Asteroid Phaethon breaks all the rules. It acts like a comet, it supplies particles to a meteor shower. Oh, and it’s blue

Having studies countless asteroids in near-Earth space, astronomers have come to understand that the majority of these rocks fall into one of two categories: S-type (grey) and C-type (red). These are defined by the types of materials on their surfaces, with S-type asteroids being primarily composed of silicate rock and C-type asteroids being made up of carbon materials.

However, there is also what are known as blue asteroids, which make up only a fraction of all known Near-Earth Objects (NEO). But when an international team astronomers observed the blue asteroid (3200) Phaeton during a flyby of Earth, they spotted behavior that was more consistent with a blue comet. If true, then Phaeton is of a class of objects that are so rare, they are almost unheard of.

Continue reading “Asteroid Phaethon breaks all the rules. It acts like a comet, it supplies particles to a meteor shower. Oh, and it’s blue”

To Avoid Vision Problems in Space, Astronauts Will Need Some Kind of Artificial Gravity

Ever since astronauts began going to space for extended periods of time, it has been known that long-term exposure to zero-gravity or microgravity comes with its share of health effects. These include muscle atrophy and loss of bone density, but also extend to other areas of the body leading to diminished organ function, circulation, and even genetic changes.

For this reason, numerous studies have been conducted aboard the International Space Station (ISS) to determine the extent of these effects, and what strategies can be used to mitigate them. According to a new study which recently appeared in the International Journal of Molecular Sciences, a team of NASA and JAXA-funded researchers showed how artificial gravity should be a key component of any future long-term plans in space.

Continue reading “To Avoid Vision Problems in Space, Astronauts Will Need Some Kind of Artificial Gravity”

Hayabusa’s Target Itokawa Formed 4.6 Billion Years Ago, But Then it Was Smashed Up About 1.5 Billion Years Ago

Within Earth’s orbit, there are an estimated eighteen-thousands Near-Earth Asteroids (NEAs), objects whose orbit periodically takes them close to Earth. Because these asteroids sometimes make close flybys to Earth – and have collided with Earth in the past – they are naturally seen as a potential hazard. For this reason, scientists are  dedicated to tracking NEAs, as well as studying their origin and evolution.

Continue reading “Hayabusa’s Target Itokawa Formed 4.6 Billion Years Ago, But Then it Was Smashed Up About 1.5 Billion Years Ago”

Stable Lava Tube Could Provide a Potential Human Habitat on the Moon

On October 5th, 2017, Vice President Mike Pence announced the Trump administration’s plan to return astronauts to the Moon. Looking to the long-term, NASA and several other space agencies are also intent on establishing a permanent lunar base there. This base will not only provide opportunities for lunar science, but will facilitate missions to Mars and beyond.

The only question is, where should such a base be built? For many years, NASA, the ESA and other agencies have been exploring the possibility of stable lava tubes as a potential site. According to new study by a team of international scientists, the presence of such a tube has now been confirmed in the Marius Hills region. This location is likely to be the site of future lunar missions, and could even be the site of a future lunar habitat.

In 2009, data provided by the Terrain Camera aboard JAXA’s SELENE spacecraft indicated the presence of three huge pits on the Moon. These pits (aka. “skylights”) were of particular interest since they were seen as possible openings to subsurface lava channels. Since then, the Marius Hills region (where they were found) has been a focal point for astronomers and planetary scientists hoping to confirm the existence of lava tubes.

Artist’s impression of a surface exploration crew investigating a typical, small lava tunnel, to determine if it could serve as a natural shelter for the habitation modules of a Lunar Base. Credit: NASA’s Johnson Space Center

The recent study, titled “Detection of intact lava tubes at Marius Hills on the Moon by SELENE (Kaguya) Lunar Radar Sounder“, recently appeared in the journal Geophysical Research Letters. The team consisted of members from JAXA’s Institute of Space and Astronautical Science (ISAS), Purdue University, the University of Alabama, AstroLabs, the National Astronomical Observatory of Japan (NOAJ) and multiple Japanese Universities.

Together, they examined data from the SELENE mission’s Lunar Radar Sounder (LRS) from locations that were close to the Marius Hills Hole (MHH) to determine if the region hosted stable lava tubes. Such tubes are a remnant from the Moon’s past, when it was still volcanically active. These underground channels are believed to be an ideal location for a lunar colony, and for several reasons.

For starters, their thick roofs would provide natural shielding from solar radiation, cosmic rays, meteoric impacts, and the Moon’s extremes in temperature. These tubes, once enclosed, could also be pressurized to create a breathable environment. As such, finding an entrance to a stable lava tube would the first step towards selecting a possible site for such a colony.

As Junichi Haruyama, a senior researcher at JAXA and one of the co-authors on the study, explained in a University of Purdue press release:

“It’s important to know where and how big lunar lava tubes are if we’re ever going to construct a lunar base. But knowing these things is also important for basic science. We might get new types of rock samples, heat flow data and lunar quake observation data.”

The city of Philadelphia is shown inside a theoretical lunar lava tube. A Purdue University team of researchers explored whether lava tubes more than 1 kilometer wide could remain structurally stable on the moon. Credit: Purdue University/courtesy of David Blair

Granted, the LRS was not specifically designed to detect lava tubes, but to characterize the origins of the Moon and its geologic evolution. For this reason, it did not fly close enough to the Moon to obtain extremely accurate information on the subsurface. Nevertheless, as SELENE passed near the Marius Hills Hole, the instrument picked up a distinctive echo pattern.

