Having spent some time on the surface of Mars, we’ll take a look at spacecrafts in orbit around Mars this time. Let’s start with the oldest spacecraft. From there we’ll go forward in time. Eventually, we encounter spacecrafts, I already mentioned in my last post about spacecraft on the surface of Mars. Let’s get started!
Mars Odyssey
On 15 December 2010 Mars Odyssey made history, when it claimed the record for the longest operating spacecraft at Mars. Since then, it has added many more days to the record and keeps on doing so. So, let’s take a look back.
Mars Odyssey launched on 7 April 2001 onboard a Delta II 7925. After spending a couple of months getting to Mars, it arrived at Mars. There, it fired its thrusters to place itself into a capture orbit on 24 October 2001. It then used aerobraking to gradually lower its orbit. Finally ending up in a nearly Sun-synchronous polar orbit 400 × 400 kilometers at 93.1 degree-inclination. Starting its main mission to investigate the Martian environment and scout for future spacecrafts on 19 February 2002.
Instruments & Problems
Therefore, it is equipped with three main instruments. These are THEMIS, GRS and MARIE. Let’s take a look at THEMIS, short for Thermal Emission Imaging System. It is a camera capturing infrared and visible light reflected from the Marian surface. Scientist’s then us these images to create a map of the mineral distribution on the surface. For more details about THEMIS, take a look at the instruments’ website.
The next instrument is GRS, which is an acronym for Gamma Ray Spectrometer. It maps the amounts and types of chemical elements at or near the surface of Mars. Take a look at this website for a detailed description of how this is done from orbit. The last instrument is MARIE, short for Mars Radiation Environment Experiment. Its mission is to explore the radiation environment on Mars, as well as on the way to Mars. Unfortunately, it stopped working on 28 October 2003.
The problem with MARIE were not the only ones. In June 2012, one of the spacecraft’s reaction wheels failed. Luckily, this didn’t stop the mission, as a space reaction wheel could be activated and put into service. In December 2016, MArs Odyssey put itself into safe mode because of an issue related to its orientation relative to Earth and the Sun. After implementing a solution, Mars Odyssey could resume normal operations a month later.
The Mission & Results so far
The primary mission of Odyssey last to August 2004 and was extended by at least 7 two-year missions. Let’s take a look at what Mars Odyssey help us learn about Mars. In May 2002, NASA announced it had located large amounts of hydrogen. And therefore might have detected ice below the surface. In March 2008 scientists revealed that it had found salt deposits, which can be found in places where water was once abundant. By July 2010 Mars Odyssey’s camera had helped create the most accurate global map of Mars. In August 2012 Odyssey helped to select a landing site for the Mars Science Laboratory aka Curiosity. Take a look at my last post for more about its mission.
Aside from its science mission, Odyssey also can act as a communication relay for landers and did so for the Mars Exploration Rovers, the Mars Science Laboratory, and the Phoenix lander.
Next up in our list of active spacecraft at Mars is ESA’s Mars Express. Let’s take a look at the spacecraft as well as its mission.
Mars Express
ESA’s Mars Express mission launched on 2 June 2003 using a Soyuz-Fregat rocket from Baikonur. It was ESA’s first visit to another planet in the solar system. It consisted of an orbiter and a lander, called Beagle 2. On 19 December 2003 the orbiter released the lander for its descent to the surface. The orbiter kept on going and fired its thrusters to successfully enter orbit around Mars on 25 December 2003.
The lander descended to the surface for a planned landing six days after release. Neither the orbiter nor ground stations on Earth could pick up signals from the lander after landing. Neither Mars Express nor Mars Odyssey were able to find it. Until, in 2015, NASA’s Mars Reconnaissance Orbiter captured high-resolution images of the landing site. They showed, that the lander had not fully deployed all of its solar panels, which prevented it from communicating.
So, back to the orbiter. It successfully completed it nominal mission after one Martian year, which equals 687 Earth days. And is still working as of today. It has eight instruments to study Mars and its two moons, Phobos and Deimos. The mission is to study all aspects of the Red Planet. This includes its atmosphere, climate, the mineralogy, and geology of the surface and subsurface.
