by Dan Eaton
“Good answer, Myra,” Dad said.
“Now,” he continued, “who would like to go see what we’ve got done so far?”
Before anyone else could answer, Miss Gayle held her hand up and said “Me! Me! Me!”
We all laughed and Christine said, “Sorry Miss Gayle. I promise you that if you ever come up here I’ll personally take you around to all the interesting places. In the meantime, we’ll try to have them back here in a couple of hours or so.”
With that, Dad and Christine led us off to the Vehicle Bay, where there was a transport waiting for us. We trooped on board and spread out so everyone had their own window. The transport maneuvered out through the locks and then took a right turn at the top of the ramp. The turn brought us onto the new road that lead to the West past where the habitat was buried on the right side of the road. This was the furthest we had ever ridden in the transport and to illustrate how far we had to go yet the transport had steadily increased in speed until we were rolling along at forty kph.
Dad stood up in front of the transport and said, “We’re traveling along the rim of Whipple crater heading west. Our destination is the ramp that was built to allow access down to the floor of Peary crater. It should take us about 18 minutes to get there.”
We all were staring out the windows, fascinated by what we were seeing. It wasn’t just that the lunar scenery had a beauty all of its own, it was also the fact that here was something unique to see that was totally different from the unchanging view we had inside the habitat. We’d come about four kilometers when a sign flashed by on the right side of the road. It said in bold letters, Emergency shelter number one coming up in one kilometer. We hit the five kilometer mark and there was a pull off with a squat structure located to the side of it. In addition to an airlock that would mate with the transport there was a separate airlock for anyone in a space suit to use. The building was painted bright white and had an antenna sprouting from its roof to provide emergency communications.
We passed another shelter at the ten kilometer mark and then at the eleven kilometer mark there was another warning sign. This one said, Warning: Ramp road beginning in one kilometer. Decrease speed to five kph before beginning the descent. The driver slowed the transport down as we approached the edge of the crater where the ramp began. There was a paved area along the rim where the drive was able to pull off the road and give us a view down the slope of the crater wall and into Peary crater’s floor.
Dad stood up again and started telling us what we were looking at, “We’re sitting on the lip of the Whipple crater about a half kilometer above the floor of Peary crater. The ramp road that goes down there has a constant two percent grade so the ramp is 25 km long. We needed to keep the grade down to make sure we didn’t have any issues with transporting any of the payloads we might want to ship on the accelerator.”
Dad continued, “The slope of Whipple crater here has been extensively studied and reinforced to prevent any slippage. We want to make sure there aren’t any accidents when the ramp road is in use. Now that the road has been completed, we will be building the transshipment facility at the base of the ramp and then once that’s completed, we’ll be able to start on the actual track itself. It’s hard to see because of the shadows in the southern third of the crater, but where there is light you can see a whole series of smaller craters to the Southwest. The track will run due West of here and passing to the North across the top of those craters where the sun shines before beginning the ascent of the crater wall on the far side of the crater. When it’s operational, the payload module will accelerate at about 1.5 G down the track and then about 109 seconds later it will be traveling 1.6 km/s as it leaves the end of the track. That will put the payload in orbit. If we need to get rid of something we can up the acceleration and have the payload achieve a lunar escape velocity. That’s about all I have. Anybody have any questions?”
Adam spoke up and said, “That’s pretty cool Mr. Burns. Can we come see the transshipment facility when it’s done?”
Dad answered, “Thanks Adam. I think we can arrange a tour when it’s done. Most of the facility will be buried in the crater wall for shielding. We’re thinking that’s going to take about four months for the main buildings to be done. Of course, while that’s going on we have surveying robots out looking at the path for the track across the crater. The track segments are modular so we’re manufacturing them now and then the mounts that attach the track to the regolith will be built in place. Any other questions?”
Ananyu spoke up and said, “Thanks for the tour Mr. Burns. How long before the whole thing is operational?”
Dad answered, “We’re hoping to shoot the first payloads eight months from now.”
That was the end of the questions and we sat there for another ten minutes gawking at the scenery. We had a pretty good view of the Earth sitting low on the Northern horizon, but it was in the Waning Crescent phase so we couldn’t see much other than the brilliant crescent. Dad told the driver to head on home and pretty soon the transport was rolling back down the road at forty kph. We got back in time for the last hour of class. As soon as we hit the classroom, Miss Gayle had a million questions for us. Her enthusiasm for us to tell her what we saw reinforced the feeling of how fortunate we were to be here and actually get to experience the things we did. It almost made up for the feeling I got when drinking that nasty powered milk.
CHAPTER TWENTY-FIVE
Do we have enough ice?
Good morning fellow NLH residents. It’s Tuesday, March 16th, 2038.
