Future of space exploration

Space colonization is a key benefit to finding efficient methods of space travel. Those in favor of space colonization argue space colonization is a means of ensuring the survival of human civilization given a planetary disaster. Colonizing other planets allows for the dispersal of humans and thus increases the likelihood of survival given a planetary disaster. Based on research performed on the surface of the moon, researchers predict that this type of catastrophic event occurs every half a million years. Furthermore, the availability of additional resources that can be mined from space could potentially expand the capabilities of humans and largely benefit society. Leveraging these resources and moving high polluting industries to space could reduce the emissions on earth and ultimately lead to fining cleaner energy sources. However, many object to space colonization, expressing concerns for the commodification of space and a potential to perpetuate pre-existing problems, such as war and economic inequality. Currently there are no space colonies. The primary blockers to colonizing space include technological and economic challenges.[1]

Many private companies are working to make space travel more efficient in hopes to reduce the overall cost of space travel, and thus space colonization. SpaceX has been a dominant leader in this push for efficient exploration with the release of the Falcon 9, a reusable rocket.[2] NASA's Artemis program aims to land another man and the first woman on the moon by 2024 and eventually establish sustainable space travel by 2028. The Artemis program is NASA's stepping stone to their ultimate goal of landing on Mars. NASA reports advances in efficient space technology that would enable both goals to be met, and ultimately allow for humans to establish a long-term presence on another planet. In order to colonize space, humans must have access to sustainable sources of energy. NASA is currently testing the capabilities of Perovskite solar cells to provide energy in space. Compared to the current alternative, silicon solar cells, Perovskite solar cells produce extremely large amounts of energy from a relatively small number of cells. Furthermore, the Perovskite solar cells can be transported as liquid, making it safe to ship from earth to space. However, these cells are fragile and will require further research before they can be established as the primary energy source for space.

The unique attributes of space enable astronauts to conduct research that could not otherwise be executed on earth. Furthermore, the unrepeated perspective from space looking at earth enables scientists to gain more insight on the earth's natural environment. Research conducted at the International Space Station aims to benefit human civilizations on earth and extend human knowledge around space and space exploration. Currently, NASA's research at the ISS includes biomedical research, material science, technology advancement, and methods to enable further space exploration.[3]

Anti and microgravity enable astronauts to execute medical research that is impossible to perform on earth. For example, NASA's research on new treatment options for complex diseases, such as Duchenne Muscular Dystrophy, require the use of a microgravity environment to allow the microparticles in the treatment solution to stay robust. NASA has also reported research investment in microbial vaccine development and microencapsulation of drugs for targeted and more efficient treatment delivery.[3] Private companies have also begun to leverage the International Space Station for research purposes. Techshot and nScrypt launched a 3D BioFabrication Facility to the International Space Station in 2019. This device leverages microgravity to 3D print organs which can then be shipped back to earth for use. Ultimately, organs can not be printed on earth because the fragile tissue collapses under its own weight. Therefore, leveraging the elements of space Techshot and nScrypt aim to reduce the global organ shortage by printing organs and human tissue in space.[4]

Breakthrough Starshot is a research and engineering project by the Breakthrough Initiatives to develop a proof-of-concept fleet of light sail spacecraft named StarChip,[5] to be capable of making the journey to the Alpha Centauri star system 4.37 light-years away. It was founded in 2016 by Yuri Milner, Stephen Hawking, and Mark Zuckerberg.[6][7]

Smart Lander for Investigating Moon (SLIM) is a lunar lander being developed by the Japan Aerospace Exploration Agency (JAXA). The lander will demonstrate precision landing technology.[8] By 2017, the lander was to be launched in 2021,[9][10] but this has been subsequently delayed to January 2022 due to delays in SLIM's rideshare mission, XRISM.[11]

Artemis 1[12] is an upcoming uncrewed flight test for NASA's Artemis program that is the first integrated flight of the agency's Orion MPCV and Space Launch System heavy-lift rocket.

Formerly known as Exploration Mission-1 (EM-1), the mission was renamed after the introduction of the Artemis program. The launch will be held at Launch Complex 39B at the Kennedy Space Center, where an Orion spacecraft will be sent on a mission of 25.5 days, 6 of those days in a retrograde orbit around the Moon.[13] The mission will certify the Orion spacecraft and Space Launch System rocket for crewed flights beginning with the second flight test of the Orion and Space Launch System, Artemis 2 in September 2022, which will carry a crew of four around the Moon in a week-long mission and back prior to the assembly of the Lunar Gateway in lunar orbit, which will occur between 2022 and 2023.

