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suguwu · 2 years ago

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i'm so obsessed with this man.

minors and ageless blogs dni. you will be blocked.

f!reader, reader wears a skirt, reader is referred to as "my dear," established relationship, oral (f! receiving).

you look up at the rustle of cloth.

neuvillette puts down the paper he's been reading and sighs. you tilt your head, unused to such a blatant display from him, but he says nothing. instead, he reaches back and undoes the ribbon that barely keeps his hair at bay, his long, pale fingers loosening it easily.

"do you want me to braid it?" you ask.

he glances up at you and shakes his head. his hair flows with it, an elegant ripple of ivory. "not right now," he says. "thank you, though."

"mhm."

you watch curiously as he gathers his hair up into one strong hand, and a frisson of heat curls through you at the shift of his muscles beneath his billowy shirt, the thin material leaving little to the imagination. you can see each flex of his bicep, the way the lean muscle ripples.

you realize that he's putting his hair into a high ponytail, the colors intermingling like ocean foam, blue and white swirling together.

you must make a noise, because he glances at you once more, another paper in hand, a perfect eyebrow arched.

"are you alright, my dear?"

"yeah," you say, a little bit breathless. "i'm fine."

his brow furrows. "you don't sound fine."

your cheeks heat. "ah. you—um, you normally only put your hair up like that when you're going down on me."

neuvillette goes still. "i see," he says, and the tips of his ears are going faintly pink, until they match the roses he brought you just the other day, the color of the pearly dawn. it rises to his cheeks, too, a sweet flush.

he very carefully puts the paper down.

you fidget in your seat as he gets to his feet. it only takes a few short strides for him to get to the fainting couch. when he holds out a hand, you take it, ever curious.

"i didn't mean to distract you," you say as he guides you to stand up.

"you are always a distraction," he tells you bluntly. "you test my discipline daily."

"neuvillette—"

he catches you in a honeyed kiss, one that sends heat into a slow simmer beneath your skin. it's slow and sweet with a hint of filth at the edge, in the way his tongue slips between your lips and slides against yours.

you press into the kiss, craving more. his lips are cool against yours, but they heat with your movements. when he pulls away from you, they're kiss-swollen.

he dips in for another kiss before you can say anything. it's as slow as the first, a quiet type of worship that you can almost taste on your tongue.

when you part again, a cobweb-thin strand of spit connects the two of you before it snaps. heat settles low in your stomach.

"neuvillette—" you say.

"i will not leave you wanting," he says, and then he slides to the floor in front of you.

it's a heady sight, the chief justice on his knees for you. he gazes up at you with those sharp, keen eyes, his pupils dilated until there's only a thin rim of violet-blue surrounding them. his hair spills down his shoulders as he dips to press a kiss against your clothed cunt.

you can feel it even through your skirts and panties. it should scorch you, you think, but it's cool instead, oceanwater sliding against your skin, a soft, overwhelming touch.

he gathers your skirts up in one hand, crumpling the delicate lace as he pushes it high over your hips. he presses another kiss against the front of your panties. he dips lower to lave his tongue against the damp gusset and you bite down on a sharp inhale.

he keeps at it, until your wetness is indistinguishable from the damp of his saliva, and only then does he peel your panties off and discard them to the side.

you wind a hand into his ponytail as he coaxes your leg over his broad shoulder, opening you to him in a way that makes fire scorch across your cheeks. he takes advantage, leaning in and pressing a kiss against your cunt, his tongue flicking out and brushing over your clit.

a shuddering breath leaves you and he dips down to lick along the length of you. he uses just enough pressure that his tongue spreads the petals of your pussy. when you moan, he traces his tongue over your clit.

the pleasure surges in you, a strike of flint against kindling, the sparks of it building into embers. your fingers tighten in his hair.

he makes a soft noise, a low, sweet groan, and sinks his tongue into you, spearing deep inside. he presses in closer with it, his nose bumping against your clit, and you try to close your legs around his head, barely kept at bay with one strong hand against your thigh.

he's methodical with it, spearing in and out with the thick muscle of his tongue, all while supporting your unsteady form. his nose nudges your clit over and over, until you're bucking your hips against him, sparks skittering along your nerves.

he backs away when your hole clenches around him, pulling back just far enough to take your clit into his mouth. he suckles at it softly, and then harder, until you're gasping with it, fisting at his ponytail and curving over him like a bow.