In Habitat news, the SpaceX liner, Lunar Spirit, arrived yesterday afternoon with another personnel addition to the Habitat. Please welcome Jeff Barker, Terri Dentsbier, Arlie Brady, Kay Branch, Krista Cunningham, Jaliyiah Dotson, Mikala Farmer, Konner Franks, Jonna Herrera, Anne Herring, Kacey Joyce, Kassie Key, Jamilee Lawrence, Loriann Leach, Jayden Malone, Laurelynn Maxwell, Kalli Mccarthy, Cherrie Mccullough, Kristiana Olsen, Darel Ramos, Wilber Randall, Kadyn Roth, Casie Sharpe, Yates Soto, Zach Stein, Harlie Velasquez, Buddy Walker, Jolleen Watkins, Willis Williamson, and Arthur Yates to the Habitat. The Habitat’s resident population now stands at four hundred and six.
Denali Aerospace Corporation issued a press release from their NLH office yesterday announcing that construction of the second CLT30 transport has been completed. Final system verification will be completed during the next month. This CLT30 is being purchased by Virgin Galactic.
In financial news today, on the Lunar Stock Market shares of Mussconny Machine are trading steady at $24.21 a share, Mussconny Fabrication at $22.81 a share, Hotel Whipple shares are rising at $10.79. O’Reilly’s Shellfish Company is up at $16.86 a share and CDB Farms is trading steady at $11.45 a share.
I went down to the cafeteria by myself. Work had picked back up for Mom’s project on the Grand and she had gone in early to work to get a head start on things. She promised that this was just a small bump in the road and things would be back to normal in several weeks. None of us kids had been allowed anywhere near the Grand work site. We knew it was a large project to expand the habitable area of the Habitat but no one wanted to give us kids a tour. Dad had reached a point on the linear accelerator project, now nicknamed the Big Shot, where he was balancing getting the transshipment facility started versus the start of construction on the actual track. He also went in early today, but said that this was just a onetime thing and not a look at things to come.
I had messaged Willie before I left the house and he and his mom were still in the cafeteria so I was planning on eating with them. Willie was my best friend that didn’t get moody, so after going through the line and picking out a plate of scrambled eggs with home fries and a glass of imitation milk, I spotted him and his mom across the cafeteria and went to sit with them.
Mrs. Stephenson greeted me, “Hi Bryce, how are you doing this morning?”
“I’m doing fine Mrs. Stephenson. Now if I could get Willie to quit working so much so we could get a game of Gogo in, I�
�d be doing better,” I said.
She just laughed and wished me luck with that as she got up and made her way over to sit with some co-workers to give me and Willie some privacy.
Willie had been working a lot lately at his job at the Hotel Whipple. According to what Willie had been told, the Hotel would be moving to the Grand when it was opened. It would also be drastically expanding, but in the mean time they had more customers than had been foreseen. The Habitat was expanding the number of people living there. Just in the last two months the number had increased by ninety. With the work that had been done to increase the amount of food production at the Habitat, the additional living space the four new barrel vaults had provided, and the CLT30’s capacity for carrying passengers there were a lot of people coming to the Habitat. Not all of them were permanent residents so they ended up at the Whipple. Since the Hotel was moving to the Grand it made no sense to expand the Hotel in its current position so they leased one of the bunk rooms vacated by people being moved into the new barrel vaults. That meant it wasn’t contiguous with the Hotel proper and the staff had to hustle moving people and baggage between the hotel proper and the temporary space. In addition to his other duties, Willie got to do most of the extra work of keeping their remote patrons happy.
We talked for a while about when we might get to play Gogo again and then headed off to class. Miss Gayle had a full day planned for us, but it ended an hour after lunch was over.
She got our attention and said, “Guys, Christine and I have a surprise for you. As you know, the whole point of the Habitat being at the lunar North Pole is ice. I thought it was time we learn a little more about the ice operations. I spoke with Christine about it and she promised to find a guest speaker to tell us more about it.”
Christine walked in the door at that point followed by a blond haired gentleman that judging from his muscular body must be throwing around blocks of ice all day. His name was Mike Markussen and despite his Nordic looks and last name he actually hailed from Mobile, Alabama.
Mike was in charge of the ice recovery operations and was an interesting speaker.
He said, “What a lot of people don’t realize is that some of the coldest places in the Solar System are right here in our neighborhood. The floors of these craters like Whipple that never see sunlight see temperatures down around minus two hundred and thirty eight degrees Celsius. To give you some comparison points, dry ice AKA carbon dioxide boils at minus fifty seven degrees Celsius, liquid oxygen boils at about minus one hundred and eighty three degrees Celsius, and finally, liquid nitrogen boils at about minus one hundred and ninety six degrees Celsius. Which presents us with a problem.”
Mike had carried in a box from which he now pulled a Pyrex tray and a piece of flat bar steel.
“He said, “There are lots of animations out there that show a rover fitted with a blade shoveling up the ice for processing. Here is a typical piece of steel that you might find in the rover’s body or in the blade.”
He passed the piece of steel around so we all got a look at it. He then took a short piece of metal bar and laid it on the floor. Next he pulled a hammer out of the box and finally a flask of liquid nitrogen. He put on a face shield and some heavy gloves and then took the flat bar of steel that he had passed around and put it in the bottom of the Pyrex tray and poured the liquid nitrogen over the piece of steel. He let it sit there with the nitrogen boiling away for a minute and then pulled it out with some long pliers he had in the box. He laid the piece down across the top of the metal bar he had earlier laid on the floor and then whacked it with his hammer. The steel snapped in two.
