Planets
The Sun
While the Sun will probably not be physically explored in the close future, one of the reasons for going into space includes knowing more about the Sun. Once above the atmosphere in particular and the Earth’s magnetic field, this gives access to the Solar wind and infrared and ultraviolet radiations that cannot reach the surface of the Earth. The Sun generates most space weather, which can affect power generation and transmission systems on Earth and interfere with, and even damage, satellites and space probes.
MESSENGER image of Mercury
A MESSENGER image from 18,000 km showing a region about 500 km across
Mercury
Mercury remains the least explored of the inner planets. As of May 2011, the Mariner 10 and MESSENGER missions have been the only missions that have made close observations of Mercury. MESSENGER entered orbit around Mercury in March, 2011, to further investigate the observations made by Mariner 10 in 1975 (Munsell, 2006b). A third mission to Mercury, scheduled to arrive in 2020, BepiColombo is to include two probes. BepiColombo is a joint mission between Japan and the European Space Agency. MESSENGER and BepiColombo are intended to gather complementary data to help scientists understand many of the mysteries discovered by Mariner 10’s flybys.
Flights to other planets within the Solar System are accomplished at a cost in energy, which is described by the net change in velocity of the spacecraft, or delta-v. Due to the relatively high delta-v to reach Mercury and its proximity to the Sun, it is difficult to explore and orbits around it are rather unstable.
Mariner 10 image of Venus
Venus
Venus was the first target of interplanetary flyby and lander missions and, despite one of the most hostile surface environments in the solar system, has had more landers sent to it (nearly all from the Soviet Union) than any other planet in the solar system. The first successful Venus flyby was the American Mariner 2 spacecraft, which flew past Venus in 1962. Mariner 2 has been followed by several other flybys by multiple space agencies often as part of missions using a Venus flyby to provide a gravitational assist en route to other celestial bodies. In 1967 Venera 4 became the first probe to enter and directly examine the atmosphere of Venus. In 1970 Venera 7 became the first successful lander to reach the surface of Venus and by 1985 it had been followed by eight additional successful Soviet Venus landers which provided images and other direct surface data. Starting in 1975 with the Soviet orbiter Venera 9 some ten successful orbiter missions have been sent to Venus, including later missions which were able to map the surface of Venus using radar to pierce the obscuring atmosphere.
The “marble” Earth picture taken by Apollo 17
First television image of Earth from space
Earth
Space exploration has been used as a tool to understand the Earth as a celestial object in its own right. Orbital missions can provide data for the Earth that can be difficult or impossible to obtain from a purely ground-based point of reference.
For example, the existence of the Van Allen belts was unknown until their discovery by the United States’ first artificial satellite, Explorer 1. These belts contain radiation trapped by the Earth’s magnetic fields, which currently renders construction of habitable space stations above 1000 km impractical. Following this early unexpected discovery, a large number of Earth observation satellites have been deployed specifically to explore the Earth from a space based perspective. These satellites have significantly contributed to the understanding of a variety of earth based phenomena. For instance, the hole in the ozone layer was found by an artificial satellite that was exploring Earth’s atmosphere, and satellites have allowed for the discovery of archeological sites or geological formations that were difficult or impossible to otherwise identify.
The Moon as seen from the Earth
Luc Viatour (Belgium)
Apollo 16 astronaut John Young
Earth’s Moon
Earth’s Moon was the first celestial body to be the object of space exploration. It holds the distinctions of being the first remote celestial object to be flown by, orbited, and landed upon by spacecraft, and the only remote celestial object ever to be visited by humans.
In 1959 the Soviets obtained the first images of the far side of the Moon, never previously visible to humans. The U.S. exploration of the Moon began with the Ranger 4 impactor in 1962. Starting in 1966 the Soviets successfully deployed a number of landers to the Moon which were able to obtain data directly from the Moon’s surface; just four months later, Surveyor 1 marked the debut of a successful series of U.S. landers. The Soviet unmanned missions culminated in the Lunokhod program in the early ’70s which included the first unmanned rovers and also successfully returned lunar soil samples to the Earth for study. This marked the first (and to date the only) automated return of extraterrestrial soil samples to the Earth. Unmanned exploration of the Moon continues with various nations periodically deploying lunar orbiters, and in 2008 the Indian Moon Impact Probe.
