September 10, 2015 – NASA’s MAVEN spacecraft, in orbit at Mars since Sept. 21, 2014, has completed the fourth deep-dip campaign of its primary science mission. The series of five-day campaigns are designed to lower the periapsis (lowest altitude) of the spacecraft above #Mars in order to achieve a targeted atmospheric density corridor and to sample the lower, well-mixed portion of the Martian upper atmosphere. The density at 125 km (78 mi) can be 30 times that encountered during the nominal science orbits, where the periapsis is approximately 150 km (93 mi).
The latest deep-dip campaign concluded in the early hours of Sept. 10th with the second of two “walk-out” maneuvers, designed to raise the periapsis of MAVEN back to near 150 km. The minimum periapsis altitude achieved during the campaign was 121 km (75 mi) above the #Martian surface. The maximum atmospheric density encountered was 3.0 kg/km³.
The two “walk-out” maneuvers (executed on Sept. 9 & 10) had ∆V (delta-V) magnitudes of 3.3 m/sec and 0.6 m/sec, and raised the periapsis by 20 km (12 mi) and 4 km (2.5 mi) respectively. These maneuvers returned MAVEN to a nominal periapsis altitude of 145 km (90 mi) and achieved an estimated density of 0.11 kg/km³.
MAVEN’s measurements will allow scientists to characterize the current state of the upper atmosphere and ionosphere, determine the rates of loss of gas to space today, and extrapolate backward in time in order to determine the total loss to space through time.
MAVEN is the first mission dedicated to studying the upper atmosphere of Mars. The spacecraft launched atop a United Launch Alliance Atlas V rocket on November 18, 2013, from Cape Canaveral Air Force Station in Florida. MAVEN successfully entered Mars’ orbit on September 21, 2014.
MAVEN is led by Principal Investigator Bruce Jakosky, from the University of Colorado at Boulder. The university built two of the eight science instruments and is conducting the mission’s science operations. Lockheed Martin of Littleton, Colorado, built the spacecraft and is performing mission operations.
NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the MAVEN project and provided two science instruments for the mission. The University of California at Berkeley’s Space Sciences Laboratory also provided four science instruments for the mission. NASA’s Jet Propulsion Laboratory in Pasadena, California provides navigation and Deep Space Network support, as well as the Electra telecommunications relay hardware and operations.