"Intelligent life, once liberated by the resources of space, is the greatest resource in the solar system ... the highest fulfillment of life is unbounded intelligence and compassion."
Chapter 16: Tracking
Endeavour roared into the darkening Florida sky, their instruments transmitted signals unceasingly to the Atlantic Missile Range’s tracking computers. Electrons ran back and forth millions of times per second on finely-manufactured transmission antennas, inducing the minute oscillations in magnetic and electric fields that propagated down to receivers on Earth.
Constitution, when she had been at her greatest downrange distance, was below the horizon and invisible to observers at Cape Canaveral;
Endeavour remained so, as she continued her long arc around the Earth. The two craft beamed their signals instead to the USNS
Redstone, a former oil tanker built during the Second World War to support Allied forces in the Pacific. Now, she provided logistical support of a different kind, receiving and retransmitting signals from the two spacecraft, boosting them over the horizon again to Cape Canaveral.
Redstone’s sensitive tracking antennas and telephoto-lens cameras continuously adjusted to match the spaceships’ trajectories, following a combination of pre-programmed data about the planned trajectories and feedback from their own computers. Today,
Redstone supported a human crew, but she was getting on in years, and her replacements, the great TDRSS satellites, had already started going up. Like many machines before her, one of her last services was to help render herself obsolete.
Millions of times per second, electrons ran back and forth. Thousands of times per second, sensors lining the two spaceships’ propulsion and life-support systems took their precise measurements. Hundreds of times per second, these measurements made their way down to
Redstone and back to Cape Canaveral and to Houston, where they were automatically routed to flight controllers’ computers and to archaic recording equipment, which, built years before the craft they now monitored, carefully embedded the information onto strips of iron oxide.
In such manner, vital information about the performance of rocket motors and human bodies made its way to men (and, more and more often with every passing year, women) who could not themselves experience the crushing pressures of a combustion chamber or feel the pulse of the men who, at that instant, were the fastest on Earth.
The transition from the Bush Administration to the Clinton Administration caused a great deal of concern at NASA and its prime contractors (and their surrounding communities) as to the fate of the Space Exploration Initiative. The National Space Council and NASA had assumed that President Bush would have two terms with which to implement their recommendations, but the lackluster performance of the American economy and Bush’s backtracking on his promise to not raise taxes left him a one-term President. The disruption at NASA and the NSC was not so great as might have been feared--the NSC’s successful implementation of the first steps toward the SEI showed the competence of its leaders, and the imminent debut of a new American launch vehicle (one built and operated without much oversight from NASA, at that) underscored the need for a council to advise the President on all aspects of American space policy. Administrator Goldin, for his part, continued his work at the agency, which is not a surprise given his party affiliation.
President Clinton, to all accounts, had not given space policy a great deal of thought during his election campaign, and as Governor of Arkansas it had never been on his radar. When he took office in 1993, he was thus a fairly blank slate on which his advisors could write. Those parts of the Space Exploration Initiative that had been approved in 1991 and 1992 were still early enough in their development that, if he had so chosen, he could have cancelled them and replaced them with something else with minimal complaint about sunk costs. However, neither his Vice President, Al Gore (who took Dan Quayle’s place on the NSC), nor his OMB director, Leon Panetta, took a decisive stand against the programs. The Space Exploration Initiative’s programs (Armstrong and the Lunar Transfer Vehicle) were, at the time, on-budget and on-schedule, and Administrator Goldin managed to play up the long-term cost savings of the LTV for commercial satellite deployment. He also managed to sell Clinton on the merits of Armstrong for strengthening ties to the Russian and European aerospace engineering industries, which played well to the Administration’s interest in cooperation with Russia. However, the sustainability of the Space Exploration Initiative would depend on the initial testing of the LTV and the preparations of Armstrong to remain on time.
While administration officials debated the future of NASA’s manned missions beyond Low Earth Orbit, it was the agency’s most distant missions that were making the most tangible progress. The first Mariner Mark II mission since Magellan’s failure to reach the launch pad was Cassini
, originally the Saturn Orbiter/Titan Probe. Launched on November 26, 1995 by a Lifter-Centaur rocket, Cassini
was quickly injected on a Trans-Jovian orbit, picking up a slight gravity assist from that planet before continuing on to Saturn. After releasing its Saturn atmospheric probe, the spacecraft entered orbit around the ringed planet. Cassini
then cut Huygens
loose, sending the small, spin-stabilized probe on its own brief, independent journey to Titan.
