SPACE TOURISM: PROBLEMS, LIMITATION AND POSSIBLE SOLUTIONS

Today, new kinds of space travel are emerging. The year 2001 marked the beginning of space tourism, as a wealthy California businessman, Dennis Tito, became the first paying passenger for a space flight. He paid $20 million to be launched by Soyuz TM-32 via arrangements made between an American company called Space Adventures and a Russian company MirCorp, which oversaw the Mir space station. The ticket sale was to fund the maintenance of the Mir space station; however, a premature deorbit decision diverted Tito’s destination to the International Space Station (ISS). For 8 days, Tito enjoyed a unique vacation in orbit and spent seven days on board the International Space Station(ISS). Initially, there were many controversies in NASA in regards to the possible delays that such tourism would cause for the scheduled work. However, the concerns proved to be unfounded as no delays were experienced. Many other laypersons followed Tito’s footsteps: Mark Shuttleworth, a South African technology entrepreneur in 2002; Gregory Olsen, an American entrepreneur-engineer-scientist in 2005; Anousheh Ansari, an Iranian American businesswoman in 2006; and several other wealthy persons. Given the orbital nature of these flights, most of these commercial space travellers needed to go through arduous training for their missions, alongside professional astronauts. However, several private companies are developing suborbital space vehicles to commercialize space travel, which would take passengers to an altitude of 100 km (62 miles). In the coming years, it is expected that such suborbital space tourism will become more affordable, safer, and easier for a wider range of customers.

In 2004, a concrete step towards realizing suborbital space tourism was achieved. During the $10 million Ansari X Prize challenge, private companies competed with each other to launch a reusable manned spacecraft twice within two weeks. On October 4, 2004, Virgin Galactic and Burt Rutan of Scaled Composites won the X Prize with their successful SpaceShipOne and opened the new era of commercial manned spaceflight. In the same year, the U.S. Commercial Space Launch Amendments Act (CSLAA) was instituted to have the Federal Aviation Administration (FAA) regulate the safety of commercial human spaceflight in the U.S. Under this Act, every commercial space launch, landing, and operation will be attended and evaluated by FAA representatives; all spaceflight participants will also be guided through an informed consent process, in writing, about the risks of launch and reentry, including the safety record of the launch vehicle.

Although these safety regulations are still in their early stages of development and implementation, Sir Richard Branson’s Virgin Galactic has already sold more than 625 seats at $200,000 per ticket for its 2.5-hour suborbital space tourism flights on SpaceShip Two. SpaceShip Two was officially disclosed to the public in December, 2009 in California and is tentatively scheduled to start its operations in 2014. The official date for the inaugural launch has never been set, but the tentative start date has been delayed since 2007 due to Virgin Galactic’s rigorous safety testing. With a new former Air Force pilot joined, a spaceport opened, a commercial space system license was applied for, and a powered test flight was successfully performed in 2013, however, Virgin Galactic is confident that their customers trust them to launch when it is truly safe to do so. When that time comes, SpaceShipTwo will be carried to launch altitude (15.25 km) by a jet-powered mothership, the Scaled Composites’ White Knight Two, before turning up its rocket engines to fly up to 110 km in the upper atmosphere. The passengers will feel about 5 minutes of weightlessness as they get amazing views of the planet Earth. The spacecraft will stabilize itself for reentry through “feathering” the wings, then glide back to Earth for a conventional runway landing.

Currently, Virgin Galactic remains as the only private space tourism company that successfully air-launched its SpaceShipTwo vehicle. However, Virgin Galactic is definitely not alone in its venture into space tourism, as it is being seen as lucrative industry for the upcoming many decades. For example, SpaceDev/Sierra Nevada Corporation has its reusable space plane Dream Chaser under development, which would take up to 4 passengers on a suborbital flight. Astrium, a subsidiary of European Aeronautic Defense and Space Company, announced its space tourism project in 2007 and started to develop its rocket plane Mach 3 in 2008. Mach 3’s $250,000 price tag will include spaceflight participant training, luxury resort accommodation, as well as a round-trip to the spaceport. The California-based XCOR Aerospace also revealed its smaller suborbital spacecraft Lynx in 2008, designed to carry a pilot and a single passenger at a time. Its $95,000 ticket includes pre-flight training sessions, and is scheduled to start providing flights by 2014. The price is significantly lower than the competitors, in order to make commercial spaceflight more accessible to the public. XCOR already has over 175 reservations. Among these suborbital space tourism companies, Texas-based company Blue Origin’s New Shepard spacecraft is also distinct from its peers, due to its vertical take-off and landing design. Supported by a $22 million grant from NASA, New Shepard boasts its innovative biconic shape that “provides greater cross-range and interior volume than traditional capsules without the weight penalty of winged spacecraft. In addition, the spacecraft features a “pusher escape system” that allows the crew to escape in an emergency situation during any phase of ascent into suborbital flight. Rob Meyerson, president and program manager of Blue Origin, stated that “providing crew escape without the need to jettison the unused escape system gets us closer to our goal of safe and affordable human spaceflight.