Mike continued, “So we just saw what happens when most metals are cooled down to the boiling point of nitrogen, which is still over forty degrees warmer than what we typically see on the crater floor. To make it worse, ice at that temperature is more like granite in hardness than the soft stuff that comes out of our ice makers.”
He paused for a minute to let things sink in and to put his equipment back in the box.
He said, “There are metals like nickel, copper, aluminum, lead, silver, and gold that can handle the extreme cold, but they have other issues when you’re thinking about using them for mining equipment. That was a problem a lot of people gave a lot of thought to. Eventually, somebody realized that maybe instead of digging up the ice it might be easier to melt it in place.”
Mike threw a picture of the latest version of an ice miner up on the classroom’s screen. There was a small upper exoskeleton that contained the unit’s processor, leg attachment points, and power unit. Four sets of spindly legs extended out to each side providing stability on the rough terrain of the crater floor. The eight legs were designed to provide the maximum maneuverability while working while limiting the actual contact area with the crater floor to keep thermal losses through the legs down to acceptable limits. Underneath the upper exoskeleton hung a rectangular box with an open bottom that could be lowered down to the crater floor. When the box was in the raised position there was a mesh cage located behind the box that hung down from the exoskeleton. Ice that was collected from the extraction box was collected in the mesh cage.
Pointing at the screen, Mike said, “This is what we call an ice crab. It measures a couple of meters long by a little over a meter wide. In use we send it as far towards the crater wall as it can go. Once in place it drops the collection box and then raises all of its legs into the air. This cuts off any possible heat loss via thermal conduction down the legs. The collection box has microwave emitters seeded in the upper surface of the box and they start beaming microwave energy down into the surface beneath the collection box. The end result of a carefully controlled process is we end up generating water vapor, which is then collected by a cold trap at the top of the box. When the cold trap is full of ice we lower the legs, raise the box and then eject the freshly collected ice into the collection basket. We then move the crab in away from the crater wall the length of the collection box and repeat the process. The crab ends up working a strip in the collection zone until its collection box is full, at which point it returns to the lower processing unit we have at the base of the crater wall and empties its collection basket, refuels, and then goes to its next assignment.”
Gayle was fascinated by this topic and asked Mike, “How long does it take to make one collection and how much ice do you get?”
Mike replied, “Good questions Miss Gayle. The cold trap produces a one Liter ice slug when it’s full. How long that takes depends on how much ice is in the ground beneath the collector. As a rule of thumb we leave the box on the ground for no more than an hour. If the patch isn’t producing at least one liter an hour, then it’s not worth messing with so we move on. On solid ice during that time we get about ten liters of ice.” Mike looked around at us and said, “I can keep talking but I think we should get a move on so you can at least get a look at the ice facility so maybe what I’m saying will stick a little better.”
Christine and Mike led us out of the classroom and over to the vehicle bay. As I was leaving the classroom, I looked back and Miss Gayle gave me a sad little wave. I thought it must be very frustrating for her. She was so wrapped up in our lives and the adventure we were on yet her view was always limited to what she could see and hear through the camera. When we got to the vehicle bay, we all trooped onto the transport which then proceeded through the locks and out onto the road. We headed east along the road past both landing pads. At that point the road swung to the Southeast and brought us to the ice reclamation facility.
There wasn’t that much to see from the outside. The building was a typical buried barrel vault, although in this case the structure was only partially buried with the remaining covering pushed up the building’s sides to give a meter of regolith over the top. The back half of the facility had a ramp leading down into it to remove the consumables produced by the plant. On the side towards the crater lip there was a wide area paved with sintered stone. The transport pulled onto the stone and mane
uvered over to the lift head where we could have a view down into the crater. The crater wall fell off at about a thirty five degree angle. This location had been carefully scouted since the route to the crater floor was smooth with no sudden falls or irregular terrain to make getting the bottom more difficult.
Once the location had been found. Paving robots had been turned loose to make a paved path from the lip of the crater down to the floor. The path was three point six kilometers long by the time it was complete and then the robots paved a small landing area on the floor of the crater. With the ramp in place the lower processing unit was put in place to support the ice crabs in their work. Consumables for the ice crabs were loaded into the lower processing unit via a removable cartridge that attached to the wall of the unit that faced the ramp. Power for the unit was supplied by a power cable run down the path from the lip of the crater. The power cable was attached to a hose that connected to the lower processing unit on one end and the ice reclamation facility. The lower processing unit melted the ice slugs that were brought in by the ice crabs and pumped the liquid up the hose to the reclamation facility.
Mike stood up to get our attention and said, “You’re looking down into Whipple crater. In front of us is the lift head with the cable that allows us to lower/raise payloads down the path to the crater floor. Currently, it’s just used to deliver consumable modules to the lower processing plant on the crater floor. You can also see the hose through which the liquid that is pumped up top to the processing plant flows. You can’t actually see the crater floor from here because sunlight never shines down into the crater. The crater floor covers about twenty square kilometers of area and is covered to a depth of about one half meter to six meters in the deepest areas.”
