A couple of weeks ago, for the first time since its launch, NASA's Exoplane Transit Survey Satellite fired its propellers early Wednesday to begin to propel its orbit towards the Moon for a maneuver Gravity assistance on May 17 helps catapult the probe into its unique scientific orbit.
The ship's propellers were lit early Thursday to raise the furthest point of the TESS orbit around the Earth closest to the moon. The maneuver was scheduled when TESS reached its first perigee, the low point of its elongated orbit, since its launch on April 18 from Cape Canaveral aboard a SpaceX Falcon 9 rocket.
The Falcon 9 launcher deposited TESS in an orbit elliptical that stretched around 170,000 miles (270,000 kilometers) from Earth. TESS briefly fired its thrusters on Saturday when it reached the farthest point, or apogee, of its initial orbit to raise its perigee from about 150 miles (250 kilometers) to about 1,400 miles (2,250 kilometers).
The next maneuver was made early on Wednesday, positioning the TESS apogee at approximately 220,000 miles (354,000 kilometers), more than 90 percent of the distance from the lunar orbit, according to tracking data published by the US military.
Wednesday's shooting was the second of six maneuvers planned to send TESS into its final operational orbit. The TESS will reach its new apogee during the next apogee, followed by two other perigee maneuvers that will adjust the trajectory of the satellite and will be established for a flyby of the moon on May 17.
The lunar flyby next month – pointing to a distance of around 5,000 miles (8,000 kilometers) from the moon – will cause TESS to enter an orbit that takes it beyond the lunar distance, and a final final shot of the moon. propeller will reduce the peak altitude of the satellite in June.
17, TESS will be in its final orbit of science and ready to begin the search for the planet.
TESS will end in a resonant orbit with that of the moon, which ranges from 67,000 miles (108,000 kilometers) to 233,000 miles (376,000 kilometers) from Earth. In that orbit, TESS will circle the Earth every 13.7 days, half the time it takes for the moon to circle the Earth.
Since the launch on April 18, ground controllers at Orbital ATK in Dulles, Virginia, who built the spacecraft, have lit key components in the satellite, including reaction wheels and star trackers. used to keep TESS pointed correctly in space. On Wednesday, engineers sent commands to turn on the satellite's Ka-band transmitter, which routes the signals through a high-gain antenna needed to send full-screen images to Earth from TESS's four 16.8-megapixel scientific cameras.
start activating the cameras as early as Thursday, beginning several weeks of calibrations and revisions to make sure MIT cameras are scientific observations ready.
Each of the four cameras is equipped with four red-sensitive CCD detectors, designed to detect planets in transit from their host stars. The cameras will search for short falls in starlight to find the planets, and sophisticated software algorithms will allow astronomers to scan wide swaths of the sky once the full-frame images are off-center to Earth.
During the two-year, $ 337 million TESS mission, the MIT-built cameras will examine more than 85 percent of the sky, looking at approximately 200,000 bright, preselected nearby stars, including the approximately 6000 stars that are visible to the naked eye in the night sky.
Read our previous story for details about the mission.
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