These developments in commercial suborbital spacecrafts are the fruit of human creativity and passion that persisted in the face of formidable technical challenges and financial constraints. Although still limited to suborbital flights within the confines of the Earth’s gravity, it is predicted that the growth of this industry sector will not only profit companies, but also provide the impetus for further progress in human space flight beyond the moon, Mars, and the Milky Way galaxy.

One of the major safety concerns for space travel, perhaps surprisingly, has to do with the space debris that we have created since the 1960s. Nicholas Johnson, chief scientist at NASA’s Orbital Debris Program Office, stated that orbiting space debris has increased linearly since the 1960s, even with the technological advances that decreased the amount of debris left in each space flight. Currently, it is estimated that there are approximately 30,000 plus items of junk bigger than 10cm in diameter orbiting around the Earth, at speeds higher than 465m/sec. Because of such high travelling speeds of space debris, even pieces smaller than 10cm can penetrate and damage most spacecraft or spacesuits. In fact, NASA has calculated that a 10cm-long piece of space debris can cause as much damage as 25 sticks of dynamite. This cadre of space junk includes whole satellites, rocket bodies, and fragments from explosions in fuel tanks and batteries, as well as from the colossal impacts between objects. For example, a Chinese missile test on a satellite caused a significant increase in the amount of space debris, as the missile collided with two orbiting satellites. Experts noted that this incident alone had increased the risk for the 2009 shuttle mission to the Hubble Space Telescope by 8 percent; it is also known that NASA needs to replace several windows on their satellites every year due to collisions with space debris. To be more exact, during NASA’s 54 shuttle missions, space debris and meteoroids struck the windows 1,634 times, and necessitated 92 window replacements; the radiator was hit 317 times, creating holes in the radiator’s external body 53 times.

With the accuracy of a four-day forecast, NASA does track with radar pieces of debris and meteoroids larger than 10cm to identify impending collision danger, and then makes an evasive manoeuvre to move space vehicles out of harm’s way. NASA estimates that it has had to conduct around one collision avoidance manoeuvre per year for its shuttles and International Space Station (ISS). However, some difficulty exists in that the ISS generally needs 30 hours of advance notice to be manoeuvred, and that several tens of thousands of smaller pieces move undetected and cause harm. With this growing problem of space debris, a larger systemic effort was begun in 1995 by NASA, which issued the first comprehensive set of guidelines for orbital debris mitigation in the world. This became the basis for the U.S. government’s issuance of its Orbital Debris Mitigation Standard Practices 2 years later. Other countries and organizations soon followed with their own guidelines; the efforts culminated in the establishment of the Inter-Agency Space Debris Coordination Committee (IADC) in 2002, with space agencies from more than 10 countries as members. Since February, 2007 the United Nations has also joined the effort through the United Nations’ Committee on the Peaceful Uses of Outer Space (COPUOS). Together, these member countries and guidelines are now working to prevent the creation of new debris, to design satellites to withstand small debris collision, and to implement operational procedures, such as inspecting a spacecraft before re-entry to increase the chance of safety in case of collision (e.g. rescue of crew by another spacecraft). More recently proposed solutions to the space debris issue include developing specialized bulldozer-like spacecraft that could catch and forcibly deorbit the pieces of debris.