"neuvillette," you pant, tightening your grip on his hair. "neuvillette, please."

he hums; the vibrations sink into you, melt under your skin to stoke the embers into flames. he gazes up at you over the curve of your belly and sucks hard.

you cry out sharply. the flames roar into a forest fire, scorching down your nerves as you cum against his mouth, your grip on his hair fierce. he drinks you down, keeping you steady against his broad shoulder with a careful hand, and only pulling back when you tug at his ponytail.

he ducks out from between your legs and guides you back against the chaise when you wobble. his lips are shining with your slick; even his cheeks are wet with it.

you glance away.

he pulls you back to face him. when he leans in for a kiss, you don't shy away; you can taste yourself sharp on his tongue.

he kisses you softly, again and again, a little series of quiet, humble prayers at your altar. when he finally pulls away, you pull him onto the chaise with you. you should clean up, but you're still jelly-legged, and neuvillette follows your lead.

he curls up around you as best he can on the chaise. you turn into him and tuck your face into the crook of his neck, still riding the wave of your pleasure as it dies back down to embers.

"i really didn't mean to distract you," you say quietly.

he hums. "i know."

"but i'm glad that i did."

he breathes out a little laugh.

"yes, my dear," he says. "i'm sure that you are."

#genshin x reader #neuvillette x reader #bee writes genshin

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house-towers-westfall · 2 months ago

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What the Storm Brings

title: what the storm brings

pairing: chaol westfall x yrene towers

synopsis: chaol and yrene are enjoying a peaceful retreat to the beaches in antica when the confession slips out.

for: @sjmromanceweek 2025, day 3: "i love you" prompt

notes: a chapter set near the end of my (incomplete) canon-divergent fic, but can be read without knowledge of it + can also be interpreted as set near the end of tower of dawn. enjoy!

Yrene had seen the monsters men could be: the ones who grabbed at her skirts and flashed her lewdy smiles in Innish. Then, she had never imagined to find, to trust someone so wholly that she could sit next to them in the briny wind, far away from any others, and feel comfortable. Settled, at ease in this moment by his side.

She had seen men be monsters, yes, but Chaol was not one of them. His smiles were few and far between but when he did offer them, they lit her whole world, bathing her in light brighter than the sun. The mere brush of their fingers, controlled when they would be accidental in anyone else, were enough to heat her cheeks.

A realisation settled into her like a stone sinking into water. She had always known it but now, it was as if a candle had been held to it when it had been wreathed in the darkness of her mind before.

Yrene opened her mouth but found it dry. She shifted on Chaol's shoulder. He noted it, the change in her countenance, as he did all things. Especially when it concerned her.

He leaned his head further on her hair and Yrene relished the closeness and comfort it brought. "Is anything wrong?"

Before she could lose the nerve, she drew her head back from him. Glancing once at the rippling waves of the ocean, as if to beseech it for help, she slipped her hand into his. He gripped it tight and the touch was as familiar to her as her own reflection.

"No. Nothing at all." The slight breeze lifting her hair, the palm trees and the ocean seemed to watch her, giving her courage, as she said, "I love you."

For a moment, there was no sound but the swaying palms and the light washing of oceanwater over the sand. Chaol let go of her hand and her chest caved in at the motion. He might as well have crushed her heart with an axe, with that subtle rejection. She was a fool for having so freely trusted and loved–

Two hands took her face in them. Ones made rough by years of swordfighting and handling weapons and yet she did not find them off-putting. It was only testament to what the man before her had done to reach this point.

Words could not have described the kiss that followed: they never had been. Like a rug had been swept from beneath her and she were falling in an endless pit. Yet, you wanted it more and more, like you would long for cool during a fever or the warmth of a hearth in the worst of winters.

His skin was warm under her hand as she placed a hand on his cheek and drew him closer, pressing her lips tighter to his.

She dug her fingers into the lapel’s of Chaol's tunic to keep from losing herself entirely. Tugging him closer, she deepened their kiss.

Yrene could have gone on like that for eternity, kissing him beneath the palms and the moon and night’s shadow. She was aflame, a comet shooting across the sky, too bright to behold for more than a few seconds, as Chaol laid his hand on her cheek and tilted her face ever so gently up.

