“I take it that those blue ray gun things don't kill people?”
“No, Sergeant, they're stun guns—like a taser without wires—we call them stunners. It was never our intention to harm you. By the way, you don't have any 40mm grenades, I checked. It was your threat to use grenades that forced the Captain to order the attack.”
“Yeah, well sorry about that, Lieutenant. It seemed like a good idea at the time.”
“Well its over now,” said the First Officer. “The Captain will be along to speak with you now that you've regained consciousness. If I leave you in the corpsman's care will you promise not to do something stupid?”
“Since Doc is the only one fully mobile, I don't think we'll be trying anything too John Wayneish, Lieutenant. Particularly with no weapons and that attack bear of yours wandering around. That was a polar bear, wasn't it?”
“Yes, Sergeant, that was most definitely a polar bear.”
“I could swear that, just before I passed out, the bear spoke to me. That polar bear really can't talk, can he?”
“Of course not, Gunnery Sergeant,” the tall Lieutenant said with a mischievous glint in her eye. “He was just showing off.”
Bridge, Parker's Folly
The Captain reclaimed the bridge and proceeded to finish the post launch checklist. A number of critical systems had not been fully online when the ship took off. Included among them were the suite of external sensors—radar, LIDAR, radiation detectors, video and others—which he was now activating. As he brought the charged particle detectors online he noticed that exterior levels were significantly higher than the display indicated as normal.
“Mr. Medina, could you cross check the particle radiation readings please?”
“Yes, Captain. It looks about twice normal levels and rising.”
“Are we expecting a solar storm? Did anyone think to check before we took off? I certainly didn't.”
“Sir, I'm accessing the Internet through a comsat and NASA has issued a solar flair warning. Wow! If what they are saying is true, there has been a massive eruption on the Sun. Earth is about to be hit with a monster wave of charged particles in about three hours.”
“Are the interior levels OK?”
“Yes, Sir. But I suggest we boost the repulsor shields just to make sure things stay that way.”
“Very well, Mr. Medina.” When Jack had taken over as the ship's captain he had promised that he would never utter the words “make it so.” He didn't ever wish to be confused with any fictional spaceship captain. “Also, Mr. Medina. My board is showing that the deck gravity grid has checked out and is ready to power up.”
“Yes, Sir. Should I engage the deck gravity?”
The Captain cringed at the use of “engage” for the same reason he eschewed the use of “make it so.” Instead he spoke to the engineer, saying “Let's not tempt fate with a possibly damage causing gravity level. Set up for a tenth of a G in all habitable spaces but don't activate the grid. I'll sound the warning and then we will give everyone time to prepare.”
The klaxon sounded its three warning blasts and the Captain announced over the PA “Attention! All habitable spaces will be placed under a one tenth G gravity in five minutes. Secure yourselves and all equipment for cabin gravity in five minutes.”
“Captain?” helmsman Vincent inquired. “There's something you should see on the TV. They're showing pictures of the space station and acting real upset.”
“What are they saying, Mr. Vincent?”
“I can't tell, it's a Russian station, Sir.” With that, Billy Ray turned the sound up until it was audible.
“They are saying,” said Lt. Curtis, just arriving on the bridge. “That there are two heroic Russian cosmonauts trapped on the ISS, along with a Japanese scientist.”
“Very good, Lieutenant,” the Captain noted. “I believe your command of Russian is better than mine. The question is, what the hell are they doing in orbit with a potentially lethal solar storm about to hit?” The ISS orbital inclination of 51° was a compromise with the Russians to accommodate launch geometries from the Baikonur Cosmodrome. It also increased normal radiation exposure. Crew members on both the space station and the American space shuttle reported seeing bright flashes of light that were actually caused by energetic particles passing through their eyeballs. Even so, the ISS in LEO was normally safe from solar flares. Evidently, the impending flood of radiation from the massive solar eruption was something else again.
“Mr. Danner, Mr. Vincent. Please locate the space station and plot a course that will intersect its path while matching its orbit.”
“Yes, Captain.” the two helmsmen replied in unison.
