Lucy Spacecraft Will Slingshot Around Earth – Transcript






NASA’s Lucy mission is heading to the Jupiter Trojans – two swarms of primitive asteroids trapped in Jupiter’s orbit that may hold clues to the formation of the planets.


Lucy launched on October 16, 2021. After a year in orbit around the Sun, it is returning home on its launch anniversary for the first of three Earth gravity assists.


On October 16, 2022, Lucy will fly by the Earth like a partner in a swing dance, boosting its speed and elongating its orbit around the Sun.


Two years later, it will return for a second gravitational tango to lengthen its orbit even further, allowing it to reach the L4 Trojan asteroids that travel ahead of Jupiter.


After Lucy completes its first tour of the Trojans, it will make its third pas de deux with Earth in December 2030.


This final flyby will increase its orbital tilt and bend its path toward the L5 Trojans that follow Jupiter.


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As Lucy approaches its first gravity assist, it will use the Earth and the Moon to calibrate its instruments.


A day before it arrives, NASA will begin scanning for potential collisions.


Lucy’s path runs through a cloud of over six thousand Earth-orbiting satellites, and about twenty times as many bits of inactive debris.


If any potential collisions are detected, the spacecraft will fire its thrusters to speed up its arrival by a few seconds, avoiding a catastrophic impact.


Because Lucy will approach from Earth’s dayside, it will initially be invisible to observers on the ground.


It will take pictures of the Eastern Hemisphere and attempt to image Ethiopia, home of the famous hominin fossil for which the mission is named.


Lucy will then pick up speed as it races toward the evening terminator, or boundary between day and night.


It will emerge from the Sun’s glare as night falls on Western Australia – with its expansive solar arrays reflecting the daylight.


An hour after sunset, at 6:55 pm, Western Australia time, stargazers will be treated to a magnificent sight as Lucy streaks across the sky.


Seven minutes later, Lucy will once again slip from view as it crosses into the shadow of the Earth.


At 7:04 pm, Lucy will make its closest approach at just 219 miles above the planet: lower than the International Space Station.


This exceptionally close shave will increase its velocity by four-and-a-half miles per second.


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Lucy will traverse the night side of Earth, rapidly gaining in altitude, and emerge from the planet’s shadow at 4:26 am, Pacific Time.


If skies are clear, early birds in the Western US will be able to spot the spacecraft through binoculars.


Lucy will appear in the southwestern sky between Cetus and Pisces, rising eastward until it is overtaken by the dawn.


As the Sun rises over the Rocky Mountains, Lucy will speed away from Earth at more than 14,000 miles per hour – crossing the lunar orbit in less than a day.


Lucy will take a few final images as it approaches the Moon and bids farewell to home, preparing for over two years in deep space…


Until it returns for its second gravity assist in December 2024.


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