Moon For Sale

by Jeff Pollard

  “So the OR-1250, that's an override of the LRF, is that right?” K asks.

  “Hold on, let me check that,” Guidance replies as he looks up the OR-1250 code.

  “So we should be good?” K asks.

  “It doesn't say which way, just that it's an override of the HIL-decision on the guidance-input-disagreement.

  “So we don't know which one it ignored?” K asks.

  “That's affirm,” Guidance replies ominously.

  “10 seconds to landing,” Tim says, just reading off essentially a stop-watch with no incoming data from the Pegasus 2.

  “Come on, give me a picture,” K begs the space gods.

  “5, 4, 3,” Tim counts off. The pictures are still blank. “That's it.”

  “Did it land?” Caroline asks K as they all watch and wait for any signal at all.

  “Won't know till we get a signal back,” K replies.

  “What was that, OR-1250, what is that?” Caroline asks.

  “It's an alert from the Pegasus that the guidance computer has taken an action to override one of its program rules. It's not supposed to do that on its own. But if the problem occurred while we were out of contact, the guidance computer can go ahead and make a decision to override without any human involvement.”

  “Override what?” Caroline asks.

  “It has both a landing radar that's feeding it the altitude, and then it has the Griffin-Eye system on the base, the sensors we use for docking, it's a pair of cameras and some lasers that are able to use binocular vision to determine the distance to the target. We call that Laser-Range-Finder, LRF.”

  “Landing plus 15,” Tim says as they still await a signal.

  “The LRF apparently was reading off-scale low, which means it's saying altitude is zero, which it can't be, because even if when we land, it's not touching the surface.”

  “Unless it crashed?” Caroline asks.

  “Right, but the radar was still telling the computer it was several km high, and that should be right, based on where we were in the descent. So when the guidance computer is getting conflicting data on its altitude, it knows one or both of the systems are malfunctioning. Normally, it would notify us with a warning that its data doesn't make sense, then we would have seen that obviously the LRF was giving us a bad reading, and tell the computer to ignore it and to trust the radar data instead. But we were out of contact, so the guidance computer went ahead and made the call on its own, overriding what we call human-in-the-loop, or HIL. So when we got contact back, it told us it had made this override decision.”

  “So it ignored the laser-range and is trusting the radar?” Caroline asks.

  “We don't know,” K replies. “We know that it ignored one of them, but not which one.”

  “It should have ignored the LRF,” Tim adds, “it changed suddenly, the radar would have been very close to the inertial system and the descent profile, so it should be smart enough to know it's the LRF that's wrong . . . But computers can be really dumb sometimes.”

  “What happens if it picked the wrong one?” Caroline asks.

  “It really shouldn't,” K replies. “But if it did, it would have thought it was very close to the ground since the LRF altitude was zero, then it would slow its descent to a crawl until it made lunar contact. And since it was still several km high, it would use up all its fuel in a hover well above the surface, and then it would hit the low-fuel abort-trigger and it would automatically flip to ascent mode and return to orbit.”

  “L+60,” Tim says. They're now a full minute past expected landing time and have had no contact for nearly 90 seconds.

  “Flight, GDC!” Guidance calls out.

  “Go,” the director replies.

  “We might consider the possibility that override wasn't of one of the two, but was ignoring both systems,” Guidance calls back.

  “Both LRF and radar?” K shouts back.

  “Yeah.”

  “Why would it do that? The radar was fine last we saw, right?” K asks Tim.

  “What if it was a little long at the time it made the override call, then the descent path would have expected them to have an altitude above Bell crater, but if it was actually above the southern rim of Bell crater, the radar might have returned a lower altitude than the guidance computer expected, so it could have ignored both of them.”

  “Were we landing long?” K asks Tim.

  “I don't think so, but we only got the signal back for an instant,” Tim replies.

  “So if it's just using the internal guidance and ignoring both radar and LRF, and we're landing long, then what are we looking at here?” K asks.

  “Then it would think it was coming down in the middle of Sasserides, but if it's overshooting enough, then it's actually landing on the southern rim of Sasserides. That rim rises 6000 feet above the floor, that's a big difference.”