Normally, when pursuing another object in orbit, the spacecraft doing the chasing must decelerate, in effect slow down, to overtake its quarry. This seeming contradiction is a result of Newton's laws of motion combined with the inverse square law governing gravitational attraction. Examples are easier to understand than the equations.
For a spacecraft to achieve Earth orbit, it must be launched to an elevation above Earth's atmosphere and accelerated to orbital velocity. As previously mentioned, the ISS is in an orbit averaging 350 km in height above Earth's surface traveling at 27,500 km/hr. In this orbit it takes about 94 minutes to complete a single trip around the planet.
Many communications satellites are in orbit 35,785 km above the planet, in what is called a geosynchronous orbit. In geosynchronous orbit a satellite circles Earth once a day. If that orbit is a circular one in the plane of the equator, the satellite will appear to hang motionless in the sky. This is because it is making a full revolution at the same rate the planet below is turning—once every 24 hours. The orbital velocity in geosynchronous orbit is 11,066 km/hr. Even farther out, the Moon has an altitude of about 384,400 km, a velocity of about 3,700 km/hr and its orbit takes 27.322 days.
The space station orbits the planet many times faster in terms of revolutions per hour than a geosynchronous communications satellite or the Moon because it is in a lower orbit. The salient point is that to catch up with something in orbit, orbital mechanics requires a spacecraft drop to a lower orbit. In that lower orbit the ship is circling the planet faster than the object in the higher orbit. Then, at the appropriate point, the pursuing ship transfers back to the higher orbit, hopefully arriving alongside its target.
The confusing part is that, when transferring from a higher orbit to a lower one, the change of velocity is opposite to the direction of motion—in other words, the ship must slowdown. Yet, when the lower orbit is achieved, its orbital velocity will be higher and it will complete more orbits in a set amount of time.
When transferring from a lower orbit to a higher orbit, the change in velocity is applied in the direction of motion—in other words, forward acceleration. When the higher orbit is attained, its orbital velocity will be less than the velocity in the lower orbit and it will take longer to complete a full circle around the globe.
Ordinarily, when changing orbits it is desirable to use the smallest possible amount of energy, which usually leads to using a Hohmann transfer orbit. Such a transfer trajectory describes an ellipse that is tangent to both the initial and final orbits. However, if a spacecraft needs to change orbits more quickly, a faster transfer called a One-Tangent Burn can be used. What type of transfer is used depends on how much energy a spacecraft is able to expend.
In this case, Parker's Folly needed to not only dip down lower than its current altitude and then back up, it also had to change its orbital inclination, the plane it was orbiting in, to match that of the ISS. To do this quickly would require a great deal of energy. Fortunately, the ship possessed a surfeit of energy—as much as a large nuclear power plant. The ship's computer was programed to solve such orbital problems and the appropriate maneuvers were quickly plotted.
“Mr. Medina, now would be a good time for that gravity. We shall see if the cabin gravity system can compensate for the ship's acceleration as advertised.”
“Aye, Captain, one tenth of a G coming right up.”
“Helm, let's pay the International Space Station a call.”
Destiny Module, International Space Station
Ludmilla Tropsha was startled to hear a voice through the crackling static on the station's radio. Perhaps her mind was starting to play tricks on her. No, there it was again, a man's voice speaking English.
“ISS, this is Parker's Folly, do you read me?”
She must be hallucinating, they had lost contact with mission control half an hour ago.
“ISS, ISS, this is Parker's Folly, is there anyone on board? Please respond.”
Feeling as though she was in a dream, Luda moved to the radio console and answered. “Party calling ISS, this is Lt. Col. Ludmilla Tropsha. Please state your name and the purpose of this call.”
“Colonel Tropsha, this is Captain Jack Sutton on board the spaceship Parker's Folly, we were afraid that you were already gone.”
Ludmilla felt her anger rising, what kind of cruel, twisted man would play such a trick? “Is this some kind of sick joke? We will all be gone soon enough!”
“I assure you this is not a joke, Colonel. Please look out of your observation port and you will see my ship.”