This pattern was characterized by a decrease in echo power followed by a large second echo peak. These two echoes correspond to radar reflections from the Moon’s surface, as well as the floor and ceiling of the open lava tube. When they analyzed this pattern, the research team interpreted it is evidence of a tube. They found similar echo patterns at several locations around the hole, which could indicate that there is more than one lava tube in the region.

To confirm their findings, the team also consulted data from NASA’s Gravity Recovery and Interior Laboratory (GRAIL) mission. Consisting of two spacecraft, this collaborative effort collected high-quality data on the Moon’s gravitational field between 2011 and 2012. By using GRAIL data that identified mass deficits under the surface, which are evidence of caverns, the team was able to narrow down their search.

Jay Melosh, a GRAIL co-investigator and Distinguished Professor of Earth, Atmospheric and Planetary Sciences at Purdue University, was also a co-author on the paper. As he explained:

“They knew about the skylight in the Marius Hills, but they didn’t have any idea how far that underground cavity might have gone. Our group at Purdue used the gravity data over that area to infer that the opening was part of a larger system. By using this complimentary technique of radar, they were able to figure out how deep and high the cavities are.”

Arched passages in the main tube show the classic lava tube shape. The floor was the crust on a former lava lake that fell inward as it drained from beneath. Credit: Dave Bunnell/Under Earth Images/Wikipedia Commons

On Earth, stable lava tubes have been found that can extend for dozens of kilometers. To date, the longest and deepest to be discovered is the Kazumura Cave in Hawaii, which is over a kilometer (3,614 feet) deep and 65.5 km (40.7 mi) long. On the Moon, however, lava tubes are much larger, due to the fact that the Moon has only a fraction of the Earth’s gravity (0.1654 g to be exact).

For a lava tube to be detecting using gravity data, it would need to be several kilometers in length and at least one kilometer in height and width. Since the tube in Marius Hills was detectable, it is likely big enough to house a major city. In fact, during a presentation at the 47th Lunar and Planetary Conference, researchers from Purdue University showed GRAIL data that indicated how the tube beneath the MHH could be large enough to house Philadelphia.

This most recent study was also the subject of a presentation at the 48th Lunar and Planetary Conference. Similar evidence of possible stable lava tubes in the Sea of Tranquility was also obtained by the Lunar Reconnaissance Orbiter (LRO) back in 2010. However, this latest combination of radar and gravity data has provided the clearest picture yet of what a stable lava tube looks like.

Similar evidence of lava tubes has also been discovered on Mars, and possible even Mercury. On Mars in particular,  chains of pit craters, broad lava fans, skylights and partially collapsed lava tubes all indicate the presence of stable tubes. Based on this latest study, future mission to the Red Planet (which could include the creation of a habitat) might also entail the investigation of these features.

In fact, lava tubes could become the means through which a human presence is established throughout the Solar System someday!

Further Reading: Purdue University, Geophysical Research Letters

Venus Express Probe Reveals the Planet’s Mysterious Night Side

Venus’ atmosphere is as mysterious as it is dense and scorching. For generations, scientists have sought to study it using ground-based telescopes, orbital missions, and the occasional atmospheric probe. And in 2006, the ESA’s Venus Express mission became the first probe to conduct long-term observations of the planet’s atmosphere, which revealed much about its dynamics.

Using this data, a team of international scientists – led by researchers from the Japan Aerospace and Exploration Agency (JAXA) – recently conducted a study that characterized the wind and upper cloud patterns on the night side of Venus. In addition to being the first of its kind, this study also revealed that the atmosphere behaves differently on the night side, which was unexpected.

The study, titled “Stationary Waves and Slowly Moving Features in the Night Upper Clouds of Venus“, recently appeared in the scientific journal Nature Astronomy. Led by Javier Peralta, the International Top Young Fellow of JAXA, the team consulted data obtained by Venus Express’ suite of scientific instruments in order to study the planet’s previously-unseen cloud types, morphologies, and dynamics.

The atmospheric super-rotation at the upper clouds of Venus. While the super-rotation is present in both day and night sides of Venus, it seems more uniform in the day. Credits: JAXA, ESA, J. Peralta and R. Hueso.

Whereas plenty of studies have been conducted of Venus’ atmosphere from soace, this was the first time that a study was not focused on the dayside of the planet. As Dr. Peralta explained in an ESA press statement:

This is the first time we’ve been able to characterize how the atmosphere circulates on the night side of Venus on a global scale. While the atmospheric circulation on the planet’s dayside has been extensively explored, there was still much to discover about the night side. We found that the cloud patterns there are different to those on the dayside, and influenced by Venus’ topography.

Since the 1960s, astronomers have been aware that Venus’ atmosphere behaves much differently that those of other terrestrial planets. Whereas Earth and Mars have atmospheres that co-rotate at approximately the same speed as the planet, Venus’ atmosphere can reach speeds of more than 360 km/h (224 mph). So while the planet takes 243 days to rotate once on its axis, the atmosphere takes only 4 days.

This phenomena, known as “super-rotation”, essentially means that the atmosphere moves over 60 times faster than the planet itself. In addition, measurements in the past have shown that the fastest clouds are located at the upper cloud level, 65 to 72 km (40 to 45 mi) above the surface. Despite decades of study, atmospheric models have been unable to reproduce super-rotation, which indicated that some of the mechanics were unknown.