In the spirit of the Mariner Mark II design philosophy, and taking advantage of the budget increases NASA had seen under the Bush Administration for SEI, Cassini
had received an additional atmospheric probe, whose design had been lifted with some slight modification from the Galileo Jupiter Probes that had performed so admirably almost two decades earlier. Fitting into one of the two attachment rings on the standard Mariner Mark II Bus (with Huygens
operating the other ring), the Saturn Probe plunged into the planet’s mostly-hydrogen atmosphere on October 7, 2002. Though the two largest planets in the Solar System have a broadly similar chemical composition, Saturn is far lighter than Jupiter, and its gravitational pull is consequently weaker. The Probe entered the atmosphere at only 27 km/s, to the Galileo Probes’ 47 km/s, and as it fell through the Saturnian atmosphere, the pressures and temperatures it measured rose far more slowly than those encountered by its Jovian ancestors. Galileo’s probes had failed at roughly 23 atmospheres of pressure 55 minutes after their parachutes deployed. The Cassini
probe, however, would take 55 minutes just to reach the 5 atmosphere depth required to succeed in its primary mission. There was a risk that Cassini
would fall below the horizon, out of sight of its probe, while the probe futiley beamed its data out into space. The solution adopted at JPL was to simply cut the parachute loose after the probe slowed to terminal velocity, allowing it to fall through the desired depth while Cassini remained above the horizon. The scientists were not disappointed: the Cassini
Probe survived to a pressure of 23.9 atmospheres before it ceased communications with the Orbiter, descending through almost a thousand kilometers of Saturn’s atmosphere, and the orbiter caught every bit of it.
Probe’s structure and Entry/Descent equipment drew heavily from that on the Galileo Probe, but its instruments were redesigned to tackle a new set of scientific questions. Planetary scientists disagreed on the actual way in which the Gas Giants had accreted, whether the heavy elements that formed the (presumed) core of the planets had been in the form of clathrate-hydrate asteroids and comets drawn into the cores, or whether they had been evenly mixed into the material that eventually formed the atmospheres of Jupiter and Saturn. To constrain models of planetary formation, scientists wanted data on the abundances of the “heavy” (heavier than helium) elements, namely oxygen, sulfur, phosphorus, and nitrogen. The Voyager
spacecraft had already shown that carbon grew more abundant further out from Jupiter, but the abundances of other elements were much less well-understood. To address that issue, the Cassini
Probe carried as its primary instrument a mass-spectrometer to characterize the abundances of the heavy elements, particularly in the deeper, better-mixed Saturnian atmosphere.
Though the spectrometer was the main instrument on the Probe, it also carried an optical camera to help characterize cloud structures and wind behavior in Saturn’s atmosphere. While the environment grew too dark for useful photography before the end of the Probe’s mission, the early phase of the Probe’s descent saw the recovery of dozens of photos of Saturn’s cloud-tops, and one particularly impressive photo of white-yellow clouds under a pale blue sky, with Saturn’s rings setting into the distant horizon. These were the first photographs returned from the Saturn system by the Cassini
spacecraft, and they whet the appetite of scientists and the public for more.
, a spacecraft built by the European Space Agency, occupied Cassini
’s second attachment ring until its separation from the main spacecraft in June of 2002. For six months the probe drifted slowly away from Cassini
, aimed at the thickly-veiled moon Titan. Last examined by the Voyager 1 spacecraft in the 1970s, Titan and its thick, nitrogen-and-hydrocarbon atmosphere held out the tantalizing possibility of a geologically and chemically active world, a world analogous to Earth, with seas of ethane and snows of tar. The engineers who designed Huygens
half expected the spacecraft to splash down into an ethane sea, and designed the probe accordingly to float if it did.
