InSight
The Interior Exploration using Seismic Investigations, Geodesy and Heat Transport mission is a robotic lander designed to study the deep interior of the planet Mars. It was manufactured by Lockheed Martin Space Systems, is managed by NASA's Jet Propulsion Laboratory, and most of its scientific instruments were built by European agencies. The mission launched on 5 May 2018 at 11:05 UTC aboard an Atlas V-401 rocket and successfully landed at Elysium Planitia on Mars on 26 November 2018 at 19:52:59 UTC. InSight traveled during its journey.
InSight objectives are to place a seismometer, called SEIS, on the surface of Mars to measure seismic activity and provide accurate 3D models of the planet's interior; and measure internal heat flow using a heat probe called HP3 to study Mars' early geological evolution. This could bring a new understanding of how the Solar System's terrestrial planets – Mercury, Venus, Earth, Mars – and Earth's Moon form and evolve.
The lander was originally planned for launch in March 2016. An instrument problem delayed the launch beyond the 2016 launch window. NASA officials rescheduled the InSight launch to May 2018 and during the wait the instrument was repaired. This increased the total cost from to $830 million.
History
Discovery Program selection
InSight was initially known as GEMS, but its name was changed in early 2012 following a request by NASA. Out of 28 proposals from 2010, it was one of the three Discovery Program finalists receiving $3 million in May 2011 to develop a detailed concept study. In August 2012, InSight was selected for development and launch. Managed by NASA's Jet Propulsion Laboratory with participation from scientists from several countries, the mission was cost-capped at $425 million, not including launch vehicle funding.By reusing the landing system designed for the Mars Phoenix lander, which successfully landed on Mars in 2008, mission costs and risks were reduced.
Schedule issues
Lockheed Martin began construction of the lander on 19 May 2014, with general testing starting on 27 May 2015.A persistent vacuum leak in the CNES-supplied seismometer known as the Seismic Experiment for Interior Structure led NASA to postpone the planned launch in March 2016 to May 2018. When InSight was delayed, the rest of the spacecraft was returned to Lockheed Martin's factory in Colorado for storage, and the Atlas V rocket intended to launch the spacecraft was reassigned to the WorldView-4 mission.
On 9 March 2016, NASA officials announced that InSight would be delayed until the 2018 launch window at an estimated cost of $150 million. The spacecraft was rescheduled to launch on 5 May 2018 for a Mars landing on 26 November at 15:00. The flight plan remained unchanged with launch using an Atlas V rocket from Vandenberg Air Force Base in California. NASA's Jet Propulsion Laboratory was tasked with redesigning and building a new vacuum enclosure for the SEIS instrument, while CNES conducted instrument integration and testing.
On 22 November 2017, InSight completed testing in a thermal vacuum, also known as TVAC testing, where the spacecraft is put in simulated space conditions with reduced pressure and various thermal loads. On 23 January 2018, after a long storage, its solar panels were once again deployed and tested, and a second silicon chip containing 1.6 million names from the public was added to the lander.
Science background
Seismic vibrations
Seismometers on both Viking spacecraft were mounted on the lander, and picked up vibrations in 1976 from various operations of the lander and from the wind. However, the Viking 1 lander's seismometer did not deploy properly and did not unlock; the locked seismometer could not operate.The Viking 2 seismometer did unlock, and was able to vibrate and return data to Earth. One problem was accounting for other data. On Sol 80, the Viking 2 seismometer detected an event. No wind data were recorded at the same time, so it was not possible to determine whether the data indicated a seismic event or wind gust. Other lacking data would have been useful to rule out other sources of vibrations. Two other problems were the location of the lander and that a certain level of wind on Mars caused a loss of sensitivity for the Viking 2 seismometer. InSight has many other sensors, is placed directly on the surface, and also has a windshield.
Despite the difficulties, the Viking 2 seismometer readings were used to estimate a Martian geological crust thickness between at the Viking 2 lander site. The Viking 2 seismometer did detect vibrations from Mars winds complementing the meteorology results. There was the aforementioned candidate for a possible marsquake, but is not particularly definitive. The wind data did prove useful in its own right, and despite the limitations of the data, widespread and large marsquakes were not detected.
Seismometers were also left on the Moon, starting with Apollo 11 in 1969, and also by Apollo 12, 14, 15 and 16 missions and provided many insights into lunar seismology, including the discovery of moonquakes. The Apollo seismic network, which was operated until 1977, detected at least 28 moonquakes up to 5.5 on the Richter scale.