I love you, I love you, I love you. The words coursed through her, their rhythm matching the pounding of her heart and his, too.

A raindrop fell on them from above and yet they made no move to break seat. Nothing mattered anymore; nothing was of consequence when she and Chaol were here, melded into one.

None of the droplets that continued to fall were enough to deter them. Not even when the rain soaked every inch of the sand around them. It was only when Yrene shivered, the slightest tremor against the silken heat of her lips, that Chaol drew back.

She immediately reached for his hand, not wanting to be without his touch for more than a heartbeat, but he drew his back. He shrugged his leather jacket off and, even numb from the rain, his fingers buckled it deftly around her shoulders.

A laugh escaped her. “Your jacket is as equally drenched as my dress is. I don’t think it will be of much use.”

His fingers, numb as they were, woven into hers, as they stood slowly together. The rain lashed at them, daring to pry them apart, but Chaol and Yrene kept close, huddled together against its chill.

“Better the jacket than a dress with no sleeves,” he said. Chaol stumbled as he took a step and Yrene caught him, two hands dug into his shoulders. She looked up, searching his face for any of the discomfort she had been trained to look out for, but there was none. Only awe and adoration so complete that her own heart stumbled at the force of emotion in it. Yrene stepped away.

Before she could speak – for she indeed wasn’t sure she could – Chaol put up both hands in the air, exposing them. “I’m fine.” Goosebumps rose on his bare arms, but he continued, “You most certainly are not." Chaol gave her a look: she hadn’t realised how thoroughly she was trembling, from head to tie.

An arm wrapped around her and she stole from its warmth as he guided her. “Let us go to the inn.” Her shivering abated as she lifted her eyes to the quiet building hidden behind the swaying palms.

“There isn’t any point running to escape the rain, is there?” The sky gave a rumble, as if it had heard her question.

“None whatsoever.”

Yrene sighed.

Yrene found Chaol seated very comfortably in an armchair, with a lap rug thrown across his lap. He held a book in his hands and there was a small crease between his eyebrows as he read.

He had insisted on her taking the single washing room for herself, to clean herself up, after the rain had drenched her.

Chaol looked up at the sound of her slippers against the wooden floors. “You’re back,” he said, blinking, lost in the story and trying to find his way to the real world. Yrene couldn’t say she knew the feeling well, but she knew that someone lost in books when she saw one.

“What are you reading?” she asked softly as she came around the armchair and leaned over it.

Chaol tilted his head back, looking up at her through his eyelashes. Every inch of his attention was on her, his golden-brown eyes focused fully on her. Yrene could feel the heat of his breath on her skin as he said, “What The Storm Brings.”

She swallowed before replying, “Is it any good?”

“I haven't read much of it yet,” he told her, closing the book before sitting up straight to show her how far he had read – not much. “Will you pick one out?”

“What – a book?”

He nodded.

Yrene had had little cause to read for pleasure and the only books or scrolls she could remember reading were to do with healing. Though if she thought more of it, there was an inkling of memory… A soft, female voice reading to her as her eyelids drooped shut… The stories that had given her a sense of wonder in a world where it felt like the walls were narrowing every day, where she feared people’s whispers as a sign that they would soon be caught. Imprisoned and thrown into flame. Like her mother was in the end. Yrene inhaled sharply.

She blinked and there was a concerned face staring down at her. He touched the crook of her elbow, the slightest brush of his hand against hers, before asking, “What is it?”

The worry written all across his face, brimming in his eyes and his tensed features, reminded her why she loved him. Every single day.

I love you, she had said. But there had been no response. Chest tightening, she turned away to approach the shelves lined with books. She shook her head, no longer facing him.

She ran a finger along the edge of the shelves, picking up all the dust that had collected on the oak wood.

“Will you?”

Soft steps padded along the rug that covered this half of the room and he had come next to her.

She tilted her head in question, hair falling to one side with the movement. “Will I do… what exactly?”

“Will you tell me what’s bothering you?” It was not a demand, lacking any of the command in one, but a mere request, one he’d be happy to have her turn down.

She again ran a finger absentmindedly along the shelves to delay her response.

