Last week's CSP draft... (Patreon)

Sorry I didn't think to push to finish CSP in time for last weekend's anniversary of Apollo 11.

Anyway, here's a different landing... well, crash, I guess...

At Mission Elapsed Time 158:42 on the capsule’s clock, Cherry Berry fired the engines- not a short burst like her prior orbital adjustments, but a long, full-throttle burn. Below her- almost, but not quite, directly below- lay the target landing zone, where the Royal Astronomical Society had requested surface readings for whatever reason. The highlands of Minmus rolled up and down- not with the suddenness of the areas immediately next to the frozen lakes, but a more gentle gradient that, Faust willing, would allow a relatively level landing.

In fact, Cherry noted as she looked out the hatch porthole at the surface below, the surface looked pretty flat from up here. Flat, and glittery, sparkling all sorts of colors here on the daylight side, colors that blurred together into the general aqua-gray that one saw from farther away. 

But she could only look for a second- just long enough to verify that the terrain was safe for landing. Cherry committed her glance to memory, then turned her attention back to her instruments, which she would need for the rest of the landing. The ship would land in the same position it launched in, which meant Cherry would be lying on her back in the flight couch... in a position where she couldn’t possibly see the ground beneath her. That meant relying on three instruments: the speed indicator(408), the altimeter from surface, and the nav-ball and its indications of ship orientation, prograde and retrograde vectors, and angle of attack.

The speed indicator whirred down closer and closer to zero. The idea, in theory, was to bring the ship to a complete stop in relation to Minmus’s surface, currently fourteen hundred meters below. This would allow a vertical drop that would allow a controlled level landing, In practice, Cherry wanted to allow a little bit of drift, since she’d have to use the engines to slow the final part of the descent anyway. That last burn would let her kill any remaining lateral motion and, at the same time, keep Minmus’s weak gravity from hauling her down too quickly and smashing the spindly little landing legs(409).

“Horseton, Twenty-two,” she said, shutting down the engines and returning momentarily to free-fall, “deorbit burn complete, entering landing phase. Please confirm proper landing zone.”

“Stand by, Twenty-two.”

Cherry’s ears would have flipped backwards in annoyance if they hadn’t been covered by her spacesuit headset. “Horseton, be advised that gravity has something to say about my ability to ‘stand by.’ Am I in the right place, affirmative or negative?”

“Negative,” Chrysalis’s voice grumbled. “We’re trying to figure out why. Do the best you can with your on-board systems.”

“Negative??” Cherry checked the plot on her trajectory indicator. “Horseton, the map says I’m right on the money! How small is this zone I’m supposed to hit?”

“We’re working the problem, Twenty-two,” Chrysalis said. “Do what you can with your computer, but don’t risk the landing over it. If it feels unsafe, abort.”

“Roger, Horseton,” Cherry grumbled back. “One thousand meters and descending, mark.” She looked closer at the trajectory plot. The screen was tiny, and it showed only thin and kind of wobbly lines and two markers practically on top of one another. But... maybe she was a little west of the zone? “Adjusting descent.” She tipped the ship a bit, fired the engines for a few seconds, noting her descent speed slowing even as her retrograde vector momentarily vanished from the top of the nav-ball. “Eight hundred meters and descending at twenty meters per second and accelerating. Descent stage fuel at thirty-seven percent.”

“We copy, Twenty-two.”

Cherry found the retrograde marker on the ball, reoriented the ship until it lined up with the top of the ball, and waited for a little while. The speed readout slowly ticked upwards, as the marker crawled very slowly up the nav-ball. Finally, at five hundred meters, Cherry kicked the engines back on, wiggling the ship a little to kill the lateral momentum again. “Horseton, if I’m not in the zone now, something’s way wrong. I’m committing to landing, and if it works, fine. If not, we’ll send a probe.”

“We don’t get it either,” Chrysalis admitted. “We show you as go for landing. Be sure to null out your lateral way before landing.”

“Roger.” Cherry kept the engines firing, just above their lowest setting, which gradually decelerated the ship. “Three hundred meters and falling at fifteen meters per second,” she reported. 

