vendredi 25 mai 2018

Take a Virtual Trip to a Strange New World with NASA













Exoplanets - Exobiology logo.

May 25, 2018


Image above: With NASA's interactive Exoplanet Exploration website, you can virtually explore an imagined surface of planets that lie outside our solar system. Shown here, the imagined surface of Kepler-186f, an Earth-size planet orbiting a small red star located 492 light-years from Earth. No real photos of Kepler-186f exist. Image Credits: NASA/JPL-Caltech.

Are you looking for an exotic destination to visit this summer? Why not take a virtual trip to an Earth-size planet beyond our solar system with NASA's interactive Exoplanet Travel Bureau?

We live in a universe teeming with exoplanets, or planets outside our solar system. Unfortunately, even the nearest exoplanets are light-years away, so sending spacecraft and humans to these intriguing worlds remains a distant dream.

But on NASA's Exoplanet Exploration website, you can explore an imagined surface of an alien world via 360-degree, interactive visualizations. As you investigate each planet's surface, you'll discover fascinating features, like the blood-red sky of TRAPPIST-1d, or stand on a hypothetical moon of the massive planet Kepler-16b, which appears larger than either of the planet's two suns. The view from each planet's surface is an artist's impression based on the limited data that is available; no real photos of these planets exist.

The newest planet to feature this 360-degree surface visualization is Kepler-186f, an Earth-size planet orbiting a star much cooler and redder than the Sun. Scientists don't know if Kepler-186f has an atmosphere, but with the NASA visualization tool, you can see how the presence or absence of an atmosphere would change the view of the sky from the planet's surface.


Animation above: The imagined surface of exoplanet Kepler-186f, on NASA's interactive Exoplanet Exploration website. Kepler-186f is an Earth-size planet orbiting a small red star, which may or may not have an atmosphere. No real photos of Kepler-186f exist. Animation Credits: NASA/JPL-Caltech.

Many of the exoplanets featured on the Exoplanet Exploration website were discovered by NASA's Kepler space telescope.

"Because Kepler-186f and the majority of Kepler-discovered planets are so distant, it is currently impossible to detect their atmospheres -- if they exist at all -- or characterize their atmospheric properties," said Martin Still, program scientist for NASA's newest space-based planet-hunting observatory, the Transiting Exoplanet Survey Satellite (TESS).

"Consequently, we have limited knowledge about what these distant worlds are really like, but these surface visualizations allow us to imagine some of the possibilities," Still said. "Current and future NASA missions, including TESS and the James Webb Space Telescope, will find the nearest exoplanets to our solar system and characterize their atmospheres, bridging the gap between speculation and what's really out there."


Image above: Download free travel exoplanet travel posters from NASA's Exoplanet Exploration website (https://exoplanets.nasa.gov/resources/2159/planet-hop-from-trappist-1e/?layout=magic_shell&travel_bureau=true). The posters imagine what it might be like for humans to visit these new worlds; however, even the nearest exoplanets are light-years away, so sending spacecraft and humans to these intriguing worlds remains a distant dream. Image Credits: NASA/JPL-Caltech.

All the 360-degree visualizations are viewable on desktop and mobile devices, or in virtual reality headsets that work with smartphones. You can also peruse travelposters of such distant worlds as Kepler 186f; TRAPPIST-1e, or PSO J318.5-22, where the "nightlife never ends" because the planet doesn't orbit a star, but is instead floating freely through space.

Many exoplanets share characteristics with the planets that orbit our Sun -- some are gaseous like Saturn and Jupiter, while others are rocky like Earth and Mars. But these alien worlds also have unique features that set them apart. NASA is helping scientists discover and learn about these alien worlds with multiple telescopes and observatories, both on the ground and in space. For even more information and visualizations of these alien worlds, check out NASA's Eyes on Exoplanets mobile app.

The Exoplanet Travel Bureau was developed by NASA's Exoplanet Exploration Program communications team and program chief scientists. Based at the agency's Jet Propulsion Laboratory in Pasadena, California, which is a division of Caltech, the program is NASA's search for habitable planets and life beyond our solar system. The program develops technology and mission concepts, maintains exoplanet data archives and conducts ground-based exoplanet science for NASA missions.