Chandrayaan 3 is ISRO's third lunar space mission. Unlike Chandrayaan 2, which had an orbiter, lander and rover, Chandrayaan 3 will have only a lander and an orbiter. If this mission is successful, it will make ISRO the world's fourth space agency to conduct a soft lunar landing after the administration of the former USSR, NASA and CNSA.

Rosalind Franklin,[14] previously known as the ExoMars rover, is a planned robotic Mars rover, part of the international ExoMars programme led by the European Space Agency and the Russian Roscosmos State Corporation.[15][16]

Initially scheduled to launch in July 2020, but has since been delayed due to testing issues with the rover's landing mechanism. The new launch date is set for July 2022.[17] the plan calls for a Russian launch vehicle, an ESA carrier module, and a Russian lander named Kazachok,[18] that will deploy the rover to Mars' surface.[19] Once safely landed, the solar powered rover will begin a seven-month (218-sol) mission to search for the existence of past life on Mars. The Trace Gas Orbiter (TGO), launched in 2016, will operate as Rosalind Franklin's and lander's data-relay satellite.[20]

Computer-design drawing for NASA's Perseverance rover

Mars 2020 is a Mars rover mission by NASA's Mars Exploration Program that includes the Perseverance rover which launched on 30 July 2020 at 11:50 UTC, and has a scheduled touch down in Jezero crater on Mars on 18 February 2021.[21][22] It will investigate an astrobiologically relevant ancient environment on Mars and investigate its surface geological processes and history, including the assessment of its past habitability, the possibility of past life on Mars, and the potential for preservation of biosignatures within accessible geological materials.[23][24] It will cache sample containers along its route for a potential future Mars sample-return mission.[24][25][26] The Mars 2020 mission was announced by NASA on 4 December 2012 at the fall meeting of the American Geophysical Union in San Francisco.[27] The Perseverance rover's design is derived from the Curiosity rover, and will use many components already fabricated and tested, new scientific instruments and a core drill.[28] It will also carry a helicopter drone.

The Mars Global Remote Sensing Orbiter and Small Rover (HX-1) is a planned project by China to deploy an orbiter and rover on Mars.[29] The mission is planned to be launched in July or August 2020[30][31] with a Long March 5 heavy lift rocket.[32][33][34] Its stated objectives are to search for evidence of both current and past life, and to assess the planet's environment.[35][36]

Mars Orbiter Mission 2 (MOM 2), also called Mangalyaan-2, is India's second interplanetary mission planned for launch to Mars by the Indian Space Research Organisation (ISRO). As per some reports emerged, the mission was to be an orbiter to Mars proposed for 2024.[37] However, in a recorded interview in October 2019, VSSC director has indicated the inclusion of a lander and rover.[38] The orbiter will use aerobraking to lower its initial apoapsis and enter into an orbit more suitable for observations.[39][40][41]

The Hope Mars Mission is a space exploration probe mission to Mars built by the United Arab Emirates and set for launch in 2020. Upon launch, it will become the first mission to Mars by any Arab or Muslim majority country. The probe will study the Martian atmosphere and provide details regarding the daily climate and through seasonal cycles, the weather events in the lower atmosphere such as dust storms, as well as the weather on Mars different geographic areas. The probe will attempt to answer the scientific community questions of why Mars atmosphere is losing hydrogen and oxygen into space and the reason behind Mars drastic climate changes.

An article in science magazine Nature suggested the use of asteroids as a gateway for space exploration, with the ultimate destination being Mars. In order to make such an approach viable, three requirements need to be fulfilled: first, "a thorough asteroid survey to find thousands of nearby bodies suitable for astronauts to visit"; second, "extending flight duration and distance capability to ever-increasing ranges out to Mars"; and finally, "developing better robotic vehicles and tools to enable astronauts to explore an asteroid regardless of its size, shape or spin." Furthermore, using asteroids would provide astronauts with protection from galactic cosmic rays, with mission crews being able to land on them without great risk to radiation exposure

The spacecraft's path (green) is shown in a frame of reference where Jupiter remains stationary. Lucy has two close Earth flybys before encountering its Trojan targets. After 2033, Lucy will continue cycling between the two Trojan clouds every six years.

