Progress is a My Little Pony: Friendship Is Magic fanfic by Andrew J. Talon, which originally started as a one-shot titled Luna vs. the Microwave. The story stars Princess Luna as she attempts to catch up on how much life has changed in Equestria.It can be found here.
Aborted Arc: For the time being, Andrew has abandoned "PONIES IN SPACE" in order to focus more on Luna as a character; he mentioned plans to resume it at some later point, but later removed it entirely from the FIMFiction version of the story.
All Part of the Show: In "Luna vs. Vigilantism 3", Sundance thinks the Great and Powerful Trixie (who is trying to steal a powerful book of magic from the Canterlot Library) is part of Luna's superhero play-acting.
Amusing Injuries: Luna casts a spell during a baseball game, making all foul balls fly towards her and her friends. However, she also forgot she can't catch the balls without revealing her true self. As a side note, she now has a major phobia for all things baseball.
And I Must Scream: In "Luna versus the Dreamlands" Part 2, Luna traps Discord's dreamself in stone, leaving him petrified in a physical and mental sense.
Luna also doesn't take too kindly to others messing with her subjects as numerous characters discover: a Kong and Rex who threaten the Cutie Mark Crusaders in "Luna vs. Ponyville Part 7", Prince Blueblood after he shamelessly hits on Sundance in "Ponies in Space Part 2", and Discord in "Luna vs. the Dreamlands Part 2".
Celestia's is Luna getting hurt. Quoth the Princess:
"I am a very old pony. I’ve seen things. And banishment? Isn’t nearly creative enough."
Bilingual Bonus: In "Ponies In Space 2", Sundance insults Prince Blueblood in French, telling him things like "Your brain must have been optional," and "Reality and you don't get along, am I right?"
Borrowed Catchphrase: It's subtle, but in "Ponies in Space 1", Luna says "Eeyup!", Big Macintosh's catchphrase.
Bread, Eggs, Milk, Squick: A list of items found on one tourist in "Ponies in Space" includes "Chocolate bars, caramel bars, fruit pops, candied apples, cotton candy, gummy bears, jelly babies, gum drops, peanut butter chocolate cups, hot chocolate, cherry twists, lemon snaps, pressed sugar glass, a butterfly knife-"
Bullying a Goddess: Sure Angel, let's go pelt the local Lunar Goddess with baseballs, what could possibly go wrong?
The Cameo: In part 3 of "Luna vs. Lodging", Doctor Whoof and his companion Derpy pop in for a quick spot.
Chapter 21 features the ponified MythBusters as scientists in the space program.
Canon Discontinuity: The "Ponies in Space" arc was cut from the story as of "Luna vs. Vigilantism 3", with a new chapter to replace it in the works (as otherwise Sundance's pregnancy comes out of nowhere). The same author's note that declared this also made "Luna vs. Threesomes" canonical...
Caught With Their Nethers Exposed: Luna walks in on Sundance and Hoyden... er, "being together." Celestia decides to have Luna visit Ponyville to let it all simmer down.
Chivalrous Pervert: Sundance's coltfriend Hoyden is prone to interesting fantasies about his marefriend and Luna, but he is supportive of Sundance, and he knows when he messes up.
Clark Kenting: Luna disguises herself as "Selene" by hiding her wings and/or horn and putting on a pair of glasses. It works with the Apple family and Rainbow Dash, but not so much with Sundance or Pinkie Pie.
The Apple Family actually justifies how they could have missed that: Most of them had never seen Luna's true appearance before, and Applejack claims she didn't get a good look at Luna before Luna left for Canterlot.
Later, Fluttershy says the pieces of Apple Bloom's Celestia costume are "leftovers from (her) modeling career."
"Luna Vs. The Dreamlands 2" definitely takes place after The Return of Harmony Part 2 as it deals with Discord, and "PONIES! IN! SPAAAACE! Part 4" is set after "the Discord incident." The latter also follows "Luna Eclipsed", as Luna mentions a colt "who isn't fully grown yet but is so darling" - clearly Pipsqueak.
Word Of God says that the series starts after the events of "Luna Eclipsed."
Luna vs Vigilantism all takes place after "The Mysterious Mare Do Well," as Sundance listened in on Twilight Sparkle's letter to Celestia explaining what had happened.