Visit NASA's Exoplanet Exploration website:

https://exoplanets.nasa.gov/alien-worlds/exoplanet-travel-bureau/

Related links:

TRAPPIST-1d: https://exoplanets.nasa.gov/alien-worlds/exoplanet-travel-bureau/explore-trappist-1d/?travel_bureau=true

Kepler-16b: https://exoplanets.nasa.gov/alien-worlds/exoplanet-travel-bureau/explore-kepler-16b/?travel_bureau=true

NASA visualization tool: https://exoplanets.nasa.gov/alien-worlds/exoplanet-travel-bureau/explore-kepler-186f/

NASA's Kepler space telescope: https://www.jpl.nasa.gov/news/news.php?feature=6874

Transiting Exoplanet Survey Satellite (TESS): https://www.nasa.gov/tess-transiting-exoplanet-survey-satellite

Kepler 186f: https://exoplanets.nasa.gov/resources/2081/where-the-grass-is-always-redder/

TRAPPIST-1e: https://exoplanets.nasa.gov/resources/2159/planet-hop-from-trappist-1e/?layout=magic_shell&travel_bureau=true

PSO J318.5-22: https://exoplanets.nasa.gov/resources/2085/where-the-nightlife-never-ends/?layout=magic_shell&travel_bureau=true

NASA's Eyes on Exoplanets mobile app: https://eyes.nasa.gov/eyes-on-exoplanets.html

Images (mentioned), Animation (mentioned), Text, Credits: NASA/JPL/Calla Cofield.

Best regards, Orbiter.ch

Climate Change May Lead to Bigger Atmospheric Rivers












NASA - EOS Aqua Mission logo.

May 25, 2018

A new NASA-led study shows that climate change is likely to intensify extreme weather events known as atmospheric rivers across most of the globe by the end of this century, while slightly reducing their number.

The new study projects atmospheric rivers will be significantly longer and wider than the ones we observe today, leading to more frequent atmospheric river conditions in affected areas.


Image above: n early 2017, the Western United States experienced rain and flooding from a series of storms flowing to America on multiple streams of moist air, each individually known as an atmospheric river. Image credits: NASA/JPL-Caltech.

"The results project that in a scenario where greenhouse gas emissions continue at the current rate, there will be about 10 percent fewer atmospheric rivers globally by the end of the 21st century," said the study's lead author, Duane Waliser, of NASA's Jet Propulsion Laboratory in Pasadena, California. "However, because the findings project that the atmospheric rivers will be, on average, about 25 percent wider and longer, the global frequency of atmospheric river conditions -- like heavy rain and strong winds -- will actually increase by about 50 percent."

The results also show that the frequency of the most intense atmospheric river storms is projected to nearly double.

Atmospheric rivers are long, narrow jets of air that carry huge amounts of water vapor from the tropics to Earth's continents and polar regions. These "rivers in the sky" typically range from 250 to 375 miles (400 to 600 kilometers) wide and carry as much water -- in the form of water vapor -- as about 25 Mississippi Rivers. When an atmospheric river makes landfall, particularly against mountainous terrain (such as the Sierra Nevada and the Andes), it releases much of that water vapor in the form of rain or snow.

These storm systems are common -- on average, there are about 11 present on Earth at any time. In many areas of the globe, they bring much-needed precipitation and are an important contribution to annual freshwater supplies. However, stronger atmospheric rivers -- especially those that stall at landfall or that produce rain on top of snowpack -- can cause disastrous flooding.

EOS Aqua satellite. Image Credit: NASA

Atmospheric rivers show up on satellite imagery, including in data from a series of actual atmospheric river storms that drenched the U.S. West Coast and caused severe flooding in early 2017.

The Study

Climate change studies on atmospheric rivers to date have been mostly limited to two specific regions, the western United States and Europe. They have typically used different methodologies for identifying atmospheric rivers and different climate projection models -- meaning results from one are not quantitatively comparable to another.

The team sought to provide a more streamlined and global approach to evaluating the effects of climate change on atmospheric river storms.

The study relied on two resources -- a set of commonly used global climate model projections for the 21st century developed for the Intergovernmental Panel on Climate Change's latest assessment report, and a global atmospheric river detection algorithm that can be applied to climate model output. The algorithm, developed earlier by members of the study team, identifies atmospheric river events from every day of the model simulations, quantifying their length, width and how much water vapor they transport.


Animation above: A series of atmospheric rivers that brought drought-relieving rains, heavy snowfall and flooding to California this week is highlighted in a new movie created with satellite data from the Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua satellite. Animation credits: NASA/JPL-Caltech.

The team applied the atmospheric river detection algorithm to both actual observations and model simulations for the late 20th century. Comparing the data showed that the models produced a relatively realistic representation of atmospheric rivers for the late 20th century climate.