Manned exploration of the Moon began in 1968 with the Apollo 8 mission that successfully orbited the Moon, the first time any extraterrestrial object was orbited by humans. In 1969 the Apollo 11 mission marked the first time humans set foot upon another world. Manned exploration of the Moon did not continue for long, however. The Apollo 17 mission in 1972 marked the most recent human visit to another world, and there is no further planned human exploration of an extraterrestrial body, though robotic missions are still pursued vigorously.
Mars as seen by the HST
Part of a panorama taken by the Spirit rover in 2004
Mars
The exploration of Mars has been an important part of the space exploration programs of the Soviet Union (later Russia), the United States, Europe, and Japan. Dozens of robotic spacecraft, including orbiters, landers, and rovers, have been launched toward Mars since the 1960s. These missions were aimed at gathering data about current conditions and answering questions about the history of Mars. The questions raised by the scientific community are expected to not only give a better appreciation of the red planet but also yield further insight into the past, and possible future, of Earth.
The exploration of Mars has come at a considerable financial cost with roughly two-thirds of all spacecraft destined for Mars failing before completing their missions, with some failing before they even began. Such a high failure rate can be attributed to the complexity and large number of variables involved in an interplanetary journey, and has led researchers to jokingly speak of The Great Galactic Ghoul which subsists on a diet of Mars probes. This phenomenon is also informally known as the Mars Curse.
Phobos
The Russian space mission Phobos-Grunt, Scheduled to launch in 2011, will begin exploration of the Phobos and Martian circumterrestrial orbit, and study whether the moons of Mars, or at least Phobos, could be a “trans-shipment point” for spaceships travelling to Mars.
Asteroids and comets
Until the advent of space travel, objects in the asteroid belt were merely pinpricks of light in even the largest telescopes, their shapes and terrain remaining a mystery. Several asteroids have now been visited by probes, the first of which was Galileo, which flew past two: 951 Gaspra in 1991, followed by 243 Ida in 1993. Both of these lay near enough to Galileo’s planned trajectory to Jupiter that they could be visited at acceptable cost. The first landing on an asteroid was performed by the NEAR Shoemaker probe in 2000, following an orbital survey of the object. The dwarf planet Ceres and the asteroid 4 Vesta, two of the three largest asteroids, are targets of NASA’s Dawn mission, launched in 2007.
While many comets have been closely studied from Earth sometimes with centuries-worth of observations, only a few comets have been closely visited. A few long-period comets are currently the furthest known objects in the solar system. In 1985, the International Cometary Explorer conducted the first comet fly-by (21P/Giacobini-Zinner) before joining the Halley Armada studying the famous comet. The Deep Impact probe smashed into 9P/Tempel to learn more about its structure and composition while the Stardust mission returned samples of another comet’s tail. The Philae lander will attempt to land on a comet in 2014.
Hayabusa was an unmanned spacecraft developed by the Japan Aerospace Exploration Agency to return a sample of material from a small near-Earth asteroid named 25143 Itokawa to Earth for further analysis. Hayabusa was launched on 9 May 2003 and rendezvoused with Itokawa in mid-September 2005. After arriving at Itokawa, Hayabusa studied the asteroid’s shape, spin, topography, colour, composition, density, and history. In November 2005, it landed on the asteroid to collect samples. The spacecraft returned to Earth on 13 June 2010.
Deep space exploration
Jupiter
Voyager 1 image of Jupiter
Image of Io taken by the Galileo spacecraft
The exploration of Jupiter has consisted solely of a number of automated NASA spacecraft visiting the planet since 1973. A large majority of the missions have been “flybys”, in which detailed observations are taken without the probe landing or entering orbit; the Galileo spacecraft is the only one to have orbited the planet. As Jupiter is believed to have only a relatively small rocky core and no real solid surface, a landing mission is nearly impossible.
Reaching Jupiter from Earth requires a delta-v of 9.2 km/s,[20] which is comparable to the 9.7 km/s delta-v needed to reach low Earth orbit. Fortunately, gravity assists through planetary flybys can be used to reduce the energy required at launch to reach Jupiter, albeit at the cost of a significantly longer flight duration.
Jupiter has over 60 known moons, many of which have relatively little known information about them.
A picture of Saturn taken by Voyager 2.
