1-14-19 Livewriting: CSP- Can they get the bird down on Minmus? (Patreon)

 Livewriting goes on hiatus while I finish writing, rewriting, and editing this chapter of CSP offline. 

When I resume livewriting, it'll be here:

https://docs.google.com/document/d/1q8CL4JfXQT9PI2yeI0TlbV0jt3qRnBk4oV8j0FIxSwU/edit 

Discord for chats:  https://discord.gg/QjREED 

Here's what I wrote tonight:

“Fly up, fly up, yeah, I get that,” Dragonfly snapped. “I’ve only been flying ever since I pupated!” Her hooves flew across the controls. Five seconds later, the lander put its engines forward and down, firing not just to slow the ship’s forward momentum but also to stop it falling. “Flight, capcom, request comms discipline be enforced,” she continued. “It’s tough enough not knowing what I’m doing until five seconds after I’ve done it. I don’t need kibbitzing!”

“I’m sorry,” Cherry Berry said contritely.

“Don’t be sorry, be quiet!”

“I’M SORRY!!”

“No more talk except for velocity and altitude call-outs,” Occupant said. “Trajectory, that’s you.”

“Copy, Flight,” said George Bull. “Thirty-one hundred meters above zero elevation and falling. Velocity at two hundred ninety meters per second and falling.”

“Flight, what’s the altitude of that bluff?” Dragonfly asked.

“Twenty-three hundred meters, approximately,” George Bull said.

“Right.” Dragonfly ordered the lander to angle its engines a bit more downwards. Five seconds later it did so, the engines firing more towards the surface. 

“Three thousand meters above zero and steady,” George Bull said. “Velocity two hundred ten and falling.”

Satisfied, Dragonfly reduced the throttle on the controls. “C’mon, baby,” she muttered. “Gotta get over that last valley...”

The valley before the plateau formed an almost black pit below the spacecraft on the screens. The walls ran so steeply as to be next best thing to sheer. Even a soft landing anywhere near that hole would be disastrous for R4. The ship coasted on, thrusting just enough to gradually slow the ship and keep it at an altitude that would carry it above the top of the plateau.

“Thirty-one hundred meters above zero, slow climb,” George Bull said. “Velocity one hundred twenty-five and slowly falling.”

“Just a little farther...” Dragonfly’s hoof eased the throttle back another couple of notches. 

Minmus’s surface crawled past below the ship on the projection screen, the dark shadows of the valley giving way to the bright, shiny plateau top. 

“Twenty-nine hundred meters above zero and slow fall,” George Bull said. “Velocity ninety-five meters and falling. We are now over the target zone.”

“Good enough.” Dragonfly slapped the throttle open to full for a couple of seconds, then backed off almost to nothing, pushing the control flightstick forward and then re-centering it. “Go to activate landing program,” she said, carefully bringing her hooves completely off the controls. 

“Landing program loaded!!” Marked Knee reported. “Setting listening mode! Landing program activation code sent!”

Mission Control went silent as Mission R4, up until now basically a remote-controlled device, took over its own flight operations for the first time. 

The landing program that activated five seconds later in the Probodobodyne computer core of the lander was, in essence, as simple as could be imagined. It had to be- the computer had to land almost blind, and thus couldn’t make any real adjustments. It couldn’t even tell reliably where the ground was. The program told it to reduce speed to twenty meters per second, adjusting thrust to bring its prograde vector directly below itself, further reduce speed to a range between three and seven meters per second, and cut off the engines when it stopped descending. That was it. 

The program wasted fuel. With hundreds of meters to fall, it would have been more efficient to just drop until a single full-thrust burn would bring its speed to zero just as it touched down. But the computer didn’t know where the ground was- didn’t even know ground existed. It could sense the input from the navigation system built into the capsule, and that was all it could sense. The long, slow descent threw fuel away by the wagonloads each second, but it gave the controllers five seconds and a million kilometers away the maximum opportunity to abort the landing if necessary.

“Descent three hundred forty-five by ninety-two,” George Bull said, calling out the coordinates on the nav-ball. “Descent eighteen meters per second.”

Dragonfly’s hooves, which had stayed off the controls for the switchover to internal control, went back to them now, just in case. 