Artist’s impression of the atmosphere of Venus, showing its lightning storms and a volcano in the distance. Credit and ©: European Space Agency/J. Whatmore

As such, Peralta and his international team – which included researchers from the Universidad del País Vasco in Spain, the University of Tokyo, the Kyoto Sangyo University, the Center for Astronomy and Astrophysics (ZAA) at Berlin Technical University, and the Institute of Astrophysics and Space Planetology in Rome – chose to look at the unexplored side to see what they could find. As he described it:

“We focused on the night side because it had been poorly explored; we can see the upper clouds on the planet’s night side via their thermal emission, but it’s been difficult to observe them properly because the contrast in our infrared images was too low to pick up enough detail.”

This consisted of observing Venus’ night side clouds with the probe’s Visible and Infrared Thermal Imaging Spectrometer (VIRTIS). The instrument gathered hundreds of images simultaneously and different wavelengths, which the team then combined to improve the visibility of the clouds. This allowed the team to see them properly for the first time, and also revealed some unexpected things about Venus’ night side atmosphere.

What they saw was that atmospheric rotation appeared to be more chaotic on the night side than what has been observed in the past on the dayside. The upper clouds also formed different shapes and morphologies – i.e. large, wavy, patchy, irregular and filament-like patterns  – and were dominated by stationary waves, where two waves moving in opposite directions cancel each other out and create a static weather pattern.

Examples of new types of cloud morphology discovered on the night side of Venus thanks to Venus Express (ESA) and the infrared telescope IRTF (NASA). Credits: ESA/NASA/J. Peralta and R. Hueso.

The 3D properties of these stationary waves were also obtained by combining VIRTIS data with radio-science data from the Venus Radio Science experiment (VeRa). Naturally, the team was surprised to find these kinds of atmospheric behaviors since they were inconsistent with what has been routinely observed on the dayside. Moreover, they contradict the best models for explaining the dynamics of Venus’ atmosphere.

Known as Global Circulation Models (GCMs), these models predict that on Venus, super-rotation would occur in much the same way on both the dayside and the night side. What’s more, they noticed that stationary waves on the night side appeared to coincide with high-elevation features. As Agustin Sánchez-Lavega, a researcher from the University del País Vasco and a co-author on the paper, explained:

Stationary waves are probably what we’d call gravity waves–in other words, rising waves generated lower in Venus’ atmosphere that appear not to move with the planet’s rotation. These waves are concentrated over steep, mountainous areas of Venus; this suggests that the planet’s topography is affecting what happens way up above in the clouds.

This is not the first time that scientists have spotted a possible link between Venus’ topography and its atmospheric motion. Last year, a team of European astronomers produced a study that showed how weather patterns and rising waves on the dayside appeared to be directly connected to topographical features. These findings were based on UV images taken by the Venus Monitoring Camera (VMC) on board the Venus Express.

Schematic illustration of the proposed behaviour of gravity waves in the vicinity of mountainous terrain on Venus. Credit: ESA

Finding something similar happening on the night side was something of a surprise, until they realized they weren’t the only ones to spot them. As Peralta indicated:

It was an exciting moment when we realized that some of the cloud features in the VIRTIS images didn’t move along with the atmosphere. We had a long debate about whether the results were real–until we realised that another team, led by co-author Dr. Kouyama, had also independently discovered stationary clouds on the night side using NASA’s Infrared Telescope Facility (IRTF) in Hawaii! Our findings were confirmed when JAXA’s Akatsuki spacecraft was inserted into orbit around Venus and immediately spotted the biggest stationary wave ever observed in the Solar System on Venus’ dayside.

These findings also challenge existing models of stationary waves, which are expected to form from the interaction of surface wind and high-elevation surface features. However, previous measurements conducted by the Soviet-era Venera landers have indicated that surface winds might too weak for this to happen on Venus. In addition, the southern hemisphere, which the team observed for their study, is quite low in elevation.

And as Ricardo Hueso of the University of the Basque Country (and a co-author on the paper) indicated, they did not detect corresponding stationary waves in the lower cloud levels. “We expected to find these waves in the lower levels because we see them in the upper levels, and we thought that they rose up through the cloud from the surface,” he said. “It’s an unexpected result for sure, and we’ll all need to revisit our models of Venus to explore its meaning.”

Artist’s impression of Venus Express performing aerobreaking maneuvers in the planet’s atmosphere in June and July 2014. Credit: ESA–C. Carreau

From this information, it seems that topography and elevation are linked when it comes to Venus’ atmospheric behavior, but not consistently. So the standing waves observed on Venus’ night side may be the result of some other undetected mechanism at work. Alas, it seems that Venus’ atmosphere – in particular, the key aspect of super-rotation – still has some mysteries for us.

The study also demonstrated the effectiveness of combining data from multiple sources to get a more detailed picture of a planet’s dynamics. With further improvements in instrumentation and data-sharing (and perhaps another mission or two to the surface) we can expect to get a clearer picture of what is powering Venus’ atmospheric dynamics before long.

With a little luck, there may yet come a day when we can model the atmosphere of Venus and predict its weather patterns as accurately as we do those of Earth.

Further Reading: ESA, Nature Astronomy

New Japanese mission will be going to the Moons of Mars

In the coming decades, the world’s largest space agencies hope to mount some exciting missions to the Moon and to Mars. Between NASA, Roscosmos, the European Space Agency (ESA), the Chinese National Space Agency (CNSA) and the Indian Space Research Organization (ISRO), there is simply no shortage of proposals for Lunar bases, crewed missions to Mars, and robotic explorers to both.