The Instruments
Let’s take a closer look at the instruments. They can be divided into two groups. The first group has instruments to study the surface and subsurface of Mars. The three instruments are HRSC, OMEGA and MARSIS.
- HRSC, short for High Resolution Stereo Camera, is a full color camera with a resolution of 10 meters (on the ground). In addition, it can take images of selected areas with a resolution of 2 meters. Combining both resolutions increases the accuracy even further. Last not least, it can take images in 3D, revealing Mars topography in full color.
- OMEGA, short for a name that translates to Visible and Infrared Mineralogical Mapping Spectrometer in english. It is comparable to the THEMIS instrument on Mars Odyssey, as it maps the mineral distribution using infrared and visible light.
- MARSIS, short for Mars Advanced Radar for Subsurface and Ionospheric Sounding, is mapping the sub-surface structure to a depth of a few kilometers. Therefore, it is using a 40 meters long antenna.
The second group of instruments analyses the atmosphere and plasma. The five instruments are PFS, SPICAM , ASPERA, MaRS and VMC.
- PFS, short for Planetary Fourier Spectrometer. It creates global scale maps of vertical temperature profiles in the atmosphere.
- SPICAM, short for Spectroscopy for the Investigation of the Characteristics of the Atmosphere of Mars. It analyses light that passed through the atmosphere of Mars. Doing so, it can determine the composition of the Martian atmosphere.
- ASPERA, short for Analyzer of Space Plasma and Energetic Atoms. It focuses on the outer atmosphere and its interaction with the solar wind.
- MaRS, short for Mars Radio Science Experiment, is not really an instrument. Instead, it’s an experiment, that uses the radio signal used for communication between Mars Express and ground stations. By analyzing how the signals change or are reflected, it can derive the structure of the atmosphere or the roughness of the surface.
- VMC, short for Visual Monitoring Camera, is an engineering camera used to confirm the separation of the Beagle 2 lander from the orbiter. Since 2007 it is regularly taking pictures of Mars, which are published on the internet. Getting the instrument the nickname “Mars webcam”. Since 2016 scientist also use the pictures for global monitoring of clouds, dust and atmospheric structures.
Results so far
Do you want to know more about the instruments? Take a look at this article. Meanwhile, we take a look at what Mars Express has discovered. Maybe most important is the discovery of hydrated minerals, which can only form in the presence of liquid water. Thus being evidence, that Mars had liquid water in the past. In addition, it possibly has detected methane in the atmosphere as well as recent and periodic volcanism. And a lot more, you can look up in this article.
So far, we have one spacecraft from NASA and one from ESA. Let’s take a look at another orbiter from NASA.
Mars Reconnaissance Orbiter (MRO)
Two years after ESA’s Mars Express, NASA on 12 August 2005 launched the Mars Reconnaissance Orbiter aboard an Atlas V. It inserted itself in an orbit around Mars by firing its thrusters on 10 March 2006. From 7 April to 11 September, it used a technic called aerobraking to lower its orbit. This is done by skimming the upper atmosphere and letting drag reduce the speed of the spacecraft and thereby the orbit.
The primary mission of Mars Reconnaissance Orbiter, or short MRO, is to map the surface as well as investigate the Martian atmosphere, climate, weather, and geology. It also serves as an important communication relay between spacecraft of the surface of Mars and Earth. Therefore, it carries a navigation camera and a communications package.
The instruments
It is equipped with six primary science instruments. Let’s start with the High-Resolution Imaging Science Experiment Camera, or HiRISE. It is a camera with a telescopic lens, which allows taking pictures with a resolution to distinguish objects the size of 1 meter. That’s more than previous missions. The Context Camera, or CTX, takes wide-area pictures to add context to the detailed analysis of the other instruments. The Mars Color Imager (MARCI), on the other hand, takes pictures of clouds and dust storms, which makes it an instrument for weather forecasting.