“Twenty-five hundred meters altitude,” George Bull said. “Attitude at stable one, repeat attitude at stable one. Decelerating to seven meters per second.”

In the VIP gallery, Chrysalis leaned forward along with all the others as, on the screen, the green-tinted snow began rising up towards the descending ship.

“Twenty-four hundred meters, velocity four point five meters per second.”

For a moment, the ship seemed to hop on the screen.

“Burnout on landing stages,” von Brawn announced. “Continuing on return stage engine. Fuel in return stage at seventy-one percent.”

“Twenty-three hundred meters, velocity three point nine meters per second.”

The building, the stands outside, even the ships in the bay, all went silent.

“Contact.”

The ship bounced, turned rapidly, and rocked back and forth. 

“Contact. Engine off.”

The lander settled on its six legs... and began tipping over. The plateau, apparently, hadn’t been nearly as flat as it looked at first. Then, long after it seemed like the lander had passed the tipping point, it froze in mid-flop and reversed, righting itself almost, but not quite, to a vertical position. 

“Six feet on the surface,” von Brawn said at last. “Ship is holding itself upright using reaction wheels at full power. We can’t stay long, but we have landed.”

There wasn’t any cheering. After a moment, there was polite applause from the VIP gallery and from the stands outside. But no cheering, especially not from the control room floor. The near disaster had turned anticipation into worry among the spectators, including Chrysalis, while below the controllers fought to keep their own worry subdued. The mission wasn’t down safely. In fact, if the batteries ran dry, the mission would fail immediately...

... and the reaction wheels which, through the power of torque, turned the ship even without the rockets firing, those reaction wheels were burning through electricity far faster than the two small solar panels could resupply it. 

Success or failure hung in the balance of a space probe that wanted to fall over.

“Okay,” Occupant said. “Dragonfly, get the experiments going and get them stored in the box.” He took a deep breath, then said, “Booster, can we get back to Equus with the fuel remaining?”

“We have to,” von Brawn said. “We absolutely can’t stay here. If the batteries go dry, we lose the probe. We have to launch before that happens.”

“How soon?”

“At current rate of consumption,” Marked Knee said in an uncommonly subdued tone for him, “seventeen minutes!”

“Whew. Okay,” Occupant said. “We have a little time, then. Booster, I need to know if the fuel on board is enough to at least get back into Minmus orbit.”

“Affirmative, Flight,” von Brawn said. “We can’t be certain until we drop the landing stages, but I believe we can make it back to Equus on what remains with a comfortable margin.”

“That’s good news,” Occupant said. “But we can make orbit and return the science data via radio transmission if absolutely necessary.”

“Affirmative,” von Brawn said. “But we can’t use the main transmitter for long streams on the surface, not as we are now. The batteries would drain to zero in almost nothing.”

“Copy, Doctor,” Occupant said respectfully. “Capcom, we are NO STAY, repeat NO STAY on this landing. Prepare for immediate takeoff once all data collection is complete and stored in the can.”

“Copy, Flight,” Dragonfly said. “Stand by. Temperature and barometic data already transferred. Just waiting on the imaging from the Science Jr. experiments.”

“I’m a little sad we couldn’t find room for goo cannisters on this flight,” Occupant muttered.

“We’ll have room for them next flight,” Dragonfly said. “What with not hauling a big heavy satellite along with us next time.”

“What do you mean ‘we’ and ‘us’?” Cherry Berry asked from the back row of the floor. “I’m the one who’ll be flying the next flight.”

“Data transfer complete,” Dragonfly reported. “Standing by for ascent burn.”

“Landing program cleared!!” Marked Knee called out. “Probe reports ready to receive!!”

“Go for ascent, Capcom,” Occupant said.

“Roger,” Dragonfly said. “Ignition.”

One. Two. Three. Four.

On five the lander on the telepresence screen lifted off, rising at an angle due to the uneven surface it had been sitting on. 

“Decoupling landing stage!” Dragonfly said, slapping the staging button even as her other hoof wrestled with the control stick, ordering the probe to straighten up and come round to an easterly track.

The ship on the screen, after the usual five-second delay, shed the outer two fuel tanks, engines and landing legs, leaving only the central shaft of the much-reduced ship to fly up, straightening and then bowing towards the far horizon as it received its ongoing instructions from Horseton. 