Yrene did her best to build up a wall between who she had become and who she had been and what she had had. Sometimes, the barrier was too much to uphold and it came crashing down.

For scars of the past very rarely do fade. Especially ones that sliced deep.

Today was one such day; she’d been laid bare by her confession and had gotten nothing back, no return of the vulnerability she had been so frightened to show.

Her mindless spirals across the shelves was halted by Chaol’s hand. His brown eyes focused on her as both of his arms came to rest on her shoulders, anchoring her. She felt every bit of that unflinching focus upon her as he repeated, “What is it?”

She inhaled sharply. “My mother… I remembered her in that moment.” Her chest felt as if it were being crushed but she continued, “She read to me every night and I loved it.” A bit softer, she added. “I loved her, so much that when she…” She shook her head. “I shouldn’t.”

“You should,” he said huskily. “You listened to me, Yrene. Allow me to listen to you now.”

Love swelled in her chest, both for the woman her mother had been and the man that stood in front of her. “We built constellations out of scraps. We had nothing. But somehow it felt like we had everything.” She bit her lip to stop a sob escaping her. “I thought– I think she was the best person to exist. And I loved her.” The words echoed through the room, as final as the emotion she felt welling in her heart. Yrene exhaled and, with it, the smell of smoke, the one that had followed her from the moment she had seen that burning corpse, left her for good.

She squeezed her eyes shut and it was only when she felt a tear trickle down her cheek did she realise that she was crying.

Yrene had not cried for two years. Not since the moment she had broken into tears in front of Hafiza. Since that day, she had not shed a single tear, only straightened her spine and thrown back her shoulders in an effort to hold her sadness behind a dam.

Chaol's fingers brushed across her cheek, halting the path of her tears. It was not out of the knowledge that he was the only person in the room that she recognised his touch, but her knowledge of him, so complete that she knew the graze of his fingers as well as she knew the palm of her hand.

It was not until he had laid that hand on her that she realised how much ice had crept into her bones or how much she wished for someone to backhand the night’s chill with her. And he had. In the midst of the lashing rain and a storm, they had stayed united, unlike everything else that had torn those she loved from her.

She would not let go now. They could pry what she had out of her cold, dead hands, she thought, with sudden vigour.

Things always ended with a storm. But this love would not.

“I-” Yrene started, but Chaol silenced her with a long, steady look that made her go still for a few moments.

With his eyes, he held her in place in a way she had never thought anyone could do. The rich brown of his eyes swam with brightness and another emotion that she couldn’t begin to dismantle now, one that pinned her to the spot. She wasn’t sure she could move if she willed it.

His free hand clasped her own, which seemed insignificant in his larger one. Outside, a thunderbolt struck on the ocean’s surface, but neither heard it.

Chaol’s thumb stroked across her palm. “I love you.” He did not smile but Yrene understood him well enough to know what the expression in his face meant. He cared.

Slowly, ever so slowly, he guided her hand to his chest, to where his heart beat. Yrene had learnt where to find it on a patient, to check how quickly or slowly it was beating, but it had never made her breath hitch the way it was now.

In a low voice, he asked, “Can you hear it?”

Yes. It was the only thing in the world that she was able to hear right now, despite the rumbling thunder and wind outside. Only him.

“It is yours, Yrene, to command. Tell me to do whatever you please, because I would do anything to spare those tears I saw just now.” The light illuminated the golden specks in his irises and she could tell he meant every word.

A tremor went through Yrene’s body. He meant every word. Swallowing, she said the words that she had held back. “I love you too, Chaol Westfall. And there is nothing I would not do to find you once more.” The conviction in her words should have shocked her, but it did not.

“You crossed mountains and seas to get here, Yrene,” Chaol said, in awe, as his hand slid up the back of her neck, to the clasp of the locket she wore.

“I would do it again, if I had to.” There was little she would not have done if she could reach this moment, the end of the dark path.

“I know,” he said. “That is why I love you.” Their lips collided together at the right moment, sealing that promise.

When they broke away at last, breathing heavily and staring at each other as if there was no one else in the world, they both looked out towards the window, at the raging storm and rain outside.

Yrene turned to Chaol. “It is strange,” she said, “what a storm can bring.”