They then applied the algorithm to model projections of climate in the late 21st century. In doing this, they were able to compare the frequency and characteristics of atmospheric rivers for the current climate with the projections for future climate.

The team also tested the algorithm with a different climate model scenario that assumed more conservative increases in the rate of greenhouse gas emissions. They found similar, though less drastic changes. Together, the consideration of the two climate scenarios indicates a direct link between the extent of warming and the frequency and severity of atmospheric river conditions.

What does this mean?

The significance of the study is two-fold.

First, "knowing the nature of how these atmospheric river events might change with future climate conditions allows for scientists, water managers, stakeholders and citizens living in atmospheric river-prone regions [e.g. western N. America, western S. America, S. Africa, New Zealand, western Europe] to consider the potential implications that might come with a change to these extreme precipitation events," said Vicky Espinoza, postdoctoral fellow at the University of California-Merced and first author of the study.

And secondly, the study and its approach provide a much-needed, uniform way to research atmospheric rivers on a global level -- illustrating a foundation to analyze and compare them that did not previously exist.

Limitations
Data across the models are generally consistent -- all support the projection that atmospheric river conditions are linked to warming and will increase in the future; however, co-author Marty Ralph of the University of California, San Diego, points out that there is still work to be done.

"While all the models project increases in the frequency of atmospheric river conditions, the results also illustrate uncertainties in the details of the climate projections of this key phenomenon," he said. "This highlights the need to better understand why the models' representations of atmospheric rivers vary."

The study, titled "Global Analysis of Climate Change Projection Effects on Atmospheric Rivers," was recently published in the journal Geophysical Research Letters.

More information about AIRS can be found at: https://www.jpl.nasa.gov/spaceimages/airs.jpl.nasa.gov

Aqua Earth-observing satellite mission: https://aqua.nasa.gov/

Images (mentioned), Animation (mentioned), Text, Credits: NASA/JPL/Alan Buis/Written by Esprit Smith.

Greetings, Orbiter.ch

jeudi 24 mai 2018

Robotics Controllers Install Cygnus Resupply Ship on Station











ISS - Expedition 55 Mission patch.

May 24, 2018

The Orbital ATK Cygnus cargo ship was bolted into place on the International Space Station’s Earth-facing port of the Unity module at 8:13 a.m. EDT. The spacecraft will spend about seven weeks attached to the space station before departing in July. After it leaves the station, the uncrewed spacecraft will deploy several CubeSats before its fiery re-entry into Earth’s atmosphere as it disposes of several tons of trash.


Image above: May 24, 2018: International Space Station Configuration. Four spaceships are attached to the space station including the Orbital ATK Cygnus resupply ship, the Progress 69 resupply ship and the Soyuz MS-07 and MS-08 crew ships. Image Credit: NASA.

Orbital ATK’s Cygnus was launched on the company’s Antares rocket Monday, May 21, from the Mid-Atlantic Regional Spaceport Pad 0A at NASA’s Wallops Flight Facility in Virginia. The spacecraft’s arrival brings about 7,400 pounds of research and supplies to support Expedition 55 and 56. Highlights include:

- The Biomolecule Extraction and Sequencing Technology (BEST), an investigation to identify unknown microbial organisms on the space station and understand how humans, plants and microbes adapt to living on the station
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7687

- The Cold Atom Laboratory, a physics research facility used by scientists to explore how atoms interact when they have almost no motion due to extreme cold temperatures
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=7396

- A unique liquid separation system from Zaiput Flow Technologies that relies on surface forces, rather than gravity, to extract one liquid from another
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7696

- The Ice Cubes Facility, the first commercial European opportunity to conduct research in space, made possible through an agreement with ESA (European Space Agency) and Space Applications Services.
http://www.esa.int/Our_Activities/Human_Spaceflight/Research/Ice_Cubes_cool_new_commercial_opportunity_on_the_International_Space_Station

- The Microgravity Investigation of Cement Solidification (MICS) experiment is to investigate and understand the complex process of cement solidification in microgravity with the intent of improving Earth-based cement and concrete processing and as the first steps toward making and using concrete on extraterrestrial bodies.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7658

- Three Earth science CubeSats

- RainCube (Radar in a CubeSat) will be NASA’s first active sensing instrument on a CubeSat that could enable future rainfall profiling missions on low-cost, quick-turnaround platforms.
https://www.jpl.nasa.gov/cubesat/missions/raincube.php