One of the aspects of the InSight mission is to compare the Earth, Moon, and Mars seismic data to learn more.
Planetary nutation
Radio Doppler measurements were taken with Viking and twenty years later with Mars Pathfinder, and in each case the axis of rotation of Mars was estimated. By combining this data the core size was constrained, because the change in axis of rotation over 20 years allowed a precession rate and from that the planet's moment of inertia to be estimated. InSight measurements of crust thickness, mantle viscosity, core radius and density, and seismic activity should result in a three- to tenfold increase in accuracy compared to current data.Objectives
The InSight mission placed a single stationary lander on Mars to study its deep interior and address a fundamental issue of planetary and Solar System science: understanding the processes that shaped the rocky planets of the inner Solar System more than four billion years ago.InSight primary objective is to study the earliest evolutionary processes that shaped Mars. By studying the size, thickness, density and overall structure of Mars' core, mantle and crust, as well as the rate at which heat escapes from the planet's interior, InSight will provide a glimpse into the evolutionary processes of all of the rocky planets in the inner Solar System. The rocky inner planets share a common ancestry that begins accretion. As the body increases in size, its interior heats up and evolves to become a terrestrial planet, containing a core, mantle and crust. Despite this common ancestry, each of the terrestrial planets is later shaped and molded through the poorly understood process of differentiation. InSight mission's goal is to improve the understanding of this process and, by extension, terrestrial evolution, by measuring the planetary building blocks shaped by this differentiation: a terrestrial planet's core, mantle and crust.
The mission will determine if there is any seismic activity, measure the rate of heat flow from the interior, estimate the size of Mars' core and whether the core is liquid or solid. This data would be the first of its kind for Mars. It is also expected that frequent meteor airbursts will provide additional seismo-acoustic signals to probe the interior of Mars. The mission's secondary objective is to conduct an in-depth study of geophysics, tectonic activity and the effect of meteorite impacts on Mars, which could provide knowledge about such processes on Earth. Measurements of crust thickness, mantle viscosity, core radius and density, and seismic activity should result in a three- to tenfold increase in accuracy compared to current data. This is the first time a robotic lander dug this deep into the martian crust.
In terms of fundamental processes shaping planetary formation, it is thought that Mars contains the most in-depth and accurate historical record, because it is big enough to have undergone the earliest accretion and internal heating processes that shaped the terrestrial planets, but is small enough to have retained signs of those processes. The science phase is expected to last for two years.
Design
The mission further develops a design based on the 2008 Phoenix Mars lander. Because InSight is powered by solar panels, it landed near the equator to enable maximum power for a projected lifetime of two years. The mission includes two relay microsatellites called Mars Cube One that launched with InSight but were flying in formation with InSight to Mars.Three major aspects to the InSight spacecraft are the cruise stage, the entry, descent, and landing system, and the lander.
Overall specifications
;Mass- Total mass during cruise:
- * Lander:
- * Aeroshell:
- * Cruise stage:
- * Propellant and pressurant:
- Relay probes flew separately but they weighed each
Lander specifications
- Lander mass:
- * Mars weight :
- About wide with solar panels deployed.
- The science deck is about wide and between high.
- The length of the robotic arm is
- Tilt of lander at landing on Mars: 4°
Power
- Rechargeable batteries
- Solar panels yielded 4.6 kilowatt-hours on Sol 1
Payload
InSight performs three major experiments using SEIS, HP3 and RISE. SEIS is a very sensitive seismometer, measuring vibrations; HP3 involves a burrowing probe to measure the thermal properties of the subsurface. RISE uses the radio communication equipment on the lander and on Earth to measure the overall movement of planet Mars that could reveal the size and density of its core.
- The Seismic Experiment for Interior Structure is measuring marsquakes and other internal activity on Mars, and the response to meteorite impacts, to better understand the planet's history and structure. SEIS was provided by the French Space Agency, with the participation of the Institut de Physique du Globe de Paris, the Swiss Federal Institute of Technology, the Max Planck Institute for Solar System Research, Imperial College, Institut supérieur de l'aéronautique et de l'espace and JPL. The seismometer can also detect sources including atmospheric waves and tidal forces from Mars' moon Phobos. A leak in SEIS in 2016 had forced a two-year mission postponement. The SEIS instrument is supported by meteorological tools including a vector magnetometer provided by UCLA that measures magnetic disturbances, air temperature, wind speed and wind direction sensors based on the Spanish/Finnish Rover Environmental Monitoring Station; and a barometer from JPL.