Lucy, part of NASA's Discovery Program, is scheduled to launch in October 2021 to explore six Trojan Asteroids and a Main Belt asteroid. The two Trojan swarms ahead of and behind Jupiter are thought to be dark bodies made of the same material as the outer planets that were pulled into orbit near Jupiter.[42] Lucy will be the first mission to study the Trojans, and scientists hope the findings from this mission will revolutionize our knowledge of the formation of the solar system. For this reason, the project is named after Lucy, a fossilized hominid that provided insight on the evolution of humans. The asteroids studied are ancient fossils of planet formation which could hold clues to the origins of life on Earth.[43]

The Psyche spacecraft, part of NASA's Discovery Program, is scheduled to launch at the end of 2022 to 16 Psyche, a metallic object in the asteroid belt.[44] 16 Psyche is 130 miles (210 km) wide, and it is made almost entirely of iron and nickel instead of ice and rock. Because of this unique composition, scientists believe it is the remnants of a planet's core that lost its exterior through a series of collisions, but it is possible that 16 Psyche is only unmelted material.[42] NASA hopes to obtain information about planetary formation from directly studying the exposed interior of a planetary body, which would otherwise not be possible.[45]

The OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) is a NASA asteroid study and sample-return mission.[46] The mission's main goal is to obtain a sample of at least 60 grams (2.1 oz) from 101955 Bennu, a carbonaceous near-Earth asteroid, and return the sample to Earth for a detailed analysis. The material returned is expected to enable scientists to learn more about the formation and evolution of the Solar System, its initial stages of planet formation, and the source of organic compounds that led to the formation of life on Earth.[47] If successful, OSIRIS-REx will be the first U.S. spacecraft to return samples from an asteroid. The Lidar instrument used aboard the OSIRIS-REx was built by Lockheed Martin, in conjunction with the Canadian Space Agency.[48][49]

OSIRIS-REx was launched on 8 September 2016, flew past Earth on 22 September 2017, and reached the proximity of Bennu on 3 December 2018,[50] where it began analyzing its surface for a target sample area over the next several months. It is expected to return with its sample to Earth on 24 September 2023.[51]

The JUpiter ICy moons Explorer (JUICE) is an interplanetary spacecraft in development by the European Space Agency (ESA) with Airbus Defence and Space as the main contractor. The mission is being developed to visit the Jovian system focused on studying three of Jupiter's Galilean moons: Ganymede, Callisto, and Europa (excluding the more volcanically active Io) all of which are thought to have significant bodies of liquid water beneath their surfaces, making them potentially habitable environments. The spacecraft is set for launch in June 2022 and would reach Jupiter in October 2029 after five gravity assists and 88 months of travel. By 2033 the spacecraft should enter orbit around Ganymede for its close up science mission and becoming the first spacecraft to orbit a moon other than the moon of Earth.

Animation of Europa Clipper trajectory around Jupiter

Europa Clipper[52] (previously known as Europa Multiple Flyby Mission) is an interplanetary mission in development by NASA comprising an orbiter. Set for a launch in 2025,[53] the spacecraft is being developed to study the Galilean moon Europa through a series of flybys while in orbit around Jupiter.

This mission is a scheduled flight of the Planetary Science Division, designated a Large Strategic Science Mission, and funded under the Planetary Missions Program Office's Solar System Exploration program as its second flight.[54][55] It is also supported by the new Ocean Worlds Exploration Program.[56] Europa Clipper will perform follow-up studies to those made by the Galileo spacecraft during its eight years in Jupiter orbit, which indicated the existence of a subsurface ocean underneath Europa's ice crust. Plans to send a spacecraft to Europa were initially conceived with projects such as Europa Orbiter and Jupiter Icy Moons Orbiter, in which a spacecraft would be injected into orbit around Europa. However, due to the adverse effects of radiation from Jupiter's magnetosphere in Europan orbit, it was decided that it would be safer to inject a spacecraft into an elliptical orbit around Jupiter and make 45 close flybys of the moon instead. The mission began as a joint investigation between the Jet Propulsion Laboratory and the Applied Physics Laboratory.