The Destiny lab module has a single Earth-facing window, made of optically pure, telescope-quality glass, located in an open rack bay. Cursing herself for a fool, Ludmilla moved over to the 20 inch circular window. Despite herself, Luda felt hope rising in her breast. She was almost too afraid to look out the window, afraid to have that spark of hope dashed. She looked out and... there was a ship hanging in space next to the space station.
And what a ship it was! A long gleaming silver cigar of a ship with a nose like Baccarat crystal. Where did it come from? How could such a thing exist? The ISS was supposed to be the biggest thing mankind had ever sent into space—the habitable assembly 51 meters long, the truss 109 meters wide, weighing 370 metric tons. The silver vision floating outside the window easily dwarfed the station. Plus, the strange ship was solid, all of one piece, while the ISS looked like some cobbled together collection of space junk.
Luda's vision became blurred as tears of joy filled her eyes—in zero-gravity tears do not flow down cheeks, they simply well up on the surface of the eyes and must be wiped or batted away by blinking. She went back to the radio console, now half afraid that the silver ship would disappear when she left the window.
“Captain, this is the ISS. Who are you? Where did you come from?” She paused and then added, “Are you from Earth?”
“Why yes, Ma'am. Actually, we're from Texas.”
Chapter 8
Captain's Sea Cabin, Parker's Folly
Captain Sutton had assembled his engineering team, along with Lt. Curtis, in his sea cabin to discuss how to get the stranded cosmonauts off of the International Space Station. It was beginning to look like rescuing the endangered ISS crew was going to be a bit more difficult than just pulling along side and saying “hop on.”
“ISS, this is Captain Sutton on board Parker's Folly. With me I have the ship's First Officer Lt. Gretchen Curtis, head engineer Dr. Rajiv Gupta and engineers Medina and Adams. Dr. Tropsha, have you assembled your colleagues?”
“Yes, Captain Sutton. With me are Colonel Ivan Kondratov, acting mission commander, and Dr. Yuki Saito. We are wondering how we can transfer to your vessel, do you have an airlock that can dock with the station?”
“I'm afraid not, we have no airlocks that are compatible with the station's docking facilities. We were wondering if you could EVA over to us. We have a large cargo door aft of midships and the cargo hold can be depressurized. In effect it is a big airlock.”
“Captain, this is Ivan Kondratov. Other than myself the people on board are not experienced spacewalkers. Is there some other way to effect the transfer?”
“Perhaps they could all get into the main airlock module? We could disconnect the module and haul it aboard,” suggested Freddy Adams. The Joint Airlock, or Quest Module, gave the station the capability to conduct spacewalks using U.S. spacesuits. It was based on the Space Shuttle airlock and was attached to the station during the 10th space shuttle assembly flight.
“The Crew Lock will not hold all three of us in suits at the same time,” replied Ivan. The six meter long Quest Airlock is composed of two connected cylindrical chambers—the larger Equipment Lock and the smaller Crew Lock. It was designed to accommodate two suited spacewalkers at a time. This can be either two American Extravehicular Mobility Units, two Russian Orlan-M spacesuits, or one of each design.
“What if you didn't wear spacesuits?” asked Jo Jo Medina. “Could the three of you fit then?”
“We could probably squeeze in but that isn't a procedure I would be happy with. If the lock developed a leak while being detached from the station it could depressurize. The only way to be safe would be to wear spacesuits, putting us back to two.”
“I believe that the airlock would not be easy to detach from the station either,” said Dr. Saito, joining the conversation.
“Yuki is right. It would probably take two experienced spacewalkers several hours to detach the airlock,” added the Russian Colonel. “I doubt that the module was ever intended to be removed—it may not be possible to disconnect it safely.”
“Regardless, we don't have the time,” the Captain concluded. “So we are back to needing you folks to EVA over from the station. How long would it take to cycle the airlock twice?”
“Actually,” said Ivan, “I could use the Pirs Docking Module airlock.” Before the Joint Airlock was installed the only way for cosmonauts to exit the station was through the older airlock on the Russian built docking adapter. That airlock was a Russians only entrance, since the US EMU suits were too bulky to fit through its tight opening. Pirs was the same module that the broken Soyuz capsule was docked at.