The beginnings of a smile tugged on his mouth. “Not strange,” he breathed, smile deepening. “It is beautiful what the storm brings.”

Yrene took his arm. “Beautiful,” she agreed. “Very beautiful indeed.”

thanks for reading!

#chaorene #chaol westfall #yrene towers #yrene towers westfall #tower of dawn #throne of glass #chaol x yrene #yrene x chaol #house-towers-westfall fic #sjmromanceweek2025

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whispersinthedawn · 1 year ago

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Fluttering fireflies 2

“You never said creature wrangling was part of your job description,” the minor god next to Triton announced.

A minor god that Apollo had somehow failed to notice until that very moment, but who Apollo couldn’t take his eyes off once he’d seen him.

The golden ichor beading at his lip, the hair pulled back in a small ponytail at the base of his neck, bare muscular chest liberally coated in black and blue monster blood, and a tail double the length of the god’s torso sparkling iridescently with scales the colour of the inside of an abalone shell – it was like the god was designed to attract attention. And since they were gods capable of shapeshifting, he might as well have been.

“It’s not part of my job description,” Triton announced like the pompous prince he was. “As my guard for this trip, however, it is yours.”

The minor god laughed in incredulity even as he grabbed the arm of a squid, impervious to the sharp suckers on the appendage, and tossed it away in a twist of muscles that made Apollo’s mouth dry out.

He surreptitiously parted his mouth and allowed some of the oceanwater in. Never mind the salt – he desperately needed some hydration, however deceptive.

“You sure are popular,” the unknown god remarked.

Triton brushed the conch shell hanging at his waist with mock humility. “Well, I am the prince of the seas. I carry messages of global importance that could pit the ocean at war if they were to fall into the wrong hands. People are always after me.”

The minor god ignored the blades of the seaweed furtively attempting to encircle him and placed a brave, brave hand on Triton’s shoulder. “You should get a bodyguard,” he advised. “Or a PR team that is better at making friends than you.”

If Apollo could, he would have held his breath. Had this god – minor, unimportant, with no backing but his own wits – not only dared to touch Triton, but also tease him in a manner reserved to family?

“At least I warrant a PR team,” Triton said sardonically, folding his arms. “You haven’t even figured out your own domain.”

The completely brazen god pouted. “But that’s what I have you for, isn’t it? To help me figure out what I’m good at!”

Triton rubbed one of the horns on his forehead in a gesture Apollo recognised from the mirror. That of a much-beleaguered sibling.

“You’re good at getting on people’s nerves,” Triton scolded.

“Now, now,” the new god said with arms raised in placation. “You have to admit. I am quite proficient at destruction as well.”

With only his words as warning, the god swung his tail at the weed and ripped all its blades off. Another swing of his tail, a vertical slash this time instead of the previous horizontal curve, and a rift opened up in the seabed.

An explosion of gases had Apollo looking away for a moment, but by the time he’d managed to create protective upper lids, bubbling lava had replaced the initial explosion.

Triton clapped his hands together. “I know what you can be god of! Sudden underwater volcanic eruptions!”

The other god placed his hands on his hips and raised his eyebrows sceptically. “Isn’t that Hephaestus?”

“You can share,” Triton assured.

They really couldn’t, Apollo knew. But it didn’t matter. The heart in Apollo’s chest that he kept around only for form’s sake had begun beating, keeping pulse with the swings of the other god’s tail.

Swings that swept the waters clear of anyone hoping to approach Triton.

Including Apollo.

But it didn’t matter. Because he’d already seen what he’d come there to.

When he resurfaced beside Artemis’s carriage, it was to find her eyeing him with deep approbation. “No,” she instructed firmly like he was a dog to be brought to heel.

“Yes,” Apollo insisted as he climbed inside the chariot, unrepentantly dripping all over the fur rug.

“No.”

“You don’t even know what I’m planning,” Apollo protested.

“I don’t need to in order to recognise that look on your face.”

Apollo pouted.

Artemis pressed a hand to her forehead. “Please, just please, don’t make a stalker shrine this time. I am tired of making excuses for my idiot of a brother.”