Now that we are done with the cameras, let’s continue with other instruments. The Compact Reconnaissance Imaging Spectrometer, or CRISM, uses light to identify minerals on the surface. Especially those related to water. Another instrument looking for water is Shallow Subsurface Radar, or SHARAD for short. It uses a radar to detect water as deep as one meter below the surface. Finally, the Mars Climate Sounder, or MCS, detects variations in temperature, dust and water vapor in the atmosphere.
Firsts, problems and recovery
MRO’s primary science mission lasted from November 2006 to November 2008. Not only did MRO transmit scientific data back to Earth, but it also became the first spacecraft to photograph another spacecraft landing on Mars. After completing this mission, MRO entered into the Extended Science Phase, which lasted from November 2008 to December 2010. Followed by two Extended Mission phases. The first until October, which focused on exploring seasonal processes and surface changes. The second Extended Mission officially lasted until October 2014, but is still ongoing. Its focus is on adding on to previous science and act as support and relay spacecraft for missions to the Martian surface.
In all those years, MRO faced numerous technical challenges. NASA stopped the operation of the Mars climate sounder by December 2006. On 26 August 2009 MRO shut itself down. It took the engineers until 8 December 2009 to recovery it. By April 2015 MRO had put itself into save mode seven times. However, it could also be recovered and returned to delivering scientific data. So it did. On 3 March 2010 it had transmitted 100 terabits of data. By October 2014 it had transmitted over 200 terabits of data.
MRO is an important mission. Not only for the science it delivered, but also for other missions to Mars. Especially to the surface, including the once I talked about in the post About a little helicopter on Mars and his fellow travelers. Let’s continue with the next NASA spacecraft orbiting Mars.
MAVEN – Mars Atmosphere and Volatile Evolution mission
Mars Atmosphere and Volatile Evolution, no, this is not the title of a scientific paper, it is just the name of a NASA mission to Mars. As well as the name of the spacecraft, which is often shortened to MAVEN. It launched onboard an Atlas V on 18 November 2013. It’s the first mission dedicated to studying the upper atmosphere. MAVEN arrived in Mars orbit on 21 September 2014 and started its one-year primary science mission on 16 November 2014. It included five “deep-dip” campaigns, when MAVEN lowered its orbit to collect data about the boundary between the upper and the lower atmosphere. It since has surpassed it planned mission duration by a couple of years and might continue doing so, at least the fuel should allow operations until 2030.
The instruments
All instruments onboard MAVEN build on heritage from previous missions throughout the solar system. MAVEN has three groups or packages of instruments. The one with the most instruments is the Particles and Fields package. It consists of six instruments:
- Solar Wind Electron Analyzer (SWEA) measures the energy and direction of electrons with mid-range energies, which are sufficient to ionize molecules in the atmosphere.
- Solar Wind Ion Analyzer (SWIA) measures the solar wind in the interplanetary medium and as it interacts with the upper atmosphere. To be more specific, it measures the density, temperature, and velocity of the solar wind.
- Supra Thermal and Thermal Ion Composition (STATIC) measures the composition and velocity of high-energy ions in the upper atmosphere. This measurement might help us understand how Mars lost its atmosphere.
- Solar Energetic Particle Experiment (SEP) measures energetic ions coming from the Sun to Earth. The goal is to understand how much energy comes into the upper atmosphere, as well as understand the role they play in heating the upper atmosphere.
- Langmuir Probe and Waves Experiment (LPW) is also an instrument to help us understand the loss of atmosphere at Mars. Scientists can use its measurements to delineate the boundaries and the density of the ionosphere.
- Magnetometer (MAG) as the name suggests, it measures the magnetic environment the spacecraft travels through. Thereby supporting the measurements of the other instruments.
The second is the Remote Sensing Package. It consists of the Imaging Ultra Violet Spectrograph (IUVS) and the Remote Sensing Data Processing Unit. It uses UV light to chemically map the composition of the upper atmosphere.
Finally, the third package, consists of one instrument, the Neutral Gas and Ion Mass Spectrometer (NGIMS). It measures the composition of neutral gases, which provides information about the composition and structure of the upper atmosphere. In addition, the measurements will show how atmospheric events affect the amount of gas escaping the upper atmosphere.
