Rescued From Paradise

by Robert L. Forward

  Congressman Ootah had a chauffeur, who got out of the front of the robocar, opened the rear door for the congressman, then ordered the vehicle to park itself while he went to the coffee shop to wait for the congressman to return. Fred shook his head at the thought of what a boring life the chauffeur must have, since no one was allowed to touch the controls on a robocar inside the D.C. limits. Still, it was a job, and those were hard to find now that robots did nearly everything.

  Ootah came bustling up to Fred and gave him a hearty two-handed congressional-candidate handshake. "Hooter" had played linebacker for the Saskatchewan Elks before running for Congress, and Fred's hand was swallowed by the massive paws.

  "Hello, Fred! I hear you have some exciting news for the subcommittee."

  "Nothing that you haven't already heard on the TV."

  "But now it'll be official. Nothing really counts until it gets into the Congressional Record."

  They entered the elevator. The person sitting in the chair next to the audio pickup for the automatic elevator controller was obviously another of Congressman Ootah's appointees, for he greeted him warmly and inquired about his ailing mother.

  "Second floor," said the operator to the elevator, and they were whisked upward, bypassing the first floor even though the floor indicator had a blinking white light flashing in back of the number 1.

  They walked down the corridor together and entered hearing room 2318. Fred was relieved to see that Dr. Philipson from Cornell had made it—the weather was usually bad in Ithaca in January—and went to sit next to him in the front row of spectator seats. The hearing room was packed with a number of reporters and space buffs, Fred recognizing many of them. The congressman, meanwhile, made his way to his chair at the front as the room clerk announced the start of the meeting.

  "There will now be a hearing before the Subcommittee on Space, Communication, Power, and Extraterrestrial Mining, of the Committee of Science and Technology, of the Greater United States House of Representatives, One-Hundred-and-Forty-Fourth Congress, second session. The chairman of the subcommittee, the Honorable John Ootah, State of Saskatchewan, presiding!"

  Ootah banged his gavel. "The subcommittee will be in order. Without objection, permission will be granted for radio, video, and holophotography during the course of the hearing. During the next two days, on Tuesday and Wednesday, the fourteenth and fifteenth of January 2076, the subcommittee will review the reports recently received from the brave crew of interstellar explorers visiting the Barnard system nearly six lightyears distant—the first ambassadors of the Greater United States to the worlds across the great void of interstellar space."

  "Our first witness this morning is Dr. Morris Philipson, Professor of Astronomy at Cornell University, who will brief us about Barnard and its unusual planetary system. Then the Honorable Frederick Ross, Chief Administrator for the Greater National Aeronautics and Space Agency, will describe the mission and the vehicles used in carrying it out. We will ask the witnesses to present their testimony first. Then we will have questions after all of the testimony is completed. The House is going into session at eleven o'clock. There will be a series of votes, then a lengthy recess which will allow adequate time for more testimony. We hope in this process the delays in the testimony will be held to a minimum. Dr. Philipson, if you will proceed?"

  Dr. Philipson stepped forward to the presentation table, notes in one hand and some videochips in the other. "Mr. Chairman and members of the Subcommittee on Space, Communication, Power, and Extraterrestrial Mining, I appreciate this opportunity to testify before you about the Barnard system. I have some color holoslides of a few figures that I would like to project during my testimony." He handed the chips to a projectionist seated on one side of the table, who turned and gave them to a motile, who scampered off and put them into the holoprojector that took up one corner of the room. Dr. Philipson then pulled out an envelope from his stack of notes and passed them to the clerk sitting at the other side of the table.

  "I brought along black-and-white flatview versions of some of the holoslides that can be included in the committee minutes at the appropriate places."

  Congressman Ootah nodded. "Thank you for your foresight, Dr. Philipson. Would the Guardian of the Committee Room Door please ask the room robots to dim the lights so we may better view the holoslides?" The door guard spoke into an audio pickup in the wall by the door and the room lights dimmed. "Thank you," said Ootah to the guard. "You may proceed, Dr. Philipson."

  "Thank you, Mr. Chairman. I will read from a personally proofed printout. With your permission, we can relieve the clerk from having to transcribe manually the robotic record and just insert the printout into the committee robotic reader." He passed his notes to the clerk, who looked at the chairman for permission first.

  "That will be fine, Dr. Philipson."

  The clerk dropped the sheets of paper into the input tray, and when they reappeared in the output tray, handed them back to the speaker. Dr. Philipson took back the notes and started to read from them.

  "Barnard is a red dwarf star that is the second closest star to the solar system after the three-star Alpha Centauri system. Barnard can be found in the southern skies of Earth, but it's so dim it requires a telescope to see it. A 3D computer-animated view of the Barnard planetary system can be seen on the holoview screen in the corner."

  The holoprojector went through its brief "audience attention focusing" mode, which started out with the floor-to-ceiling quarter-cylinder screen brightly lit with white light. The light seemed to lift from the curved surface and collect into a white ball floating in front of the screen, while at the same time a quadraphonic audio whistle added cues by focusing sound at the same point as the floating ball. With the audience's eyes and attention now focused in front of the screen instead of on the surface of the screen, the white ball faded and its place was taken by a three-dimensional image of a small glowing red ball, a slightly larger mottled red globe surrounded by a number of smaller balls of various colors, and a small whirling double planet. The large planet circled majestically at a fixed distance from the central star, while the double-planet moved in a smaller and highly elliptical orbit.