Crazy-Prepared: The Cakes are insured against acts of goddesses. (Though considering that they live with Pinkie Pie, Reality Warper extraordinaire, it may not be so crazy after all.)
Deadpan Snarker: Sundance, in chapter 14, when Luna is attempting to construct an air conditioner for the house from scratch. Luna wants helium to make an ideal heat sink, but the only way to get it, as Sundance points out, is through nuclear fusion, and "I'm not in the mood for a second sun, your majesty."
Ditzy Genius: Luna reorganized the irrigation system for an entire province, established a whole new system of emergency response and management for the entire kingdom, and made sense of the tax code, but is even more socially awkward than Twilight Sparkle, and thought twenty seven minutes was the perfect amount of time to cook popcorn.
In addition, when wanting to make an ideal heat sink to cool off the house, she outlines her plan to separate the hydrogen and oxygen from the water and fuse the hydrogen into helium. It takes Sundance to point out that doing so would probably be a bad idea.
In "Ponies in Space", Luna figures out a mathematical theorem to prove that pi and e are transcendental numbers from scratch... Despite the fact that if they're already building moon rockets, it means her theorem would have been revolutionary about a century ago.
Do Not Taunt Cthulhu: In "Luna vs Ponyville Part 6" Angel Bunny finds out the hard way that even Luna has her limits.
Double Entendre: Luna guiding Applebloom through the astronaut training simulator in "Ponies in Space 3", much to the amusement of Snips and Snails.
Dramatic Thunder: As Nightmare Moon in the Past, almost every line she speaks is accompanied by this, to the point where she got annoyed, and chastised the Shadow Bolts for playing on the thunderclouds.
Dream Weaver: One of Luna's powers as the pony goddess of the night. Her power is absolute in the dreamworld, something Discord found out the hard way.
The Exit Is That Way: In "Ponies in Space 3", Luna offers to show the Cutie Mark Crusaders the simulator room where they train astronauts, and the Crusaders eagerly rush through the nearest door... which turns out to be the janitor's closet.
Sundance's eyes literally popped out of her head. Then popped back in. And then she rolled around on the ground in pain for a few minutes.
The Family for the Whole Family: In the "Luna vs. Vigilantism" arc, Luna's career as a superhero becomes pretty boring because even Canterlot's mafia turns out to be pretty well-behaved. Specifically, they show her that they'd just completed a toy drive for orphans, and ask her to help promote volunteer deliveries.
Flat "What.": On several occasions. In the side story "Luna vs. Threesome", Hoyden goes the extra mile to say "What is this I don't even" to Luna's attempt to seduce him and Sundance.
Also in Luna vs Threesome:
"What!? No, why would she do that? She’s my sister. That’s gross. No, she told me to fetch five or six of her guards, and then she was going to get them to run a train on me! I don’t like trains, Hoyden! I always worry that the car I’m riding in is going to get separated from the others and jump the tracks and I’ll wind up in another country!" Hoyden’s jaw worked, but between the arousal, the sudden panic, the confusion, more panic, and then even more confusion, his brain decided to just give up and go play reruns of Equestria’s Funniest Home Videos.
Follow the Leader: This story started the recurring MLP meme that Luna has an abbacus, which has been mentioned in fanart and fanfiction countless times since.
"Nooooo!" Rainbow Dash, the greatest flyer in Equestria, wrapped her hooves around Pinkie Pie and shook her. "Nooo! You can’t leave me alone! What about..." She sobbed dramatically but wiped her eyes, "what about our future?! Our dreams and hopes?! Our... Our child!" "Wait, you have a child?" Twilight asked. "We were going to adopt, you got a problem with that?!" Rainbow Dash snarled. Twilight raised her hooves. "N-No! No! No problem!" "We’re not gay if that’s what you’re thinking! I’M NOT GAY! I’LL DO EVERY COLT IN EQUESTRIA IF I HAVE TO PROVE IT!" "Rainbow Dash, sugah, yer makin’ her die faster," Applejack pointed out.
Head Desk: In "Luna vs. Ponyville, Part 7", Luna makes a Badass Boast to a T. rex and a giant ape... who, much to her frustration, completely fail to recognize her. Cue this trope.