“Twenty-two,” Chrysalis replied, in a tone of voice that suggested that the speaker thought the listener had missed the previous statement, “we’re still showing a bit of lateral drift. A lot of lateral drift, in fact.”

“Throttling up,” Cherry said. “Two hundred meters and falling at eight meters per second. Retrograde vector’s on top of the ball, Horseton.”

A long silent pause, in which Cherry imagined she could hear echoes of voices other than Chrysalis’s over the comms channel. Then the changeling queen’s voice came through, sharp and clipped: “Confirm nav-ball set to surface mode, repeat confirm nav-ball set to surface! Over!”

Cherry checked her altitude- one hundred fourteen meters, three and a half meters per second descent speed- and then she saw it.

The speed indicator said: Orbital - 3.5 m/s.

The nav-ball and its built-in computer had different functions for orbital, surface flight, and target modes. Part of the checklist immediately prior to the descent burn had been to switch the ball to surface mode- but either she’d hit the wrong switch or, somehow, the computer had switched the nav-ball back on its own. (Which was entirely possible, since the system was built to auto-switch in Equus’s upper atmosphere, during launch and re-entry.)

Cherry hit the switch, and her eyes widened with shock as the speed indicator went from Orbital - 3.3 m/s to Surface - 23.8 m/s. At the same time, the retrograde marker flashed from the top of the ball to the far left-hand side of it.

Mission 22 wasn’t slowly dropping to the surface. It was skimming just barely above the surface- the surface Cherry couldn’t see beneath her- at over fifty miles an hour, as fast as the Friendship Express on the flat land between Ponyville and the base of Mt. Canter.(410) At this speed, if the ship so much as touched a rock sticking above ground level, it would rip itself to shreds in the resulting crash. 

“Abort, abort, abort!” Cherry shouted, goosing the throttle to full for one second of direct vertical thrust. The retrograde marker vanished, and the prograde marker appeared not far from the top of the ball. 

For a moment, part of Cherry prepared to go into full Ponyville Moment mode. 

And then the pilot in her said: Okay, we were waved off the runway and we’re circling around. How can we stick the landing this time?

First thing first: kill that lateral motion. Now that the nav-ball and speed indicator were in the correct mode, this was a simple enough matter, and a little soft burn of the descent engines put the prograde marker at the top of the ball. A few moments later, it flickered off the ball, replaced by the retrograde marker. She was falling again. 

Second: reconfirm safe landing zone. Cherry tipped the ship over again so she could see out the hatch window. Glittering green-gray snow filled the tiny porthole. She saw no shadows to speak of, no rocks, nothing that showed anything other than a safe landing area. 

Third: the wheels go towards the ground. Or the legs, in this case. Having seen what she needed to see, Cherry righted the craft, ticking the engines back on to slow her second descent. The retrograde marker stayed on the point of the ball.

Fourth: report in. “Horseton, Twenty-two,” Cherry said, “I’ve evaluated the problem and taken corrective action. Fuel at twenty-two percent, altitude three hundred fifty meters and descending at five point four meters per second. Zero lateral way, repeat zero lateral way.”

“We confirm, Twenty-two,” Chrysalis said. “Are you sure you want to make a second attempt? We still have the fuel for a landing at the lakes.”

“But I’m here, now,” Cherry replied. “Three hundred meters and descending. It’ll only take a little more fuel to put the bird down.”

“All right, Twenty-two,” Chrysalis replied. “Just be careful. We’re seeing some steep hills on the horizon.”

“Looked flat from in here,” Cherry said. 

“Just be careful.” Pause. “I want that ship back, you know.”

“Two hundred meters. Slowing down a little.”

Cherry kept glancing between the altimeter and the speed indicator. Coming down too slowly meant wasted fuel, but any landing faster than five meters per second risked breaking the landing legs. So she watched the fuel levels drop on the indicator, watched the altimeter creep downwards past one hundred meters, then past fifty meters. 

“Twenty-two, Horseton,” Chrysalis’s voice broke into her concentration. “We’re seeing a bit of a slope beneath you.”

