"Wherrre small noisy thing?"
I gaped in astonishment. A small pink blob had suddenly appeared between the bigger flouwen! Little Purple sounded proud, as he performed the introduction:
"Reiki, Richard, this is our youngling!"
"Rrrrreiki, Rrrrrichard?"
Startled, I giggled, but instantly quashed it. I had not heard "r"s so rolled since I left Scotland!
Little White explained, "It will learn better speech, but it does say that particular sound in a repetitive way. We call this youngling Warm Chirring Pink!"
"We all have younglings now," said Little Purple calmly, as it carefully placed the tiny pink human child on top of the large pink flouwen youngster so it could scan the baby.
"Our young bigger than your young!" bragged Little Red.
"Be quiet, Little Red!" chided Little White. "That is not polite!"
Little Red ignored the reproof.
"Our young can talk!" Little Red said proudly. "Human young can't talk. Human young DUMB!"
Little Red glided the baby off the pink youngster and back to Richard's waiting hands, then started moving off toward the mouth of the lagoon.
"Come on!! I feel a storm coming up . . .let's go SURF!!!
"Watch out for the sharks!" I called after him. Then I felt a strange foreboding as I gathered my baby from Richard's strong arms. This world is like Eden, but the inhabitants of the original Eden had come across animals that had introduced death to their hitherto deathless world. We have only explored part of one small island on this Edenlike world and we know only a few of the animals that must inhabit it. The recent discovery of the existence of the sharks is but one example of our ignorance. What other creatures and what dangers will we and our children encounter as the years go by? I shudder and hold my baby close as I face the unknown future.
(To Be Continued)
Technical Report
BSE-TR-71-0868
July 2071
BARNARD STAR EXPEDITION
PHASE IV REPORT
VOLUME I—EXECUTIVE SUMMARY
Submitted by:
George G. Gudunov, Colonel, GUSAF
Acting Commander, Barnard Star Expedition
INTRODUCTION
This Volume I is the Executive Summary of the information collected to date by the Barnard Star Expedition, especially the more recent information gathered during Phase IV of the expedition, which primarily consisted of the landing of an exploration crew on the Gargantuan moon Zuni. Although the mission could not be considered a complete success because the landing rocket crashed and sank on arrival at the surface, the exploration crew did manage to survive and return a significant amount of information on the lifeforms found there. This Executive Summary is a brief condensation of the highly technical material to be found in the companion volume, Volume II—Technical Publications. Volume II, as well as similar publications that followed Phases I through III, contains a series of technical papers and reports on various aspects of the mission, each of which runs to hundreds of pages, including tables. These papers are intended for publication either in archival videojournals or as scientific or technical monovids, and contain many specialized terms that would be understood only by experts in those particular fields.
For the benefit of the reader of this volume, who is assumed to be interested only in a brief summary in non-technical language without extensive numerical detail, the more precise specialized words and phrases used in the technical reports and papers have been replaced in this summary with common words, and most of the numerical data have either been eliminated or rounded off to two or three places. In addition, to assist those readers of this Executive Summary who may not have read the previous summary reports, pertinent background material from those reports has been included here.
The three major topics discussed in this Executive Summary are covered in three sections:
Section 1 — Equipment Performance. A report on the configuration and performance of the technical equipment used to carry out the Barnard Star Expedition.
Section 1—Barnard System Astronomical Data. A summary of the pertinent astronomical data concerning the Barnard star planetary system, with emphasis on the moons around the giant planet Gargantua, and specific emphasis on the moon Zuni, the site of the fourth landing.
Section 3—Biology. A summary report of the biology of the alien lifeforms discovered on Zuni.
SECTION 1
EQUIPMENT PERFORMANCE
Prepared by:
Caroline Tanaka—Acting Chief Engineer
Anthony Roma, Captain, GUSSF—Chief Lightsail Pilot
Thomas St. Thomas, Captain, GUSAF—ChiefLander Pilot
George G. Gudunov, Colonel GUSAF—Acting Chief Aircraft Pilot
Equipment Configuration At Launch
The expedition sent to the Barnard star system consisted of a crew of twenty persons and their consumables, a habitat for their long journey, and four lander vehicles for visiting the various planets and moons of the Barnard system. This payload, weighing 3000 tons, was carried by a large reflective lightsail 300 kilometers in diameter. The lightsail was of very lightweight construction consisting of a thin film of finely perforated metal stretched over a sparse frame of wires held in tension by the slow rotation of the lightsail about its axis. Although the lightsail averaged only one-tenth of a gram per square meter of area, the total mass of the payload lightsail was over 7000 tons, for a total mass of payload and lightsail of 10,000 tons. Light pressure from photons reflected off the lightsail provided propulsion for the lightsail and its payload. The lightsail used retroreflected coherent laser photons from the solar system to decelerate the payload at the Barnard system, while, for propulsion within the Barnard system, it used incoherent photons from the star Barnard.