***

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#fanfiction #pjo #perpollo #sea fam #apollo #percy jackson #percy x apollo #triton #artemis #god percy

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mariasklodowskastwixbar · 2 months ago

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What i think different spider verse characters taste like

Margo- sonic oceanwater

Pav- cinnamon + nutmeg hot chocolate mixed with vanilla chai

Miles- sour patch kids

Gwen- pink monster energy

Hobie- every soda in the machine mixed together, aka suicide drink

#atsv #itsv #hobie brown #margo kess #miles morales #pavitr prabhakar #gwen stacy

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synapticconstruction · 11 months ago

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Oceanwater Soup 🌊🍲

#diminish #apollo #werewolf #diminish webseries #unfiction #art #I got sick so we’re preoccuping ourselves with stuff we had on the back burner #see you next month 🙂‍↕️

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avatar-of-the-blank · 1 year ago

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the Vast tastes like… Minty gum? but I don’t like mint gum… - Vast avatar

I WAS TRYING TO IMAGINE A FLAVOR THAT RESEMBLED THE TASTE OR AIR FLOODING YOUR MOUTH AS YOU TRY TO SCREAM WHILE FALLING FROM A GREAT, GREAT HEIGHT. 3AM ICE WATER AND MINTY GUM CAME TO MIND

IF YOU WANT YOU CAN IMAGINE YOURSELF AS OCEANWATER! MAYBE WITH PRIMORDIAL PARTICLES IN IT, IF YOU CAN IMAGINE THE FLAVOR OF THOSE!!

#tma #the magnus archives #michael distortion #the spiral #the vast

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spacetimewithstuartgary · 4 months ago

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Planning autonomous surface missions on ocean worlds

hrough advanced autonomy testbed programs, NASA is setting the groundwork for one of its top priorities—the search for signs of life and potentially habitable bodies in our solar system and beyond. The prime destinations for such exploration are bodies containing liquid water, such as Jupiter's moon Europa and Saturn's moon Enceladus.

Initial missions to the surfaces of these "ocean worlds" will be robotic and require a high degree of onboard autonomy due to long Earth-communication lags and blackouts, harsh surface environments, and limited battery life.

Technologies that can enable spacecraft autonomy generally fall under the umbrella of Artificial Intelligence (AI) and have been evolving rapidly in recent years. Many such technologies, including machine learning, causal reasoning, and generative AI, are being advanced at non-NASA institutions.

NASA started a program in 2018 to take advantage of these advancements to enable future icy world missions. It sponsored the development of the physical Ocean Worlds Lander Autonomy Testbed (OWLAT) at NASA's Jet Propulsion Laboratory in Southern California and the virtual Ocean Worlds Autonomy Testbed for Exploration, Research, and Simulation (OceanWATERS) at NASA's Ames Research Center in Silicon Valley, California.

NASA solicited applications for its Autonomous Robotics Research for Ocean Worlds (ARROW) program in 2020, and for the Concepts for Ocean worlds Life Detection Technology (COLDTech) program in 2021.

Six research teams, based at universities and companies throughout the United States, were chosen to develop and demonstrate autonomy solutions on OWLAT and OceanWATERS. These two- to three-year projects are now complete and have addressed a wide variety of autonomy challenges faced by potential ocean world surface missions.

OWLAT

OWLAT is designed to simulate a spacecraft lander with a robotic arm for science operations on an ocean world body. Each of the OWLAT components is detailed below.

The hardware version of OWLAT is designed to physically simulate motions of a lander as operations are performed in a low-gravity environment using a six degrees-of-freedom (DOF) Stewart platform. A seven DOF robot arm is mounted on the lander to perform sampling and other science operations that interact with the environment. A camera mounted on a pan-and-tilt unit is used for perception.

The testbed also has a suite of onboard force/torque sensors to measure motion and reaction forces as the lander interacts with the environment. Control algorithms implemented on the testbed enable it to exhibit dynamics behavior as if it were a lightweight arm on a lander operating in different gravitational environments.

The team also developed a set of tools and instruments to enable the performance of science operations using the testbed. These various tools can be mounted to the end of the robot arm via a quick-connect-disconnect mechanism. The testbed workspace where sampling and other science operations are conducted incorporates an environment designed to represent the scene and surface simulant material potentially found on ocean worlds.