“Roger.” Cherry barely gave the information a thought. She had to concentrate on the speed, keeping the retrograde vector on top of the ball, dropping the ship between three and four meters per second, preparing to kill the engines when she felt the ship make contact. 

Twenty... ten... five-

Contact. 

The ship settled a bit forwards, and the sun flashed across the hatch window.

“Touchdown,” Cherry declared. “Engine shutdown.”

The engines shut off. 

And then, very, very slowly, the tipping motion continued. 

And continued.

And kept right on continuing.

Mission Twenty-two flopped onto its belly, rocking a little bit, and then settling to rest on the side of a very steep hill in the Minmus midlands. 

Cherry, now seated upright instead of on her back, waited for all movement to stop completely. She made a quick check of the instruments, saw no indication of a hull breach or any significant damage to the engines, batteries or fuel tanks, and breathed a sigh of relief. The good news was, she still had a fully functional ship.

The bad news was, the ship was not only on its side, its nose now pointed downslope- a position rocket ships are generally not designed to launch from.

“Horseton, this is Mission Twenty-two,” Cherry said. “One pony, down safe. But I think we can skip the stay-no stay checklist...”

Footnotes:

(408) Calculated based on radio pings from the orbiting R4 communications relay satellite. The older version of the system had calculated speed from Horseton Space Center, but that was now five light-seconds away and, moreover, on the other side of Minmus, and thus not available. The computer instructions that allowed this to work were among George Bull’s most complex work yet, since they relied partly on continual radar of the surface and radio signals from a constantly moving object overhead. The system took over half of the capsule’s tiny computing machine’s runtime by itself, and most of the rest of its runtime now consisted of communicating this data with the trajectory calculation computer and the backup Probodobodyne autopilot in the compartment just beneath the capsule. 

(409) And, more important, the rest of the ship as well, including its lone crewpony.

(410) Also (and this number was more relevant to Cherry at the moment) only a touch slower than the required takeoff speed for her biplane. Had she had wheels under her and some practical way of seeing where she was going, she wouldn’t have worried. The fact that she was landing on legs, blind, with only instruments to guide her, rendered the analogy worthless for purposes of not scattering her internal organs across another world in the upcoming five seconds, and so she stuck with the train comparison.

On Mission Control’s telepresence screen, a giant image of Cherry Berry planting the changeling flag on the surface of Minmus gave the VIPs and press in the gallery something to talk about and take photos of. Despite the crash (411) Cherry had been sent out to perform the various scientific experiments and the flag-planting ceremony because... well, why not? The ship and its equipment were there and working fine, and (by a stroke of luck) it had landed hatch side up, so there wasn’t any reason why that part of the mission shouldn’t go ahead. 

The reason most of the controllers had abandoned their stations to go into a huddle around the bullpen was whether or not there would be any mission after that.

The slope had been a lot steeper even than the control crew had thought when they saw it on the screen. Even so, based on their experience with Mission R4, the reaction wheels ought to have been enough to keep the ship, if not upright, at least standing. The tipping point (literally) came when two of the six landing legs- the two facing downslope, and thus taking almost all the weight of the ship- had retracted under the strain. The ship had tipped faster than the automatic systems could compensate, with the result that it now lay on the alien snow like a dead fish.

“So, they’re broken, then,” Chrysalis said, stating the fact. 

“Not necessarily,” von Brawn rumbled. “Those two legs are retracted, but they’re not visibly broken. Nor do they read as broken on our telemetry.”

“Which might just mean our telemetry is broken, too,” Goddard the Griffon snapped.

“Well, we could ask Cherry to look and see if they look broken,” Occupant said. “I mean, they look fine from here, but maybe she’d see something up close? And if she doesn’t, then maybe that means they’re safe to use?”

“We’d have to re-extend them,” von Brawn said. “And that’s something I don’t recommend with tons of metal sitting on top of them.”

“All right,” Chrysalis said. She walked back to the capcom station in the back row of desks, levitated her headset back onto her head, and said, “Twenty-two, Horseton. Before you begin the flight tests on the suit thruster system, we’d like you to do a visual inspection of the two collapsed landing legs, over.”