As it happened, the probe’s descent did not take it into a Titanian sea, but it did reach the next-best thing: a dry riverbed, resembling for all the world an Arabian Wadi. As the probe descended through the atmosphere, barely falling at all in Titan’s low gravity and thick atmosphere, its cameras sent back pictures of a narrow, steep-sided valley stretching from horizon to horizon. The probe’s slow descent through Titan’s atmosphere took 2 hours and 30 minutes, at the end of which it had very little battery power with which to actually study Titan’s surface, but the brief readings it did transmit to Cassini
(which crossed under the horizon sooner than it might have, as the banks of the Wadi al-Huygens rose many meters above the icy sand on which Huygens
actually landed) revealed a surface mostly composed of water-ice, with a thin slick of methane and methane-ice. Boulders of water-ice were strewn liberally across the Wadi’s bed, often dwarfing Huygens
itself, indicating that the Wadi had been the site of a cataclysmic flood akin to the flash floods that often take place in Arabian and American deserts during rare thunderstorms.
had been specifically aimed at Titan’s equatorial-to-temperate latitudes (between 60 N and 60 S). As it happened, Cassini
’s on-board radar revealed, during subsequent close approaches to Titan, that the moon’s filled seas and lakes were mostly above 70 degrees north, with a few scattered around the South Pole as well. Though Huygens
had missed landing in an actual body of liquid, the images it sent back of the Wadi al-Huygens were, if anything, more useful to characterizing Titan’s “methanosphere” than an actual splash-down would have been. Combined with studies of Titan’s atmosphere and repeated close approaches by Cassini
, the results from Huygens
helped planetary scientists to understand that Titan’s methane cycle operates on much longer time-scales than Earth’s water cycle does, with cataclysmic flash-floods of methane separated by decades of drought.
itself went on to a productive primary mission after both its probes were expended. Powered by a plutonium RTG, the spacecraft made repeated close approaches to Titan and other moons of Saturn (particularly Enceladus, whose polar water geysers inspired even more hope for a sudden, monumental breakthrough than Titan’s strange, non-polar chemistry), and observed the planet Saturn and its magnetosphere. The planet’s relatively benign radiation belts and gentle magnetic field were an interesting contrast to vicious, dynamic Jupiter, and Cassini
’s data on these phenomena and Saturn’s atmospheric behavior over the course of the spacecraft’s life helped develop and refine models of the behavior of giant planets, models which would soon gain another point when the Le Verrier
mission reached Neptune.
The most unique planetary science mission of the first decade of the new millennium, however, was not revolutionary in its propulsion technology or its instruments, but in the identity of its organizers. In 1994, as Geostar prepared to expand its network’s coverage to Europe and the former Warsaw Pact, one of the Geostar II satellite busses (Geostar IIC), suffered major damage in manufacturing when it fell from the truck bed on which it was being transported. Though the company partially repaired the bus, insurers were unwilling to cover the satellite on future launches, leaving a very expensive lump of aluminum, electronics, and solar panels sitting in a sealed nitrogen tank at the Geostar assembly plant in San Jose. The bus was set to be scrapped when, in 1995, the Space Studies Institute unexpectedly purchased it (at scrap-metal prices). The SSI had previously funded the development of advanced space technologies (in particular, it helped pave the way for the integration of Soviet Hall-effect thrusters into the Geostar II series, and sent numerous space manufacturing experiments up to Spacelab and Mir), but the SSI’s plans for Geostar IIC were more ambitious than anything it had done before. Though microgravity manufacturing of metals and crystals still attracted a great deal of scientific interest, investors in the 1980s and early 1990s had still been lukewarm to the idea. The SSI, directed by its late founder, Gerard K. O’Neill, to keep working “until people are living and working in space,” began to search for an alternate “killer application” to catalyze the movement of people and industry beyond Earth’s atmosphere. As launch costs in the 1990s began to fall again, due first to competition from the former Soviet Union and then to the emergence of more reusable launch systems, the idea of asteroid mining, long a fixture in science fiction, came back into vogue.
The arguments in favor of asteroid mining are well-known: of the multitudes of minor planets in the solar system, some orbit close enough to Earth that the cost of propellant to access them is less than that needed to land on the Moon. Of those, some have useful resources that can be processed and returned to cislunar space or, more optimistically, Earth itself. A metallic asteroid can contain precious metals, which could be returned to Earth, and more mundane ones, which could be used in space. A carbonaceous asteroid or a comet could contain volatile ices, which could be refined into rocket propellant or plastics or other materials. However, there were in the early 1990s (and remain to this day) many unknowns about how exactly one could extract useful materials in the absence of gravity or a useful atmosphere. Serious planning for asteroid mining could not begin until basic questions about metallic asteroid morphology and chemical distribution were answered.