  “Shit,” K says.

  “What does that mean?” Caroline asks.

  “It might have plowed into the southern rim of the crater, thinking it was still a few thousand feet higher than it was,” K replies. “What's the exact velocity at that point in the descent, if it was landing long and hit the southern rim?” K asks Guidance.

  “Worst case, it could have been going 80 meters per second,” Guidance replies.

  “In which case we have just created Pegasus Crater,” K says.

  “But the southern rim is a good 20 kilometers of an overshoot,” Tim interrupts. “Last I saw, we were a little long, but nowhere near 20 kilometers.”

  “Comms, what's the situation?” Flight asks.

  “We think the dish isn't pointed in the right direction, but the lunar station should fly over in about ten minutes and we can connect directly on the omni and reposition the dish. Assuming there's a Pegasus to talk to.”

  “Roger,” control replies.

  “So we wait for the lunar station,” K says to Caroline. The drama is playing out live on screens across the planet, showing the possible disaster of a crashed lander. With the loss of signal continuing for minutes, the breaking news across the planet is that the SpacEx lunar landing test, the near equivalent of Apollo 10, seems to have suffered some kind of malfunction. The talking heads immediately begin to wildly speculate about crashes.

  Nobody at Mission Control needs to say out loud the obvious truth, that a crashed lunar lander would be a huge setback and make it nearly impossible for them to beat the Chinese landing planned for October. The next Pegasus wouldn't be ready in time. They could theoretically use the Pegasus 1 prototype docked to Excalibur, but Pegasus 1 had always been meant to be a test article that would never land on the Moon. Kingsley now wonders about the possibility of pressing the Pegasus 1 into service. Not only would it be risky in that it was a prototype, but they also would need to put people into it after the second Pegasus had already crashed. It would be a very risky proposition. They would have to try the unmanned test landing again, which would set back the manned landing time-table.

  “She should be fine,” K says quietly to Caroline. “The LRF altitude dropped suddenly, we've got competent programmers, she saw the spike, ignored the LRF, used the radar data, landed right on target in the middle of Sasserides, and the dish is just stuck or the code is pointing it the wrong direction. She should be fine.”

  “Here comes MJ,” Tim says to K. K rushes back to the console. The SS Marie Juliette has an HD video camera pointed ahead of it. On the screen they can see the view out the front of the orbiting station as it crosses the face of the Moon from north to south.

  “We should get a signal back once we have line-of-sight,” K says hopefully.

  “There's Hell,” Tim says, spotting the crater. He knows this stretch of terrain better than almost anybody, as he's been training to land the Pegasus at the rim of Tycho Crater for nearly a year.

  “That's Ball,” K points to a few pixels. “As soon as we can see over the southern rim of Ball, we should have a sign
al.”

  The SS Marie Juliette orbits silently with the lunar terrain rolling by. The Sasserides Crater comes into view and Kingsley looks to the other screens for data from the Pegasus.

  “Comms, where are we?” the Flight Director asks.

  “Still nothing.”

  “Can you zoom that in?” K asks Tim. Tim zooms in on the Sasserides crater and tracks it with a joystick. “You see anything?”

  “I don't see a thing,” Tim replies. “Maybe it aborted and its in orbit on the back-side right now.” K doesn't acknowledge the theory and stares at the screen, searching for a black dot, a shadow, a hint of gold coloring, or perhaps an expensive crater, anything. Sasserides comes into full view as the SS Marie Juliette approaches and then crosses over, directly overhead. The camera can't track anymore as it is on the front of the spacecraft and can't point backwards. The view now scans along past Sasserides, over the western rim of Tycho Crater.

  “I didn't see a thing,” Caroline says.