Saturn
Saturn has been explored only through unmanned spacecraft launched by NASA, including one mission (Cassini–Huygens) planned and executed in cooperation with other space agencies. These missions consist of flybys in 1979 by Pioneer 11, in 1980 by Voyager 1, in 1982 by Voyager 2 and an orbital mission by the Cassini spacecraft which entered orbit in 2004 and is expected to continue its mission well into 2010.
Saturn has at least 62 satellites, although the exact number is debatable since Saturn’s rings are made up of vast numbers of independently orbiting objects of varying sizes. The largest of the moons is Titan. Titan holds the distinction of being the only moon in the solar system with an atmosphere denser and thicker than that of the Earth. As a result of the deployment from the Cassini spacecraft of the Huygens probe and its successful landing on Titan, Titan also holds the distinction of being the only moon (apart from Earth’s own Moon) to be successfully explored with a lander.
Uranus from Voyager 2
Voyager 2 image showing the tortured surface of Miranda
Uranus
The exploration of Uranus has been entirely through the Voyager 2 spacecraft, with no other visits currently planned. Given its axial tilt of 97.77°, with its polar regions exposed to sunlight or darkness for long periods, scientists were not sure what to expect at Uranus. The closest approach to Uranus occurred on January 24, 1986. Voyager 2 studied the planet’s unique atmosphere and magnetosphere. Voyager 2 also examined its ring system and the moons of Uranus including all five of the previously known moons, while discovering an additional ten previously unknown moons.
Images of Uranus proved to have a very uniform appearance, with no evidence of the dramatic storms or atmospheric banding evident on Jupiter and Saturn. Great effort was required to even identify a few clouds in the images of the planet. The magnetosphere of Uranus, however, proved to be completely unique and proved to be profoundly affected by the planet’s unusual axial tilt. In contrast to the bland appearance of Uranus itself, striking images were obtained of the moons of Uranus, including evidence that Miranda had been unusually geologically active.
Picture of Neptune taken by Voyager 2
Triton as imaged by Voyager 2
Neptune
The exploration of Neptune began with the August 25, 1989 Voyager 2 flyby, the sole visit to the system as of 2009. The possibility of a Neptune Orbiter has been discussed, but no other missions have been given serious thought.
Although the extremely uniform appearance of Uranus during Voyager 2’s visit in 1986 had led to expectations that Neptune would also have few visible atmospheric phenomena, Voyager 2 found that Neptune had obvious banding, visible clouds, auroras, and even a conspicuous anticyclone storm system rivaled in size only by Jupiter’s small Spot. Neptune also proved to have the fastest winds of any planet in the solar system, measured as high as 2,100 km/h. Voyager 2 also examined Neptune’s ring and moon system. It discovered 900 complete rings and additional partial ring “arcs” around Neptune. In addition to examining Neptune’s three previously known moons, Voyager 2 also discovered five previously known moons, one of which, Proteus, proved to be the last largest moon in the system. Data from Voyager further reinforced the view that Neptune’s largest moon, Triton, is a captured Kuiper belt object.
Pluto
Pluto and Charon (1994)
The dwarf planet Pluto (considered a planet until the IAU redefinition of “planet” in October 2006presents significant challenges for spacecraft because of its great distance from Earth (requiring high velocity for reasonable trip times) and small mass (making capture into orbit very difficult at present). Voyager 1 could have visited Pluto, but controllers opted instead for a close flyby of Saturn’s moon Titan, resulting in a trajectory incompatible with a Pluto flyby. Voyager 2 never had a plausible trajectory for reaching Pluto.
Pluto continues to be of great interest, despite its reclassification as the lead and nearest member of a new and growing class of distant icy bodies of intermediate size, in mass between the remaining eight planets and the small rocky objects historically termed asteroids (and also the first member of the important subclass, defined by orbit and known as “Plutinos“). After an intense political battle, a mission to Pluto dubbed New Horizons was granted funding from the US government in 2003. New Horizons was launched successfully on January 19, 2006. In early 2007 the craft made use of a gravity assist from Jupiter. Its closest approach to Pluto will be on July 14, 2015; scientific observations of Pluto will begin five months prior to closest approach and will continue for at least a month after the encounter.
Energy
An Artificial Leaf Invented Which Can Solve Power Crisis
An important step toward realizing the dream of an inexpensive and simple “artificial leaf,” a device to harness solar energy by splitting water molecules, has been accomplished by two separate teams of researchers at MIT
Scientists have created the world’s first practical artificial leaf that can turn sunlight and water into energy, which they claim could pave the way for a cheaper source of power.