Breakthrough Enceladus is an astrobiology space probe mission concept to explore the possibility of life on Saturn's moon, Enceladus.[57] In September 2018, NASA signed a collaboration agreement with Breakthrough to jointly create the mission concept.[58] This mission would be the first privately funded deep space mission.[59] It would study the content of the plumes ejecting from Enceladus's warm ocean through its southern ice crust.[60] Enceladus's ice crust is thought to be around two to five kilometers thick,[61] and a probe could use an ice-penetrating radar to constrain its structure.[62]

CHEOPS (Characterising Exoplanets Satellite) is a planned European space telescope for the study of the formation of extrasolar planets. The launch window for CHEOPS is the fourth quarter of 2019.[63]

The mission aims to bring an optical Ritchey–Chrétien telescope with an aperture of 30 cm, mounted on a standard small satellite platform, into a Sun-synchronous orbit of about 700 km (430 mi) altitude. For the planned mission duration of 3.5 years, CHEOPS is to examine known transiting exoplanets orbiting bright and nearby stars.[64]

Planetary Transits and Oscillations of Stars (PLATO) is a space telescope under development by the European Space Agency for launch in 2026.[65] The mission goals are to search for planetary transits across up to one million stars, and to discover and characterize rocky extrasolar planets around yellow dwarf stars (like our sun), subgiant stars, and red dwarf stars. The emphasis of the mission is on earth-like planets in the habitable zone around sun-like stars where water can exist in liquid state.[66] It is the third medium-class mission in ESA's Cosmic Vision programme and named after the influential Greek philosopher Plato, the founding figure of Western philosophy, science and mathematics. A secondary objective of the mission is to study stellar oscillations or seismic activity in stars to measure stellar masses and evolution and enabling the precise characterization of the planet host star, including its age.[67]

The James Webb Space Telescope (JWST or "Webb") is a space telescope that is planned to be the successor to the Hubble Space Telescope.[68][69] The JWST will provide greatly improved resolution and sensitivity over the Hubble, and will enable a broad range of investigations across the fields of astronomy and cosmology, including observing some of the most distant events and objects in the universe, such as the formation of the first galaxies. Other goals include understanding the formation of stars and planets, and direct imaging of exoplanets and novas.[70]

The primary mirror of the JWST, the Optical Telescope Element, is composed of 18 hexagonal mirror segments made of gold-plated beryllium which combine to create a 6.5-meter (21 ft; 260 in) diameter mirror that is much larger than the Hubble's 2.4-meter (7.9 ft; 94 in) mirror. Unlike the Hubble, which observes in the near ultraviolet, visible, and near infrared (0.1 to 1 μm) spectra, the JWST will observe in a lower frequency range, from long-wavelength visible light through mid-infrared (0.6 to 27 μm), which will allow it to observe high redshift objects that are too old and too distant for the Hubble to observe.[71] The telescope must be kept very cold in order to observe in the infrared without interference, so it will be deployed in space near the Earth–Sun L₂ Lagrangian point, and a large sunshield made of silicon- and aluminum-coated Kapton will keep its mirror and instruments below 50 K (−220 °C; −370 °F).[72]

Commercial Crew Development (CCDev) is a human spaceflight development program that is funded by the U.S. government and administered by NASA. CCDev will result in US and international astronauts flying to the International Space Station (ISS) on privately operated crew vehicles.

Operational contracts to fly astronauts were awarded in September 2014 to SpaceX and Boeing.[73] Test flights of Dragon 2 and CST-100 are scheduled for 2019.[74] Pending completion of the demonstration flights, each company is contracted to supply six flights to ISS between 2019 and 2024.[75] The first group of astronauts was announced on 3 August 2018.[76]

The Artemis program is an ongoing crewed spaceflight program carried out by NASA, U.S. commercial spaceflight companies, and international partners such as ESA,[77] with the goal of landing "the first woman and the next man" on the Moon, specifically at the lunar south pole region by 2024. Artemis would be the next step towards the long-term goal of establishing a sustainable presence on the Moon, laying the foundation for private companies to build a lunar economy, and eventually sending humans to Mars.