“Good, it sounds like you can all exit the station simultaneously. We should be able to shoot you a line from the open cargo door that you can use as a guideline.”
“Actually, Captain, there is another problem,” said Ludmilla. “The normal spacewalk protocol requires staying overnight in the Crew Lock, before exiting the ISS. The Americans called it ‘camping out.’”
“Surely you can skip that, Doctor?” said Lt. Curtis.
“No, you don't understand. It is because of the difference in air pressure and nitrogen absorbed by the body's tissues. The space station is kept at 1 bar, sea-level pressure, using a mixture of oxygen and nitrogen, much like conditions on Earth. Pressure in a spacesuit is only around 0.3 bar, about 4 psi. Making the change from cabin to spacesuit too quickly can cause decompression sickness—the bends.”
“Just like SCUBA divers surfacing without properly decompressing,” said the Lieutenant. “Yes, I understand now. Spacewalkers spent the night slowly lowering the air pressure to safely purge their bodies of nitrogen.”
“That is correct, Lieutenant. We lower air pressure in stages while breathing pure oxygen. I'm afraid that going outside without taking precautions could debilitate one or more of us.”
“Pardon me, Doctor, this is Rajiv Gupta. I seem to remember that the Joint Airlock was not added to the station until construction was well underway. How were spacewalks done before the Quest module was attached?”
“We used to use the Russian airlock,” Ivan answered. “The Americans could only go outside when a Space Shuttle was docked.”
“That is correct,” Ludmilla added. “Ivan, there was an older protocol that was used before the big airlock was added. Yes, it is here in my tablet.” All space station crew members carried around tablet computers with access to the station’s wifi network.
“Yes, here it says: Station astronauts are to begin the pre-breathe protocol by exercising vigorously on the space station's cycle ergometer for a total of 10 minutes while breathing pure oxygen via an oxygen mask. After 50 total minutes of breathing pure oxygen, including the 10 minutes initially spent exercising, the pressure
in the station's airlock will be lowered to 10.2 pounds per square inch. During airlock depressurization, the spacewalkers will breathe pure oxygen for an additional 30 minutes. At the end of those 30 minutes, with the airlock now at 10.2 psi, the spacewalkers will put on their space suits. Once their spacesuits are on, the spacewalkers will breathe pure oxygen inside the suits for an additional 60 minutes before making final preparations to leave the station and begin their spacewalk. This protocol provides a total of 2 hours and 20 minutes of pre-breathe time, including the 10 minutes of vigorous exercise at the beginning of the procedure.”
“I don't think we have 2 hours and 20 minutes, Doctor,” said the Captain. “Can we cut that down to under an hour?”
“Yes, I think so. Any purging helps reduce the risk of decompression sickness. Less acute cases of decompression sickness often do not present symptoms for hours after exposure. Between the exercise and breathing pure oxygen we should be OK, if the transfer does not take to long.”
“If it takes too long, getting the bends will be the least of our worries, Ludmilla,” Yuki added.
“Very good, Captain,” said Ivan. “I can use the Pirs lock while Ludmilla and Yuki use the Crew Lock. Yuki, you are not familiar with the Russian spacesuits?”
“No, Ivan. I trained on the American suits at NASA. I would feel more comfortable in an EMU.”
“Very well. Ludmilla can help you suit up. Captain, we need to begin our prep if we are to exit the airlocks within an hour.”
“Yes of course Colonel,” affirmed the Captain. “We need to start depressurizing the cargo hold and suiting up ourselves. We will continue to monitor this frequency if you need us, otherwise signal when you are ready to transfer. Parker's Folly out.”
* * * * *
“OK people, do we have what we need to do this?” the Captain asked the crew members in the sea cabin once the radio link had been muted.
“Freddy and I will go back to the cargo hold and ensure it is ready,” said Dr. Gupta. “Then we will start the decompression. I would like to recover as much of the air as possible.”
Parker's Folly Page 12
