[ad_1]
Engineers have made progress in makes an attempt to totally unfurl a photo voltaic array wing that snagged on NASA’s Lucy asteroid explorer shortly after launch final October, including to optimism that the spacecraft can full its 12-year mission as deliberate.
One in all Lucy’s two UltraFlex round photo voltaic arrays opened to about 96% of its absolutely deployed state after arriving in area final October following a launch from Cape Canaveral. The opposite photo voltaic array absolutely unfurled because the spacecraft started a robotic science mission to fly via swarms of unexplored asteroids that lead and path Jupiter in its orbit across the solar.
In latest weeks, floor groups at a Lockheed Martin management heart in Colorado have uplinked instructions for Lucy run major and backup motors to drive the caught photo voltaic array nearer to full deployment.
NASA believes a lanyard used to tug the photo voltaic array open by some means misplaced stress and fell off a spool in the course of the preliminary deployment final October, stopping the array from fully opening.
Extra makes an attempt to tug the photo voltaic array open have additional reeled within the lanyard. The primary attempt Could 9 concerned working the deployment motors in a collection of brief intervals to keep away from overheating. Floor controllers despatched extra instructions Could 12, additional advancing the photo voltaic array deployment and including stress to the construction, serving to stabilize the array.
Engineers made extra progress throughout two extra deployment makes an attempt Could 26 and June 2. “Whereas the array nonetheless didn’t latch, the information signifies that it continued to additional deploy and stiffen all through the try,” NASA mentioned.
Most just lately, the Lucy floor staff despatched one other command to run the deployment motors June 9, which continued to “additional stabilize the array,” NASA mentioned. “There are future alternatives to repeat the deployment instructions if essential.”
Officers are more and more optimistic that the Lucy mission can proceed with none points, even when the photo voltaic array doesn’t latch into place. Earlier than the latest tries to totally deploy the array, the spacecraft’s energy system was producing greater than 90% of the anticipated degree of 18,000 watts.
“Whereas there is no such thing as a assure that extra makes an attempt will latch the array, there may be sturdy proof that the method is placing the array beneath extra stress, additional stabilizing it,” NASA mentioned in a press release. “Even when the array doesn’t finally latch, the extra stiffening could also be sufficient to fly the mission as deliberate.”
“We’re seeing important tensioning of the array,” mentioned Hal Levison, Lucy’s principal investigator from the Southwest Analysis Institute. “This stuff are made out of material, and the place you get a whole lot of the energy is by placing it beneath stress. And we’re clearly at some extent the place we’re tensioning the array, which makes it probably, even when we don’t get the factor latched, we’ll be capable of fly the mission as is.”
One concern engineers have studied is the impact of engine burns on the partially deployed array. The Lucy spacecraft accomplished its first trajectory correction maneuver June 7 to assist information it towards a flyby with Earth in October, the primary of a number of gravity assists to slingshot the probe towards Jupiter’s orbit within the distant photo voltaic system.
Lucy has additionally prolonged the platform holding its scientific devices, and the sensors are all working as designed, Levison mentioned.
Lucy will grow to be the farthest spacecraft from the solar to ever depend on solar energy, reaching a most distance of 530 million miles (853 million kilometers), practically six occasions farther than Earth’s orbit. When it reaches the Trojan asteroids, Lucy’s photo voltaic arrays had been anticipated to generate simply 500 watts of energy.
That degree of energy output is ample to feed Lucy’s three science devices, which solely want about 82 watts of energy throughout every asteroid encounter. Lucy’s flight pc, communications system, and different elements may also draw on energy generated by the UltraFlex arrays.
The $981 million Lucy Mission is the primary to discover the Trojan asteroids, which scientists say are leftover constructing blocks much like objects that got here collectively to type the photo voltaic system’s large outer planets. The probe will fly by eight Trojan asteroids between 2027 and 2033, plus one object in the principle asteroid belt in 2025.
That’s yet one more asteroid than scientists anticipated Lucy to go to when it launched final 12 months.
One of many Trojan asteroids on Lucy’s tour, named Polymele, has a companion. Scientists found an obvious satellite tv for pc of Polymele throughout a ground-based occultation statement in March, when Polymele briefly handed in entrance of a star, briefly blocking its gentle from reaching Earth.
The occultation observations had been meant to assist the Lucy science staff decide the form of Polymele, which solely seems as some extent of sunshine in telescope photos.
“We obtained a very nice projected form of Polymele, after which we had been very stunned to detect an object about 200 kilometers (120 miles) away from Polymele,” Levison mentioned final week in a presentation to NASA’s Small Our bodies Advisory Group. “It’s 5 kilometers (3 miles) in diameter, and it’s sitting virtually precisely in Polymele’s equatorial aircraft.”
Lucy’s science staff has briefly named the thing Shaun, after “Shaun the Sheep” within the present “Wallace and Gromit.”
Extra information on the thing’s actual place and orbit are required to assign a everlasting title to Polymele’s companion, and that in all probability gained’t occur till after Lucy’s flyby in 2027.
Polymele itself has an “oblate spheroid,” or gourd-like, form and measures about 17 miles (27 kilometers) lengthy and eight miles (13 kilometers) vast. The form of Polymele suggests it’s probably a leftover remnant from the younger photo voltaic system greater than 4.5 billion years in the past, and should have prevented any collisions with different objects all through its historical past.
“It’s laborious to think about you will get that form … out of an object that’s collisionally developed, so my pondering proper now’s Polymele might be a primordial object, which goes to make seeing it actually fascinating.”
Polymele’s companion isn’t the primary asteroid to be added to Lucy’s flight plan because the mission was authorized by NASA in 2017. Astronomers introduced in 2020 that observations with the Hubble Area Telescope confirmed a small object, lower than 1 kilometer in diameter, orbiting asteroid Eurybates, one other Lucy goal within the Trojan belt.
Electronic mail the creator.
Observe Stephen Clark on Twitter: @StephenClark1.
[ad_2]
Source link