.
12 - NASA successfully planted two rovers, Spirit and Opportunity, on Mars in June and July, 2003. Spirit stayed active for over 6 years and covered 7.73 km (4.8 miles), both far exceeding expectations. Opportunity operated for 14 years, 138 days (57 times its designed lifespan) and covered 45 km (28 miles) before getting stuck.
13 - NASA's Mars Reconnaissance Orbiter (MRO) was intended to search for water on Mars. It reached orbit on March 10, 2006 and is still operational. It took over for Pathfinder as a relay station for Spirit and Opportunity. NASA also successfully placed its sixth lander, Phoenix, on Mars from May 25, 2008, to November 2, 2008. Its duties were to assess the local habitability and to research the history of water. It landed like the Viking landers, with a parachute and retro rockets, unlike Pathfinder. It was the first to land near any of the poles. In one of its experiments, it scraped the dirt, found subsurface ice, and monitored it evaporate to demonstrate its chemical composition. It was operational for 161 days (expected 90) until a sandstorm covered its solar panels.
Phoenix landing and results of subsurface ice evaporation (Wikipedia)
14 - Next, NASA executed a risky landing procedure for the Curiosity rover of the Mars Science Laboratory (MSL) on August 6, 2012. Because it was meant to collect massive amounts of data in preparation for future manned landings, Curiosity had more than ten times the mass of scientific instruments as Spirit and Opportunity, was twice as long, and was five times heaver (899 kg (1,982 lb)), so the balloon cushion was not an option. Instead, NASA developed a "sky crane".
Sky crane landing operation after parachute is ejected (spaceflightnow.com)
Curiosity was designed to operate for 687 days and cover an area of 5x20 km (3.1x12.4 miles). Eleven years later, it is still there providing data.
15 - India got into the space game with its Mars Orbiter Mission. It entered orbit on 24 September 2014. Its mission concluded on September 27, 2022. Goals: atmospheric studies and mapping.
16 - MAVEN (Mars Atmosphere and Volatile Evolution) is an ongoing U.S. orbiter project that began on September 22, 2014 and is still operational. Its goal is to study how atmospheric gases are lost to space.
17 - The ExoMars Trace Gas Orbiter is a joint effort by the ESA and Russia. It entered orbit on October 19, 2016 and is still operational, although its Shiaparelli lander crashed. Its goal is for a better understanding of methane (CH4) and other trace gases.
18 - America's InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) lander landed on November 26, 2018, and its last contact was December 15, 2022. It was meant to study the deep interior of the planet.
Two probes MarCO A and MarCO B (Mars Cube One) launched on the same rocket as InSight but separated soon after launch to travel independently. Their purpose was to test new miniaturized communication and navigation technologies as InSight landed. These were the first CubeSat (cube-shaped satellites) used outside Earth orbit. Each was only 10×20×30 cm.
19 - Hope is the name for the orbiter still in operation and put up by the United Arab Emirates on 9 February 2021. Its goal is to study daily and seasonal weather cycles, weather events in the lower atmosphere such as dust storms, and how the weather varies in different regions.
20 - China joined the space race to Mars in 2021 with a complex of orbiters and landers. The Tianwen-1 ("heavenly questions") orbiter entered orbit on February 10, 2021 and is still operational. It was intended to study surface and subsurface geology, atmosphere, and presence of water. Its Tianwen-1 lander made landfall on May 14, 2021. From the lander, the Zhurong rover (named after a Chinese mytho-historical figure associated with fire and light) was deployed on May 22, 2021 and is still operational.
Tianwen-1 package of orbiter and lander/rover (Wikipedia)
The rover set up a remote camera on the surface, while in space In September 2020, the Tianwen-1 orbiter deployed the Tianwen-1 First Deployable Camera (TDC-1). It is a small satellite with two cameras to take photos of and test the radio connection with the orbiter.
21 - Finally, the U.S. Perseverance lander and Ingenuity helicopter rover are the most recent Mars projects to date. They landed as a package using the sky crane technology on 18 February 2021. Ingenuity was deployed from Perseverance on 3 April 2021 and made its first flight on April 19, 2021. Since then, it has made 54 missions despite the expected five.Both instruments are still operating.
Landing sites over history (interactive map on Wikipedia)
Here is a good NASA website with many of the explorations mentioned above.
In case you're wondering how big these landers and rovers are, here's a really cool 5-minute YouTube video with background music, showing all landers (successful or otherwise), their moving parts, and their relative size to a person.
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