  “I'll bet she aborted. It's the only thing that makes sense,” Tim says. “I mean, we've passed directly over the landing site and didn't get a signal, didn't see a crash-site, I'll bet she picked the LRF altitude, hovered, ran out of fuel, and is on the other side, orbiting just fine and we'll get the signal back as she crosses over the north-”

  Tim stops dead and everyone in Mission Control goes silent as the two largest screens at the front of the room are suddenly changed from blackness to two stark-white views of the lunar surface. The signal is back, relayed through the SS Marie Juliette. The Pegasus landed safely well within the propellant margins, but as some suspected, the dish is stuck. The dish is mounted on top of the lander, as descent began, the dish was pointed almost straight up (relative to the lunar surface), and as descent progressed, the lander progressively pitched up from perfectly horizontal at the start of descent to perfectly vertical at landing. The dish should have rotated 90 degrees through that maneuver, but was unable to perform. The dish is stuck pointing about 45 degrees above the southern horizon, which is where the SS Marie Juliette was when the signal was regained. But the orbiting station would only stay in contact with the lander for a few minutes at best.

  The communications team was prepared for a number of possible problems and when the signal came back and they saw the position of the dish, they knew it had gotten stuck. There are a number of reasons why it could be stuck. The Comms team sends up a series of commands to be executed. Signal is quickly lost again. The first command is for the dish to point back down to the southern horizon, then to try to point to the correct, nearly vertical position. The hope is that the mechanism will come unstuck. If it doesn't work, the instructions uploaded by the Comms team have the lander attempt several more times, including moving the dish in every direction in an attempt to free it up. It's the remote-robotics version of “have you tried turning it off and on again?”

  The room grows silent again, but with far less tension this time. They know their lander isn't a two hundred million dollar crater.

  “Well, we've got two things to add to our checklist on Pegasus 3,” K says to Tim.

  “Fix the dish and what else?”

  “Figure out what's wrong with the LRF,” K replies.

  “I don't need no range finder to tell me how high I am,” Tim replies. The signal returns and the dish has righted itself.

  “There we go,” Flight Director says.

  “Okay, proceed with post-landing checklist,” K says to the director and retreats to the back row to sit with Caroline. “You didn't lose faith did you?”

  “No,” Caroline replies. “There's enough nerds in this room to fix just about anything. Other than body odor.”

  “Oh come on, it's not like it's a Magic: The Gathering tournament in here.”

  The connection restored, the world witnesses the view in Sasserides Crater. The lander has just two TV cameras, and one of the cameras is pointed at the ground directly beneath the lander. The real money shot wouldn't come until they deployed the rover. The vehicle is folded up and hidden in a cargo bay in the side of the lander's body. A gold-Mylar panel opens toward the lunar surface, bringing a dense block of cargo with it. The cube of a rover is folded into three segments, and the four wheels are themselves folded into the structure. The rover unfolds in a series of steps that transforms it from a metallic cube one-point-five meters on each side into a three meter long, four-wheel, four-seat vehicle. There is a pair of video cameras mounted on an arm that extends above the front of the vehicle, giving a remote-driver binocular vision of the lunar surface. The rover includes batteries, solar panels, a pair of antennas, a manipulator arm for picking up samples, compartmentalized storage for easy identification of samples, four wheels made of wire mesh, and four electric motors to drive the wheels. The drive system of motors and batteries was produced by Tezla. The solar panels came from Solar City.

  The rover unfurls itself and drives off of the panel just far enough onto the lunar surface to allow the panel to close. The cameras pan slowly, revealing the crater, and giving the world an external view of the gold and silver Pegasus lander in the bright lunar day. All of this maneuver from the opening of the cargo bay to the roll-out and surveying of the site was accomplished by the click of a single button that initiated a string of actions. Now the rover is in standby-mode, awaiting instructions.

  The new SpacEx Robotics Division is an impressive sounding name for a group of six people, the oldest of which is 31. The idea is that the rover will be continuously operated by a three teams of two in rotating eight-hour shifts. But at this moment, all six members of the team are in the Robotics Control Room, which is a fancy name for a large closet adjacent to Mission Control containing a VR teleoperations console consisting of an advanced Oculus headset, a pair of force-feedback motion-control arms, and of course a person with his or her head and limbs hidden inside the hardware.