It is those questions that the Space Studies Institute set out to answer when it bought the Geostar IIC bus and rechristened it Flying Mountain 1
. Under the direction of Principal Investigator John S. Lewis of the University of Arizona, the bus was outfitted with an array of spectrometers, a microwave antenna, a radar antenna, and a high-gain communications dish. A high-resolution optical telescope, purchased from the Ameriglobe corporation (which used similar telescopes for their commercial imaging satellites), completed the set in 1999. Flying Mountain 1
spent the next three years awaiting a launch opportunity that would allow it to rendezvous with its target, the asteroid 1986 DA. This asteroid had attained brief notoriety in 1991, when radar observations showed it to be unusually smooth and reflective, supporting the hypothesis that it was a fraction of a differentiated body, spun off in a catastrophic collision--in other words, a fraction of a minor planet’s core. The prevailing theory of planetary formation holds that iron cores contained the bulk of the gold, platinum, iridium, and other comparatively rare metals that went into a planet during accretion, as these so-called “siderophilic” elements bonded easily to iron, which sinks underneath silicate. Popular science magazines thus briefly carried a headline about an asteroid that carried “10,000 tons of gold and 100,000 tons of platinum”--1986 DA. Flying Mountain 1
, launched in 2002, set out to prospect the asteroid and see whether it could finally provide the “killer application” for spaceflight.
However much public imagination was fired by the achievements of NASA and even non-governmental agencies in the push for renewed exploration of the outer reaches of the solar systems, the critical decisions about about the direction of American efforts in spaceflight under the new administration would depend more on the successes and failures of the manned spaceflight program--as the saying went: “No Buck Rogers, No Bucks.” While NASA awaited the new President’s decision on the fate of the SEI’s programs, they did their best to push on in spite of the uncertainties. Their major development projects, Armstrong and the Lunar Transfer Vehicle, were both in stages of development where progress was rapid, but largely unseen. The spring of 1993 found both projects rapidly moving through design reviews as parts began to pass out of design software and simulations and into the hands of manufacturing and test engineers.
As the portion of the program most immediately tied to human spaceflight, the new Armstrong Partial Gravity Laboratory seized much of the spotlight, with the Lunar Transfer Vehicle trailing along in its shadow for lack of a decisive plan for what activities it would be enabling in lunar orbit beyond extended versions of the Apollo 8 mission. Armstrong’s mass ultimately came to slightly over 40 tonnes, mostly concentrated in the Equipment and Service Module (which, during launch, held a great deal of the equipment that would be used to outfit the Wet Workshop). This weight precluded the launch of a crew with the station, as had been done on STS-100, and necessitated a second flight for checkout and setup of the space station, leading to a phenomenon unseen since the Gemini program: two NASA launches from Cape Canaveral in the same day. The launch of Armstrong went off flawlessly on October 9, 1995 with the launch of STS-238 by the Space Lifter Liberty, followed just hours later by the launch of the Space Shuttle Destiny on STS-239 aboard the Space LIfter Independence, which docked with the Shuttle in the early morning of October 10. Over the course of a three-week mission, the crew of Destiny transferred equipment from the ESM to the Wet Workshop, bringing that space to a much greater degree of utility than the Wetlab workshop had ever achieved. They also transferred from their MPEM a number of furnishings and instruments which could not fit inside the ESM during launch, filled as it was with Wet Workshop equipment.
Before undocking on Mission Day 14, the crew of Destiny spun the space station up to 3.5 rotations per minute, enabling the ‘lowest’ level of the Wet Workshop to experience approximately 30% of Earth’s gravity at its floor, while the upper levels experienced progressively smaller accelerations until acceleration was virtually zero at the Docking Module. The ESM, on the opposite side, experienced an acceleration equivalent to that on the Moon’s surface.
The need to keep the station spinning to simulate low gravity complicated both its design and operations involving it, and played a role in delaying the debut of European Crew Return Vehicle originally designed for a permanent docking at Spacelab. As the station drew its power from the sun (whether through photovoltaic conversion or dynamic conversion), it needed to track the sun over the course of its orbit around the Earth, and the Earth’s own orbit around the sun. While a fairly straightforward problem on a microgravity platform, it was complicated by the station’s rapid rotation, which forced the panels to stick out from the end of the ESM, parallel to the spin axis and mounted on bearings that themselves spun at 3.5 rotations per minute to counteract the station’s rotation. A great deal of work had been done on the ground to ensure that these bearings would have a long lifetime, but their replacement still constituted the single most frequent reason for EVAs during Armstrong’s lifetime. The problem of thermal control of a spinning station was similarly difficult. The fact that the station appeared to be spinning whether one spun with it or not led to a number of comparisons by observers on the ground, from windmills to the throne of God, described by Ezekiel as containing wheels within wheels.
