NASA STEREO A & B Spacecraft Communications to be Blocked by the Sun - Video

NASA Stereo Project team have stated that communication with the two STEREO spacecraft will soon cease when the sun blocks Earth's view of them. This position is known in astronomy as a superior conjunction.

This will happen for STEREO-Ahead from March 24 to July 7, 2015. STEREO-Behind will be in superior conjunction from January 22 to March 23, 2015.

During this period the NASA Stereo Project team claim that at least one spacecraft will always be collecting data, but that because of their position relative to the Sun, communications will be severely reduced.

The ability of Stereo A and Stereo B to gather scientific data on the Sun and transmit data back to Earth, will be greatly reduced during 2015 and on into 2016.

JAXA Hinode SOT Solar Image: Sunspot Activity - Active Region 11967

Active Region 11967 consisted of a major sunspot that released numerous solar flares in early 2014. 

Above is an image taken by the Solar Optical Telescope (SOT) aboard Hinode in the Calcium II H line on Feb. 7, 2014 at 16:09 UT. 

Below is a wider view of Active Region 11967 as seen by SDO on Feb.12, 2014, at 01:35 UT. 

By studying the sun's magnetic field, scientists hope to shed new light on explosive solar activity that can interfere with satellite communications and electric power transmission grids on Earth and threaten astronauts on the way to or working on the surface of the moon. 

Solar Optical Telescope (SOT)

In particular they want to learn if they can identify the magnetic field configurations that lead to these explosive energy releases and use this information to predict when these events may occur. 

The Honide mission is led by the Japan Aerospace Exploration Agency (JAXA), and is a collaboration between the space agencies of Japan, the United States, the United Kingdom and Europe. 

NASA helped in the development, funding and assembly of the spacecraft's three science instruments. 

Hinode is part of the Solar Terrestrial Probes (STP) Program within the Heliophysics Division of NASA's Science Mission Directorate in Washington, which are also responsible for the Solar Dynamcis Observatory (SDO). 

Image credit: NASA/JAXA/Lockheed Martin

NASA Voyager-1: Public Invited to Fly along

The public will be able to fly along with NASA's Voyager spacecraft as the twin probes head towards interstellar space, which is the space between stars. 

As indicated in this artist's concept, a regularly updated gauge using data from the two spacecraft will indicate the levels of particles that originate from far outside our solar system and those that originate from inside our solar bubble. 

Those are two of the three signs scientists expect to see in interstellar space. 

The other sign is a change in the direction of the magnetic field. 

Credit: NASA/JPL-Caltech

A gauge on the Voyager home page, tracks levels of two of the three key signs scientists believe will appear when the spacecraft leave our solar neighborhood and enter interstellar space.

When the three signs are verified, scientists will know that one of the Voyagers has hurtled beyond the magnetic bubble the sun blows around itself, which is known as the heliosphere.

The gauge indicates the level of fast-moving charged particles, mainly protons, originating from far outside the heliosphere, and the level of slower-moving charged particles, also mainly protons, from inside the heliosphere.

If the level of outside particles jumps dramatically and the level of inside particles drops precipitously, and these two levels hold steady, that means one of the spacecraft is closing in on the edge of interstellar space. These data are updated every six hours.

Scientists then need only see a change in the direction of the magnetic field to confirm that the spacecraft has sailed beyond the breath of the solar wind and finally arrived into the vast cosmic ocean between stars.

The direction of the magnetic field, however, requires periodic instrument calibrations and complicated analyses. These analyses typically take a few months to return after the charged particle data are received on Earth.

Voyager 1

VOYAGER-1
Voyager 1, the most distant human-made spacecraft, appears to have reached this last region before interstellar space, which scientists have called "the magnetic highway." Inside particles are zooming out and outside particles are zooming in.

However, Voyager 1 has not yet seen a change in the direction of the magnetic field, so the consensus among the Voyager team is that it has not yet left the heliosphere.

Voyager-2

VOYAGER-2
Voyager-2, the longest-operating spacecraft, but not as distant as Voyager 1, does not yet appear to have reached the magnetic highway, though it has recently seen some modest drops of the inside particle level.

NASA's Eyes on the Solar System program, a Web-based, video-game-like tool to journey with NASA's spacecraft through the solar system, has added a Voyager module that takes viewers along for a ride with Voyager 1 as it explores the outer limits of the heliosphere.

Time has been sped up to show one day per second. Rolls and other maneuvers are incorporated into the program, based on actual spacecraft navigation data. The charged particle data are also shown.

Visit that module HERE

The Voyager spacecraft were built and continue to be operated by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Caltech manages JPL for NASA.

The Voyager missions are a part of NASA's Heliophysics System Observatory, sponsored by the Heliophysics Division of the Science Mission Directorate at NASA Headquarters in Washington.

More information about the Voyager spacecraft here.