The MAVEN navigation team executed maneuvers on Tuesday and Wednesday of this week that provided a total delta-V (∆V) of 4.0 m/sec. to the spacecraft and lowered the periapsis (lowest altitude) by a total of 24.5 km to 120.5 km above the #Martian surface.
This Deep Dip campaign—the 6th of the mission to-date—is located in shadow near midnight on the red planet, and spans both sides of #Mars’ equator.
(Video credit: NASA/GSFC)
NASA / GSFC
MAVEN at Mars
The MAVEN mission to Mars completed its one-Earth-year primary mission in November 2015, is in the middle of its first (relatively short) extended mission that runs through September 2016, and was just approved for a two-year extended mission that runs through September 2018. Now is a good time to take stock of we’ve learned so far and to describe our plans for the extended mission.
#MAVEN principal investigator Bruce Jakosky has written a very nice summary of the mission results to-date and offers unique insight into what new observations to expect during the two-year extended mission that runs through September 2018.
The article appears as a “guest blog” on The Planetary Society web site:
Earth’s magnetosphere, the region of space dominated by Earth’s magnetic field, protects our planet from the harsh battering of the solar wind. Like a protective shield, the magnetosphere absorbs and deflects plasma from the solar wind which originates from the Sun. When conditions are right, beautiful dancing auroral displays are generated. But when the solar wind is most violent, extreme space weather storms can create intense radiation in the Van Allen belts and drive electrical currents which can damage terrestrial electrical power grids. Earth could then be at risk for up to trillions of dollars of damage.
Announced today in Nature Physics, a new discovery led by researchers at the University of Alberta shows for the first time how the puzzling third Van Allen radiation belt is created by a “space tsunami.” Intense so-called ultra-low frequency (ULF) plasma waves, which are excited on the scale of the whole magnetosphere, transport the outer part of the belt radiation harmlessly into interplanetary space and create the previously unexplained feature of the third belt. “Remarkably, we observed huge plasma waves,” says Ian Mann, physics professor at the University of Alberta, lead author on the study and former Canada Research Chair in Space Physics. “Rather like a space tsunami, they slosh the radiation belts around and very rapidly wash away the outer part of the belt, explaining the structure of the enigmatic third radiation belt.”
The complete article courtesy of Ross Lockwood, University of Alberta, here.
Photo Courtesy of NASA’s MAVEN Mission to Mars
#MAVEN began its fifth “deep dip” campaign of the mission this week. Three maneuvers were successfully carried out to lower the periapsis (or lowest) altitude of the spacecraft by approximately 29 km, placing MAVEN into the targeted density corridor, where the average density of Mars’ atmosphere is 3.0 kg/km³.
The fifth deep dip for MAVEN is uniquely located over the solar terminator (the boundary between dayside and nightside), close to the ecliptic plane, and at a #Martian latitude of 35ºN.
The three maneuvers—carried out on June 7 & 8—required a total ∆V of 4.6 m/s and resulted in a periapsis altitude of ~119 km (74 miles).
The purpose of the MAVEN deep dip campaigns is to sample a full range of altitudes within the upper atmosphere of Mars, providing complete coverage. At 119 km, MAVEN reaches the Martian homopause, which is the lower, well-mixed region of Mars’ upper atmosphere, where the density is about thirty times greater than at periapsis during a typical science orbit.
NASA – National Aeronautics and Space Administration
NASA Jet Propulsion Laboratory
After 14 days, 13 hours and 17 minutes of flight, NASA’s super pressure balloon completed its first circumnavigation.
NASA’s 18.8 million-cubic-foot super pressure balloon hit another milestone at 9:17 a.m. EDT Tuesday, May 31, crossing the 169.24 east longitude line, officially completing its first circumnavigation of the globe.