While the Space Shuttle had been designed with some ability to grapple and dock with spinning objects, the ability had seldom been used, as the most frequent targets for Shuttle docking missions (Spacelab, Hubble, and USAF reconnaissance satellites) generally were despun to simplify the maneuver. Such operations with spinning spacecraft required precise control of the vehicle’s center-of-mass. When the crew of Destiny undocked from Armstrong, one of their first tasks was to fly out to a distance of 100 meters, de-spin their craft, then re-spin and re-dock, in order to prove the feat was possible at all. A number of accelerometers aboard Destiny fed information into the Shuttle’s docking computer, confirming that the vehicle’s center-of-mass was close enough to the docking axis to enable it to spin properly about that axis. Once de-spun and re-spun, Destiny, under the control of her pilot, Eileen Collins, carefully navigated back to the station. The procedure was repeated a number of times under different lighting conditions and with a number of Armstrong’s tracking features (lights and radio beacons) disabled, but ultimately, all the tests were successful, and the space station was formally open for business by October 26, 1995.
Destiny departed Armstrong and made a brief, 4-kilometer flight to Spacelab, where her crew performed routine maintenance on experiments aboard the station and collected samples for analysis on the ground. In the future, such missions would be delegated to the European CRV, which was evolving from an emergency return vehicle into a more generic, more capable vehicle. Though three Block I CRVs had been manufactured (under the original program name, “Asclepius”), focus had quickly shifted to Bock II, dubbed “Hermes,” which would take over the role of return vehicle, inter-station transfer vehicle, and, ultimately, translunar crew capsule.
The Block II eCRV, with an uprated heatshield capable of returning from a translunar trajectory and improved life-support hardware for its long sojourns to lunar orbit, enjoyed a great deal of commonality with the Block I prototype. While the spacecraft carried more lithium hydroxide (for atmospheric filtration) and more storage space allocated to mission consumables, its outer mold line was essentially identical to that of the Block I capsule, and most of its reentry hardware was only slightly modified. The Service Module was now worthy of the title--rather than a mere array of retrorockets, it was now a modified communications satellite bus that enabled the eCRV to maneuver between Armstrong and Spacelab, and to control the finer aspects of its trajectory during final approach to Earth on high-speed translunar reentries. The spacecraft was put through its paces from 1994 to 1995 in ground tests and in one unmanned orbital test flight, during which an Ariane 3 launched a Block II eCRV on a three-orbit mission to verify its thermal control, power generation, and communications systems, and to demonstrate the capability of ESA and Australian personnel to recover the spacecraft.
The eCRV would finally arrive at Armstrong several months after Destiny’s crew first checked out and completed the station. Launched on an Ariane 3 in March of 1996, the first operational Block II eCRV took up residence at one of Armstrong’s two axial docking ports, leaving the other free for visiting Space Shuttles. In April, the first long-term Armstrong crew, composed of the astronauts Sharon Lucid, Jerry Linenger, and the German Reinhold Ewald, with Russian cosmonaut Vasili Tsibliyev (the first Russian to launch aboard an American rocket), began their six-month stay aboard the station, during which they would conduct groundbreaking experiments in partial-gravity medicine and biochemistry and service experiments aboard Spacelab three times. The eCRV completed its manned shakedown tests with flying colors. Together with the unmanned eCRV reentry test in 1995, the Armstrong 1 mission certified the eCRV for its coming missions beyond Low Earth Orbit.