Both tyrannosaur and megaprimate were treated to the rare sight of a deity in wrath beating her head against the wall.
Heroic Sacrifice: This is what happened to Luna's unnamed suitor about a thousand years ago (pre-Nightmare Moon) according to Luna Vs. Storytelling. In the "Progressverse," the smooze from the G1 movie was pretty much how it would be if it was a real Eldritch Abomination, and it attempted to devour Equestria during that time. When it was revealed that he sacrificed himself to buy time for all the ponies to be saved, Manly Tears were shed along with any possible tears that Luna, Sundance, or Hoyden shed.
Humongous Mecha: Luna built a giant robot alicorn dubbed "Mechapony 1" to push and pull rockets. Since she based it on a robot she built 1000 years ago for the purpose of killing Celestia, Mechapony 1 also comes equipped with eyebeams and thrusters (with missile launchers coming in the following week). When Twilight asks why a robot built for moving rockets needs so many weapons, everyone else asks "Why not?"
"Luna vs. Vigilantism" reveals that it promptly went berserk when they put Twilight Sparkle behind the controls (for whatever reason), and that's why Luna isn't in the space program anymore.
Imagine Spot: There is usually at least one a chapter, usually by Luna, wildly exaggerating the current issue.
Lampshaded in Vs Ponyville part 3 by Applejack and Big Mac.
I'm a Humanitarian: In the non-canon (Cupcakes parody)"Gelatin", the Jello is made from humans.
Lethal Chef: Luna manages to light her kitchen on fire after trying to use the microwave. Subverted when she takes it as a learning experience, and is able to prepare a decent meal a few weeks later. Double subverted when she ends up setting Sundance's kitchen on fire in a panic.
Long List: The baseball fan paraphernalia offered to Luna during "Luna vs. Baseball".
Mad Scientist: Luna becomes a good-natured one in the "PONIES! IN! SPAAAACE!" chapters.
Mare Fight: Luna and Sundance in "Luna vs. The Heat", the heat having put both of them on edge. Hoyden of course can't help but stare.
Meaningful Name: "Luna vs. the Dreamlands, Part 2" suggests that, due to Luna's Dream Weaver powers, Nightmare Moon was more than a pun.
Morning Sickness: At the start of "Ponies in Space", Sundance is introduced recovering from a bout of nausea she brushes off as 'something I ate'. Sure enough, as many fans suspected, Sundance turns out to be with foal in "Luna vs. the Dreamlands, Part 2".
Never Live It Down: In-Universe: When Sundance goes to the bathroom, Hoyden tells her not to fall in. Her response? "That only happened once..."
She also mentions in "Luna vs. The Microwave" that she had a great deal of confusion over the first airplane, wondering why it's wings didn't move and it didn't have feathers.
Oblivious to Love: Luna doesn't realize that the two colts who asked to buy her a drink are actually flirting with her. She reacts... violently when they start making stronger advances on her.
Subverted with Big Mac as she seems to completely overblow their not-so-blind date, punctuated with a ridiculous Imagine Spot.
Oh Crap: Sundance and Hoyden freak out when Luna, on Sundance's advice, starts revealing the secret wishes they made on stars which, being the pony goddess of night, Luna can hear. Hoyden is especially frightened when Luna innocently reveals that he wants a threesome with her and Sundance.
Oh Wait: Celestia, in "Luna vs. The Facts of Life":
"Oh yes! Mmm... Sometimes I just see a colt and I think to myself, 'Oh, if only I was an immortal, beautiful, sexy goddess that all would love to mate until I couldn't stand up.' And then I think 'Oh wait! I totally am!' And then-!"
Only Sane Mare: Sundance finds herself feeling this way, between Hoyden's exuberance and Luna's ... reason for this fic being written.
Paper-Thin Disguise: Luna attends a baseball game with the Apple Family, wearing only large glasses and using magic to hide her wings and horn. Nobody can tell.
It's somewhat implied she didn't even hide her horn or wings seeing how she cast a spell later that day, oh and she mentions she used to be Nightmare Moon.
It was also noted that Applejack only saw her for a few minutes, while the rest of the Apples had never met her. When she tries using it on Sundance, who's around her on a regular basis, she sees right through it.
However, Pinkie Pie sees through it immediately, while only viewing her previously for the same amount of time Applejack did. (Then again, it is Pinkie Pie we're talking about here.)