The balloon, flying the Compton Spectrometer and Imager (COSI) payload, achieved the milestone 14 days, 13 hours and 17 minutes after launching from Wanaka Airport, New Zealand. At the moment the balloon crossed the meridian, it was flying at an altitude of 110,170 feet heading northeast at 53.85 knots.
The COSI science team continues to collect and transmit data back to the payload’s control center at the University of California, Berkeley. On May 30, the COSI team had a significant breakthrough in detecting and localizing their first gamma ray burst, GRB 160530A (recorded in Gamma-ray Coordinates Network Circular 19473). Gamma ray bursts are comprised of the most energetic form of light and can last anywhere from milliseconds to several minutes. The phenomenon is associated with many types of deep space astrophysical sources, such as supernovas and the formation of black holes. The COSI gamma ray telescope observed the burst for nearly 10 seconds.
The complete article courtesy of NASA is here:
diagram showing Earth’s ring current in periods with (right) and without (left) geomagnetic storms
During periods when there are no geomagnetic storms affecting the area around Earth (left image), high-energy protons (with energy of hundreds of thousands of electronvolts, or keV; shown here in orange) carry a substantial electrical current that encircles the planet, also known as the ring current. During periods when geomagnetic storms affect Earth (right), new low-energy protons (with energy of tens of thousands of electronvolts, or keV; shown here in magenta) enter the near-Earth region, enhancing the pre-existing ring current.
Credits: Johns Hopkins APL
New findings based on a year’s worth of observations from NASA’s Van Allen Probes have revealed that the ring current – an electrical current carried by energetic ions that encircles our planet – behaves in a much different way than previously understood.
The ring current has long been thought to wax and wane over time, but the new observations show that this is true of only some of the particles, while other particles are present consistently. Using data gathered by the Radiation Belt Storm Probes Ion Composition Experiment, or RBSPICE, on one of the Van Allen Probes, researchers have determined that the high-energy protons in the ring current change in a completely different way from the current’s low-energy protons. Such information can help adjust our understanding and models of the ring current – which is a key part of the space environment around Earth that can affect our satellites.
The findings were published in Geophysical Research Letters, here:
NASA successfully launched a super pressure balloon (SPB) from Wanaka Airport, New Zealand, at 11:35 a.m. Tuesday, May 17, (7:35 p.m. EDT Monday, May 16) on a potentially record-breaking, around-the-world test flight. The purpose of the flight is to test and validate the SPB technology with the goal of long-duration flight (100+ days) at mid-latitudes. In addition, the gondola is carrying the Compton Spectrometer and Imager (COSI) gamma-ray telescope as a mission of opportunity. The science and engineering communities have previously identified long-duration balloon flights at constant altitudes as playing an important role in providing inexpensive access to the near-space environment for science and technology. The current record for a NASA super pressure balloon flight is 54 days As the balloon travels around the Earth, it may be visible from the ground, particularly at sunrise and sunset, to those who live in the southern hemisphere’s mid-latitudes, such as Argentina and South Africa. Anyone may track the progress of the flight, which includes a map showing the balloon’s real-time location.
Article Courtesy of NASA Wallops Flight Facility
The COSI balloon was designed and built here at UC Berkeley Space Science Lab under the direction of Professor Steve Boggs.
COSI is a balloon-borne soft gamma-ray (0.2-10 MeV) telescope designed to study astrophysical sources of nuclear line emission and gamma-ray polarization. NASA successfully launched this super pressure balloon (SPB) from Wanaka Airport, New Zealand, at 11:35 a.m. Tuesday, May 17, (7:35 p.m. EDT Monday, May 16) on a potentially record-breaking, around-the-world test flight.
See the video in Youtube: https://www.youtube.com/watch?v=BfvMS76whEU
Live trajectory: http://www.csbf.nasa.gov/newzealand/wanaka.htm
A post in the NASA-Wallops-Flight-Facility webpage: https://www.nasa.gov/centers/wallops/home
COSI official web-page: http://cosi.ssl.berkeley.edu