At the time of launch from the solar system, the 300 kilometer payload lightsail was surrounded by a larger retroreflective ring lightsail, 1000 kilometers in diameter, with a hole in the center where the payload lightsail was attached. The ring lightsail had a mass of 72,000 tons, giving a total launch weight of lightsails and payload of over 82,000 tons.
Interstellar Laser Propulsion System
The laser power needed to push the 82,000 ton interstellar vehicle at an acceleration of one percent of earth gravity was just over 1300 terawatts. This was obtained from an array of 1000 laser generators orbiting around Mercury. Each laser generator used a thirty kilometer diameter lightweight reflector that collected 6.5 terawatts of sunlight. The reflector was designed to pass most of the solar spectrum and only reflect into its solar-pumped laser the 1.5 terawatts of sunlight that was at the right wavelength for the laser to use. The lasers were quite efficient, so each of the 1000 lasers generated 1.3 terawatts, to produce the total of 1300 terawatts needed to send the expedition on its way.
The transmitter lens for the laser propulsion system consisted of rings of thin plastic film stretched over a spiderweb-like circular wire mesh held in tension by slow rotation about the mesh axis. The lens was designed with circular zones of decreasing width that were alternately empty and covered with plastic film whose thickness was chosen to produce a phase delay of one half a wavelength in the laser light. This huge Fresnel zone plate, 100 kilometers in diameter, collimated the laser beam coming from Mercury and sent it off to Barnard with essentially negligible divergence. The relative configuration of the lasers, lens, and lightsails during the launch and deceleration phases can be seen in Figure 1.
The accelerating lasers were left on for eighteen years while the spacecraft continued to gain speed. The lasers were turned off, back in the solar system, in 2044. The last of the light from the lasers traveled for two more years before it finally reached the interstellar spacecraft. Thrust at the spacecraft stopped in 2046, just short of twenty years after launch. The spacecraft was now at two lightyears distance from the Sun and four lightyears from Barnard, and was traveling at twenty percent of the speed of light. The mission now entered the coast phase. For the next 20 ye
ars the spacecraft and its drugged crew coasted through interstellar space, covering a lightyear every five years, while back in the solar system, the transmitter lens was increased in diameter from 100 to 300 kilometers. Then, in 2060, the laser array was turned on again at a tripled frequency. The combined beams from the lasers filled the 300 kilometer diameter Fresnel lens and beamed out toward the distant star.
Figure 1—Interstellar laser propulsion system.
[J. Spacecraft, Vol 21, No. 2,pp. 187-195(1984) ]
After two years, the lasers were turned off, and used elsewhere. The two-light-year-long pulse of high energy laser light traveled across the six lightyears to the Barnard system, where it caught up with the spacecraft as it was 0.2 lightyears away from its destination. Before the pulse of laser light reached the interstellar vehicle, the revived crew on the interstellar vehicle had separated the lightsail into two pieces. The inner 300 kilometer lightsail carrying the crew and payload was detached and turned around to face the ring-shaped lightsail. The ring lightsail had computer-controlled actuators to give it the proper optical curvature. When the laser beam arrived, most of the laser beam struck the larger 1000 kilometer ring sail, bounced off the mirrored surface, and was focused back onto the smaller 300 kilometer payload lightsail as shown in the lower portion of Figure 1. The laser light accelerated the massive 72,000 ton ring lightsail at one percent of Earth gravity and during the two year period the ring lightsail increased its velocity slightly. The same laser power focused back on the much lighter payload lightsail, however, decelerated the smaller lightsail at nearly ten percent of Earth gravity. In the two years that the laser beam was on, the payload lightsail and its cargo of humans and exploration vehicles slowed from its interstellar velocity of twenty percent of the speed of light to come to rest in the Barnard system. Meanwhile, the ring lightsail continued on into deep space, its function completed.
Prometheus
The interstellar lightsail vehicle that took the exploration crew to the Barnard system was named Prometheus, the bringer of light. Its configuration is shown in Figure 2, and consists of a large lightsail supporting a payload containing the crew, their habitat, and their exploration vehicles. Running all the way through the center of Prometheus is a four-meter-diameter, sixty-meter-long shaft with an elevator platform that runs up and down the shaft to supply transportation between decks. A major fraction of the payload volume was taken up by four exploration vehicle units. Each unit consisted of a planetary lander vehicle called the Surface Lander and Ascent Module (SLAM), holding within itself a winged Surface Excursion Module (SEM).
The largest component of Prometheus is the lightsail, 1000 kilometers in diameter at launch, and 300 kilometers in diameter during the deceleration and exploration phases of the mission. The frame of the lightsail consists of a hexagonal mesh trusswork made of wires held in tension by a slow rotation of the lightsail around its axis. Attached to the mesh wires are large ultrathin triangular sheets of perforated reflective aluminum film. The perforations in the film are made smaller than a wavelength of light, so they reduce the weight of the film without significantly affecting the reflective properties.
Capping the top of Prometheus on the side toward the direction of travel is a huge double-decked compartmented area that holds the various consumables for use during the 50-year mission, the workshops for the spaceship's computer motile, and an airlock for access to the lightsail. At the very center of the starside deck is the starside science dome, a three-meter-diameter glass hemisphere that was used by the star-science instruments to investigate the Barnard star system as Prometheus was moving toward it.