However, the Japanese Aerospace Exploration Agency (JAXA) has a different mission in mind when it comes to the coming decades. Instead of exploring the Moon or Mars, they propose exploring the moons of Mars! Known as the Martian Moons Exploration (MMX) mission, the plan is to have a robotic spacecraft fly to Phobos and Deimos to explore their surfaces and return samples to Earth for analysis.

The spacecraft would be deployed sometime in the 2020s, and would be tasked with two main objectives. The first would be to help scientists determine the origins of Phobos and Deimos, which has been a subject of debate for some time. Whereas some believe that these moons are capture asteroids, others have argued that they were created when fragments ejected from Mars (due to giant impacts on the surface) came together.

Phobos and Deimos, photographed here by the Mars Reconnaissance Orbiter, are tiny, irregularly-shaped moons that are probably strays from the main asteroid belt. Credit: NASA

As Dr. Masaki Fujimoto, a Professor at JAXA’s Institute of Space and Astronautical Science (ISAS) and the Team Manager of the MMX mission, told Universe Today via email:

“MMX will land on Phobos and acquire samples of at least 10 grams from more than 2cm below the surface. Analysis of samples returned to Earth will clarify the nature of the asteroid that led to the formation of the moon. Deimos observations will be limited to flyby imaging, but combined with ground data to be obtained for Phobos, we should be able to constrain its origin in a substantial manner.”

The second objective focuses on the characterization of conditions both on and around the moons of Mars. This includes surface processes on Phobos and Deimos, the nature of the environment in which they orbit, and the global and temporal dynamics of Mars atmosphere – i.e. dust, clouds and water vapor.

“Airless bodies such as asteroids are exposed to space weathering processes,” said Dr. Fujimoto. “In the case of Phobos, an impact event on the surface releases many dust particles. Unlike an asteroid in the interplanetary space, dust particles will not be simply lost but will orbit around Mars and return and hit the Phobos surface. This is regarded as the reason that Phobos has a very thick regolith layer. Knowing this process is to know the attributes of returned samples better.”

Artist’s impression of the MMX spacecraft in launch configuration. Credit: JAXA/ISAS

Another major objective of this mission is to learn more about small bodies coming from the outer Solar System. As the outermost rocky planet, Mars’ orbit marks the boundary between the terrestrial planets – which have solid surfaces and variable atmospheres (ranging from super-thing to dense) – and the gas and ice giants of the outer Solar System that have highly dense atmospheres.

Because of this, studying Mars’ moons, determining their origin, and learning more about the Martian orbital environment could teach us a lot about the evolution of the Solar System. Not only does such a mission present opportunities to study how planets like Mars formed, but also the process of by which primordial materials were transported between the inner and outer Solar Systems during its early history. As Dr. Fujimoto explained:

“These small bodies were the delivery capsules for water from outside the Frost Line to the Habitable Zone of the solar system, where our planet is situated. Earth was born dry and needed delivery of water for its habitability to be switched on at all. It is likely that one of the (failed) deliveries led to the formation of Phobos, and, sample analysis will tell us about the failed capsule.

“This is obviously the case when the capture idea turns out to be correct. Even for the case of giant impact, the scale of the impact is considered to be not too gigantic to alter fully the materials, implying that sample analysis would tell us something about the impactor asteroid.”

As it stands, the probe is scheduled to launch in September 2024, taking advantage of the fact that Earth and Mars will be at the nearest point to each other  in their orbits at this time. It will arrive around Mars by 2025, conduct its studies for a three-year period, and then return to Earth by July of 2029. Once there, it will rely on a suite of scientific instruments to conduct surveys and obtain samples.

Artist’s concept of the MMX spacecraft in orbital configuration, with its scientific instruments indicated. Credit: JAXA/ISAS

These instruments include a Neutron and Gamma-ray Spectrometer (NGRS), a Near-Infrared Spectrometer (NIRS), a Wide Angle Multiband Camera (WAM), a Telescopic Camera (TL), a Circum-Martian Dust Monitor (CMDM), a Mass Spectrum Analyzer (MSA), and a Light Detection and Ranging (LIDAR) instrument.

Details on the mission profile and the instruments were included in a presentation made by Dr. Fujimoto and the MMX Science Board members at the recent 48th Lunar and Planetary Science Conference. The mission profile and information on the objectives were also made available in an abstract that was issued in advance of the upcoming European Planetary Science Congress 2017.

The mission will also leverage some key partnerships that JAXA is currently engaged in. These include an agreement reached with NASA back in late March to include the Neutron and Gamma-ray Spectrometer (NGRS) in the MMX’s instrument suite.  And in April, JAXA and the National Center for Space Studies (CNES) signed an Implementation Agreement (IA) that would allow the French national space agency to participate in the mission as well.

If all goes as planned, JAXA will be spending the next decade gathering information that could bridge findings made by Lunar and Martian missions. Whereas lunar research will reveal things about the history of the Moon, and Martian missions will offer new insights into Mars’ geology and evolution (and perhaps if life still exists there!), the MMX mission will reveal things about the history of Mars’ moons and the early Solar System as a whole.

Other proposals that JAXA is currently working on include the Jupiter Icy Moons Explorer (JUICE) and SPICA, two missions that will explore Jupiter’s Galilean Moons and conduct infrared astronomy (respectively) in the coming decade.