  "The Barnard planetary system consists of the red dwarf star Barnard, the giant planet Gargantua and its retinue of moons, and a corotating double planet called Rocheworld. Gargantua is in a standard near-circular planetary orbit around Barnard, while Rocheworld is in a highly elliptical orbit that takes it in very close to Barnard once every orbit, and very close to Gargantua once every three orbits. It has been suggested that one lobe of Rocheworld was once an outer large moon of Gargantua, while the other lobe was a stray planetoid that interacted with the outer Gargantuan moon to form Rocheworld in its present orbit.

  Barnard Planetary System

  "Rocheworld consists of two moon-sized rocky bodies that whirl about each other with a rotation period of six hours. The two lobes of Rocheworld are so close that they are almost touching, but their spin speed is high enough that they maintain a separation of about eighty kilometers. There are exactly one hundred and sixty rotations of Rocheworld around its common center, or a Rocheworld 'day', to one rotation of Rocheworld in its elliptical orbit around Barnard, or a Rocheworld 'year'. There are also exactly three orbits of Rocheworld around Barnard to one rotation of Gargantua around Barnard. This locking of Rocheworld's rotation period and orbital period to the orbital period of Gargantua keeps Rocheworld fixed in its highly elliptical orbit and keeps the double-lobed planet rotating fast enough to prevent its two lobes from touching each other. The energy input needed to compensate for the energy losses in the system due to tidal friction comes from the gravitational tug of Gargantua on Rocheworld during Rocheworld's close passage every third orbit."

  The holoimage faded and the room lights came back on. Congressman Ootah turned and looked at the presenter.

  "Thank you very much, Dr. Philipson. That's quite a spectacular planetary system there. If your schedule permits, we will pr
oceed with the other witnesses and then have the questions and answers. The next witness will be the Honorable Frederick Ross, Chief Administrator for the Greater National Aeronautics and Space Administration. We want to welcome you here and congratulate you for one of GNASAs most successful missions."

  Fred took Dr. Philipson's place at the presenters table.

  "Thank you very much, Mr. Chairman, and members of the committee. I hope you remember your congratulations when you are working on our budget for the coming year." A ripple of laughter passed through the audience and the chairman smiled.

  "We most certainly will, Administrator. I personally will recommend a major new start to send a follow-on expedition."

  "Thank you, Mr. Chairman. I will be glad to work with your staff on the details of the bill. Some of my engineering staff have been busy with their plans for the follow-on mission vehicles and will present them at the session tomorrow morning. Now, having been in office only five years, I can take credit for only one-tenth of this fifty-year long mission."

  Fred bent forward and passed some papers and video-chips to the clerk and projectionist.

  "The vehicles used on the Barnard expedition were unusual because of the unusual nature of the target. I will go through their structure and function in some detail. The first component was the interstellar laser propulsion system. The payload sent to the Barnard system consisted of the crew of twenty persons and their consumables, totalling about 300 metric tons; four landing rockets for the various planets and moons at 500 tons each; four nuclear powered VTOL exploration airplanes at 80 tons each; and the interstellar habitat for the crew that made up the remainder of the 3500 tons that needed to be transported to the star system. This payload was carried by a large light sail 300 kilometers in diameter. The sail was of very light construction, a thin film of finely perforated metal, stretched over a lightweight frame. The payload sail was not only used to decelerate the payload at the Barnard system, but also for propulsion within the Barnard system. The 300-kilometer payload sail was surrounded by a larger ring sail, 1000 kilometers in diameter, with a hole in the center where the payload sail was attached during launch from the solar system. The ring sail had a total mass of 71,500 tons, giving a total launch weight of the sails and the payload of over 82,000 tons.

  "The laser power needed to accelerate the 82,000-ton interstellar vehicle at one percent of earth gravity was just over 1300 terawatts. This was obtained from an array of 1000 solar-pumped laser generators orbiting around Mercury.

  "The final transmitter lens for the laser propulsion system was a thin film of plastic net, initially 100 kilometers in diameter. Called a Fresnel zone lens, it had alternating circular zones that either were empty or covered with a thin film of plastic that caused a half-wave-length phase delay in the laser light. Such a Fresnel zone lens can transmit a laser beam many lightyears without the beam spreading significantly. The configuration of the lasers, lens, and sail during the launch phase can be seen in the top part of the diagram.

  "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 twenty years the spacecraft and its drugged crew coasted through interstellar space, covering a lightyear every five years. Back in the solar system, the laser array was used to launch another manned interstellar expedition. During this period, the Barnard Fresnel zone lens was increased in diameter to 300 kilometers. Then, in 2060, the laser array was turned on again at a power level of 1500 terawatts and a tripled frequency. The combined beams from the lasers filled the 300-kilometer diameter Fresnel zone lens and beamed out toward the distant star. After two years, the lasers were turned off, and used elsewhere. The two-lightyear 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.