A team at Massachusetts Institute of Technology (MIT) says that the artificial leaf from silicon, electronics and various catalysts which spur chemical reactions within the device, can use sunlight to break water into hydrogen and oxygen which can then be used to create electricity in a separate fuel cell.
“A practical artificial leaf has been one of the Holy Grails of science for decades. We believe we have done it. And placed in a gallon of water and left in sun, these artificial leaves could provide a home in the developing world with basic electricity for a day,” Daniel Nocera, who led the team, said.
He added: “Our goal is to make each home its own power station. One can envision villages in India and Africa not long from now purchasing an affordable basic power system based on this technology.”
Both teams produced devices that combine a standard silicon solar cell with a catalyst developed three years ago by professor Daniel Nocera. When submerged in water and exposed to sunlight, the devices cause bubbles of oxygen to separate out of the water.
The next step to producing a full, usable artificial leaf, explains Nocera, the Henry Dreyfus Professor of Energy and professor of chemistry, will be to integrate the final ingredient: an additional catalyst to bubble out the water’s hydrogen atoms. In the current devices, hydrogen atoms are simply dissociated into the solution as loose protons and electrons. If a catalyst could produce fully formed hydrogen molecules (H2), the molecules could be used to generate electricity or to make fuel for vehicles. Realization of that step, Nocera says, will be the subject of a forthcoming paper.
The reports by the two teams were published in the journals Energy & Environmental Science on May 12, and the Proceedings of the National Academy of Sciences on June 6. Nocera encouraged two different teams to work on the project so that each could bring their special expertise to addressing the problem, and says the fact that both succeeded “speaks to the versatility of the catalyst system.”
Nocera’s ultimate goal is to produce an “artificial leaf” so simple and so inexpensive that it could be made widely available to the billions of people in the world who lack access to adequate, reliable sources of electricity. What’s needed to accomplish that, in addition to stepping up the voltage, is the addition of a second catalyst material to the other side of the silicon cell, Nocera says.
Making hydrogen gas (the bubbles) from a solar cell in water, a Sun Catalytix prototype.
The “leaf” system, by contrast, is “still a science project,” Nocera says. “We haven’t even gotten to what I would call an engineering design.” He hopes, however, that the artificial leaf could become a reality within three years.
Space Shuttle Columbia
Space Shuttle Columbia (NASA Orbiter Vehicle Designation: OV-102) was the first spaceworthy Space Shuttle in NASA‘s orbital fleet. First launched on the STS-1 mission, the first of the Space Shuttle program, it completed 27 missions before being destroyed during re-entry on February 1, 2003 near the end of its 28th, STS-107. All seven crew members were killed. Following an independent investigation into the cause of the accident, NASA decided to retire the Shuttle orbiter fleet in 2010 in favor of the Constellation program and its manned Orion spacecraft. However, President Obama signed the NASA Authorization Act 2010 on October 11 which officially brought the Constellation program to an end.
| Columbia OV-102 |
|
|---|---|
 Space Shuttle Columbia rolls towards Launch Pad 39A, atop the Mobile Launcher Platform, carried by a crawler-transporter (underneath), prior to launching on STS-107. Columbia disintegrated on re-entry at the end of this mission |
|
| OV designation | OV-102 |
| Country | United States |
| Contract award | July 26, 1972 |
| Named after | Columbia (1773) (renamed Columbia Rediviva, 1787) |
| Status | Destroyed February 1, 2003 |
| First flight | STS-1 April 12, 1981 – April 14, 1981 |
| Last flight | STS-107 January 16, 2003 – February 1, 2003 |
| Number of missions | 28 |
| Crews | 160 |
| Time spent in space | 300 days 17:40:22[1] |
| Number of orbits | 4,808 |
| Distance travelled | 201,497,772 km (125,204,911 miles) |
| Satellites deployed | |
Flights
Space Shuttle Columbia flew 28 flights, spent 300.74 days in space, completed 4,808 orbits, and flew 125,204,911 miles (201,497,772 km) in total, including its final mission.