- The Heat Flow and Physical Properties Package, provided by the German Aerospace Center includes a radiometer and a heat flow probe. The probe, referred to as a "self-hammering nail" and nicknamed "the mole", was designed to burrow below the Martian surface while trailing a tether with embedded heat sensors to study the thermal properties of Mars' interior, and thus reveal unique information about the planet's geologic history. The tether contains precise temperature sensors every to measure the temperature profile of the subsurface.
- The Rotation and Interior Structure Experiment led by the Jet Propulsion Laboratory, is a radio science experiment that uses the lander's X band radio to provide precise measurements of planetary rotation to better understand the interior of Mars. X band radio tracking, capable of an accuracy under, builds on previous Viking program and Mars Pathfinder data. The previous data allowed the core size to be estimated, but with more data from InSight, the nutation amplitude can be determined. Once spin axis direction, precession, and nutation amplitudes are better understood, it should be possible to calculate the size and density of the Martian core and mantle. This should increase the understanding of the formation of terrestrial planets and rocky exoplanets.
- Temperature and Winds for InSight, fabricated by the Spanish Astrobiology Center, monitors weather at the landing site.
- Laser RetroReflector for InSight is a corner cube retroreflector provided by the Italian Space Agency and mounted on InSight top deck. It enables passive laser range-finding by orbiters after the lander is retired, and will function as a node in a proposed Mars geophysical network. This device previously flew on the Schiaparelli lander as the Instrument for Landing-Roving Laser Retroreflector Investigations, and is an aluminum dome in diameter and in mass featuring eight fused silica reflectors.
- Instrument Deployment Arm is a robotic arm that deployed the SEIS, wind and thermal shield, and HP3 instruments to Mars' surface. It is a 4 DOF motorized manipulator, constructed from carbon-fiber composite tubes. Originally intended for the canceled Mars Surveyor mission, the IDA features a scoop, wax actuated grappling claw, and the IDC camera.
- The Instrument Deployment Camera is a color camera based on the Mars Exploration Rover and Mars Science Laboratory navcam design. It is mounted on the Instrument Deployment Arm and images the instruments on the lander's deck and provides stereoscopic views of the terrain surrounding the landing site. It features a 45° field of view and uses a 1024 × 1024 pixel CCD detector. The IDC sensor was originally black and white for best resolution; a program was enacted that tested with a standard Hazcam and, since development deadlines and budgets were met, it was replaced with a color sensor.
- The Instrument Context Camera is a color camera based on the MER/MSL Hazcam design. It is mounted below the lander's deck, and with its wide-angle 120° panoramic field of view provides a complementary view of the instrument deployment area. Like the IDC, it uses a 1024 × 1024 pixel CCD detector.
Journey to Mars
Launch
On 28 February 2018, InSight was shipped via C-17 cargo aircraft from the Lockheed Martin Space Systems building in Denver to the Vandenberg Air Force Base in California in order to be integrated to the launch vehicle. The lander was launched on 5 May 2018 and arrived on Mars at approximately 19:54 UTC on 26 November 2018.rocket carrying InSight and MarCO from Vandenberg Space Launch Complex 3-E.
The spacecraft was launched on 5 May 2018 at 11:05 UTC on an Atlas V 401 launch vehicle from Vandenberg Air Force Base Space Launch Complex 3-East. This was the first American interplanetary mission to launch from California.
The launch was managed by NASA's Launch Services Program. InSight was originally scheduled for launch on 4 March 2016 on an Atlas V 401 solid rocket boosters/single from Vandenberg Air Force Base in California, U.S., but was called off in December 2015 due to a vacuum leak on the SEIS instrument. The rescheduled launch window ran from 5 May to 8 June 2018.
Major components of the launch vehicle include:
- Common Core Booster
- This launch did not use additional solid rocket boosters
- Centaur with Relay CubeSats
- InSight in a Payload fairing
Cruise
After its launch from Earth on 5 May in 2018, it coasted through interplanetary space for 6.5 months traveling across for a touchdown on 26 November in that year.InSight cruise stage departed Earth at a speed of. The MarCo probes were ejected from the 2nd stage Centaur booster and traveled to Mars independent of the InSight cruise stage, but they were all launched together.