Further Reading: MMX

Japan Becomes A Military Space Player With Latest Launch

The Japanese Aerospace Exploration Agency (JAXA) has accomplished some impressive things over the years. Between 2003 (when it was formed) and 2016, the agency has launched multiple satellites – ranging from x-ray and infrared astronomy to lunar and Venus atmosphere exploration probes – and overseen Japan’s participation in the International Space Station.

But in what is an historic mission – and a potentially controversial one – JAXA recently launched the first of three X-band defense communication satellites into orbit. By giving the Japanese Self-Defense Forces the ability to relay communications and commands to its armed forces, this satellite (known as DSN 2) represents an expansion of Japan’s military capability.

The launch took place on January 24th at 4:44 pm Japan Standard Time (JST) – or 0744 Greenwich Mean Time (GMT) – with the launch of a H-IIA rocket from Tanegashima Space Center. This was the thirty-second successful flight of the launch vehicle, and the mission was completed with the deployment of the satellite in Low-Earth Orbit – 35,000 km; 22,000 mi above the surface of the Earth.

Artist’s concept of a Japanese X-band military communications satellite. Credit: Japanese Ministry of Defense

Shortly after the completion of the mission, JAXA issued a press release stating the following:

“At 4:44 p.m., (Japan Standard Time, JST) January 24, Mitsubishi Heavy Industries, Ltd. and JAXA launched the H-IIA Launch Vehicle No. 32 with X-band defense communication satellite-2* on board. The launch and the separation of the satellite proceeded according to schedule. Mitsubishi Heavy Industries, Ltd. and JAXA express appreciation for the support in behalf of the successful launch. At the time of the launch the weather was fine, at 9 degrees Celsius, and the wind speed was 7.1 meters/second from the NW.”

This launch is part of a $1.1 billion program by the Japanese Defense Ministry to develop X-band satellite communications for the Japan Self-Defense Forces (JSDF). With the overall goal of deploying three x-band relay satellites into geostationary orbit, its intended purpose is to reduce the reliance of Japan’s military (and those of its allies) on commercial and international communications providers.

While this may seem like a sound strategy, it is a potential source of controversy in that it may skirt the edge of what is constitutionally permitted in Japan. In short, deploying military satellites is something that may be in violation of Japan’s post-war agreements, which the nation committed to as part of its surrender to the Allies. This includes forbidding the use of military force as a means of solving international disputes.

An H-2A rocket, Japan’s primary large-scale launch vehicle. Credit: JAXA

It also included placing limitations on its Self-Defense Forces so they would not be capable of independent military action. As is stated in Article 9 of the Constitution of Japan (passed in 1947):

“(1) Aspiring sincerely to an international peace based on justice and order, the Japanese people forever renounce war as a sovereign right of the nation and the threat or use of force as means of settling international disputes.
(2) In order to accomplish the aim of the preceding paragraph, land, sea, and air forces, as well as other war potential, will never be maintained. The right of belligerency of the state will not be recognized.”

However, since 2014, the Japanese government has sought to reinterpret Article 9 of the constitution, claiming that it allows the JSDF the freedom to defend other allies in case of war. This move has largely been in response to mounting tensions with North Korea over its development of nuclear weapons, as well as disputes with China over issues of sovereignty in the South China Sea.

This interpretation has been the official line of the Japanese Diet since 2015, as part of a series of measures that would allow the JSDF to provide material support to allies engaged in combat internationally. This justification, which claims that Japan and its allies would be endangered otherwise, has been endorsed by the United States. However, to some observers, it may very well be interpreted as an attempt by Japan to re-militarize.

In the coming weeks, the DSN 2 spacecraft will use its on-board engine to position itself in geostationary orbit, roughly 35,800 km (22,300 mi) above the equator. Once there, it will commence a final round of in-orbit testing before commencing its 15-year term of service.

Further Reading: Spaceflight Now

What is the International Space Station?

After the historic Apollo Missions, which saw humans set foot on another celestial body for the first time in history, NASA and the Russian Space Agency (Roscosmos) began to shift their priorities away from pioneering space exploration and began to focus on developing long-term capabilities in space. In the ensuing decades (from the 1970s to 1990s), both agencies began to build and deploy space stations, each one bigger and more complex than the last.

The latest and greatest of these is the International Space Station (ISS), a scientific facility that resides in Low-Earth Orbit around our planet. This space station is the largest and most sophisticated orbiting research facility ever built, and is so large that it can actually be seen with the naked eye. Central to its mission is the idea of fostering international cooperation for the sake of advancing science and space exploration.

Origin:

Planning for the ISS began in the 1980s and was based in part on the successes of Russia’s Mir space station, NASA’s Skylab, and the Space Shuttle Program. This station, it was hoped, would allow for the future utilization of  low-Earth Orbit and its resources, and serve as an intermediate base for renewed exploration efforts to the Moon, mission to Mars, and beyond.

The Mir space station hangs above the Earth in 1995 (photo taken by the mission crew of the Space Shuttle Atlantis, STS-71). Credit: NASA

In May of 1982, NASA established the Space Station task force, which was charged with created a conceptual framework for such a space station. In the end, the ISS plan that emerged was a culmination of several different plans for a space station – which included NASA’s Freedom and the Soviet’s Mir-2 concepts, as well as Japan’s Kibo laboratory, and the European Space Agency’s Columbus laboratory.