Columbia was the only shuttle to have been spaceworthy during the Shuttle-Mir and International Space Station programs and yet to have never visited either Mir or ISS. In contrast, Discovery, Atlantis, and Endeavour have all visited both stations at least once, as Columbia was not suited for high-inclination missions. Challenger was destroyed before the Shuttle-Mir Program began, and Enterprise never flew in space.
| # | Date | Designation | Launch pad | Landing location | Notes |
|---|---|---|---|---|---|
| 1 | 1981, April 12 | STS-1 | 39-A | Edwards Air Force Base | First shuttle mission. Launch witnessed by the band Rush; inspired the song “Countdown” on their 1982 album Signals. |
| 2 | 1981, November 12 | STS-2 | 39-A | Edwards Air Force Base | First re-use of manned space vehicle |
| 3 | 1982, March 22 | STS-3 | 39-A | White Sands Space Harbor | First mission with an unpainted External tank. Only time that a space shuttle has landed at the White Sands Space Harbor. This launch was dedicated by Ronald Reagan to “the people of Afghanistan“. |
| 4 | 1982, June 27 | STS-4 | 39-A | Edwards Air Force Base | Last shuttle R&D flight |
| 5 | 1982, November 11 | STS-5 | 39-A | Edwards Air Force Base | First four-person crew, first deployment of commercial satellite. |
| 6 | 1983 November 28 | STS-9 | 39-A | Edwards Air Force Base | First six-person crew, first Spacelab. |
| 7 | 1986, January 12 | STS-61-C | 39-A | Edwards Air Force Base | Representative Bill Nelson (D–FL) on board/ final successful shuttle flight before Challenger disaster |
| 8 | 1989, August 8 | STS-28 | 39-B | Edwards Air Force Base | Launched KH-11 reconnaissance satellite |
| 9 | 1990, January 9 | STS-32 | 39-A | Edwards Air Force Base | Retrieved Long Duration Exposure Facility |
| 10 | 1990, December 2 | STS-35 | 39-B | Edwards Air Force Base | Carried multiple X-ray & UV telescopes |
| 11 | 1991, June 5 | STS-40 | 39-B | Edwards Air Force Base | 5th Spacelab – Life Sciences-1 |
| 12 | 1992, June 25 | STS-50 | 39-A | Kennedy Space Center | U.S. Microgravity Laboratory 1 (USML-1) |
| 13 | 1992, October 22 | STS-52 | 39-B | Kennedy Space Center | Deployed Laser Geodynamic Satellite II |
| 14 | 1993, April 26 | STS-55 | 39-A | Edwards Air Force Base | German Spacelab D-2 Microgravity Research |
| 15 | 1993, October 18 | STS-58 | 39-B | Edwards Air Force Base | Spacelab Life Sciences |
| 16 | 1994, March 4 | STS-62 | 39-B | Kennedy Space Center | United States Microgravity Payload-2 (USMP-2) |
| 17 | 1994, July 8 | STS-65 | 39-A | Kennedy Space Center | International Microgravity Laboratory (IML-2) |
| 18 | 1995, October 20 | STS-73 | 39-B | Kennedy Space Center | United States Microgravity Laboratory (USML-2) |
| 19 | 1996, February 22 | STS-75 | 39-B | Kennedy Space Center | Tethered Satellite System Reflight (TSS-1R) |
| 20 | 1996, June 20 | STS-78 | 39-B | Kennedy Space Center | Life and Microgravity Spacelab (LMS) |
| 21 | 1996, November 19 | STS-80 | 39-B | Kennedy Space Center | 3rd flight of Wake Shield Facility (WSF)/ longest Shuttle flight |
| 22 | 1997, April 4 | STS-83 | 39-A | Kennedy Space Center | Microgravity Science Laboratory (MSL)- cut short |
| 23 | 1997, July 1 | STS-94 | 39-A | Kennedy Space Center | Microgravity Science Laboratory (MSL)- reflight |
| 24 | 1997, November 19 | STS-87 | 39-B | Kennedy Space Center | United States Microgravity Payload (USMP-4) |
| 25 | 1998, April 13 | STS-90 | 39-B | Kennedy Space Center | Neurolab – Spacelab |
| 26 | 1999, July 23 | STS-93 | 39-B | Kennedy Space Center | Deployed Chandra X-ray Observatory |
| 27 | 2002, March 1 | STS-109 | 39-A | Kennedy Space Center | Hubble Space Telescope service mission (HSM-3B) |
| 28 | 2003, January 16 | STS-107 | 39-A | Did not land (Planned to land at Kennedy Space Center) | A multi-disciplinary microgravity and Earth science research mission. Shuttle destroyed during re-entry on February 1, 2003 and all seven astronauts on board died. |
Technology Evolution
Theory of technological evolution
According to Richta and later Bloomfield, technology (which Richta defines as “a material entity created by the application of mental and physical effort to nature in order to achieve some value”) evolves in three stages: tools, machine, automation. This evolution, he says, follows two trends: the replacement of physical labour with more efficient mental labour, and the resulting greater degree of control over one’s natural environment, including an ability to transform raw materials into ever more complex and pliable products.
