Mars InSight Has Been Busy

insight selfie
This is NASA InSight’s first full selfie on Mars. It displays the lander’s solar panels and deck. On top of the deck are its science instruments, weather sensor booms and UHF antenna. Credit: Nasa/JPL-Caltech.

So I have talked previously about the launch of the latest lander on Mars, named Mars Insight. Launched on the 5th of May 2018 by an Atlas V 401 from Vandenberg AFB, it began its 6 month journey to the red planet. Travelling across 484 million km it landed on 26th of November 2018. It landed much like the Curiosity and Phoenix missions with a parachute decent and then using rockets to lower the lander onto the surface gently. The mass of the lander is about 358 kg, but due to the gravity on Mars being two thirds less it only weighs 134.6 kg on the surface. Just a few hours after touchdown the Mars Odyssey orbiter relayed signals indicating that the solar panels had successfully opened, generating power. The relayed signal also contained a pair of images of the landing site. For the next few weeks InSight checked the health of the on board systems and monitor the weather and temperature of the landing site.

InSights workspace
This mosaic, made of 52 individual images from NASA’s InSight lander, shows the workspace where the spacecraft will eventually set its science instruments. The lavender annotation shows where InSight’s seismometer and heat flow probe can be placed. Credit: NASA/JPL-Caltech

The images relayed were used to find the best area to place the Seismometer instrument. There was then some time for scientists to evaluate the information and pick the best spot to place the sensitive instrument. On the 19th of December Insight used its 8ft robotic arm to pick up the Seismometer from the deck of the lander, and place it on the ground nearby. The position picked was one fairly free of rocks, making the leveling process easier. There was then another set of a few weeks to adjust the cable and ensure the SEIS instrument was perfectly placed. Then the arm picked up a protective cover from the lander to place over the instrument. This is designed to minimise noise from the surrounding atmosphere, being introduced from huge temperature changes and wind vibrations. This will allow the seismometer to pick up the tiny tremors that the planet may have. This is the first time another planet has been studied this way, the only other planetary body being the Moon. Viking 1 and 2 had seismometers on board but design flaws meant the results were inconclusive.

Temperature is one of the biggest issues with a mission like this. On Mars the temperature can range over 90 degrees Celsius in just a single sol (Martian day). The protective cover is ringed with a thermal barrier and a section of chain mail around the bottom. The wind and thermal shield has been specifically designed for the environment to moderate the temperatures. JPL has a history dealing with Mars temperatures from the many missions it has sent there including the Phoenix lander, and the Curiosity rover. The SEIS instrument was provided by the French Space Agency CNES, and developed by the Institut de Physique du Globe de Paris, with JPL building the wind and thermal shield. There is also a great British part of the instrument with some of the silicon sensors designed and fabricated by Imperial College London. The microseismometers were designed to pick up the faintest seismic activity from the surface. Scientists from Oxford’s Department of Physics also supported the development, and the Rutherford Appleton Laboratory’s RAL Space worked closely with the team to develop the front electronics of the instrument as well as the space qualification.

SEIS instrument cutaway
Cutaway illustration showing interior components of SEIS. Credit: NASA/JPL-Caltech/CNES/IPGP
One of the microseismometer sensors, carved from a single piece of silicon 25mm square. Credit: Imperial College/T.Pike.

On the 12th of February the lander deployed the HP3 package onto the surface. Known as the Heat Flow and Physical Properties Package, it was placed about a meter away from the seismometer. The Idea of HP3 is to measure the heat flow through Mars’s subsurface, hopefully helping scientists to figure out how much energy it takes to build a rocky planet like Mars. An interesting instrument, it has a self-hammering spike, or mole, allowing it to burrow up to 5m below the surface. This is much deeper than any previous mission. Viking 1 only scooped down 8.6 inches, and the predecessor of Insight, Phoenix dug to 7 inches. The probe was provided by the German Aerospace Centre (DLR). A tether attached to the top of the mole features heat sensors to measure the temperature of the Martian subsurface. Heat sensors in the mole itself will measure the soils thermal conductivity (how easily the heat moves through the surface). The mole plans to stop every 50 centimetres to take the measurements, as the hammering creates friction, releasing heat that would likely impact the instruments readings. It is then heated up by 28 degrees Celsius over 24 hours, with the temperature sensors measuring how rapidly this happens.

A GIF of the Insight lander placing the instruments on the ground. Credit: NASA/JPL-Caltech

Along with the Insight lander, the launch also contained a new first, a pair of cubesats known as MarCO-1 and MarCO-2. The size of small suitcases the pair were the first cubesats to enter and work in deep space. The team nicknamed the WALL-E and EVE, and they functioned as communications relays during the insight landing, beaming back data from the decent, along with the first image. WALL-E also managed to capture its own great images of Mars as it soared past it. The mission cost was about $18.5 million, much less than most missions, and was designed by JPL as a technology demonstrator mission. Neither is still in contact with Earth, with WALL-E losing contact on the 29th of December 18, and EVA losing contact on the 4th of January 19. JPL says they will attempt to contact the pair again in the future, but it is unlikely. The MarCO satellites will still live on though, with some of the spare parts going towards other cubesat missions, including experimental radios, antennas and propulsion systems. They also pushed the idea of using commercial parts to develop the system.

Engineer Joel Steinkraus uses sunlight to test the solar arrays on one of the Mars Cube One (MarCO) spacecraft at NASA’s Jet Propulsion Laboratory. Credit: NASA/JPL-Caltech
MarCO-B, one of the experimental Mars Cube One (MarCO) CubeSats, took these images as it approached Mars. Credit: NASA/JPL-Caltech

Just as an addition, there is a great comic that can be found here about Mars Insight, by the oatmeal. It is worth a quick read.

Thank you for reading, take a look at my other posts if you are interested in space, electronics, or military history. If you are interested, follow me on Twitter to get updates on projects I am currently working on.

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