The Freedom concept called for a modular space station to be deployed to orbit, where it would serve as the counterpart to the Soviet Salyut and Mir space stations. That same year, NASA approached the Japanese Aerospace and Exploration Agency (JAXA) to participate in the program with the creation of the Kibo, also known as the Japanese Experiment Module.

The Canadian Space Agency was similarly approached in 1982 and was asked to provide robotic support for the station. Thanks to the success of the Canadarm, which was an integral part of the Space Shuttle Program, the CSA agreed to develop robotic components that would assist with docking, perform maintenance, and assist astronauts with spacewalks.

In 1984, the ESA was invited to participate in the construction of the station with the creation of the Columbus laboratory – a research and experimental lab specializing in materials science. Construction of both Kibo and Columbus were approved of in 1985. As the most ambitious space program in either agency’s history, the development of these laboratories was seen as central to Europe and Japan’s emerging space capability.

Skylab, America’s First manned Space Station. Photo taken by departing Skylab 4 crew in Feb. 1974. Credit: NASA

In 1993, American Vice-President Al Gore and Russian Prime Minister Viktor Chernomyrdin announced that they would be pooling the resources intended to create Freedom and Mir-2. Instead of two separate space stations, the programs would be working collaboratively to create a single space station – which was later named the International Space Station.

Construction:

Construction of the ISS was made possible with the support of multiple federal space agencies, which included NASA, Roscosmos, JAXA, the CSA, and members of the ESA – specifically Belgium, Denmark, France, Spain, Italy, Germany, the Netherlands, Norway, Switzerland, and Sweden. The Brazilian Space Agency (AEB) also contributed to the construction effort.

The orbital construction of the space station began in 1998 after the participating nations signed the Space Station Intergovernmental Agreement (IGA), which established a legal framework that stressed cooperation based on international law. The participating space agencies also signed the Four Memoranda of Understandings (MoUs), which laid out their responsibilities in the design, development and use of the station.

The assembly process began in 1998 with the deployment of the ‘Zarya’ (“Sunrise” in Russian) Control Module, or Functional Cargo Block. Built by the Russians with funding from the US, this module was designed to provide the station’s initial propulsion and power. The pressurized module – which weighed over 19,3oo kg (42,600 pounds) – was launched aboard a Russian Proton rocket in November 1998.

On Dec. 4th, the second component – the ‘Unity’ Node – was placed into orbit by the Space Shuttle Endeavour (STS-88), along with two pressurized mating adapters. This node was one of three – Harmony and Tranquility being the other two – that would form the ISS’ main hull. On Sunday, Dec. 6th, it was mated to Zarya by the STS-88 crew inside the shuttle’s payload bay.

The next installments came in the year 2000, with the deployment of the Zvezda Service Module (the first habitation module) and multiple supply missions conducted by the Space Shuttle Atlantis.  The Space Shuttle Discovery (STS-92) also delivered the stations third pressurized mating adapted and a Ku-band antenna in October. By the end of the month, the first Expedition crew was launched aboard a Soyuz rocket, which arrived on Nov. 2nd.

In 2001, the ‘Destiny’ Laboratory Module and the ‘Pirs’ Docking Compartment were delivered. The modular racks that are part of Destiny were also shipped using the Raffaello Multi-Purpose Logistic Modules (MPLM) aboard the Space Shuttle Endeavour, and put into place using the Canadarm2 robotic arm. 2002 saw additional racks, truss segments, solar arrays, and the Mobile Base System for the Station’s Mobile Servicing System being delivered.

In 2007, the European Harmony module was installed, which allowed for the addition of the Columbus and Kibo laboratories – both of which were added in 2008. Between 2009 and 2011, construction was finalized with the addition of the Russian Mini-Research Module-1 and -2 (MRM1 and MRM2), the ‘Tranquility’ Node, the Cupola Observation Module, the Leonardo Permanent Multipurpose Module, and the Robonaut 2 technology suite.

The structure of the ISS (exploded in this diagram) showing the various components and how they are assembled together. Credit: NASA

No additional modules or components were added until 2016, when Bigelow Aersopace installed their experimental Bigelow Expandable Activity Module (BEAM). All told, it took 13 years to construct the space station, an estimated $100 billion, and required more than 100 rocket and Space Shuttle launches, and 160 spacewalks.

As of the penning of this article, the station has been continuously occupied for a period of 16 years and 74 days since the arrival of Expedition 1 on November 2nd, 2000. This is the longest continuous human presence in low Earth orbit, having surpassed Mir’s record of 9 years and 357 days.

Purpose and Aims:

The main purpose of the ISS is fourfold: conducting scientific research, furthering space exploration, facilitating education and outreach, and fostering international cooperation. These goals are backed by NASA, the Russian Federal Space Agency (Roscomos), the Japanese Aerospace Exploration Agency (JAXA), the Canadian Space Agency (CSA), and the European Space Agency (ESA), with additional support from other nations and institutions.

As far as scientific research goes, the ISS provides a unique environment to conduct experiments under microgravity conditions. Whereas crewed spacecraft provide a limited platform that is only deployed to space for a limited amount of time, the ISS allows for long-term studies that can last for years (or even decades).

Many different and continuous projects are being conducted aboard the ISS, which are made possible with the support of a full-time crew of six astronauts, and a continuity of visiting vehicles (which also allows for resupply and crew rotations). Scientists on Earth have access to their data, and are able to communicate with the science teams through a number of channels.