- TEMPEST-D (Temporal Experiment for Storms and Tropical Systems Demonstration) is mission to validate technology that could improve our understanding of cloud processes.
https://www.jpl.nasa.gov/cubesat/missions/tempest-d.php

- CubeRRT (CubeSat Radiometer Radio Frequency Interference Technology) will seek to demonstrate a new technology that can identify and filter radio frequency
interference, which is a growing problem that negatively affects the data quality collected by radiometers, instruments used in space for critical weather data and climate studies.
https://www.nasa.gov/feature/goddard/2018/cubesat-to-test-instrument-for-crystal-clear-data-collection


Image above: Sunrise over South Pacific Ocean, seen by EarthCam on ISS, speed: 27'601 Km/h, altitude: 407,72 Km, image captured by Roland Berga (on Earth in Switzerland) from International Space Station (ISS) using ISS-HD Live application with EarthCam's from ISS on May 24, 2018 at 16:49 UTC. Image Credits: Orbiter.ch Aerospace/Roland Berga.

Related links:

Expedition 55: https://www.nasa.gov/mission_pages/station/expeditions/expedition55/index.html

Commercial Resupply: http://www.nasa.gov/mission_pages/station/structure/launch/index.html

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Text, Credits: NASA/Mark Garcia/Orbiter.ch Aerospace/Roland Berga.

Best regards, Orbiter.ch

Kepler Begins 18th Observing Campaign with a Focus On Star Clusters












NASA - Kepler Space Telescope patch.

May 24, 2018

NASA's planet-hunting Kepler spacecraft began the 18th observing campaign of its extended mission, K2, on May 12. For the next 82 days, Kepler will stare at clusters of stars, faraway galaxies, and a handful of solar system objects, including comets, objects beyond Neptune, and an asteroid. The Kepler spacecraft is expected to run out of fuel within several months.

Campaign 18 is a familiar patch of space, as it's approximately the same region of sky that Kepler observed during Campaign 5 in 2015. One of the advantages of observing a field over again is that planets outside the solar system, called exoplanets, may be found orbiting farther from their stars. Astronomers hope to not only discover new exoplanets during this campaign, but also to confirm candidates that were previously identified.

Image (drawing) Credits: NASA/Ames Research Center/Ann Marie Cody

Open clusters are regions where stars formed at roughly the same age, including Messier 67 and Messier 44, otherwise known as Praesepe or the Beehive cluster. Home to six known exoplanets, the Praesepe cluster will be searched anew for objects that are transiting, or crossing, around these and other stars.

At approximately 800 million years old, the stars in Praesepe are in their teenage years compared to our Sun. Many of these youthful stars are active and have large spots that can reveal information about a star's magnetic field, a fundamental component of a star that drives flaring and other activity that may have influence over habitability. By comparing brightness data collected in Campaign 18 and 5, scientists can learn more about how a star's spots cycle over time.

At several billion years, the Messier 67 cluster is much older and has many Sun-like stars. It is one of the best-studied open clusters in the sky. Astronomers will continue their studies of stellar astrophysics by analyzing Messier 67's stars for changes in brightness. They will search for the signatures of exoplanets, observe the pulsations of evolved stars, and measure the rotation rates of many other stars in the cluster.

Beyond these clusters, Kepler will observe blazars, the energetic nuclei of faraway galaxies with black holes in their centers. These objects propel jets of hot plasma toward Earth (though they are far too distant to affect us). The most notable of these targets is OJ 287, a system hosting two black holes in orbit around each other, one of which weighs 18 billion times the mass of the Sun!

NASA's planet-hunter Kepler / K2 missions. Image Credit NASA

Even closer to home, Kepler will look at solar system objects, including comets, trans-Neptunian objects, and the near-Earth asteroid 99942 Apophis. This 1,000-foot chunk of rock will pass within 20,000 miles of Earth in the year 2029 -- close but still comfortably far enough to not pose any danger to Earthlings.

NASA's Ames Research Center in California's Silicon Valley manages the Kepler and K2 missions for NASA's Science Mission Directorate. NASA's Jet Propulsion Laboratory in Pasadena, California, managed Kepler mission development. Ball Aerospace & Technologies Corporation operates the flight system with support from the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

NASA's planet-hunting Kepler and K2 missions: https://keplerscience.arc.nasa.gov/
and https://www.nasa.gov/mission_pages/kepler/main/index.html

Images (mentioned), Text, Credits: NASA/Ames Research Center/Michele Johnson/JPL/Calla Cofield.