  The Pegasus will stay on the surface for four days, and during that time, the three robotics teams will explore the Sasserides Crater remotely, collecting samples. On day four, they will place the sample collection in the second cargo bay of the lander, then drive to a safe distance and record the ascent of Pegasus as she begins her trip back to orbit. Then the rover will have three months to travel to the landing site of Pegasus 3, near the rim of Tycho Crater. The trip is around 100 km in a straight line. The rover's top speed is only 10 km/h. However, when being remotely-operated from Earth, there's a fairly significant delay. The Earth and Moon are on average around 1.3 light-seconds away from each other. So when a lunar obstacle is captured by the camera, it takes 1.3 seconds for the image to reach the driver, and his or her reaction to hit the brakes takes another 1.3 seconds to reach the rover. Thus, driving the rover is just like driving a car with a 2.6 second delay, and that's why it's a good idea not to drive very fast. Eventually this rover, or others like it, could be remotely-operated by astronauts in lunar orbit or on a lunar surface base, in which case, there would be almost no delay at all. Even with the strict speed limit of .75 km/h, the rover will be able to cover the 100+ km journey with plenty of time for breaks along the way before it needs to be at the landing site in early August.

  When the crew of Pegasus 3 shows up on the rim of Tycho Crater, the rover should be there waiting for them with three months of exploration worth of samples, and will then serve as their long-distance transportation, capable of carrying the whole crew of four across great distances.

  The rover also features a pair of small spherical aluminum tanks that contains pressurized hydrazine. The tank feeds into tubing that actually serves as structural elements of the rover, but also carry this monopropellant. The tubes lead to four small thruster pods on the corners of the rover, each pod featuring four nozzles. You could look over the rover and pay so much attention to the manipulator arms and cameras that you might overlook the thruster pods. But they serve an important function. This rover is like a lunar ejection seat. If for some reason the Pegas
us were to fail. The crew of four could strap in, activate the thrusters, and take off from the lunar surface. To actually reach orbit, the rover needs to lose weight in order to get up to speed with such a limited supply of fuel. So the astronauts would remove pins and thus at liftoff, the tubular frame, the four seats, and the tank of fuel would liftoff, leaving behind the wheels, cameras, batteries, electric motors, and most of the rover body. The astronauts would ride what looks like little more than the frame of a go-kart into orbit, with no protection from the elements, in just their space suits.

  NASA studied many such devices during the Apollo era. As they advanced into longer stays on the surface, NASA worried more and more about the lunar module failing to light and stranding astronauts on the Moon. But with the strict weight constraints on Apollo, the Lunar Escape Systems had to be very light. Many designs brought along no fuel, since the system would only be used in the event of an ascent stage failure, they figured they could siphon the fuel from the useless ascent stage. Some of these systems had no controls at all, just a single rocket that the astronaut steered by shifting his weight. Literally an ass-guided rocket-chair. Other designs were much more robust. One was called the Lunar Flyer. It was like a mini-lunar lander, featuring four landing legs. The flyer would be used like the rover, carrying two astronauts and enabling long-range exploration. The proponents of the lunar flyer argued that the flyer would provide an increased exploration capability as well as an emergency escape system. However, driving from point to point in a rover might be fairly safe, but flying and doing powered landings in a vertical take-off and landing rocket was probably not a very safe proposition. That and the lunar flyer would have been quite heavy. Ultimately, with slashed budgets (blame Nixon), Apollo ended at six landings and the stays never lasted more than three days on the surface. No Lunar Escape Systems were built.

  With Pegasus 2 going to and from the surface of the Moon unmanned, this gave the lander a larger payload mass to the surface than would be available on manned missions that had to haul around the mass of people and consumables. That payload was spent on this rover, which could then be reused on multiple missions, and thus, hopefully, if there is a Pegasus failure, the astronauts wouldn't be automatically doomed to die on the lunar surface. Instead, they could still have a possible escape plan involving an untested “spaceship” consisting of little more than tubes and chairs, with no walls, no life support other than their suits, no auto-pilot, and with small rocket thrusters firing within an arm's length of their seats.