Results and further uses
MAVEN uncovered two unanticipated phenomena in the Martian atmosphere. Firstly, it detected high-altitude dust cloud between 150 and 300 kilometers altitude. Secondly, it observed a bright ultraviolet auroral glow in the northern hemisphere of Mars. It also helped to determine the most accurate rate at which Mars’ atmosphere is losing gas.
In 2017 MAVEN and ESA’s Trace Gas Orbiter, which I will bring up shortly, coordinated their observations of the Martian atmosphere.
Besides doing its science, MAVEN is also used as a replay data from other spacecraft, e.g., Curiosity, to Earth. Therefore, it carries Electra, an ultra-high-frequency transceiver. Using the relay, the rovers on the surface can transfer more data as if using direct communication. In early 2019 MAVEN lowered its orbit to act as a data-relay for NASA’s Mars 2020 rover. Mars Odyssey and Mars Reconnaissance Orbiter currently are providing relay services.
The spacecraft from NASA and ESA are not alone at Mars anymore. So let’s take a look at the first mission to Mars from India.
Mars Orbiter Mission – Mangalyaan
The Mars Orbiter Mission (MOM) is India’s first mission to Mars. It is also called Mangalyaan, which is Hindi for “Mars Craft”. Its mission is to demonstrate technology as well as study topography, morphology, mineralogy, and atmosphere from orbit. It launched on 5 November 2013 onboard a PSLV-C25. It arrived at Mars on 23 September 2014, where it fired its thrusters to successfully enter into an orbit.
The instruments
Mangalyaan is equipped with five scientific instruments. The Mars Color Camera (MCC) is a tri-color camera for taking pictures of the Martian surface. It’s useful to monitor dynamic events and weather of Mars. Another instrument is the Lyman Alpha Photometer (LAP). It observes the abundance of deuterium and hydrogen in the upper atmosphere, which allows us to understand the loss of water from Mars’ atmosphere. The Thermal Imaging Spectrometer (TIS) measures thermal emissions from the surface. This allows scientists to create maps of surface composition, as many soil types have characteristic spectra. Finally, the Methane Sensor for Mars (MSM) measures the amount of Methane in the atmosphere.
Mission goals
As Mangalyaan is not only a scientific mission, but also a technical demonstration, it has technological and scientific objectives. To put it simple, the technological objects are, putting the spacecraft on the way to Mars, let it reach Mars, perform a successful orbit insertion and operations in Mars orbit. As well as autonomous operation of the spacecraft for times without communication to Mars. MENCA, short for Mars Exospheric Neutral Composition Analyzer, is a mass spectrometer also analyzing the composition.
The scientific objectives are the exploration of Mars. Or as stated above, Exploration of Mars surface features, morphology, mineralogy, and Martian atmosphere.
For the first mission of a country to Mars, the mission is a great success. Are you excited about their next step, as I am? Meanwhile, let’s look at another mission from Europe.
ESA ExoMars – Trace Gas Orbiter
ExoMars is a cooperation between ESA and Roscosmos and consists of two missions. The Trace Gas Orbiter is part of the first mission in this program. It includes two spacecrafts, the orbiter and a lander called Schiaparelli. Both launched on 14 March 2016 onboard a Proton-M/Breeze-M.
On 19 October 2016 they arrived at Mars and the orbiter entered into an orbit. The lander, meanwhile, descended for a landing attempt to the surface of Mars. Unfortunately, the lander failed to land. For more details, take a look at this article about the investigation.
The main goal of the ExoMars program is to investigate, if life ever existed on Mars. With the focus of the Trace Gas Orbiter being trace gases in the atmosphere of Mars. Those make up less than 1% of the total atmosphere and include methane, water vapor and nitrogen dioxide. Methane in particular is of interest to the mission.
To investigate these gases, the orbiter has four instruments or suits of instruments. The Nadir and Occultation for MArs Discovery (NOMAD) combines three spectrometers to identify and map atmospheric components. The Atmospheric Chemistry Suite (ACS) will extend the coverage by using its three infrared instruments to investigate the chemistry and structure of the atmosphere. The Colour and Stereo Surface Imaging System (CaSSIS) will provide context to the results of NOMAD and ACD by taking color and stereo images. This includes images of sources and sinks of trace gases. Finally, the Fine Resolution Epithermal Neutron Detector (FREND) can detect hydrogen up to one meter below the surface. It can thereby reveal deposits of water-ice.