The software-only version of OWLAT models, visualizes, and provides telemetry from a high-fidelity dynamics simulator based on the Dynamics And Real-Time Simulation (DARTS) physics engine developed at JPL. It replicates the behavior of the physical testbed in response to commands and provides telemetry to the autonomy software.

The autonomy software module interacts with the testbed through a Robot Operating System (ROS)-based interface to issue commands and receive telemetry. This interface is defined to be identical to the OceanWATERS interface. Commands received from the autonomy module are processed through the dispatcher/scheduler/controller module and used to command either the physical hardware version of the testbed or the dynamics simulation (software version) of the testbed.

Sensor information from the operation of either the software-only or physical testbed is reported back to the autonomy module using a defined telemetry interface. A safety and performance monitoring and evaluation software module ensures that the testbed is kept within its operating bounds. Any commands causing out of bounds behavior and anomalies are reported as faults to the autonomy software module.

OceanWATERS

At the time of the OceanWATERS project's inception, Jupiter's moon Europa was planetary science's first choice in searching for life. Based on ROS, OceanWATERS is a software tool that provides a visual and physical simulation of a robotic lander on the surface of Europa.

OceanWATERS realistically simulates Europa's celestial sphere and sunlight, both direct and indirect. Because we don't yet have detailed information about the surface of Europa, users can select from terrain models with a variety of surface and material properties. One of these models is a digital replication of a portion of the Atacama Desert in Chile, an area considered a potential Earth-analog for some extraterrestrial surfaces.

JPL's Europa Lander Study of 2016, a guiding document for the development of OceanWATERS, describes a planetary lander whose purpose is collecting subsurface regolith/ice samples, analyzing them with onboard science instruments, and transmitting results of the analysis to Earth.

The simulated lander in OceanWATERS has an antenna mast that pans and tilts; attached to it are stereo cameras and spotlights. It has a 6 degree-of-freedom arm with two interchangeable end effectors—a grinder designed for digging trenches, and a scoop for collecting ground material. The lander is powered by a simulated non-rechargeable battery pack. Power consumption, the battery's state, and its remaining life are regularly predicted with the Generic Software Architecture for Prognostics (GSAP) tool.

To simulate degraded or broken subsystems, a variety of faults (e.g., a frozen arm joint or overheating battery) can be "injected" into the simulation by the user; some faults can also occur "naturally" as the simulation progresses, e.g., if components become over-stressed. All the operations and telemetry (data measurements) of the lander are accessible via an interface that external autonomy software modules can use to command the lander and understand its state. (OceanWATERS and OWLAT share a unified autonomy interface based on ROS.)

The OceanWATERS package includes one basic autonomy module, a facility for executing plans (autonomy specifications) written in the PLan EXecution Interchange Language, or PLEXIL. PLEXIL and GSAP are both open-source software packages developed at Ames and available on GitHub, as is OceanWATERS.

Mission operations that can be simulated by OceanWATERS include visually surveying the landing site, poking at the ground to determine its hardness, digging a trench, and scooping ground material that can be discarded or deposited in a sample collection bin. Communication with Earth, sample analysis, and other operations of a real lander mission, are not presently modeled in OceanWATERS except for their estimated power consumption.

Because of Earth's distance from the ocean worlds and the resulting communication lag, a planetary lander should be programmed with at least enough information to begin its mission. But there will be situation-specific challenges that will require onboard intelligence, such as deciding exactly where and how to collect samples, dealing with unexpected issues and hardware faults, and prioritizing operations based on remaining power.

Results

All six of the research teams used OceanWATERS to develop ocean world lander autonomy technology and three of those teams also used OWLAT. The products of these efforts were published in technical papers, and resulted in the development of software that may be used or adapted for actual ocean world lander missions in the future.

TOP IMAGE: Artist's concept image of a spacecraft lander with a robot arm on the surface of Europa. Credits: NASA/JPL – Caltech

CENTRE IMAGE The software and hardware components of the Ocean Worlds Lander Autonomy Testbed and the relationships between them. Credit: NASA/JPL – Caltech

LOWER IMAGE: The Ocean Worlds Lander Autonomy Testbed. A scoop is mounted to the end of the testbed robot arm. Credit: NASA/JPL – Caltech

BOTTOM IMAGE: Screenshot of OceanWATERS. Credit: NASA/JPL – Caltech

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