Greetings, Orbiter.ch

Astronaut Commands Robotic Arm to Capture Cygnus Cargo Craft












NASA / Orbital ATK - Cygnus OA-9 Mission patch.

May 24, 2018


Image above: Orbital ATK’s Cygnus resupply ship slowly maneuvers its way toward the International Space Station before its robotic capture and installation during Expedition 47 in March of 2016. Image Credit: NASA.

At 5:26 a.m. EDT, Expedition 55 Flight Engineer Scott Tingle of NASA successfully captured Orbital ATK’s Cygnus cargo spacecraft using the International Space Station’s robotic arm, backed by NASA Astronauts Ricky Arnold and Drew Feustel.

OA-9 S.S. J.R. Thompson Cygnus capture

Robotic ground controllers will position Cygnus for installation to the orbiting laboratory’s Earth-facing port of the Unity module.


Image above: The Cygnus space freighter is grappled by the Canadarm2 after a three-day trip to the space station. Image Credit: NASA TV.

NASA TV coverage of operations to install the Cygnus, dubbed the S.S. James “J.R.” Thompson, to the space station’s Unity module will resume at 7:30 a.m.

Learn more about the Orbital ATK CRS-9 mission by going to the mission home page at: http://www.nasa.gov/orbitalatk

Related articles:

NASA Sends New Research on Orbital ATK Mission to Space Station
https://orbiterchspacenews.blogspot.ch/2018/05/nasa-sends-new-research-on-orbital-atk.html

Small Packages to Test Big Space Technology Advances
https://orbiterchspacenews.blogspot.ch/2018/05/small-packages-to-test-big-space.html

Science Launching to Space Station Looks Forward and Back
https://orbiterchspacenews.blogspot.ch/2018/05/science-launching-to-space-station.html

Related links:

NASA TV: https://www.nasa.gov/nasatv

S.S. James “J.R.” Thompson: https://www.orbitalatk.com/news-room/feature-stories/OA9-Mission-Page/Documents/SS_JR%20Thompson_Bio.pdf

Expedition 55: https://www.nasa.gov/mission_pages/station/expeditions/expedition55/index.html

Commercial Resupply: http://www.nasa.gov/mission_pages/station/structure/launch/index.html

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Video, Text, Credits: NASA/Mark Garcia/NASA TV/SciNews.

Best regards, Orbiter.ch

mercredi 23 mai 2018

Bone and Cardio Studies as Cygnus Nears Station











ISS - Expedition 55 Mission patch.

May 23, 2018

The Cygnus space freighter from Orbital ATK is closing in on the International Space Station ready to deliver 7,400 pounds of cargo Thursday morning. The Expedition 55 crew members are getting ready for Cygnus’ arrival while also helping researchers understand what living in space does to the human body.

NASA TV is set to begin its live coverage of Cygnus’ arrival at the orbital lab Thursday at 3:45 a.m. EDT. Flight Engineer Scott Tingle will be inside the Cupola and command the Canadarm2 robotic arm to reach out and capture Cygnus at 5:20 a.m. Robotics engineers at Mission Control will then take over and remotely install Cygnus to the Earth-facing port of the Unity module later Thursday morning.


Image above: The ash plume from the Kilauea volcano on the big island of Hawaii was pictured May 12, 2018, from the International Space Station. Image Credit: NASA.

The crew started its day collecting blood and urine samples for a pair of experiments, Biochemical Profile and Repository, looking at the physiological changes taking place in astronauts. Those samples are stowed in science freezers for return to Earth so scientists can later analyze the proteins and chemicals for indicators of crew health.

Another pair of experiments taking place today is looking at bone marrow, blood cells and the cardiovascular system. The Marrow study, which looks at white and red blood cells in bone marrow, may benefit astronaut health as well as people on Earth with reduced mobility or aging conditions. The Vascular Echo experiment is observing stiffening arteries in astronauts that resembles accelerated aging.

Related links:

Orbital ATK: https://www.nasa.gov/orbital

Expedition 55: https://www.nasa.gov/mission_pages/station/expeditions/expedition55/index.html

NASA TV: https://www.nasa.gov/nasatv

Biochemical Profile: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=980

Repository: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=954

Marrow study: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1673

Vascular Echo: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=743

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Image (mentioned), Text, Credits: NASA/Mark Garcia.