The many fields of research conducted aboard the ISS include astrobiology, astronomy, human research, life sciences, physical sciences, space weather, and meteorology. In the case of space weather and meteorology, the ISS is in a unique position to study these phenomena because it’s position in LEO. Here, it has a short orbital period, allowing it to witness weather across the entire globe many times in a single day.

It is also exposed to things like cosmic rays, solar wind, charged subatomic particles, and other phenomena that characterize a space environment. Medical research aboard the ISS is largely focused on the long-term effects of microgravity on living organisms – particularly its effects on bone density, muscle degeneration and organ function – which is intrinsic to long-range space exploration missions.

The ISS also conducts research that is beneficial to space exploration systems. It’s location in LEO also allows for the testing of spacecraft systems that are required for long-range missions. It also provides an environment where astronauts can gain vital experience in terms of operations, maintenance and repair services – which are similarly crucial for long-term missions (such as mission to the Moon and Mars).

The ISS also provides opportunities for education thanks to participation in experiments, where students are able to design experiments and watch as ISS crews carry them out. ISS astronauts are also able to engage classrooms through video link, radio communications, email, and educational videos/web episodes. Various space agencies also maintain educational materials for download based on ISS experiments and operations.

Educational and cultural outreach also fall within the ISS’ mandate. These activities are conducted with the help and support of the participating federal space agencies, and which are designed to encourage education and career training in the STEM (Science, Technical, Engineering, Math) fields.

One of the best known examples of this are the educational videos created by Chris Hadfield – the Canadian astronaut who served as the commander of Expedition 35 aboard the ISS – which chronicled the everyday activities of ISS astronauts. He also directed a great deal of attention to ISS activities thanks to his musical collaboration with the Barenaked Ladies and Wexford Gleeks – titled “I.S.S. (Is Somebody Singing)” (shown above).

His video, a cover of David Bowie’s “Space Oddity”, also earned him widespread acclaim. Along with drawing additional attention to the ISS and its crew operations, it was also a major feat since it was the only music video ever to be filmed in space!

Operations Aboard the ISS:

As noted, the ISS is facilitated by rotating crews and regular launches that transport supplies, experiments and equipment to the station. These take the form of both crewed and uncrewed vehicles, depending on the nature of the mission. Crews are generally transported aboard Russian Progress spacecraft, which are launched via Soyuz rockets from the Baikonur Cosmodrome in Kazakhstan.

Roscosmos has conducted a total of 60 trips to the ISS using Progress spacecraft, while 40 separate launches were conducted using Soyuz rockets. Some 35 flights were also made to the station using the now-retired NASA Space Shuttles, which transported crew, experiments and supplies. The ESA and JAXA have both conducted 5 cargo transfer missions, using the Automated Transfer Vehicle (ATV) and the H-II Transfer Vehicle (HTV), respectively.

In more recent years, private aerospace companies like SpaceX and Orbital ATK have been contracted to provide resupply missions to the ISS, which they have done using their Dragon and Cygnus spacecraft. Additional craft, such as SpaceX’s Crew Dragon spacecraft, are expected to provide crew transportation in the future.

Alongside the development of reusable first stage rockets, these efforts are being carried out in part to restore domestic launch capability to the US. Since 2014, tensions between the Russia and the US have led to growing concerns over the future of Russian-American cooperation with programs like the ISS.

Crew activities consist of conducting experiments and research considered vital to space exploration. These activities are scheduled from 06:00 to 21:30 hours UTC (Universal Coordinated Time), with breaks being taken for breakfast, lunch, dinner, and regular crew conferences. Every crew member has their own quarters (which includes a tethered sleeping bag), two of which are located in the Zvezda Module and four more installed in Harmony.

During “night hours”, the windows are covered at to give the impression of darkness. This is essential since the station experiences 16 sunrises and sunsets a day. Two exercise periods of 1 hour each are scheduled every day to ensure that the risks of muscle atrophy and bone loss are minimized. The exercise equipment includes two treadmills, the Advanced Resistive Exercise Device (ARED) for simulated weight training, and a stationary bicycle.

Hygiene is maintained thanks to water jets and soap dispensed from tubes, as well as wet wipes, rinseless shampoo, and edible toothpaste. Sanitation is provided by two space toilets – both of Russian design – aboard the Zvezda and Tranquility Modules. Similar to what was available aboard the Space Shuttle, astronauts fasten themselves to the toilet seat and the removal of waste is accomplished with a vacuum suction hole.

Liquid waste is transferred to the Water Recovery System, where it is converted back into drinking water (yes, astronauts drink their own urine, after a fashion!). Solid waste is collected in individual bags that are stored in an aluminum container, which are then transferred to the docked spacecraft for disposal.

Food aboard the station consists mainly of freeze-dried meals in vacuum-sealed plastic bags. Canned goods are available, but are limited due to their weight (which makes them more expensive to transport). Fresh fruit and vegetables are brought during resupply missions, and a large array of spices and condiments are used to ensure that food is flavorful – which is important since one of the effects of microgravity is a diminished sense of taste.

To prevent spillage, drinks and soups are contained in packets and consumed with a straw. Solid food is eaten with a knife and fork, which are attached to a tray with magnets to prevent them from floating away, while drinks are provided in dehydrated powder form and then mixed with water. Any food or crumbs that floats away must be collected to prevent it from clogging the air filters and other equipment.