In 2017, the lunar campaign was authorized by Space Policy Directive 1, utilizing various ongoing spacecraft programs such as Orion, the Lunar Gateway, Commercial Lunar Payload Services, and adding an undeveloped crewed lander. The Space Launch System will serve as the primary launch vehicle for Orion, while commercial launch vehicles are planned for use to launch various other elements of the campaign.[78] NASA requested $1.6 billion in additional funding for Artemis for fiscal year 2020,[79] while the Senate Appropriations Committee requested from NASA a five-year budget profile[80] which is needed for evaluation and approval by Congress.[81][82]

Lockheed Martin developed a Multi-Purpose Crew Vehicle to transport crew to and from the International Space Station using the Space Launch System (SLS) Rocket. The design was fairly large at a total mass of 33,446 kg but was designed with a flight life of 21.1 days. The design proposal created as part of NASA's Constellation Program was developed alongside the European Service Module to form the Orion Spacecraft. Since the selection of the design by NASA in 2006 beating out Northrop Grumman, three flight-ready Orion spacecraft are under construction and one successful launch was performed in 2014. The longest flight performed using the spacecraft to date has been under 5 minutes long, however the planned Artemis 3 mission seeks to test the vehicle's life span design to 30 days. The first production of the Orion spacecraft design, Artemis III, will carry the first woman and next man to the Moon in 2024.[83]

The SpaceX Starship is planned to be a spacecraft launched as the second stage of a reusable launch vehicle. The concept is under development by SpaceX, as a private spaceflight project.[84] It is being designed to be a long-duration cargo- and passenger-carrying spacecraft.[85] While it will be tested on its own initially, it will be used on orbital launches with an additional booster stage, the Super Heavy, where Starship would serve as the second stage on a two-stage-to-orbit launch vehicle.[86] The combination of spacecraft and booster is called Starship as well.[87]

The 180-day long mission was originally planned for a launch date in 2012. It was postponed pending the success of the hardware demonstration and operational flight missions. Launched on 16 November 2020, the SpaceX Crew 1 Mission is the second crewed orbital flight of the Crew Dragon following the Crew Dragon Demo-2 mission and the certification of the vehicle by NASA. The launch served as the first fully crewed flight designed for operational testing to and from the International Space Station as part of NASA's Commercial Crew Program. The crew on board was three NASA astronauts and one Japanese astronaut launching atop the SpaceX Falcon 9 Rocket.

The crewed operational flight of the Crew Dragon capsule will serve as the third overall crewed orbital flight. The mission, currently proposed for launch on 30 March 2021, details a 210-day mission with two NASA astronauts, one Japanese Astronaut, and a European Space Agency Astronaut following the completion of the SpaceX Crew 1 mission and refurbishment of the Crew Dragon Endeavor capsule after the Crew Dragon Demo-2 mission.

The Boeing Crew Flight Test will serve as the first crewed mission to test the Boeing Starliner crew capsule and the first crewed spacecraft launching atop the Atlas V Rocket. The current launch date is set for June 2021 and will last anywhere from two weeks to six months. The crew comprises three NASA astronauts, one of which being the first woman to serve as a crew of an American spacecraft.

The Boeing Starliner 1 mission will be the first operational crewed mission of the Boeing Starliner and the first mission to reuse the Starliner Spacecraft. The mission is expected to launch no earlier than December 2021 using the Atlas V rocket with a crew of four astronauts, three NASA astronauts and likely one international partner astronaut from either Japan, Canada, or the European Space Agency. This mission will be the fourth US spaceflight with a female commander.

ISRO's future Gaganyaan mission, which is the first Indian Human Spaceflight Programme, comprises a crew module which is a fully autonomous 5.3-tonne (12,000 lb) spacecraft designed to carry a 3-member crew to orbit and safely return to the Earth after a mission duration of up to seven days. Its 2.9-tonne (6,400 lb) service module is powered by liquid propellant engines. It is to be launched on the GSLV Mk III launcher no earlier than 2022. About 16 minutes after liftoff from the Satish Dhawan Space Centre (SDSC), Sriharikota, the rocket will inject the spacecraft into an orbit 300–400 km (190–250 mi) above Earth. When ready to land, its service module and solar panels will be disposed off before reentry. The capsule would return for a parachute splashdown in the Bay of Bengal.

