1 00:00:01,600 --> 00:00:03,933 On November 1st, 2023, 2 00:00:03,933 --> 00:00:09,133 NASA's Lucy spacecraft will fly by a small Main Belt asteroid named Dinkinesh. 3 00:00:09,133 --> 00:00:14,133 This flyby was added to Lucy's list of targets in January 2023. 4 00:00:14,133 --> 00:00:16,566 There will now be ten asteroids that the Lucy mission 5 00:00:16,566 --> 00:00:20,533 will explore on its record breaking tour. 6 00:00:20,533 --> 00:00:23,166 Dinkinesh will be the smallest Main Belt asteroid 7 00:00:23,166 --> 00:00:25,900 to have ever been well-imaged by a spacecraft, 8 00:00:25,900 --> 00:00:29,800 registering at only about a half-mile in size. 9 00:00:29,800 --> 00:00:31,766 The primary purpose of this encounter 10 00:00:31,766 --> 00:00:36,733 is to test the spacecraft's Terminal Tracking System, which will keep Lucy's instruments 11 00:00:36,733 --> 00:00:41,366 pointing at the asteroid as it flies by at 10,000 miles per hour. 12 00:00:41,366 --> 00:00:45,600 This test may prove crucial to the overall success of the mission. 13 00:00:45,600 --> 00:00:49,200 Even with the best Earth-based observations of these distant objects, 14 00:00:49,200 --> 00:00:52,466 there will still be some uncertainty about precisely where each target 15 00:00:52,466 --> 00:00:56,233 will be as Lucy approaches it. During its journey, 16 00:00:56,233 --> 00:01:01,533 Lucy will utilize its L’LORRI instrument for optical navigation to improve that knowledge; 17 00:01:01,533 --> 00:01:05,866 but uncertainties as large as a hundred miles may still remain. 18 00:01:05,866 --> 00:01:08,200 If nothing was done, the science instruments 19 00:01:08,200 --> 00:01:13,033 could completely miss the asteroid during the closest approach. 20 00:01:13,033 --> 00:01:14,133 It's for this reason 21 00:01:14,133 --> 00:01:16,633 that Lucy uses the Terminal Tracking System 22 00:01:16,633 --> 00:01:20,166 to image the Trojan targets in the final hours of an approach, 23 00:01:20,166 --> 00:01:23,133 and to autonomously update the spacecraft's onboard 24 00:01:23,133 --> 00:01:27,433 knowledge of the location of the asteroid in space. 25 00:01:27,433 --> 00:01:31,466 This in turn, allows the instruments to aim with precision, 26 00:01:31,466 --> 00:01:36,900 which will facilitate better imaging and measurement of these small bodies. 27 00:01:36,900 --> 00:01:38,800 The Dinkinesh asteroid presents 28 00:01:38,800 --> 00:01:42,400 the perfect opportunity to test this system. 29 00:01:42,400 --> 00:01:44,400 The geometry of this encounter, 30 00:01:44,400 --> 00:01:49,033 particularly the angle that the spacecraft approaches the asteroid relative to the Sun, 31 00:01:49,033 --> 00:01:52,566 is very similar to the mission's planned Trojan asteroid encounters. 32 00:01:52,566 --> 00:01:57,266 This allows NASA to essentially carry out a dress rehearsal under similar conditions 33 00:01:57,266 --> 00:02:00,800 well in advance of the spacecraft's main scientific targets. 34 00:02:00,800 --> 00:02:06,566 It's also a full year and a half earlier than the already planned Donaldjohanson asteroid encounter, 35 00:02:06,566 --> 00:02:12,766 which will serve as a more intricate and complex test of the spacecraft's systems and instruments. 36 00:02:12,766 --> 00:02:14,666 And since Dinkinesh is much smaller 37 00:02:14,666 --> 00:02:18,500 than any of the Trojan asteroids that Lucy will be collecting data on, 38 00:02:18,500 --> 00:02:23,300 this test is meant to challenge the Terminal Tracking System’s capabilities. 39 00:02:23,300 --> 00:02:25,833 It's likely that the system will lock on to Dinkinesh 40 00:02:25,833 --> 00:02:28,800 for only a few minutes before closest approach, 41 00:02:28,800 --> 00:02:32,800 compared to the hour or more it will have for the Trojan targets. 42 00:02:32,800 --> 00:02:35,233 So, no matter the end result, 43 00:02:35,233 --> 00:02:39,066 this flyby will provide Lucy's science team and flight engineers 44 00:02:39,066 --> 00:02:43,166 with important insights into how the tracking system can function. 45 00:02:43,166 --> 00:02:47,433 After the encounter with Dinkinesh, Lucy's orbit around the Sun will bring it back 46 00:02:47,433 --> 00:02:52,100 towards Earth for its second gravity assist in December 2024. 47 00:02:52,100 --> 00:02:59,000 That assist will send the spacecraft off to meet its main objectives among the Trojan asteroids. 48 00:02:59,000 --> 00:03:01,433 While the primary purpose of the Dinkinesh encounter 49 00:03:01,433 --> 00:03:03,000 is an engineering test, 50 00:03:03,000 --> 00:03:07,866 the data collected may also provide insight on the relationship between the Main Belt asteroids 51 00:03:07,866 --> 00:03:10,866 and near-Earth asteroids. 52 00:03:10,866 --> 00:03:14,666 It's an exciting addition to Lucy's groundbreaking mission.