Rainbow Dash doesn't recognize her with the glasses and without a horn.
Fluttershy also doesn't recognize her. However, her rabbit Angel does.
In Chapter 8, it seems as though Rarity can see through her disguise. In Chapter 9 though, it's revealed Rarity had no clue whatsoever until Luna hints at it. To her credit, she tries to maintain the illusion in front of Twilight but fails. At this point Luna pretty much just gives up.
Really Gets Around: In the (possibly) canon Luna vs Facts of Life, Celestia, evidently. She was so distraught when she originally banished Nightmare Moon that she sought comfort in physical pleasures; at this point it's too fun a habit to give up.
At one point she casually (probablycanon) reveals that she's the mother of every other famous fictional horse in history. (Seriously; among the names she drops are Shadowfax and Epona.)
Recursive Fanfiction: Has inspired three fan-made side stories: Luna vs. Videogames, Luna vs. Threesome, and Celestia vs. Time.
Ring Ring CRUNCH: Luna is startled by Sundance's alarm clock and ends up blasting it through the walls.
Royals Who Actually Do Something: Blueblood's family founded and run a charity foundation, a wildlife preserve, a shelter for unemployed ponies, and a supermarket chain.
Then again, Blueblood himself was only in charge of each operation for a week.
Running Gag: Luna getting pegged by foul balls thanks to a faulty attractor spell in "Luna vs. Baseball".
Macintosh being a Sex God. Each more sillier than the last one.
From the sidestory "Luna Vs. Threesome:"
"Oh Macintosh," Sundance breathed, "I simply cannot contain my wild pony passion for you another second longer! Make love to me! Make me a mare!" "Weeellll," Macintosh drawled, shifting the stalk of hay between his teeth from one side of his mouth to the other, "ah reckon that'd be alright." The draft pony rose onto his hind legs and, despite his hooves, deftly unzipped the tight blue jeans he was wearing for no discernible reason.
Sanity Slippage: In "Luna vs. Communication", Sundance suffers Cutie Mark Failure Insanity Syndrome when she thinks she is failing to make Luna happy. This and a misplaced book on truth potions eventually leads to Luna accidentally blowing up Sundance's kitchen.
In "Luna vs Ponyville, Part 1: Television", where the first show that Luna watches on Pinkie's television is a pony version of Mister Rogers' Neighborhood, and after changing the channel and trying to find it, she apparently stumbles across a horror movie known as Cupcakes.
In "Luna vs Ponyville, Part 2", Luna finds a copy of the pony equivalent of Twilight, which is apparently a good deal... racier.
Apparently, Priness Celestia mothered a whole group of famous horses, as she explains to Luna in "Luna Versus the Facts of Life." Where to begin? Let's see, Starchild, Shadowfax, Arion, Hengroen, Epona, Widow Maker...
"Luna vs Ponyville 9" gets a massive one for Warhammer 40000... by Pinkie Pie's parents, who bust out heavy weapons and shout about exterminating "xenos" in the name of God-Queen Celestia when they think their farm house is under attack by dragons. Apparently, it runs in the family.
"Luna vs. Vigilantism" opens with Luna reading a Batpony comic (which appears to be inspired by The Killing Joke). Later Luna (as Mare-Do-Well) performs a dead ringer for the entrance of Darkwing Duck.
Shown Their Work: The author admits to referencing a real mathematical theorem, the Lindemann–Weierstrass theorem, in "Ponies in Space". "Yes, I am a colossal nerd. But given I'm writing MLP fanfiction, that's kind of a given."
Sister Bear: Celestia over Luna, especially over Luna in the side story "Luna versus the Threesome" when she comes in to work wearing an eyepatch after an accident of "cooking" with Hoyden and Sundance.
Sneeze Cut: In Luna Vs Lodging, Part 3, Luna thinks to herself how she's too old for Big Macintosh; too old for anypony, when she thinks about it. After all, who else is more than 1000 years old, besides her sister?
Spit Take: Hoyden, when Luna calls their dinner a threesome (in "vs the Threesome").
Strange Minds Think Alike: Sundance has a worrisome Imagine Spot where Luna has her thrown into a dungeon, then banished, and finally sent to a dungeon in the place she was banished to, the same fate Twilight Sparkle thought would happen to Fluttershy in A Bird In The Hoof.
