November 18, 2013
NASA’s MAVEN Mission Will Help Study Mars’ Depleting Atmosphere
UPDATE (November 18, 2013 12:30 a.m. EST)
At 11:48 a.m. EST, liquid oxygen began flowing into the Atlas first stage booster. Liquid oxygen loading of the Centaur upper stage is about 50 percent complete. There are no technical issues. Liftoff of a United Launch Alliance Atlas V rocket carrying NASA's Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft is targeted for the opening of a two-hour window at 1:28 p.m. from Space Launch Complex 41 in Florida.
UPDATE (November 18, 2013 11:30 a.m. EST)
Countdown clocks at Cape Canaveral Air Force Station have paused as planned for a 30-minute hold at the T-2 hour mark. The count will resume at 11:18 a.m. EST. Liftoff of a United Launch Alliance Atlas V rocket carrying NASA's Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft is targeted for the opening of a two-hour window at 1:28 p.m. from Space Launch Complex 41 in Florida.
UPDATE (November 18, 2013 9:00 a.m. EST)
Countdown clocks at the Atlas Space Operations Center (ASOC) began counting from the T-6:20 mark at 6:28 a.m. EST. NASA and United Launch Alliance (ULA) managers are overseeing the countdown of the ULA Atlas V-401 and its Centaur upper stage, targeted to launch NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft into space at 1:28 p.m.
Live coverage on NASA TV begins at 11:00 a.m. EST.
UPDATE (November 18, 2013 4:50 a.m. EST)
The countdown for launch of NASA's MAVEN spacecraft from the Cape Canaveral Air Force Station begins at 6:28 a.m. EST on Monday, leading toward a planned liftoff atop an Atlas V rocket at 1:28 p.m. There is a two-hour launch window that extends to 3:28 p.m
[ Watch the Video: MAVEN Readies For Launch To Mars ]
Brett Smith for redOrbit.com - Your Universe Online
When NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission launches next Monday, it will be carrying an instrument designed to scan high above the Martian surface for patterns of electrons that could explain why the Red Planet is losing its atmosphere.
The Solar Wind Electron Analyzer (SWEA) is designed to analyze electrons in two distinct regions around Mars: the solar wind passing by the planet and a layer of Mars' upper atmosphere called the ionosphere.
"We're trying to understand the boundary layer between the solar wind and the planet's ionosphere because this is a key region where planetary material is being lost," said project researcher David L. Mitchell. "We want to understand the loss processes and how the solar wind is stripping away the atmosphere."
"The instrument will tell whether the spacecraft is measuring planetary plasma or solar wind plasma" in a specific region above the planet, he added. "It determines the environment, which is important for setting the stage for interpreting other measurements."
By scanning the upper Martian atmosphere as it orbits, NASA scientists expect SWEA and other onboard instruments to be able to generate a map of the movement of charged particles high above Mars.
Another mystery scientists are hoping to solve through MAVEN is the layout of magnetic fields around Mars. While Earth creates a global magnetic field from within its core, Mars' magnetic field is generated mostly by magnetized rock in its crust. Because the Red Planet has many localized magnetic fields, it can seem as if there are many bar magnets strewn across the planet’s surface. These magnetic fields also rotate with the planet once every 24.6 hours — a full Martian day.
The interactions between Mars’ patchwork magnetic field and the charged solar wind that streams off the Sun at one million miles per hour can provide different methods for charged particles to exit.
"These two systems of magnetic fields can connect with one another," Mitchell said. "There will be times when crustal magnetic field will open up and connect with solar wind's magnetic field lines, forming a path for solar wind plasma to travel down into the atmosphere or a path for planetary ions and electrons to travel upwards and escape."
He added that SWEA measurements, along with data collected by the MAVEN Magnetometer (MAG), would help to determine if the interacting magnetic field lines are creating potential escape routes.
"This is one reason why the SWEA and MAG instruments are important," Mitchell said. "They tell us whether the magnetic field opens into the solar wind, providing a conduit for escape, or whether it forms closed loops and traps the ionosphere."
SWEA will take measurements at many different altitudes ranging from 93 miles to nearly 3,900 miles above the planet's surface. To avoid a disruptive magnetic effect from the spacecraft itself, SWEA will be placed on the end of one of the spacecraft's booms. Mitchell said this and other steps will help to provide reliable and worthwhile results.
"It's been a tremendous amount of work," Mitchell said. "But it's all coming together, and it feels good to have the instrument on the spacecraft, and we're looking forward to launching it on its way to Mars."