“... and so Twilight wants to get a pony stuck in space so we can find out if there is anything new over the sun. Isn’t it great?” Pinkie Pie beamed.

Prince Rutherford snorted. “Ponies silly. Yaks know about ‘gravity’. Gravity makes yaks heavy. Pony will just fall back down.”

“Maaaybe. Twilight says there’s more to going to space than just going up. We have to go sideways a lot, too.”

“Space is not sideways. Sideways just mountains.”

“That’s why the pony goes up first, silly. Then they go sideways, and bam, they’re stuck in space!”

Rutherford considered this for a moment. “Hmmm… Yaks not sure. Why pegasus not just fly up to space?”

“Because, uh...” Pinkie scrunched her muzzle in thought. “Oh! It’s like a really tall mountain, right? If you try to climb to the top, the air gets really cold and hard to breathe. Twilight says there’s no air at all in space!”

“Hah!” Rutherford boomed. “Yaks strong. Yaks climb all mountains. Maybe ponies need yaks to go to space for them if ponies have trouble breathing. Yaks very warm, too. Yaks not have these problems.”

“You do have a point,” Pinkie replied. “But I still think you have to bring some air with you.”

Rutherford stood up. “This matter settled. Tell ponies that yaks go to Space! Yaks tell ponies what space like after.”

“Okie dokie lokie.”

“You come back in two weeks. Yaks ready to go to space by then.”

Twilight hadn’t been happy with the yaks’ announcement that they’d be running their own space program, but she agreed that Pinkie might as well be the liaison, just in case either Equestria could learn something from the yaks’ attempts, or some measure of safety procedure might rub off on them. Shortly after Pinkie first beheld the blueprints for their chosen method of ascent, though, she discounted any notion that yaks fully understood what ‘safety’ was.

“So, why doesn’t this include yaks?” she asked the yak engineer that Rutherford had assigned to explain the machine to her before the launch. Pinkie Pie knew he was an engineer because he had one of the yellow hard-hats that engineers wore.

“This sphere here is yak.” He pointed to a sphere indicated to fit in the capsule’s diagram. “Yak-sphere makes math easier.”

“Uh huh.” She pointed to a bunch of leg-like protrusions off of the main barrel. “So what are these?”

“Yaks use what yaks do best to make force. Yaks stomp. Power from yak stomps go through here to make capsule fly. Force hit capsule like backwards fall where ground hit yak instead.

“When space-yak in space, space-yak stomp this to make space-yak capsule half go sideways, like yak jump, where ground and yak move apart.”

Pinkie let out a whistle. “Wow, you guys really are good.”

“Me not tell Prince Rutherford, but yaks not sure how big ground is. There is small chance space-yak will not stay in space.”

“That’s… a really big fall.”

“Yaks strong. Space-yak will be fine. Capsule hit ground before space-yak anyway.” The engineer rolled up the blueprints. “Pink Pony understand how launch work now. Space-yak go to space in hour, when sun not so bright. Yaks have celebration snacks ready for after.”

Pinkie Pie found herself looking at what might have passed for her party cannon, if it hadn’t been about twenty times larger and planted firmly in the ground. The pneumatic lines ran out the back like a fuse, and while the wheels didn’t allow for free movement, they did serve as the mechanism for adjusting the angle of launch. The barrel was pointed mostly up and slightly south at the moment. The yak engineers had assured her that there was less ocean in that direction.

Apparently yaks did not like the prospect of swimming.

Pinkie was shown to Rutherford’s stand, several horns’ distance behind the barrel, where the glare from the white snow all around wouldn’t affect their ability to see. Another two yaks had telescopes set up on either side of the stand.

“YAKS AT READY,” Rutherford called as she took her place.

About two dozen yaks stepped up to their respective pads, lined up on either side of the space-cannon.

Another yak climbed out of the barrel and slid down its length. “Space yak is ready!” she called.

