After trying to regain contact for nearly 2 years, National Aeronautics and Space Administration has finally reestablished communications with the sun-studying satellite, STEREO-B. At 6:27 p.m. ET, National Aeronautics and Space Administration received a downlink signal from the space vehicle exploitation the ground-based communication antennas within the part Network.
STEREO-B is one among 2 space vehicle that orbit the sun and form up the star Terrestrial Relations Observatory (or STEREO) mission. STEREO-Ahead (STEREO-A) orbits slightly nearer to the Sun than the planet, and STEREO-Behind (STEREO-B) orbits at a farther distance from the Sun than the planet. Together, they supply National Aeronautics and Space Administration with unexampled views of the way facet of the Sun.
Both craft were launched in 2006 on a biennial mission to check star activity on the way facet of the sun. But, in a very pleasant flip of events, STEREO way outlived its expected period of time.
Like different independent agency craft that came before it (e.g. star and Heliospheric Observatory in 1998, Deep Impact Mission in 2013, the Mars Spirit Rover in 2010), STEREO’s mission extension propelled the craft into new territory that semiconductor diode to a loss of contact.
In October, 2014, six years when the first mission of STEREO had completed, the 2 orbiter entered into a novel location in their orbits called star conjunction. throughout now, the Sun was positioned right between the orbiter and Earth, creating communication not possible because of star interference for over 3 months.
“The sun emits powerfully in nearly each wavelength, creating it the largest supply of noise within the sky. Most region missions solely got to affect sun interference for each day more or less, except for every of the STEREO orbiter, this era lasted nearly four months.” Dan Ossing, mission operations manager for the STEREO mission
With the future conjunction, the STEREO team place steps in situ to arrange STEREO-A and STEREO-B (machines designed to speak to the planet each single day) for an almost four-month amount of radio silence.
The tough half regarding STEREO-A and STEREO-B was that they weren’t optimized to figure properly throughout a star conjunction. each orbiter were designed with one thing referred to as a command loss timer, that is basically associate degree automatic push button. If the orbiter practiced seventy two hours of radio-silence (something that shouldn’t happen normally), the command loss timer would activate, correcting any communication problems the orbiter was experiencing.
Unfortunately, the command loss timer couldn’t be modified, that means the orbiter would be rebooting each 3 days for nearly four months throughout the star conjunction. Not ideal, however the STEREO team expected each orbiter to drag through.
But before the conjunction happened, the team needed to check the reset method. They stopped act with the orbiter for 3 days and each STEREO-A and STEREO-B activated the command loss timer reset method. STEREO-A worked nice. STEREO-B, not most.
The STEREO team believed that the orbiter was feeding half truths to itself regarding its own move speed, inflicting the orbiter to spin. In a spin, the orbiter may solely receive intermittent alternative energy creating it tough to show on its transmitter – the manner it communicates with the planet.
“If it’s not transmittal, we’ve no manner of knowing if our efforts square measure operating.” Dan Ossing, mission operations manager for the STEREO mission
In December of 2015, National Aeronautics and Space Administration discharged a handout noting that any signal that STEREO-B may transmit would doubtless be too weak for the antennas within the region Network to select up. The STEREO team thought they’ll even got to wait till 2019, once STEREO-B would be in a very location that the Edwin Hubble area Telescope may image, to receive to any extent further details regarding the spacecraft’s position.
Luckily, that didn’t prove to be the case and that we didn’t got to wait that long.
Sunday’s signal from STEREO-B provided National Aeronautics and Space Administration with valuable data regarding the spacecraft’s position. With this knowledge, the STEREO team can currently work to place a recovery arrange in situ, re-establish the spacecraft’s desired position and measure the health of its subsystems.