NASA is Mars-bound again. Eric Bogatin describes the atmosphere at a MAVEN launch event and the instruments, now hurtling toward Mars, that will collect data on atmosphere.
"We're on our way to Mars!" Dr. Fran Bagenal, spokesperson for the NASA's MAVEN project team at the Laboratory of Atmospheric and Space Physics at the University of Colorado, Boulder, shouted over the applause in the auditorium on November 18, 2013.
Fran Bagenal raising her hands in trump as the audience in the LASP auditorium watched the live broadcast of the MAVEN launch. A model of the satellite rests on the table next to the globe of Mars.
(Source: Eric Bogatin)
The MAVEN spacecraft, Mars Atmospheric Volatile EvolutioN, is a complementary follow-on mission to the Mars Curiosity Lander. The main mission is to study the upper atmosphere of Mars and search for answers to the question, "What happened to the water on Mars?"
Atop the 188-foot tall Atlas V launch vehicle and Centaur second stage rocket, the MAVEN spacecraft blasted off from the Cape Canaveral Air Force Station in Florida, right on schedule at 1:28 p.m. EST.
The Centaur second stage separated from the Atlas booster engine minutes after launch. Within half an orbit, the Centaur stage fired for nine minutes, inserting the MAVEN spacecraft into an orbital trajectory on its way to a Mars rendezvous scheduled for September 22, 2014.
Shortly after satellite separation, the solar panels deployed on the MAVEN spacecraft and the electronics began its powered on check-out sequence.
A NASA spokesperson said:
Upon its arrival at Mars in September, the spacecraft will execute an orbit insertion maneuver, firing six thrusters that will allow it to be captured by Mars' orbit. In the following five weeks, MAVEN will establish itself in an orbit where it can conduct science operations, deploy science appendages, and commission all instruments before starting its one-Earth-year scientific primary mission.
While the Mars Science Laboratory's rover, Curiosity, landed on the surface and is still exploring the local geology and chemistry of the Martian surface, MAVEN will stay in orbit and explore the properties of the upper atmosphere and the interactions with the solar wind.
Where did all the water go?
We are celebrating 65 years of being in this business. Research at LASP started off with rockets studying the Earth's atmosphere and the Mariner satellites, launched in 1964, studying the Martian atmosphere. The MAVEN mission is aimed at looking at the climate history of Mars.
The key goal is to find out, if there was water at one time on Mars producing these observed river features and minerals, where did the water go, where did the atmosphere go? Did it go down into the rocks or up into the atmosphere and gotten stripped away? That is what MAVEN will study, how much of the atmosphere has been removed.
With no intrinsic planetary magnetic field, Mars has little protection from the solar wind. And with only 38% of Earth's, Martian gravity has a more tenuous hold on its atmosphere, making it easier for "scavenging" by the solar wind.
The simulation below from NASA and the Nagoya University illustrates this process. The colors represent the density of the upper atmosphere and the arrows are the flow of ions from the atmosphere.
(Source: NASA/Nagoya University)
"We have no idea whether or not this is reality," Bagenal said. "MAVEN will go there, make measurements, and find out."
Once in orbit around Mars, the eight scientific instruments will deploy to measure particles and fields, UV emissions and the neutral gas and ion composition.
The Neutral Gas and Ion Mass Spectrometer will directly sample the atmospheric composition.
The Imaging Ultraviolet Spectrograph will remotely measure the upper atmospheric composition from its UV and optical emissions.
The Solar Energetic Particle detector will measure the highest energy particles in the solar wind and their penetration into the atmosphere, during quiet periods and during coronal mass ejections (CMEs).
- The Solar Wind Ion Analyzer will measure the density and velocity of the solar wind.
- The Solar Wind Electron Analyzer will measure the electrons both in the solar wind and that evolve from the atmosphere due to solar UV.
- The Supra Thermal and Thermal Ion Composition detector will measure the ion composition and velocity and how they migrate from the atmosphere into space.
- The Langmuir Probe and Waves will measure density and temperature of thermal ions and electric field waves that can accelerate ions to escape velocity.
- The Magnetometer will measure the residual magnetic fields from the solar wind, the ionosphere and local, remnant magnetic fields from the Martian Crust.
To probe the atmosphere, the MAVEN spacecraft will be placed in a highly elliptical orbit ranging from 150 km at closest approach to 6200 km from the surface. "Five times during the mission, the lowest altitude will be dropped to about 125 km for a week at a time," a NASA spokesperson said. "This will allow us to directly sample all the way down to the top of the lower atmosphere and to characterize all the altitudes that are important for escape."
While making its deep dips into the upper atmosphere, it will use its aerodynamic shape, almost like a badminton birdie, to stabilize its flight.
10 months to Mars
Artist concept of MAVEN spacecraft in orbit over Mars, using its aerodynamic shape to stabilize it on its deep dips.
(Source: LASP, University of Colorado, Boulder)
Mounting evidence suggests the early climate of Mars was very different than what we find today. If there was liquid water present, what happened to it today? While Curiosity is exploring the question, could the water be trapped in the ground, MAVEN will explore the question, could it have evaporated into the atmosphere, and migrated into space.
"The cost of the MAVEN program is $671M," Bagenal said. "To put this in perspective, this is about one latte per person in America. Looked at another way, it is about what it costs to make a feature movie about going to Mars."
For the same price, we get the real thing.
— Eric Bogatin writes Be the Signal.