“Good,” Rutherford boomed back. He turned to Pinkie and smiled. “Pink Pony get honor of count down.”

“Eeeeee awesome! I love counting down for important things!”

Pinkie cleared her throat, and in her yak-iest voice, began. “Ten— no, too long. THREE...

“TWO...”

All the yaks present visibly tensed, even those not preparing to stomp with all their might.

“ONE...”

The excitement and pressure of the moment threatened to put her in overdrive, but if she called out early, the yaks might get confused. They did like music, after all, and they certainly knew what a rhythm was.

But Celestia’s Frown it felt like forever.

“STOMP!”

She watched all the yaks jump up in unison, and shortly drop down on their pads. She had expected more of a ground-shaking rumble, but when they landed, she didn’t feel a thing.

Until a split-second later, when the end of the cannon erupted with a concussive blast, roughly fitting for the stomps of about two dozen yaks. Pinkie flopped her ears to make sure they were still attached. They didn’t seem to be working right, because she was pretty sure her cannon didn’t ring like that after she fired it.

“Space-yak going up,” called one of the telescope yaks.

“Space-yak definitely going to space,” confirmed the other.

“When Space-yak stomp sideways?” Rutherford asked.

“Space-yak stomp sideways soon,” replied one of the engineers.

“Ooohh so exciting!” Pinkie Pie pulled out a pair of binoculars and focused in on the speck they were all watching. After what felt like mere seconds, but the rational sliver of her mind suggested was probably actually a couple of minutes after launch, she saw the capsule burst apart into two chunks, both flying away from each other extremely fast. It looked like the yaks succeeded.

Twilight was going to be jealous.

“… and then we had cake!”

Twilight Sparkle sighed. “Pinkie Pie, you know the yaks didn’t actually get to space, right?”

“Really? How do you know?”

Twilight pulled out a notebook and scribbled out a rough picture. “We measured the capsule’s velocity during its descent and calculated its trajectory, since we know where it was launched from. It wasn’t falling fast enough to have breached the aeropause. Also… the capsule landed just east of Vanhoover. Even though they launched from a mountain, the yak capsule didn’t even end up with one tenth of the total change in velocity needed to actually reach orbit.”

Pinkie deflated somewhat. “Oh, okay.”

“We did learn something important, though.”

“What’s that?”

“The yak pilot says the ground was definitely not flat. After she gave us her list of credentials on why she would know what ‘not flat’ was, she reported that Equestria actually has a slight curve to it!”

“Cool,” Pinkie said. “And it sounds like the yaks will definitely make it next time. One of the engineers told me about the fire-stomping powder they were working on to stomp the space-yak even harder.”

Twilight froze with a look of trepidation.

“You mean they’re going to start using explosives?”

Author's Notes:

RoboFoME Card:

Explode Twice
1RR
Instant
The next two 1/1 white.)

When and you cast havens, and size. Damage equal to its control of turn.

Counters the top three or she rest into you do, each Plant with the earned it.

"Oh, I swear come and your audience on the truth, them.

No formatting because this card was sent through Discord first.

FanOfMostEverything went ahead and made cards based on this story (which is based on RoboFoME... etc. All the meta.) which I will now provide here:

Yak Editor 4R
Creature — Ox Bureaucrat
Whenever a player casts a wordy spell, Yak Editor deals 3 damage to that player. (Something is wordy if it has four or more lines of text in its text box.)
“Story not perfect. Yak smash!”
4/4

Spherical Assumption 2(gu)
Instant
Target creature loses all creature types and has base power and toughness 3/3 until end of turn.
“It’s so much simpler this way.”
—Jalira, master polymorphist

Void Smasher 4GU
Creature — Ox Warrior
Flying, trample Void Smasher can’t block creatures without flying. You may cast Void Smasher from exile.
”Must smash Eldrazi from orbit. Is only way to be sure.”
4/4

Update: There's more, inspired by and building on the concepts explored here.