NASA’s Transiting Exoplanet Survey Satellite (TESS) may possibly launch on Wednesday April 18, 2018 this week.
TESS is further effort for we humans to search for planets outside of our solar system, especially those that could support life. The mission will find exoplanets that periodically block part of the light from their host stars, events called transits. TESS will survey 200,000 of the brightest stars near the sun to search for transiting exoplanets.
What are exoplanets? If you walk outside on a clear starry night (I live in Arizona, so I have many of these) you will see stars; every star most likely has at least one planet orbiting it---these are exoplanets. Proxima Centauri is a red dwarf star which is Earth’s nearest neighboring star.
An illustrated image of Proxima Centauri b, a bit more massive than Earth, from the surface of a rocky planet four light-years distant called Proxima Centauri (Image courtesy of ESO/M Kornmesser)
We have no present means to travel to such a star or planet because they are 25 trillion miles away----4.5 light years. However, we can see them, record the temperatures on them, sample their atmosphere and search for possible life since the temperature there can support liquid water on the surface of this planet.
TESS will be able to find exoplanets as it breaks up that sky into 26 sectors, 24 degrees by 96 degrees across. Its powerful cameras will keep watch on each sector for a total of 27 days, every two minutes.
See this video:
The cameras on TESS are truly extraordinary. These cameras will transmit exoplanet data from the cameras to an on-board computer which will process the image data and then transmit it to Earth for scientists to study.
Shown here are the flight camera electronics on one of the TESS cameras. The cameras were developed by the MIT Kavli Institute for Astrophysics and Space Research (MKI). (Image courtesy of MKI)
TESS has four identical cameras mounted on a plate plus a Data Handling Unit (DHU). Each camera consists of a lens assembly containing seven optical elements. There is also a detector assembly with four CCDs along with their electronics.
Each of the four cameras can observe a 24o by 24o Field-of-View, with a 100mm effective pupil diameter and a lens assembly composed of seven optical elements, an athermal design, 600nm to 1000nm bandpass filter, and 16.8 Megapixel, low noise and low power, MIT Lincoln Lab CCID-80 detector (Image courtesy of NASA)
So, how do we get those signals to and from TESS?
There is a ground system of eight facilities across the US, linked together for command and telemetry, position and tracking data.
The MOC interfaces with the DSN and the SN for command and telemetry. The MOC also interfaces with the FDF for position and tracking data. The SOC is the center of TESS science operations and data processing. SPOC calibrates the data received and produces light curve files and also detects exoplanet transit signatures which are in turn sent to the TSO and MAST to review the data and identify objects of interest. MAST archives all mission data and also makes it publicly available on their website.
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