The Commercial Crew Program is a human spaceflight program designed to transport astronauts to and from the International Space Station. SpaceX and Boeing have been selected by NASA as the major frontrunners to develop and test designs to complete the NASA missions and will go on to fulfill the needs of safe, reliable, and cost-effective transportation of the crew in the future.[88] The Artemis Missions designed by NASA to bring the first man and woman to Mars will feature a Lockheed Martin crew capsule as part of the Orion Spacecraft.[89]

On August 2, 2020, the Dragon Crew Capsule was launched with NASA astronauts on board to complete the first commercial crew flight to the International Space Station using a private industry's design.[89] While this mission was to perform scientific experiments on board the space station and serve as a final test to the transportation vehicles, the mission success expands opportunity for future missions for a variety of purposes and crew teams.

A slightly smaller design than Lockheed Martin's Orion Spacecraft with a launch mass of 13000 kg, the Boeing Starliner is another variation of a spacecraft created to transport crew to and from the International Space Station, this time for NASA's Commercial Crew Program. The capsule features a higher crew capacity of up to 7 but much shorter design life of only 60 hours undocked flight time. The design varied as it was a reusable spacecraft that featured a ground landing rather than a splashdown recovery which can be reused 10 times.[90] The design proposal was selected by NASA in 2014 along with SpaceX's Crew Dragon to serve as the crew capsule for the Artemis Missions. Since the final design review, Boeing faced issues with docking with the International Space Station but was able to prove a successful land-based touchdown. One more hardware test flight is currently planned for the vehicle in July 2021.

The current status of space-faring technology, including propulsion systems, navigation, resources and storage all present limitations to the development of human space exploration in the near future.

The astronomical order of magnitude of the distance between us and the nearest stars is a challenge for the current development of space exploration. At our current top speed of 157,100 miles per hour (252,800 km/h), the Helios 2 probe would arrive at the nearest star, Proxima Centauri, in around 18,000 years,[92] much longer than a human lifespan and therefore requiring much faster transportation methods than currently available. It is important to note that this top speed was achieved due to the Oberth effect where the spacecraft was sped up by the Sun's gravity. The fastest escape velocity from the Solar System is that of Voyager 1 at 17 km/s.

The VASIMR Plasma based propulsion engine[93]

In terms of propulsion, the main challenge is the liftoff and initial momentum, since there is no friction in the vacuum of space. Based on the missions goals, including factors such as distance, load and time of flight, the type of propulsion drive used, planned to use, or in design varies from chemical propellants, such as liquid hydrogen and oxidizer[94] (Space Shuttle Main Engine), to plasma[93] or even nanoparticle propellants.[95]

Project Longshot Nuclear Fission Engine schematic

As for future developments, the theoretical possibilities of nuclear based propulsion have been analyzed over 60 years ago, such as nuclear fusion (Project Daedalus) and nuclear pulse propulsion (Project Longshot),[96] but have since been discontinued from practical research by NASA. On the more speculative side, the theoretical Alcubierre drive presents a mathematical solution for “faster-than-light” travel, but it would require the mass-Energy of Jupiter, not to mention the technical issues.[97]

The human element in manned space exploration adds certain physiological and psychological issues and limitations to the future possibilities of space exploration, along with storage and sustenance space and mass issues.

The transitioning gravity magnitudes on the body is detrimental to orientation, coordination, and balance. Without constant gravity, bones suffer disuse osteoporosis, and their mineral density falls 12 times faster than the average elderly adult's.[98] Without regular exercise and nourishment, there can be cardiovascular deterioration and loss in muscle strength.[99] Dehydration can cause kidney stones,[100] and constant hydro-static potential in zero-g can shift body fluids upwards and cause vision problems.[101]

Furthermore, without Earth's surrounding magnetic field as a shield, solar radiation has much harsher effects on biological organisms in space. The exposure can include damage to the central nervous system, (altered cognitive function, reducing motor function and incurring possible behavioral changes), as well as the possibility of degenerative tissue diseases.