Hazards:

Life aboard the station also carries with it a high degree of risk. These come in the form of radiation, the long-term effects of microgravity on the human physique, the psychological effects of being in space (i.e. stress and sleep disturbances), and the danger of collision with space debris.

In terms of radiation, objects within the Low-Earth Orbit environment are partially protected from solar radiation and cosmic rays by the Earth’s magnetosphere. However, without the protection of the Earth’s atmosphere, astronauts are still exposed to about 1 millisievert a day, which is the equivalent of what a person on Earth is exposed to during the course of a year.

As a result, astronauts are at higher risk for developing cancer, suffering DNA and chromosomal damage, and diminished immune system function. Hence why protective shielding and drugs are a must aboard the station, as well as protocols for limiting exposure. For instance, during solar flare activity, crews are able to seek shelter in the more heavily shielded Russian Orbital Segment of the station.

As already noted, the effects of microgravity also take a toll on muscle tissues and bone density. According to a 2001 study conducted by NASA’s Human Research Program (HRP) – which researched the effects on an astronaut Scott Kelly’s body after he spent a year aboard the ISS – bone density loss occurs at a rate of over 1% per month.

Similarly, a report by the Johnson Space Center – titled “Muscle Atrophy” – stated that astronauts experience up to a 20% loss of muscle mass on spaceflights lasting just five to 11 days. In addition, more recent studies have indicated that the long-term effects of being in space also include diminished organ function, decreased metabolism, and reduced eyesight.

Because of this, astronauts exercise regularly in order to minimize muscle and bone the loss, and their nutritional regimen is designed to make sure they the appropriate nutrients to maintain proper organ function. Beyond that, the long-term health effects, and additional strategies to combat them, are still being investigated.

But perhaps the greatest hazard comes in the form of orbiting junk – aka. space debris. At present, there are over 500,000 pieces of debris that are being tracked by NASA and other agencies as they orbit the Earth. An estimated 20,000 of these are larger than a softball, while the remainder are about the size of a pebble. All told, there are likely to be many millions of pieces of debris in orbit, but most are so small they can’t be tracked.

These objects can travel at speeds of up to 28,163 km/h (17,500 mph), while the ISS orbits the Earth at a speed of 27,600 km/h (17,200 mph). As a result, a collision with one of these objects could be catastrophic to the ISS. The stations is naturally shielded to withstand impacts from tiny bits of debris and well as micro-meteoroids – and this shielding is divided between the Russian Orbital Segment and the US Orbital Segment.

On the USOS, the shielding consists of a thin aluminum sheet that is held apart from the hull. This sheet causes objects to shatter into a cloud, thereby dispersing the kinetic energy of the impact before it reaches the main hull. On the ROS, shielding takes the form of a carbon plastic honeycomb screen, an aluminum honeycomb screen, and glass cloth, all of which are spaced over the hull.

The ROS’ shielding is less likely to be punctured, hence why the crew moves to the ROS whenever a more serious threat presents itself. But when faced with the possibility of an impact from a larger object that is being tracked, the station performs what is known as a Debris Avoidance Manoeuvre (DAM). In this event, the thrusters on the Russian Orbital Segment fire in order to alter the station’s orbital altitude, thus avoiding the debris.

Future of the ISS:

Given its reliance on international cooperation, there has been concern in recent years – in response to growing tensions between Russia, the United States and NATO – about the future of the International Space Station. However, for the time being, operations aboard the station are secure, thanks to commitments made by all of the major partners.

In January of 2014, the Obama Administration announced that it would be extending funding for the US portion of the station until 2024. Roscosmos has endorsed this extension, but has also voiced approval for a plan that would use elements of the Russian Orbital Segment to construct a new Russian space station.

Known as the Orbital Piloted Assembly and Experiment Complex (OPSEK), the proposed station would serve as an assembly platform for crewed spacecraft traveling to the Moon, Mars, and the outer Solar System. There has also been tentative announcements made by Russian officials about a possible collaborative effort to build a future replacement for the ISS. However, NASA has yet to confirm these plans.

In April of 2015, the Canadian government approved a budget which included funding to ensure the CSA’s participation with the ISS through 2024. In December of 2015, JAXA and NASA announced their plans for a new cooperative framework for the International Space Station (ISS), which included Japan extending its participation until 2024. As of December 2016, the ESA has also committed to extending its mission to 2024.

The ISS represents one of the greatest collaborative and international efforts in history, not to mention one of the greatest scientific undertakings. In addition to providing a location for crucial scientific experiments that cannot be conducted here on Earth, it is also conducting research that will help humanity make its next great leaps in space – i.e. mission to Mars and beyond!

On top of all that, it has been a source of inspiration for countless millions who one day dream of going into space! Who knows what great undertakings the ISS will allow for before it is finally decommissioned – most likely decades from now?

We have written many interesting articles about the ISS here at Universe Today. Here’s International Space Station Achieves 15 Years of Continuous Human Presence in Orbit, Beginner’s Guide to Seeing the International Space Station, Take a Virtual 3-D Spacewalk Outside the International Space Station, International Space Station Viewing and Space Station Pictures.

For more information, check out the NASA Reference Guide to the ISS and this article about the 10th anniversary of the space station.

Astronomy Cast also has relevant episodes on the subject. Here’s Questions: An Unlocked Moon, Energy Into Black Holes, and the Space Station’s Orbit, and Episode 298: Space Stations, Part 3 – International Space Station.

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