Meeting basic human needs, such as food, water, air and adequate shelter, is a challenge in space. First, space travellers must transport their own nourishment and materials with them, as there are no other known environments in outer space that a sustain human life. In terms of food, a typical astronaut on the International Space Station(ISS) uses a food ration of about 0.83 kg per meal each day, with 0.12 kg of the weight being packaging material. For a 3-year round trip to Mars, thousands of kilograms of food would then be needed: a crew of four will need to carry 10,886 kg of food with them to space. In the early years, even the food that astronauts could carry uwere unappetizing and hard to eat, as largely the same methods of food preparation and preservation were still used by the early sailing explorers. To be able to store food onboard space shuttles and ISS, astronauts were provided with freeze-dried powders, bite-size cubes, and semi-liquids in tubes. These problems have been addressed by increasing the knowledge of the space environment and developing better ways to prepare and package foods. Today, the types of available foods have become more varied through using techniques such as dehydration, temperature-stabilization, or irradiation, and can be made ready to eat by just adding water or heat.

Second, the amount of water that can be transported into space is limited due to its weight. Therefore, space shuttles are usually designed to produce their own water through using fuel cells that combine hydrogen and oxygen atoms. When these atoms are combined, they produce electricity as well as water; the water produced by this process is then recycled and used by the crew. Onboard crafts that produce electricity from solar panels (e.g. ISS), small amounts of water are recycled from cabin air. Hence, while an average American uses about 132 litres of water per day, the astronauts onboard the ISS must limit their water use to about 11 litres per day. The problem of air, however, is not resolved by the presence of oxygen for the fuel cell, as the human body is tuned to the Earth’s atmosphere, with its particular composition ofdifferent gases. Among the 1.47 psi of atmospheric pressure, 21 percent or 3psi of it is oxygen – more than that would be toxic to the body. Nitrogen needs to make up about 78 percent or 11.5psi of air in order to dilute the oxygen content, and carbon dioxide must be continually removed from the body to prevent asphyxiation. The correct composition of such breathable air must be artificially maintained for all crafts, suits, and habitats in space to sustain human life.

Thirdly, the problem of shelter can be a major hazard for space travel. Proper shelter is crucial in many aspects, including air pressure, temperature, and protection from collision. Even a tiny hole or crack can cause air pressure to decrease sharply, while leaking the mixture of air that is critical to survival. On the return of Soyuz 11 in 1971, three cosmonauts died from asphyxiation due to a small hole in the spacecraft’s air valve that was only 1/16 in diameter. When the drop in air pressure does not go to a lethally low level, the dysbarism occurs as the nitrogen in the blood bubbles throughout the circulatory system. Pain, fainting, difficulty breathing would result, and eventually lead one to death. Temperature control is also critical, as overheating would cause heat-related illnesses and death (e.g. heat stroke) and lack of heat would cause hypothermia and death, if no interventions are made.

One of the great ways to be protected from these extreme space conditions is to use well-designed space suits. The space suit provides breathable air, suitable temperature, moisture, pressure, odour and waste gas removal, as well as shelter from radiation and debris. However, the conventional soft space suits have had their limitations. Because having the normal atmospheric pressure (i.e. 14.7 psi) inside the space suit caused it to balloon out and disable the individual from executing flexible movements, the astronauts needed to go through an adjustment process for several hours to become acclimated to just 3psi of oxygen in the space suit. This was accomplished by having the individual breathe pure oxygen and have the nitrogen leave their blood through their lungs. While this process has been effective, its time requirement posed a major limitation in case of emergencies. The new space suits in development improves on these limitations by providing the regular atmospheric air pressure in rigid exoskeletons with flexible joints.

With the recently developed assistive machines and robots, human beings can be less prone to weakness in extreme environments and conditions, such as the space environment and age-related conditions. In the early years of space travel, passengers needed to go through harsh and rigorous training alongside professional astronauts, in order to get acclimated to the extreme environmental changes in space. However, by combining human strength with that of robots, greater strength, speed, endurance, and adaptation can be achieved. In other words, exoskeletons will allow for human intelligence and creativity to stay in command, making use of their copious past experiences for dealing with various complex situations and emergencies. At the same time, the constant micro environment provided by the exoskeleton can protect human capacities from extreme pressures, temperatures, radiation, or collision in space. This means that lay people would be able to travel into space without as much training by simply wearing the exoskeleton. It will also enable space travel for those who are in less than optimal health conditions, for example due to their age. Indeed, the strength and speed offered by robotic exoskeletons will enable space travellers to avoid asteroids, space debris, and other obstacles easily, thereby ameliorating some of the anxieties about accidents that could happen in space. With the growing market for space tourism, custom designed and versatile exoskeletons will be able to effectively meet the customer’s taste, health conditions, and preferences, the suit should also be customizable.