When MAVEN fires its thrusters and settles into Martian orbit next September, it will join a celebrity list of spacecraft already studying the red planet. Its launch today from Cape Canaveral, Florida, was a major step toward that goal, one that propels the satellite onward to its own fame during a year-long mission studying the atmosphere of Mars. (See “Top 5 Challenges in Store for Mars MAVEN Mission.”)
While the Curiosity rover maneuvers up the rocky slopes of Mount Sharp and the Opportunity rover investigates the rim of Endeavour Crater, MAVEN will orbit overhead analyzing the remnants of an atmosphere that once allowed for abundant liquid water to flow on the now barren terrain where they both explore. It will also join a network of satellites tasked with relaying those rovers’ data back to Earth, often a bottleneck in the interplanetary communication process.
The launch today happened on schedule at 1:28 p.m. Eastern Time, the first opportunity of a launch window that extended into December if necessary. After that, the planets would no longer be aligned in a way that a transit between them would be possible, at least until 2015. The weather forecast also worsens for the next few days, so there was a sigh of relief accompanying the shockwave of sound when the rocket roared upward and disappeared into the clouds.
It’s theorized that over hundreds of millions of years, the outflow of energetic particles from the sun, known as solar wind, has slowly eroded the Martian atmosphere and thus changed the planet’s environment. All other recent missions have established geologic evidence of surface water on an ancient Mars, but none can conclusively determine where it has gone. MAVEN will investigate the current effects of solar wind on the atmosphere to model what might have happened historically. The mission is led by principal investigator Bruce Jakosky from the University of Colorado.
Visiting MAVEN two months ago in the cleanroom at Kennedy Space Center during preparations for launch involved donning a blue bunny suit and thoroughly scrubbing all camera equipment. The satellite is surprisingly massive to witness in person: 37.5 feet (11.43 meters) from tip to tip, or about as wide as a school bus is long. Centrally mounted, the 6.56 foot (2 meter) diameter high-gain antenna dish was already covered in protective insulation for the hazards of space.
Instead of lying flat, the open solar arrays are angled 20 degrees inward on both ends to self-stabilize the satellite during dips into Mars’ upper atmosphere, an effect similar to the behavior of the feathers on a badminton shuttlecock. MAVEN’s elliptical orbits are designed to encounter different regions surrounding Mars to study where solar wind would have the most effect on the atmosphere. As a result, the orbits will routinely rise to around 3,860 miles (6,220 kilometers) and drop to about 93 miles (150 kilometers) all around the planet.
The angled solar arrays will be most helpful during the five planned “Deep Dip” campaigns that will lower even further to an altitude of just 77.6 miles (125 kilometers), where air pressure is 30 times denser.
MAVEN now heads to Mars alongside India’s Mangalayan Mission (see “India Shoots for Mars”), the country’s first Mars project, which is designed to study the planet’s composition while looking for atmospheric methane. The next NASA missions to Mars are scheduled for launch in 2016 and 2020.