Stages of technological development
The pretechnological period, in which all other animal species remain today aside from some avian and primate species was a non-rational period of the early prehistoric man.
The emergence of technology, made possible by the development of the rational faculty, paved the way for the first stage: the tool. A tool provides a mechanical advantage in accomplishing a physical task, and must be powered by human or animal effort.
Hunter-gatherers developed tools mainly for procuring food. Tools such as a container, spear, arrow, plow, or hammer that augments physical labor to more efficiently achieve his objective. Later animal-powered tools such as the plow and the horse, increased the productivity of food production about tenfold over the technology of the hunter-gatherers. Tools allow one to do things impossible to accomplish with one’s body alone, such as seeing minute visual detail with a microscope, manipulating heavy objects with a pulley and cart, or carrying volumes of water in a bucket.
The second technological stage was the creation of the machine. A machine (a powered machine to be more precise) is a tool that substitutes the element of human physical effort, and requires the operator only to control its function. Machines became widespread with the industrial revolution, though windmills, a type of machine, are much older.
Examples of this include cars, trains, computers, and lights. Machines allow humans to tremendously exceed the limitations of their bodies. Putting a machine on the farm, a tractor, increased food productivity at least tenfold over the technology of the plow and the horse.
The third, and final stage of technological evolution is the automation. The automation is a machine that removes the element of human control with an automatic algorithm. Examples of machines that exhibit this characteristic are digital watches, automatic telephone switches, pacemakers, and computer programs.
It’s important to understand that the three stages outline the introduction of the fundamental types of technology, and so all three continue to be widely used today. A spear, a plow, a pen, and an optical microscope are all examples of tools.
Theoretical implications
The process of technological evolution culminates with the ability to achieve all the material values technologically possible and desirable by mental effort.
An economic implication of the above idea is that intellectual labour will become increasingly more important relative to physical labour. Contracts and agreements around information will become increasingly more common at the marketplace. Expansion and creation of new kinds of institutes that works with information such as for example universities, book stores, patent-trading companies, etc. is considered an indication that a civilization is in technological evolution.
Interestingly, this highlights the importance underlining the debate over intellectual property in conjunction with decentralized distribution systems such as today’s internet. Where the price of information distribution is going towards zero with ever more efficient tools to distribute information is being invented. Growing amounts of information being distributed to an increasingly larger customer base as times goes by. With growing disintermediation in said markets and growing concerns over the protection of intellectual property rights it is not clear what form markets for information will take with the evolution of the information age.
Space Technology
Space technology is technology that is related to entering, and retrieving objects or life forms from space.
“Every day” technologies such as weather forecasting, remote sensing, GPS systems, satellite television, and some long distance communications systems critically rely on space infrastructure. Of sciences astronomy and Earth sciences (via remote sensing) most notably benefit from space technology.
Computers and telemetry were once leading edge technologies that might have been considered “space technology” because of their criticality to boosters and spacecraft. They existed prior to the Space Race of the Cold War (between the USSR and the USA.) but their development was vastly accelerated to meet the needs of the two major superpowers’ space programs. While still used today in spacecraft and missiles, the more prosaic applications such as remote monitoring (via telemetry) of patients, water plants, highway conditions, etc. and the widespread use of computers far surpasses their space applications in quantity and variety of application.
Space is such an alien environment that attempting to work in it requires new techniques and knowledge. New technologies originating with or accelerated by space-related endeavors are often subsequently exploited in other economic activities. This has been widely pointed to as beneficial by space advocates and enthusiast favoring the investment of public funds in space activities and programs. Political opponentscounter that it would be far cheaper to develop specific technologies directly if they are beneficial and scoff at this justification for public expenditures on space-related research.
Techsaga 