During the cruise to Mars, the InSight cruise stage made several course adjustments, and the first of these took place on 22 May 2018. The cruise stage that carries the lander includes solar panels, antenna, star trackers, sun sensor, inertial measurement unit among its technologies. The thrusters are actually on the InSight lander itself, but there are cutouts in the shell so the relevant rockets can vent into space.
The final course correction was 25 November 2018, the day before its touch down. A few hours before making contact with the Martian atmosphere, the cruise stage was jettisoned, on 26 November 2018.
Entry, descent, and landing
On 26 November 2018, at approximately 19:53 UTC, mission controllers received a signal via the Mars Cube One satellites that the spacecraft had successfully touched down at Elysium Planitia. After landing, the mission took three months to deploy and commission the geophysical science instruments. It then began its mission of observing Mars, which is planned to last for two years.The spacecraft's mass that entered the atmosphere of Mars was. There were three major stages to InSight's landing:
- Entry: after separating from the cruise stage the aeroshell enters the atmosphere and is subject to air and dust in the Martian atmosphere.
- Parachute descent: at a certain speed and altitude a parachute is deployed to slow the lander further.
- Rocket descent: closer to the ground the parachute is ejected and the lander uses rocket engines to slow the lander before touchdown.
- 25 November 2018, final course correction before EDL.
- 26 November 2018, Cruise stage jettisoned before entering the atmosphere.
- Several minutes later, the aeroshell containing the lander makes contact with the upper Martian atmosphere at.
- * At this point it is above Mars and in the next few minutes it lands, but undergoes many stages.
- Aeroshell is heated to during descent.
- At and ~ above the surface, the parachute is deployed.
- Several seconds later, the heat shield is jettisoned from the lander.
- The landing legs extended.
- Landing radar activated.
- Backshell jettisoned at a speed of about and at altitude.
- Landing rockets turned on.
- Roughly from the ground constant velocity mode is entered.
- Approaches ground at about.
- Touchdowneach of the three lander legs have a sensor to detect ground contact.
- Descent rockets are turned off at touchdown.
- Begin surface operations.
On 26 November 2018, InSight successfully touched down in Elysium Planitia.
A few hours after landing, NASA's 2001 Mars Odyssey orbiter relayed signals indicating that InSight solar panels had successfully unfurled and are generating enough electrical power to recharge its batteries daily. Odyssey also relayed a pair of images showing InSight landing site. More images were acquired in stereo pairs to create 3D images, allowing InSight to find the best locations on the surface to place the heat probe and seismometer. Over the next few weeks, InSight checked health indicators and monitor both weather and temperature conditions at the landing site.
Landing site
As InSight science goals are not related to any particular surface feature of Mars, potential landing sites were chosen on the basis of practicality. Candidate sites needed to be near the equator of Mars to provide sufficient sunlight for the solar panels year round, have a low elevation to allow for sufficient atmospheric braking during EDL, be flat and relatively rock-free to reduce the probability of complications during landing, and have soft enough terrain to allow the heat flow probe to penetrate well into the ground.An optimal area that meets all these requirements is Elysium Planitia, so all 22 initial potential landing sites were located in this area. The only two other areas on the equator and at low elevation, Isidis Planitia and Valles Marineris, are too rocky. In addition, Valles Marineris has too steep a gradient to allow safe landing.
In September 2013, the initial 22 potential landing sites were narrowed down to four, and the Mars Reconnaissance Orbiter was then used to gain more information on each of the four potential sites before a final decision was made. Each site consists of a landing ellipse that measures about.
In March 2017, scientists from the Jet Propulsion Laboratory announced that the landing site had been selected. It is located in western Elysium Planitia at. The landing site is about north from where the Curiosity rover is operating in Gale Crater.
On 26 November 2018, the spacecraft successfully touched down at its landing site, and in early December 2018 InSight lander and EDL components were imaged from space on the surface of Mars. The images provided precise position of the lander:.
Surface operations
On 26 November 2018, NASA reported that the InSight lander had landed successfully on Mars. The meteorological suite and magnetometer are operational, and the mission would take up to three months to deploy and commission the geophysical science instruments. After landing, the dust was allowed to settle for a few hours, during which time the solar array motors were warmed up and then the solar panels were unfurled. The lander then reported its systems' status, acquired some images, and it powered down to sleep mode for its first night on Mars. On its first sol on Mars it set a new solar power record of 4.6 kilowatt-hours generated for a single Martian day. This amount is enough to support operations and deploy the sensors.On 7 December 2018, InSight recorded the sounds of Martian winds with SEIS, which is able to record vibrations within human hearing range, although rather low, and these were sent back to Earth. This was the first time the sound of Mars wind was heard after two previous attempts.
