If all goes as planned, MAVEN, for Mars Atmosphere and Volatile Evolution Mission, is scheduled to be inserted into an elliptical orbit on Sept. 21. Program officials said this week that MAVEN’s current trajectory "looks good" as they continue to run simulated orbital insertions that include plenty of "what-if" scenarios.
Once in orbit around Mars, at least one "precautionary manoeuvre" is planned in October before MAVEN’s main science phase begins in early November. At the lowest point in its orbit, the 37.5-foot-wide orbiter will be 93 miles from the Martian surface.
MAVEN is the first probe dedicated to studying the Martian atmosphere and climate in an attempt to determine the fate of the planet’s ancient supply of liquid water and thick atmosphere. Scientists think the Martian atmosphere has been gradually slipping away into space over the last 1 billion years. They hope to use MAVEN’s array of instruments to find out how and why.
"The goal is to come up with a better understanding of what happened to the Martian atmosphere and how planetary atmospheres evolve over time," explained Jim Morrissey, MAVEN instruments systems manager at NASA’s Goddard Spaceflight Center in Maryland.
MAVEN and the ongoing Curiosity rover mission are, among other things, trying to establish that Mars once harboured conditions suitable for life. Planetary scientists want to know why the Martian atmosphere and climate changed over time and how solar activity contributes to atmospheric loss.
MAVEN was launched from Cape Canaveral last November and is currently traveling at a speed of about 16 miles per second on a 10-month, 442-million-mile journey to the fourth planet in our solar system.
One of MAVEN’s eight instruments, a solar wind ion analyzer, will measure the electrically charged particles in what’s left of the Martian atmosphere to find out where it went and why. Most of the ions being measured will be within the solar winds. The ions interact with neutral gas particles in the thin upper Martian atmosphere, allowing them to resist the planet’s gravitational pull.
Scientists suspect these interactions played a role in stripping the planet of its atmosphere, leaving behind a reddish desert landscape where liquid water once flowed. "Our goal is to find out what happened to the water," Morrissey said in a Sept. 10 interview.
Scientists know that some H2O was lost to chemical reactions, while some was frozen at the Martian poles or is trapped below the planet’s surface. MAVEN’s instruments will try over the next year to determine how water and the Martian atmosphere were literally "lost in space."
Other instruments like an ultraviolet spectrometer will help determine the current composition of the thin Martian atmosphere. "We’ll also see measurements over time [and] at well-sampled longitudes and latitudes" over a period of one Earth year, Morrissey noted.
This will allow scientists to analyze data about the Martian atmosphere by "playing it forward and backward," Morrissey said, in order to figure out what is happening in the upper atmosphere. These unprecedented data analysis tools should help scientists come up with data-driven insights about the evolution of planetary atmospheres.
The timing of the MAVEN mission is fortuitous. The World Meteorological Organization reported on Sept. 9 that heat-trapping CO2 levels in the Earth’s atmosphere reached record levels in 2013. Another NASA probe, the Orbiting Carbon Observatory-2, is currently monitoring the Earth’s atmospheric CO2 levels and will eventually map carbon sources and carbon sinks on Earth.
Those observations, along with MAVEN’s extensive measurements of the upper Martian atmosphere — an environment that may have looked similar to Earth’s despite the fact that Mars lacks a magnetic field — could help climate scientists better understand the evolution of the thin layer of atmosphere that protects us from the ravages of outer space.
The atmospheric data swept up by MAVEN’s sensor payload will be relayed back to Earth via a high-gain antenna. Morrissey added that a separate UHF antenna on the spacecraft will serve as a communications relay link between ground controllers and the Mars Curiosity rover currently making its way to Mount Sharp, the central peak of Gale Crater. The backup relay antenna was built by engineers at NASA’s Jet Propulsion Laboratory.
Learn more about the instruments by watching the hour-long prelaunch "hangout" with four of the mission’s instrument scientists:
This article originally appeared on EE Times — George Leopold was EE Times News Director for many years and now writes about NASA programs and all things "outer space" related.