As for the LTV that would carry it there, its engineers wrapped up the major design work on the new spacecraft and prepared for production. In order to provide for the two or more tug pairs estimated to be required for a lunar mission, NASA had placed an order for six flight-rated tugs, plus ground testing components and flight spares. By the spring of 1993, the design of more than 50% of the stage’s major components had been frozen, among them the critical dimensions of the stage’s methane and oxygen tanks. With this complete, the tooling for rolling sheet metal barrels, spinning the tank end domes, and welding them all together was being put into development. While automated techniques were being considered for future McDonnell projects, the LTV’s tank production would have more in common with their older cousins, as the cost of automation wasn’t judged worth it given the short production run. Testing was also underway with NASA assistance on the development of the forward niobium-alloy heatshield, testing the ability of sample segments to resist the planned aerobraking profile’s blowtorch environment both with and without the intended methane coolant system, ensuring that even a failure of the cooling system would allow the return of the stage to LEO for retrieval. The inconel flare and sidewall insulation shielding were subjected to their own tests, though less severe as the forward main heat shield would take the brunt of the heat loads. All passed, though not without revisions. Functional prototypes of the transfer couplings to allow propellant to be moved into an LTV from a tanker or from another LTV were added to NASA’s Six Degrees of Freedom test rig in Houston, checking that the couplings would not interfere with docking but could be successfully and reliably locked after docking, and more importantly released after use without leaks. The radar systems were tested in parallel with Shuttle’s own radar on flights to Spacelab, and a robotic test system was temporarily mounted to the station to test repeated use of the propellant transfer couplings in space. Slowly but surely, the LTV began to come together, first as drawings and mockups, then as boilerplates and sample parts, and finally as a vehicle ready for space.
The LTV’s structure wasn’t the only system to pace its progress, however. While Aerojet’s design of the small gas/gas CH4/LOX thrusters was proceeding on schedule with initial tests of ignition transients and spark igniters, the Lunar Tug Main Engine (LTME) from Pratt and Whitney was proving more of an issue. Pratt had confidently banked on their RL-10 experience and the small size of the LTME to make a transition of their expander cycle to methane operations trivial. Instead, the opposite was proving true. Thermodynamically, the lower heat capacity of methane meant less cooling capacity and pump energy was available for the same mass of coolant, while the small size of the chamber proved as much of a challenge as a benefit. The tiny chamber, described by some engineers as a “fireball in a paint can,” was so small that even minor intrusions like the walls’ brazing or the locations of temperature and pressure probes caused variations in the internal flows and the rejection of heat into the cooling jacket. Meanwhile, the requirement for >99% reliability in ignition and combustion over a design lifetime dozens of times longer than any engine other than the Lifter’s F-1B--and with less maintenance--were a major issue for testing, even if the expander cycle and methane’s low-coking properties made the LTME inherently more reusable than the massive F-1B. Still, the first components of the LTME were being fabricated and tested on lab benches, with a full-scale engine scheduled for firing by the end of the year. From there, it was anticipated that more than a year and a half of qualification firings and tests might be required, running concurrent with the production of the 30 engines required for flight operations in 1994 and 1995. The LTME posed a risk that significant further delays could postpone the start of flight testing, or require early test flights of the LTV without fully-qualified engines. Under pressure from NASA and McDonnell, Pratt buckled down to work.
In the meantime, NASA reviewed their options for communicating with the LTV on lunar trajectories. In the Apollo program, NASA had been forced to build a global network of ground stations from scratch to communicate with the Apollo crews as the Earth rotated beneath their trajectory to the moon. Even so, they had been unreachable when they were behind the moon, leading to extended period where the crew was unable to communicate with Earth. The role of the ground stations for providing continuous coverage had been taken over by the TDRSS launched by the Space Transportation System, ensuring that astronauts anywhere in cislunar space visible from Earth would be in contact at all times with mission controllers back on the ground.
However, with the communications downlink requirements of Spacelab, Armstrong, the Space Shuttle, and lunar LTV flights possibly someday including crew, the Space Exploration Initiative would require more than TDRSS could currently offer in terms of bandwidth and redundancy. Moreover, the communications blackouts on the lunar farside could no longer be tolerated: the “dark side of the moon” could no longer be under communications shadow. Thus, portions of the funding from SEI would go to a refreshed generation of TDRSS satellites able to handle more sources in orbit at once, and able to supply higher data throughput both between these sources and the ground and between the sources themselves, making use of advances in onboard switching implemented originally by commercial low-Earth-orbit development. More to the point, not all of this new generation would be placed into geostationary orbit. Instead, the new geostationary orbit birds would be joined by duplicate satellites placed into halo orbits of Lagrange Point 2 on the lunar farside, relaying from vehicles in lunar orbit and on the surface to the existing geostationary portions of TDRSS.
Much like Shuttle and Lifter had launched TDRSS, the LTV would have the responsibility of establishing the network which it would come to rely on: some of the first operational missions of the Lunar Transfer Vehicle to cislunar space in 1997 would carry next-generation TDRSS satellites to deploy to L-2. For its earliest flights to the moon, the LTV would have to be capable of operating beyond Earth’s control for critical operations, but if it proved as successful as the Space Transportation System before it, it would soon establish the infrastructure necessary for extensive manned and unmanned operations around the moon.