“Roger, Horseton,” Cherry said. “And while I’m on, for the record, the surface lighting here really fooled me. The snow crystals here reflect sunlight everywhere- scatter it. It’s really disorienting. That plus the low gravity fooled me into thinking this area was flat and level. It really isn’t. If I’d seen it from this angle, I’d never have attempted a landing.”

“We’re going to have to think about that for the moon landing,” Chrysalis replied. “The moon’s gravity is a good bit greater than Minmus’s. If something like this happened there, it wouldn’t be a soft flop-over.”

“That’s what I’m thinking, too. We can’t send a robot lander here. The same thing will happen to it. We need to land something with wheels someplace safe, something that can drive itself up here. More work for Goddard and Dr. von Brawn.”

“One thing at a time, Twenty-two,” Chrysalis said. “Let’s get you down from there first.” 

On the telepresence screen, Cherry wobbled and hopped her way back to the stricken ship. “I don’t see anything obviously wrong with this landing leg,” she said, stooping down so she could see under the port landing engine. “Can’t really tell for sure from this angle, but nothing seems to be actually bent or anything.”

After a look at the other side returned the same non-result, Chrysalis ordered Cherry to take her thruster systems for a flight, took off her headset, and returned to the huddle. “Well?” she asked. “Clear as mud, isn’t it?”

“Indeed so,” von Brawn said. “Even if the legs can be extended, we won’t know if they’ll hold weight unless we try them again. That means another landing.”

“Okay. What about another landing? Is there enough fuel left?”

“Barely,” Goddard said. “We’ll have to dip into the return stage supply. I’d say hang it and bring her home, except that we’ll have to go back again to get a successful landing. That is the whole point of this exercise- getting practice at landing something someplace without a parachute.”

“This assumes that we can launch from this position in the first place,” von Brawn said. “If our planned procedure fails, then we’re going to have to send a rescue mission, and we’ll have twelve days to get it there. Five days at most for assembly, testing and simulations.”

And that, Chrysalis knew, was cutting corners too much.(412) “The only way that works is if I fly it myself,” she said. “I’m the only one who’s had sim time on this flight besides the pony. Which means we’ll need a ship that seats two.”

von Brawn shrugged. “Add tourist cabin, subtract science equipment,” he said. “It’ll be a wash in terms of weight.”

“Nah,” Goddard said, shaking his head. “We’re finally getting the next generation engines off the production line, and we have the prototype three-crew capsule ready to fly. We build a new ship from scratch and throw away the plans for the bundle of sticks design.”

“But we don’t know how the new systems will perform in flight yet,” von Brawn protested. “Do we really want to have the testing flight be a rescue mission involving both our lead pilots?”

“Um, excuse me.” Occupant finally spoke up. “But shouldn’t we see if we can get Twenty-two flying again first? I think the plan’s a good one, based on what we saw with R4.” When Chrysalis turned her head to look at him, he added, “Of course, I could be wrong, my queen.”

“Occupant.”

“Yes, my queen?”

“You have my permission to quit being a total welcome mat for five minutes and be in charge of this room like you’re supposed to be,” Chrysalis said.

“Oh. Um... Well...” Occupant looked around the others, and then said, “Well, Miss Cherry’s done with everything except the thruster pack test. We might as well get her off the surface now. Besides, she’s been up for sixteen hours now. She’ll be getting tired, and she’ll have to land the ship again or commit to returning home before she can rest, unless we leave her there overnight.”

von Brawn shook his head. “Inadvisable,” he said. “The solar panels are only picking up a trickle of energy at this angle. If we wait overnight, the batteries will drain and she really will be stranded.”

“Okay, then,” Occupant said, sounding a little more decisive. “Let’s get Miss Cherry back in the ship and see about getting her in the air, okay?”

Footnote:

(411) Even if it’s a ludicrously slow crash, even if nothing actually breaks, if it ends with your vehicle in a position neither you nor its designers ever intended it should assume, it’s still a crash. 

(412) Believe it or not, there are actually safety margins beyond which even the Changeling Space Program will not push... mostly, anyway.