Best regards, Orbiter.ch

InSight Steers Toward Mars












NASA - InSight Mission logo.

May 23, 2018

NASA's InSight lander has made its first course correction toward Mars.

InSight, short for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport, is the first mission dedicated to exploring the deep interior of Mars.


Animation above: NASA's InSight spacecraft is currently cruising to Mars. Yesterday, it performed its first course correction guiding it to the Red Planet. Animation Credits: NASA/JPL-Caltech.

The lander is currently encapsulated in a protective aeroshell, which launched on top of an Atlas V 401 rocket on May 5 from Vandenberg Air Force Base in Central California. Yesterday, the spacecraft fired its thrusters for the first time to change its flight path. This activity, called a trajectory correction maneuver, will happen a maximum of six times to guide the lander to Mars.

Every launch starts with a rocket. That's necessary to get a spacecraft out past Earth's gravity -- but rockets don't complete the journey to other planets. Before launch, every piece of hardware headed to Mars is cleaned, limiting the number of Earth microbes that might travel on the spacecraft. However, the rocket and its upper stage, called a Centaur, don’t get the same special treatment.

As a result, Mars launches involve aiming the rocket just off-target so that it flies off into space. Separately, the spacecraft performs a series of trajectory correction maneuvers guiding it to the Red Planet. This makes sure that only the clean spacecraft lands on the planet, while the upper stage does not come close.

Precise calculations are required for InSight to arrive at exactly the right spot in Mars' atmosphere at exactly the right time, resulting in a landing on Nov. 26. Every step of the way, a team of navigators estimates the position and velocity of the spacecraft. Then they design maneuvers to deliver it to an entry point at Mars. That navigation team is based at NASA's Jet Propulsion Laboratory in Pasadena, California, which leads the InSight mission.

"This first maneuver is the largest we'll conduct," said Fernando Abilleira of JPL, InSight's Deputy Mission Design and Navigation Manager. "The thrusters will fire for about 40 seconds to impart a velocity change of 3.8 meters per second [8.5 mph] to the spacecraft. That will put us in the right ballpark as we aim for Mars."

Especially at the beginning of that cruise, navigators rely on NASA's Deep Space Network (DSN) to track the spacecraft. The DSN is a system of antennas located at three sites around the Earth. As the planet rotates, each of these sites comes into range of NASA's spacecraft, pinging them with radio signals to track their positions. The antennas also send and receive data this way.

The DSN can give very accurate measurements about spacecraft position and velocity. But predicting where InSight will be after it fires its thrusters requires lots of modeling, Abilleira said. As the cruise to Mars progresses, navigators have more information about the forces acting on a spacecraft. That lets them further refine their models. Combined with DSN tracking measurements, these models allow them to precisely drive the spacecraft to the desired entry point.

 Image of InSight spacecraft during the cruise stage. Image Credits: NASA/JPL-Caltech

"Navigation is all about statistics, probability and uncertainty," Abilleira said. "As we gather more information on the forces acting on the spacecraft, we can better predict how it's moving and how future maneuvers will affect its path."

Yesterday's 40-second burn relies on four of eight thrusters on the spacecraft. A separate group of four is autonomously fired on a daily basis to keep the spacecraft's solar panels trained on the Sun and its antennas pointed at Earth. While necessary to maintain orientation, these small, daily firings also introduce errors that navigators have to account for and counterbalance.

"Everyone has been working hard since launch to assess what these small forces have done to the trajectory," said Allen Halsell of JPL, InSight's navigation team chief. "People have worked lots of hours to look at that. For engineers, it's a very interesting problem, and fun to try to figure out."

When the spacecraft is just a few hours from Mars, the planet's gravitational pull, or gravity well, will begin to reel the spacecraft in. At that point, InSight's team will prepare for the next milestone after cruise: entering Mars' atmosphere, descending to the surface and sticking InSight's landing.

JPL, a division of Caltech in Pasadena, California, manages InSight for NASA's Science Mission Directorate in Washington. InSight is part of NASA's Discovery Program, managed by the agency's Marshall Space Flight Center in Huntsville, Alabama. The InSight spacecraft, including cruise stage and lander, was built and tested by Lockheed Martin Space in Denver.

Find more information about InSight at: https://mars.nasa.gov/insight/

Follow InSight's path to Mars by visiting NASA's Eyes on the Solar System: https://go.nasa.gov/2FSWReg

Animation (mentioned), Image (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Andrew Good.

Greetings, Orbiter.ch