If NASA was fueling a revolution in communicating with spacecraft in orbit, Trans-Pacific Launch Industries and the Space Transportation Corporation were starting to fuel one in low Earth orbit. For years, geostationary communications satellites had become an accepted and critical link in the transmission of a wide variety of communications media, from relaying satellite telephone interchanges to the distribution of satellite television. Geostar had even demonstrated its use for limited messaging in a two-way perspective for short customer messages, the status symbol of the global road warrior one step up in cost, capability, and prestige from the more common beeper. However, efforts to do other end-user communications applications from the stable platform of geostationary orbit all ran into one hard truth, the same one Admiral Grace Hopper had to teach to the Department of Defense in her era, which now had to be explained to many executives of communications companies: light could only travel so far in a millisecond, and there were a lot of those distances on the way to and from a geostationary relay satellite. The pauses of satellite relays were a common feature on new 24-hour news networks as they tied in reporters around the globe, and plagued executives trying to use international calling over satellite relays as well. To reach the masses, satellite would have to descend from their heights to the depths of low Earth orbit.
To manage this feat, the number of satellites and the variety of their orbital inclinations would be greatly increased to ensure constant relay around the globe. One satellite telephone network named itself Iridium after the 77 satellites they originally calculated to be necessary to reach their customer base, while some satellite internet providers estimated requiring more than ten times that many satellites to reach their initial operational status. The only benefit was that without the requirement to communicate all the way from geostationary orbit, the size of each individual satellite plummeted: dozens could fit in a launch of a TPLI Sierra, and the legacy Space Lifter could launch near triple digits of many of the designs, populating entire orbital planes in a single flight. Without this capacity and the low costs of the associated vehicles, the LEO comsat boom would never have been able to dream of getting off the ground. As it was, Iridium, one of the earliest and less technological aggressive of the concepts, signed a contract with TPLI to launch large portions of their initial orbital capacity in 1997. With one technical venture with high investment risk contracting to fly on another, some industry observers exchanged quiet bets over email and IRC if both could stay funded long enough.
Iridium wasn’t the only player to invest in Low Orbit communications. After the US military’s Global Positioning System became fully operational in the early 1990s, GeoStar took stock of its options and found that, while navigation had been one of their selling points in the 1980s, long-distance communication was actually the greatest service they provided. Furthermore, the rise of the internet suggested that there would soon be a market for high-bandwidth data not just in the developed world, but in the developing world. A GeoStar PowerPoint presentation from 1995 does not hide the scope of their ambitions: by proposing a global
internet constellation, they proposed to tie billions of new consumers into the exploding e-commerce market. The next slide goes on to note that there were no high-speed cables in large parts of Africa, South America, and Asia--effectively meaning that the first company to beam internet from Low Earth Orbit would have a monopoly on entire continents.
The GeoStar Arachne series of satellite busses was born from these considerations. Far smaller than the great geostationary busses they’d launched before, and produced by the truckload, each weighed just a few hundred kilograms. The only serious problem the series encountered during its development was the sheer speed at which internet speeds increased, which drove redesigns to the communications gear to process ever-greater transmission rates. Ultimately, though, GeoStar settled on a bandwidth that they felt could transmit every service of value (modest by modern standards, in the days before high-definition streaming), and Arachne began launching aboard TPLI’s Sierra in 1999.
While the development work to prepare Armstrong, the LTV, and the eCRV was underway and NASA plumbed ever deeper into the solar system in the wake of the loss of Magellan, the future of the space program was being decided elsewhere. In PowerPoint presentations in boardrooms in Silicon Valley, the comsat business was hunting for the funding for the constellations which TPLI and STC hoped might fuel the next boom in reusable launch systems. Meanwhile, in briefings between President Clinton, his advisors, Administrator Goldin, and key congressional powerbrokers, the fate of human spaceflight using the Lunar Transfer Vehicle to fly to the moon was hotly debated. The most valuable data on the future of spaceflight flowed into offices in Washington D.C., where the fate of the Space Exploration Initiative’s follow-ups would be decided by bean-counters and politicians who would never once design a combustion chamber or feel for themselves the pressure of preparing and flying a mission to space.