“Confirm staging,” von Brawn called out.

“Throttle to full!” Dragonfly said. “Let’s get this ship out of here and bring her home!”

Now the cheers, which had been withheld for the landing, erupted for the departure.

And much more quickly than it had descended, Mission R4(A)rose to the skies, leaving Minmus below it, burning for orbit... and then, after one loop around the lesser moon for course checks, burning again for home.

The celebrations moved out of the building and onto the grounds, into the village of Horseton, on board the ships in the harbor, and eventually clear back to Baltimare as the crowds dispersed... 

... leaving four controllers- Occupant, Dragonfly, George Bull and Marked Knee- alone in Mission Control to complete the first of three tiny thruster burns which, over the course of as many days, would put R4’s comms satellite in the specific orbit requested by Twilight Sparkle. 

Hardly anybody cared(B) about this last bit of business, and that was fine by the controllers. Their minds were already focused on Mission 22. They didn’t want any attention on this bit of minor orbital tweaking. They were busy with other things.

Besides, Mission R4 still had one final bit of important and dangerous work to do.

Footnote:

(A) Well, slightly less than half of it, anyway. The rest of it smashed itself to bits on Minmus’s surface.

(B) Except Twilight Sparkle, who actually made time to come to Horseton to witness the final burn... of three point seven meters per second, barely a hiccup for the satellite’s engines. But to her it was important. Even if it wasn’t her space program running the satellite, she regarded it as her satellite.

On the seventeenth day after the immense, complex multi-stack Mission R4 had launched from Horseton and rose into space through a massive ball of fire, the tiny remnant of the mission- the expanded capsule and the data container box- screamed through the upper atmosphere of Equus in a similar ball of fire.

The minotaurs had known, when planning the mission, that the Mission R4 capsule would be returning to Equus faster than any artificial object had ever traveled before- much faster than any capsule returning from space. There had been some brief discussion of attempting to brake into a low Equus orbit using leftover fuel in the return stage, but when the time had come the return stage held only twenty-nine percent of its fuel load- a large margin for the mission as it proved, but totally insufficient for braking into orbit and then dropping back out of orbit and into Equus’s atmosphere.

So it had been unavoidable: the probe had to come straight from its Minmus return trajectory into atmosphere, using nothing but air resistance to slow it down to suborbital velocity. This added a further complication. If the trajectory ran too deep, the heating from atmospheric compression would overwhelm the ablative heat shield and destroy the probe. If the trajectory was too shallow, the ship would pass through the upper atmosphere and back out into space on a week-long orbit which might even hit the moon on its way back out. Indeed, if the angle of descent was really shallow, the ship would be bounced out by air resistance and sent flying on a totally unpredicatable trajectory, possibly even out of Equus space entirely.

All of this would be no big deal for Mission R4, which of course had no pilot on board. But the point of the mission was to see what the ship designed to take Cherry Berry to Minmus would do at every stage of the mission, including return. When Mission 22 came back home, a week-long orbit (or worse) after eighteen days in flight would be, as the program called it, a Very Bad Day.

With this in mind, the brain trust of Changeling Space Program had settled on a certain altitude in the upper atmosphere, deep enough to almost burn up the ship, but not quite. Certainly deep enough to ensure that once the ship got into the atmosphere, it would stay there.

They hoped.

Of course, one of the consequences of not having stayed for any length of time on Minmus was that, when the ship returned, it would come in on the dark side of Equus... and nowhere near Horseton. That much everyone understood days before, and thus recovery teams were sent out to the other side of the world days in advance. The good news was, as on one side of the planet a massive fireball streaked across the night skies of Zebrica, on the other side of the world where Celestia’s sun shone, the young but thriving tourist industry of Horseton received another influx of space tourists eager to watch via telepresence the return(C) of the first spacecraft to touch, if briefly, the surface of another world.

Footnote:

(C) Or destruction. There is some cross-grained bit of most intelligent minds that, when watching a dangerous endeavor in progress, anticipates its failure as much as its success, if not more so. Or to put it another way: even if nobody wants a train wreck to happen, almost everybody wants to be there to see it when it happens.