The Biosphere 2 greenhouse habitat

According to NASA, isolation in space can have detrimental effects on the human psyche. Behavioral issues, such as low morale, mood-swings, depression, and decreasing interpersonal interactions, irregular sleeping rhythms, and fatigue occur independently to the level of training, according to a set of NASA's social experiments.[102] The most famous of which, Biosphere 2,[103] was a 2 year long, 8 person crew experiment in the 1990s, in an attempt to study human necessities and survival in an isolated environment. The result of which were stressed interpersonal interactions and aloof behavior, including limiting and even ceasing contact between crew members,[102] along with failing to sustain a lasting air-recycling system and food supply.[104]

Considering the future possibility of extended, manned missions, food storage and resupply are relevant limitations. From a storage point of view, NASA estimates a 3-year Mars mission would require around 24 thousand pounds (11 t) of food, most of it in the form of precooked, dehydrated meals of about 1.5 pounds (0.68 kg) a portion.[105] Fresh produce would only be available in the beginning of the flight, since there would not be refrigeration systems. Water's relative heavy weight is a limitation, so on the International Space Station (ISS) the use of water per person is limited to 11 litres (2.9 US gal) a day, compared to the average Americans' 132 litres (35 US gal).[105]

The ISS "Veggie plant growth system" and Red Romaine Lettuce

As for resupply, efforts have been made to recycle, reuse and produce, to make storage more efficient. Water can be produced through chemical reactions of Hydrogen and Oxygen in fuel cells,[105] and attempts and methods of growing vegetables in micro-gravity are being developed and will continue to be researched. Lettuce has already successfully grown in the ISS's "Veggie plant growth system", and has been consumed by the astronauts, even though large-scale plantation is still impractical,[106] due to factors such as pollination, long growth periods, and lack of efficient planting pillows.

Autonomy is defined by three requirements:

1. The ability to make and carry out decisions on their own, based on information on what they sensed from the world and their current state.
2. The ability to interpret the given goal as a list of actions to take.
3. The ability to fail flexibly, meaning they are able to continuously change their actions based on what is happening within their system and their surrounding.

Currently, there are many projects trying to advance space exploration and space craft development using AI.[107]

NASA began its autonomous science experiment (ASE) on Earth Observing-1 (EO-1), which is NASA's first satellite in the millennium program, Earth-observing series launched on November 21, 2000. The autonomy of these satellites is capable of on-board science analysis, re-planning, robust execution, and model-based diagnostic. Images obtained by the EO-1 are analyzed on-board and down linked when a change or interesting event occurs. The ASE software has successfully provided over 10,000 science images. This experiment was the start of many that NASA devised for AI to impact the future of space exploration.

NASA's goal with this project is to develop a system that can aid pilots by giving them real-time expert advice in situations that pilot training does not cover or just aid with a pilot's train of thought during flight. Based on the IBM Watson cognitive computing system, the AI Flight Adviser pulls data from a large database of relevant information like aircraft manuals, accident reports, and close-call reports to give advice to pilots. In the future, NASA wants to implement this technology to create fully autonomous systems, which can then be used for space exploration. In this case, cognitive systems will serve as the basis, and the autonomous system will completely decide on the course of action of the mission, even during unforeseen situations.[108] However, in order for this to happen, there are still many supporting technologies required.

In the future, NASA hopes to use this technology not only in flights on earth, but for future space exploration. Essentially, NASA plans to modify this AI flight Advisor for Longer range applications. In addition to what the technology is now, there will be additional cognitive computing systems that can decide on the right set of actions based upon unforeseen problems in space. However, in order for this to be possible, there are still many supporting technologies that need to be enhanced.

For this project, NASA's goal is to implement stereo vision for collision avoidance in space systems to work with and support autonomous operations in a flight environment. This technology uses two cameras within its operating system that have the same view, but when put together offer a large range of data that gives a binocular image. Because of its duo-camera system, NASA's research indicate that this technology can detect hazards in rural and wilderness flight environments. Because of this project, NASA has made major contributions toward developing a completely autonomous UAV. Currently, Stereo Vision can construct a stereo vision system, process the vision data, make sure the system works properly, and lastly performs tests figuring out the range of impeding objects and terrain. In the future, NASA hopes this technology can also determine the path to avoid collision. The near-term goal for the technology is to be able to extract information from point clouds and place this information in a historic map data. Using this map, the technology could then be able to extrapolate obstacles and features in the stereo data that are not in the map data. This would aid with the future of space exploration where humans can't see moving, impeding objects that may damage the moving space craft.[109]

Autonomous technologies would be able to perform beyond predetermined actions. They would analyze all possible states and events happening around them and come up with a safe response. In addition, such technologies can reduce launch cost and ground involvement. Performance would increase as well. Autonomy would be able to quickly respond upon encountering an unforeseen event, especially in deep space exploration where communication back to Earth would take too long. Space exploration could provide us with the knowledge of our universe as well as incidentally developing inventions and innovations. Traveling to Mars and farther could encourage the development of advances in medicine, health, longevity, transportation, communications that could have applications on Earth.[107]