ESA and Roscosmos plan to launch the next mission in the ExoMars program this year, but that’s a story for another post. Let’s take a look at another countries first mission to Mars.
https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Exploration/ExoMars
https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Exploration/ExoMars/ExoMars_Factsheet
https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Exploration/ExoMars/Trace_Gas_Orbiter_instruments
Emirates Mars Mission (EMM) – Hope Probe
On 20 July 2020 a Japanese H-IIA rocket launched the Emirates Mars Mission (EMM). It is the first mission of the United Arab Emirates to Mars. The goal of the mission, to study the Martian atmosphere on a global scale. To do just that, the spacecraft, named Hope Probe, first had to reach Mars. It did so by inserting itself into an orbit around Mars on 9 February 2021.
From its orbit, EMM studies the circulation and weather in the Martian lower and middle atmosphere. Therefore, it adds to the data delivered by other spacecraft of the upper atmosphere. To reach the goal of the first complete picture of the Martian Atmosphere, EMM features three instruments: EMIRS, EXI, and EMUS.
- EMIRS – Emirates Mars Infrared Spectrometer
The Emirates Mars Infrared Spectrometer measures the distribution of dust, ice clouds, water vapors, and temperature profiles in the lower atmosphere using infrared light. - EXI – Emirates Exploration Imager
The Emirates Exploration Imager is a camera that studies the lower atmosphere in visible and ultraviolet bands. In addition, it captures high-resolution images of Mars. - EMUS – Emirates Mars Ultraviolet Spectrometer
The Emirates Mars Ultraviolet Spectrometer is an ultraviolet spectrometer that studies carbon monoxide and oxygen in the thermosphere as well as oxygen and hydrogen in the exosphere
Combined, the results from the instruments provide the first complete picture of the Martian atmosphere. With its instruments, the Hope Probe is probably the first weather satellite in orbit at Mars. As it monitors changes throughout the day, across the planet, during all seasons.
For a first mission to Mars, EMM has been quite a success. And I think they will build upon it. Meanwhile, we take a look at another spacecraft from yet another country.
Tianwen-1
Finally, let’s take a look at a mission I already mentioned in my last post – Tianwen-1. It is China’s first Mars exploration mission. And they didn’t start simple, as it consists of an orbiter, a lander, and a rover. So, they try to orbit, land and drive around on Mars on their first independent mission. Quite an ambitious mission.
It launched onboard a Long March 5 on 23 July 2020. A couple of months later, on 10 February 2021, it entered orbit around Mars. It then started taking pictures of Mars to pinpoint a precise location for the lander. Three month later, the lander detached and on 14 May 2021 successfully landed on the surface of Mars. In doing so, China became the third country to successfully soft land on the surface.
The orbiter has multiple roles to fulfill. For once, it acts as a relay satellite for the lander and the rover on the surface. On the other side, it has scientific goals. This includes investigations about the Martian soil, geological structure, environment, atmosphere as well as water.
Therefore, the orbiter has seven instruments. These are Medium-Resolution Camera, High-Resolution Camera, Mars-Orbiting Subsurface Exploration Radar, Mars Mineralogy Spectrometer, Mars Magnetometer, Mars Ion and Neutral Particle Analyzer, Mars Energetic Particle Analyzer.
China recently released a video of the orbiter in orbit around Mars.
Conclusion
So, let’s take a look back. The main focus of science at Mars is to understand its history and if it was upon a time hosted life. With each mission, we learn more about Mars, but also about the development of the solar system and our planet. In the past, many missions failed to reach Mars or land on the surface. If you look back at just the last missions, we finally seem to learn how to go to Mars. This, and the fact that more countries successfully send spacecraft to Mars, makes me excited about the future. What about you? What are you excited about? Let me know in the comments!
Credit for Image at the top: ESA – European Space Agency