On 19 December 2018, the SEIS instrument was deployed onto the surface of Mars next to the lander by its robotic arm, and it was commissioned on 4 February 2019. After the seismometer became fully operational, the heat probe instrument was deployed on 12 February 2019.
On 28 February 2019, the Heat and Physical Properties Package probe started digging into the surface of Mars. The probe and its digging mole were intended to reach a maximum depth of after two months, but on 7 March 2019, the HP³ mole had only made it about, or three-quarters of the way out of its housing structure. Both NASA and DLR continue to look into the cause of the under-performing tool and for potential solutions. Scientifically useful measurements are possible at a depth of.
In April 2019, NASA reported that the Mars InSight lander detected its first marsquake.
In September 2019, researchers reported that InSight uncovered unexplained magnetic pulses, and magnetic oscillations.
In October 2019, the researchers at JPL concluded that the soil on Mars does not provide necessary friction for drilling, causing the mole to bounce around and form a wide pit around itself rather than dig deeper. They attempted a maneuver called in which they pressed the side of the scoop against the mole location to pin the side of the wall of the hole and increase friction. Pinning was initially successful, but then the mole backed out of its hole after a few weeks, suggesting the soil is accumulating below the mole.
On 24 February 2020, a summary of studies over the past year from InSight was presented which indicated that the planet Mars has active quakes, dust devils and magnetic pulses.
In February 2020, according to new data gathered from NASA's InSight lander, it was found that the Martian magnetic field at the landing site is about 10 times stronger than previously thought, and fluctuates rapidly.
In February 2020, the team reevaluated the risks of pushing the scoop directly against the back cap of the mole, and determined the procedure to be acceptable.
In June 2020, the team reported that the mole was finally underground, and was being evaluated to determine if the mole was able to dig as designed. On 9 July 2020, it was revealed that images taken on 20 June 2020 showed the mole bouncing again, indicating that it did not have sufficient friction to dig deeper. One suggested solution was to partially fill the hole with soil to increase friction.
MarCO spacecraft
The Mars Cube One spacecraft are a pair of 6U CubeSats that piggybacked with the InSight mission to test CubeSat navigation and endurance in deep space, and to help relay real-time communications during the probe's entry, descent and landing phase. The two 6U CubeSats, named MarCO A and B, are identical. They were launched along with InSight, but separated soon after reaching space, and they flew as a pair for redundancy while flanking the lander. They did not enter orbit, but flew past Mars during the EDL phase of the mission and relayed InSight telemetry in real time. The success of the MarCO spacecraft proved the viability of the cubesat platform for deep space missions and helped serve as a technical demonstration for potential future missions of a similar nature. On 5 February 2019, NASA reported that the CubeSats went silent, and are unlikely to be heard from again.- Mass: each.
- Dimensions: each
- Each has a reflectarray high gain antenna
- Miniaturized radio operating in UHF and X-band.
- They carry a miniature wide-angle camera.
- Cold gas thrusters for attitude adjustments.
- Star tracker for navigation.
Team and participation
Mars Exploration Rover project scientist W. Bruce Banerdt is the principal investigator for the InSight mission and the lead scientist for the SEIS instrument. Suzanne Smrekar, whose research focuses on the thermal evolution of planets and who has done extensive testing and development on instruments designed to measure the thermal properties and heat flow on other planets, is the lead for InSight HP3 instrument. The Principal Investigator for RISE is William Folkner at JPL. The InSight mission team also includes project manager Tom Hoffman and deputy project manager Henry Stone.
Major contributing agencies and institutions are:
- National Aeronautics and Space Administration
- Centre National d'Études Spatiales
- German Aerospace Center
- Italian Space Agency
- Jet Propulsion Laboratory
- Lockheed Martin
- Paris Institute of Earth Physics
- Swiss Federal Institute of Technology in Zurich
- Max Planck Institute for Solar System Research
- Imperial College London
- Institut supérieur de l'aéronautique et de l'espace
- University of Oxford
- Spanish Astrobiology Center
- Space Research Centre of Polish Academy of Sciences