Changes in space craft development will have to account for an increased energy need for future systems. Spacecraft heading towards the center of the Solar System will include enhanced solar panel technology to make use of the abundant solar energy surrounding them. Future solar panel development is aimed at their working more efficiently while being lighter.[110]

Radioisotope Thermoelectric Generators (RTEG or RTG) are solid-state devices which have no moving parts. They generate heat from the radioactive decay of elements such as plutonium, and have a typical lifespan of more than 30 years. In the future, atomic sources of energy for spacecraft will hopefully be lighter and last longer than they do currently.[111] They could be particularly useful for missions to the Outer Solar System which receives substantially less sunlight, meaning that producing a substantial power output with solar panels would be impractical.

Experiencing Low Earth Orbit as a tourist requires accommodations to allow for humans to fly or spend time in space. These accommodations will need to solve the following problems:

          1.  Physiological effects of living in microgravity will affect your body's chemistry and invoke symptoms such as motion sickness from disorientation. Long term gradual effects from time in space include Bone atrophy from a gravity scarce environment that limits the flow of minerals throughout the body.

          2. Upcoming habitats are designed for effective transport on rocket systems which means these habitats are small and confined leading to confinement problems and physiological changes in behavior like claustrophobia.

          3. Residing in earth's orbit removes the protections of the Ozone layer which absorbs harmful radiation emitted from the sun. Living in orbit around earth exposes humans to ten times more radiation than humans living on earth.[113] These radiative effects can invoke symptoms such as skin cancer.

Company Advancements in Commercialization

In 2017 Elon Musk announced the development of rocket travel to transport humans from one city to another in under an hour. Elon has challenged SpaceX to improve travel across the world through his reusable rocket propulsion to send up passengers on a suborbital trajectory to their destination.[2]

The company Virgin Galactic with CEO Sir Richard Branson is developing another method to reach planes through Aircraft propulsion. Named SpaceshipTwo which is a biplane that carries a spacecraft as its payload known as WhiteKnightTwo and carries it to cruising altitude where the rocket separates and begins to climb out of earth's atmosphere.[114] The goal is to use this method of travel for Private Spaceflight into space to experience microgravity and observe earth for some time then return home. There have been a few setbacks on the actual commercial launch however the first crewed launch took place in February 2019.[115]

The Blue Origin website highlights a small launch vehicle sending payloads into orbit. The goal is to reduce the cost of sending smaller payloads into orbit with future intentions to send humans into space.[116] The first stage is reusable while the second stage is expendable. Maximum payload dimensions are expected to be around 530 cubic feet to be carried past the Karman line.

The larger variant of the New Shepard, Blue Origin seeks to increase their payload capabilities by developing a 95-meter-tall rocket capable of reusable flight to space. Its payload is expected to be satellites or to provide humans with the opportunity to view space without astronaut training. Blue origin intends the rocket's reusability to last 25 flights into space alleviating costs increasing the possibility of commercialized travel.

Blue origin lunar lander is a designed flexible lander with capabilities to send both cargo and crew to the lunar surface.[117] This habitat will provide a sustained human presence by providing necessities such as life support systems and lunar rovers to excavate and scout the surrounding lunar surface. Further developments on this project include a Human Landing system which are detachable living quarters intended to attach and depart from the Blue Moon Lunar Lander.

The Bigelow Aerospace Corporation founded by Robert Bigelow is headquartered in Las Vegas. A research and development company with emphasis on constructing space architecture capable of housing humans and creating living conditions suitable for living in space. The company has sent two subscale spacecraft known as Genesis I and II into Low Earth Orbit along with sending a module known as Bigelow Expandable Activity Module (BEAM) which is inflated and attached to the International Space Station.[118] The BEAM Module is measured to be 14 feet in length and can be inflated or deflated for ease of transportation. Bigelow Aerospace is working toward developing their own Modules independent of the International Space Station to send Tourists and visitors.

The Aurora Space Station is being developed by Orion Span founded by Frank Bunger in 2017 working toward commercializing space through a new capsule known as Aurora.[119] The one time launch destination will maintain a Low Earth Orbit and set to hold crew members and tourists. The station is expected to launch around the year 2022.[120]