MAVEN
MAVEN is an American spacecraft orbiting Mars to study the loss of its atmospheric gases to space, providing insight into the history of the planet's climate and water. The spacecraft name is an acronym for "Mars Atmosphere and Volatile Evolution" and also a word that means "a person who has special knowledge or experience; an expert". MAVEN was launched on an Atlas V rocket from Cape Canaveral Air Force Station, Florida, on 18 November 2013 UTC and went into orbit around Mars on 22 September 2014 UTC. The mission is the first by NASA to study the Mars  atmosphere. The probe is analyzing the planet's upper atmosphere and ionosphere to examine how and at what rate the solar wind is stripping away volatile compounds. The principal investigator for the mission is Shannon Curry at the University of California, Berkeley. She took over from Bruce Jakosky of the Laboratory for Atmospheric and Space Physics at the University of Colorado Boulder, who proposed and led the mission until 2021. The project cost $582.5 million to build, launch, and operate through its two-year prime mission. Pre-launch. Proposed in 2006, the mission was the second of NASA's  Mars Scout Program, which had previously yielded Phoenix. It was selected for development for flight in 2008. On 2 August 2013, the MAVEN spacecraft arrived at Kennedy Space Center, in Florida to begin launch preparations. On 1 October 2013, only seven weeks before launch, a government shutdown caused suspension of work for two days and initially threatened to force a 26-month postponement of the mission. With the spacecraft nominally scheduled to launch on 18 November 2013, a delay beyond 7 December 2013 would have caused MAVEN to miss the launch window as Mars moved too far out of alignment  with the Earth. However, two days later, on 3 October 2013, a public announcement was made that NASA had deemed the 2013 MAVEN launch so essential to ensuring future communication with current NASA assets on Mars — the rovers "Opportunity" and "Curiosity" — that emergency funding was authorized to restart spacecraft processing in preparation for an on-time launch. Objectives. Features on Mars that resemble dry riverbeds and the discovery of minerals that form in the presence of water indicate that Mars once had a dense enough atmosphere and was warm enough for liquid water to flow on the surface. However, that  thick atmosphere was somehow lost to space. Scientists suspect that over millions of years, Mars lost 99% of its atmosphere as the planet's core cooled and its magnetic field decayed, allowing the solar wind to sweep away most of the water and volatile compounds that the atmosphere once contained. The goal of MAVEN is to determine the history of the loss of atmospheric gases to space, providing answers about Martian climate evolution. By measuring the rate with which the atmosphere is currently escaping to space and gathering enough information about the relevant processes, scientists will be able to infer  how the planet's atmosphere evolved over time. The MAVEN mission's primary scientific objectives are: Timeline. MAVEN launched from the Cape Canaveral Air Force Station (CCAFS) on 18 November 2013, using an Atlas V 401 launch vehicle. It reached Mars on 22 September 2014, and was inserted into an elliptic orbit approximately by above the planet's surface. In October 2014, as the spacecraft was being fine-tuned to start its primary science mission, the comet Siding Spring was also performing a close flyby of Mars. The researchers had to maneuver the craft to mitigate harmful effects of the  comet, but while doing so, were able to observe the comet and perform measurements on the composition of expelled gases and dust. On 16 November 2014, investigators completed MAVEN's commissioning activities and began its primary science mission, scheduled to last one year. During that time, MAVEN had observed a nearby comet, measured how volatile gases are swept away by solar wind, and performed four "deep dips" down to the border of the upper and lower atmospheres to better characterize the planet's entire upper atmosphere. In June 2015, the science phase was extended through September 2016, allowing MAVEN to  observe the Martian atmosphere through the entirety of the planet's seasons. On 3 October 2016, MAVEN completed one full Martian year of scientific observations. It had been approved for an additional 2-year extended mission through September 2018. All spacecraft systems were still operating as expected. In March 2017, MAVEN's investigators had to perform a previously unscheduled maneuver to avoid colliding with Phobos the following week. On 5 April 2019, the navigation team completed a two-month aerobraking maneuver to lower MAVEN's orbit and enable it to better serve as a communications relay for current landers as  well as the rover "Perseverance". This new elliptic orbit is approximately by . With 6.6 orbits per Earth day, the lower orbit allows more frequent communication with rovers. As of September 2020, the spacecraft is continuing its science mission as well, with all instruments still operating and with enough fuel to last at least until 2030. On August 31st, 2021, Shannon Curry became the Principal Investigator of the mission. Spacecraft overview. MAVEN was built and tested by Lockheed Martin Space Systems. Its design is based on those of "Mars Reconnaissance Orbiter" and "2001 Mars Odyssey". The orbiter has a cubical shape  of about high, with two solar arrays that hold the magnetometers on both ends. The total length is . Relay telecommunications. NASA's Jet Propulsion Laboratory provided an Electra ultra high frequency (UHF) relay radio payload which has a data return rate of up to 2048 kbit/s. The highly elliptical orbit of the MAVEN spacecraft may limit its usefulness as a relay for operating landers on the surface, although the long view periods of MAVEN's orbit have afforded some of the largest relay data returns to date of any Mars orbiter.<ref>Newest NASA Mars Orbiter Demonstrates Relay Prowess  NASA 10 November 2014