  Laser-Pushed Lighsail Propulsion System.

  [J. Spacecraft, Vol. 21, No. 2, pp. 187-195 (1984)]

  "Before the pulse of laser light had reached the interstellar vehicle, the vehicle was separated into two pieces. The inner 300-kilometer payload sail was detached and turned around to face the ring-shaped sail. The ring sail had computer-controlled actuators to give it the proper optical curvature. When the laser beam from the distant solar system arrived at the spacecraft, the beam struck the large 1000-kilometer ring sail, bounced off the mirrored surface, and was focused onto the smaller 300-kilometer payload sail as shown in the lower portion of the diagram. The laser light accelerated the massive ring sail at 1.2 percent of Earth gravity and during the two-year period the ring sail increased its velocity slightly. The same laser power reflecting back on the much lighter payload sail, however, decelerated the smaller sail and the exploration crew at nearly ten percent of Earth gravity. In the two years that the laser beam was on, the payload sail slowed from its interstellar velocity of twenty percent of the speed of light to come to rest in the Barnard system. Meanwhile, the ring sail sped on into deep space, its job done."

  Fred then went on to describe in more detail the construction of the starship's habitat, the landing rockets and the exploration airplanes. He finally concluded. "Well, those are the vehicles that the exploration crew used to travel to and in the Barnard system. It's now time to hear about what they found there. For that, I would like to utilize the scientific expertise of my capable assistant, Dr. Joel Winners. Thank you for your time, Mr. Chairman."

  "Your complete statement will be part of the record, Mr. Ross," said Congressman Ootah. "We thank you. Our next witness is Dr. Joel Winners, Associate Administrator for Space Sciences of the Greater National Aeronautics and Space Administration."

  Fred got up from the presentation table. He knew what Joel would be presenting, since he had sat through the dry run the previous day. Instead of staying to hear again about the flouwen, the intelligent aliens found on Rocheworld, he excused himself so he could set ready for the next day's session—the plans for the follow-on mission.

  THE FOLLOWING day, Fred Ross was in the meeting room early when Congressman Ootah arrived and started the second day of the Barnard Star hearings.

  "The subcommittee will be in order. Without objection, permission will be granted for radio, video, and holophotography during the course of the hearing. Today we will hear from the GNASA Administrator about the plans for the follow-on expedition to Barnard. Mr. Ross?"

  Fred Ross came to the presentation table.

  "As you know, the news from the exploration crew at Barnard about the discovery of intelligent alien lifeforms on Rocheworld only arrived back at Earth a few weeks ago. Until that discovery, there had been no serious plans for follow-on missions. The teams of explorers we have already sent to Alpha Centauri, Barnard, Lelande, Sirius, UV Ceti, Epsilon Eridani, and the other star systems further out, were all volunteers on one-way missions designed to last for an entire human lifetime. Each team was given the equipment to carry out a complete and thorough exploration, not only of the stars, but the major planets and moons of each system. Once they had completed their survey and transmitted their images and data back to Earth, there would be no need for further scientific exploration of that particular system until all the other nearby star systems had been visited in a similar manner.

  "The discovery of intelligent and friendly alien lifeforms on Rocheworld, however, has completely changed the picture. Although the exploration crew there will do their best to learn as much from these creatures as possible, and will arrange to provide them with communication equipment so that they may exchange messages with scientists on Eart
h, this leaves much to be desired. The human crew are now in their forties and fifties, and although some of them will live for many more decades, they all must die eventually, ending direct interaction between humans and aliens. The communication links back to Earth will help, but with Barnard six lightyears away, there will be a twelve-year time lag between a question and its answer—hardly suitable for proper communication between species. We need to replace the exploration crew with a suitably chosen team of scientists, and we need to get them to Barnard as fast as possible, and bring them and some aliens back. I have queried my propulsion engineering experts, and they have come up with two possible concepts to achieve rapid roundtrip interstellar travel."

  Here, Fred Ross handed a videochip to the projectionist, who handed it to a motile, who put it into the holoscreen projector.

  "This first figure will look familiar to those that were here yesterday. But something new has been added. This is a design for a laser-pushed lightsail interstellar propulsion system, like the one used in the present Barnard mission, but this one has an extra sail stage, cut out of the middle, this gives it a round-trip mission capability. Since we may want to use this design on other missions than the Barnard mission, it was sized to go to star systems further out, such as Epsilon Eridani, almost eleven lightyears distant."

  "Amazingly enough, we do not need to make any major changes to the design of the interstellar spacecraft itself, except to add the third stage. We do, however, need to upgrade the laser driver system here in the solar system, by increasing the laser power and increasing the size of the Fresnel zone lens from its present 300 kilometers to 1000 kilometers. As you can see in the figure, the lightsail on the spacecraft itself has now been divided into three stages. The outer ringsail is the same as before, 1000 kilometers in diameter with a 320-kilometer diameter hole, while the inner sail has been divided into two pieces, a rendezvous stage consisting of a sail 320 kilometers in diameter, and a return stage consisting of the inner 100-kilometer portion of the sail that carries the payload at its center.