Studyaholic: Luna spends most of her time back catching up on the modern world, enough that Celestia almost has to force her to get outside.
She's also a Workaholic as well as she spends the rest of her time helping her fellow ponies.
Sure, Let's Go with That: In "Luna vs. Threesome", Celestia decides to let Luna believe she was just joking about letting her have an orgy with some of the guards... then tells said guards that Luna isn't interested.
In "Luna vs. Vigilantism 3", the Great and Powerful Trixie has this reaction to Sundance assuming she's in on Hoyden and Luna's plan to stage a superhero/supervillain battle at the Canterlot Library.
Suspiciously Specific Denial: When Pinkie asks Luna in "Luna vs. Ponyville, Part 3" if she's still hung up over becoming Nightmare Moon, Luna insists she isn't, saying "I'm not thinking about it or worried over it and she doesn't appear in my dreams!"
Luna and Fluttershy's attempts to keep Luna's identity a secret at the start of Luna vs. Ponyville Part 7. "This is not at all an elaborate deception to conceal anything."
Luna returns to form in Luna vs. Ponyville part 9: "Y-Yes! A perfectly normal librarian who is not in any way, shape or form Princess Luna so nopony needs to feel embarrassed for any behavior they may have committed!"
Heck, Luna usually does this at least once a chapter.
Luna: Who made this? What kind of sick, twisted monster would do such a thing?! It's not even a good plot! A pink pony invites her friend over for a party... Just so she can gut her, dismember her and turn her into cupcakes? That's ridiculous!
Technology Marches On: The whole point of the first story. Also mentioned by Celestia in that same story when it came to the first planes.
Tempting Fate: At the end of part 1 of "Luna vs. Lodging", Sundance lets Luna move in with her, thinking to herself "What was the worst that could happen?" In part 2, Luna blows a hole in Sundance's apartment after getting startled by the alarm clock, then blows up a dive bar after two sleazy colts try to hit on her. In "Luna vs. Communication", Luna accidentally sets Sundance's kitchen on fire after panicking at seeing a baseball headed for her.
In the non-canon side story "Luna vs. Videogames", Hoyden says "Live and let live. It's only a Game-station, what's the worst that could happen?".
Luna catches herself doing this in "Ponies in Space". When Sundance tries it, thinking Luna is being silly, they're nearly hit by an out-of-control booster rocket.
Hoyden does it in Luna vs Vigilantism 2. Sundance promptly reprimands him.
Back in 'Ponies In Space part 4', this conversation:
"You want to slay a goddess, your Majesty-Nothing short of the Elements can do that," the technician said gravely. "Ah well... I suppose I'll just have to steal them from her," Nightmare Moon said with a shrug. "What's she going to do? Use them against me?"
Too Much Information: In "Luna vs. Lodging, Part 3", Sundance learns Luna used to listen in on wishes made on shooting stars, and suggests using that for conversation starters. Luna gets more than a little carried away...
Luna also discovers a few things about Celestia's social life in 'Luna Vs the Facts of Life', all but asking for Brain Bleach.
Tranquil Fury: Luna when dealing with Prince Blueblood after he makes inappropriate and unwelcome advances at Sundance. She remains perfectly calm...while allowing him to undergo a potentially lethal training exercise. Sundance wisely resolves to never make Luna mad.
Luna is pretty calm throughout 'Vs Dreamlands 2', as she confronts Discord, and makes sure he'll never torment another pony for a long time by trapping him in a Dream Within a Dream.
Upper Class Twit: Prince Blueblood shows up in "Ponies in Space 2", volunteering for the space program on the grounds that he's "dashing" enough for the job.
When he lists off the other positions he's held, making a big deal out of them, Luna notes that he's never held any of them more than a week.
You Need to Get Laid: Celestia's reaction to learning that Luna was considering "Abacus" as a potential name for a foal in the side story "Luna vs. the Threesome".
Your Mom: Sundance responds to Prince Blueblood's attempts to hit on her in faux-French by firing off genuine French at him. Naturally, this allows her to insult him without him being the wiser. This culminates in "Ta mere suce des ours dans la foret." ("Your mother sucks bears in the forest.")