At the base of Prometheus are five crew decks. Each deck is a flat cylinder twenty meters in diameter and three meters thick. The control deck at the bottom contains an airlock and the engineering, communication, science, and command consoles to operate the lightcraft and the science instruments. In the center of the control deck is the earthside science dome, a three-meter-diameter hemisphere in the floor, surrounded by a thick circular waist-high wall containing racks of scientific instruments that look out through the dome or directly into the vacuum through holes in the deck. Above the control deck is the living area deck containing the communal dining area, kitchen, exercise room, medical facilities, two small video theaters, and a lounge with a large sofa facing a three-by-four-meter oval view window. The next two decks are the crew quarters decks that are fitted out with individual suites for each of the twenty crew members. Each suite has a private bathroom, sitting area, work area, and a separate bedroom. The wall separating the bedroom from the sitting area is a floor-to-ceiling viewwall that can be seen from either side. There is another view screen in the ceiling above the bed.
Figure 2—Prometheus
Above the two crew quarters decks is the hydroponics deck. This contains the hydroponics gardens and the tissue cultures to supply fresh food to the crew. The water in the hydroponics tanks provides additional radiation shielding for the crew quarters below. In the ceilings of four of the corridors running between the hydroponics tanks are air locks that allow access to the four Surface Lander and Ascent Module (SLAM) spacecraft that are clustered around the central shaft, stacked upside down between the hydroponics deck and the storage deck. Each SLAM is forty-six meters long and six meters in diameter.
Surface Lander and Ascent Module
The Surface Lander and Ascent Module (SLAM) is a brute-force chemical rocket that was designed to get the planetary exploration crew and the Surface Excursion Module (SEM) down to the surface of the various worlds in the Barnard system. The upper portion of the SLAM, the Ascent Propulsion Stage (APS), is designed to take the crew off the world and return them back to Prometheus at the end of the surface exploration mission. As is shown in Figure 3, the basic shape of the SLAM is a tall cylinder with four descent engines and two main tanks.
The Surface Lander and Ascent Module has a great deal of similarity to the Lunar Excursion Module (LEM) used in the Apollo lunar landings, except that instead of being optimized for a specific airless body, the Surface Lander and Ascent Module had to be general purpose enough to land on planetoids that could be larger than the Moon, as well as have significant atmospheres. The three legs of the Surface Lander and Ascent Module are the minimum for stability, while the weight penalties for any more were felt to be prohibitive.
The Surface Lander and Ascent Module (SLAM) carries within itself the Surface Excursion Module (SEM), an aerospace plane that is almost as large as the lander. Embedded in the side of the SLAM is a long, slim crease that just fits the outer contours of the SEM. The seals on the upper portions were designed to have low gas leakage so that the SLAM crew could transfer to the SEM with minor loss of air.
The upper portion of the SLAM consists of the crew living quarters plus the Ascent Propulsion Stage. The upper deck is a three-meter-high cylinder eight meters in diameter. On its top is a forest of electromagnetic antennas for everything from laser communication directly to Earth to omni-antennas that broadcast the position of the ship to the orbiting relay satellites.
The upper deck contains the main docking port at the center. Its exit is upward, into the hydroponics deck of Prometheus. Around the upper lock are the control consoles for the landing and docking maneuvers, and the electronics for the surface science that can be carried out at the SLAM landing site.
Figure 3—Surface Lander and Ascent Module (SLAM)
The middle deck contains the galley, lounge, and the personal quarters for the crew with individual zero-gee sleeping racks, a shower that works as well in zero-gee as in gravity, and two zero-gee toilets. After the SEM crew has left the main lander, the partitions between the sleeping cubicles are rearranged to provide room for a sick bay and a more horizontal sleeping position for the four crew members assigned to the SLAM.
The galley and lounge are the relaxation facilities for the crew. The lounge has a video center facing inward where the crew can watch either videochips or six-year-old programs
from the Earth, and a long sofa facing a large viewport window that looks out on the alien scenery from a height of about forty meters. The lower deck of the SLAM contains the engineering facilities. Most of the space is given to suit or equipment storage, and a complex air lock. One of the air-lock exits leads to the upper end of the Jacob's ladder. The other leads to the boarding port for the Surface Excursion Module.
Since the primary purpose of the SLAM is to put the Surface Excursion Module on the surface of the double-planet, some characteristics of the lander are not optimized for crew convenience. The best instance is the "Jacob's Ladder," a long, widely spaced set of rungs that start on one landing leg of the SLAM and work their way up the side of the cylindrical structure to the lower exit lock door. The "Jacob's Ladder" was never meant to be used, since the crew expected to be able to use a powered hoist to reach the top of the ship. In the emergency that arose during the first expedition to Rocheworld, however, the Jacob's Ladder proved to be an adequate, although slow, route up into the ship.
Marooned on Eden Page 30
