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Europa

Europa is one of Jupiter’s moons and it is also most probably the most important moon in the Jovian system as well as perhaps the most important natural body in the Solar System. Since decades ago science fiction writers have depicted Europa as a place which can harbor life and the oceans of Europa point that life may have existed on this moon of Jupiter.

Jupiters Moon Europa may Host LifeSlightly smaller than the Earth’s Moon, Europa’s water-ice surface is crisscrossed by long, linear fractures, cracks, ridges, and bands. The moon’s ice shell is probably 10 to 15 miles (15 to 25 kilometers) thick, beneath which the ocean is estimated to be 40 to 100 miles (60 to 150 kilometers) deep. Like Earth, Europa is thought to also contain a rocky mantle and iron core.

Europa is named for a woman who, in Greek mythology, was abducted by the god Zeus — Jupiter in Roman mythology.

Decades ago, science fiction offered a hypothetical scenario: What if alien life were thriving in an ocean beneath the icy surface of Jupiter’s moon Europa? The notion pulled Europa out of obscurity and into the limelight where it has remained, stoking the imaginations of people both within and outside the science community who fantasize about humans discovering life beyond Earth. That fantasy, however, may be grounded in reality.

From ground-based telescopes, scientists knew that Europa’s surface is mostly water ice, and scientists have found strong evidence that beneath the ice crust is an ocean of liquid water or slushy ice. In 1979 the two Voyager spacecraft passed through the Jovian system, providing the first hints that Europa might contain liquid water. Then ground-based telescopes on Earth, along with the Galileo spacecraft and space telescopes, have increased scientists’ confidence for a Europan ocean.

Scientists think Europa’s ice shell is 10 to 15 miles (15 to 25 kilometers) thick, floating on an ocean 40 to 100 miles (60 to 150 kilometers) deep. So while Europa is only one-fourth the diameter of Earth, its ocean may contain twice as much water as all of Earth’s oceans combined. Europa’s vast and unfathomably deep ocean is widely considered the most promising place to look for life beyond Earth. A passing spacecraft might even be able to sample Europa’s ocean without landing on the moon’s surface because it is possible that Europa’s ocean may be leaking out into space.

Life as we know it seems to have three main requirements: liquid water, the appropriate chemical elements, and an energy source.

Astrobiologists — scientists who study the origin, evolution and future of life in the universe — believe Europa has abundant water and the right chemical elements, but an energy source on Europa has been difficult to confirm. On Earth, life forms have been found thriving near subterranean volcanoes, deep-sea vents and other extreme environments. These “extremophile” life forms give scientists clues about how life may be able to survive beneath Europa’s ice shell.

Size and Distance

With an equatorial diameter of 1,940 miles (3,100 kilometers), Europa is about 90 percent the size of Earth’s Moon. So if we replaced our Moon with Europa, it would appear roughly the same size in the sky as our Moon does, but brighter — much, much brighter. Europa’s surface is made of water ice and so it reflects 5.5 times the sunlight than our Moon does.

How far is Europa? Europa orbits Jupiter at about 417,000 miles (671,000 kilometers) from the planet, which itself orbits the Sun at a distance of roughly 500 million miles (780 million kilometers), or 5.2 astronomical units (AU). One AU is the distance from Earth to the Sun. Light from the Sun takes about 45 minutes to reach Europa. Because of the distance, sunlight is about 25 times fainter at Jupiter and Europa than at Earth.

Orbit and Rotation

Europa orbits Jupiter every 3.5 days and is locked by gravity to Jupiter, so the same hemisphere of the moon always faces the planet. Jupiter takes about 4,333 Earth days (or about 12 Earth years) to orbit the Sun (a Jovian year). Jupiter’s equator (and the orbital plane of its moons) are tilted with respect to Jupiter’s orbital path around the Sun by only 3 degrees (Earth is tilted 23.5 degrees). This means Jupiter spins nearly upright so that the planet, as well as Europa and Jupiter’s other dozens of moons, do not have seasons as extreme as other planets do.

You can watch the flyover video of Europa in this video below:

Because Europa’s orbit is elliptical (slightly stretched out from circular), its distance from Jupiter varies, and the moon’s near side feels Jupiter’s gravity more strongly than its far side. The magnitude of this difference changes as Europa orbits, creating tides that stretch and relax the moon’s surface.

Flexing from the tides likely creates the moon’s surface fractures. If Europa’s ocean exists, the tidal heating could also lead to volcanic or hydrothermal activity on the seafloor, supplying nutrients that could make the ocean suitable for living things.

Structure

Like our planet, Europa is thought to have an iron core, a rocky mantle and an ocean of salty water. Unlike Earth, however, Europa’s ocean lies below a shell of ice probably 10 to 15 miles (15 to 25 kilometers) thick and has an estimated depth of 40 to 100 miles (60 to 150 kilometers). While evidence for an internal ocean is strong, its presence awaits confirmation by a future mission.

Formation

Jupiter’s large Galilean satellites (Io, Europa, Ganymede, and Callisto) likely formed out of leftover material after Jupiter condensed from the initial cloud of gas and dust surrounding the sun, early in the history of the solar system. Those four moons are likely about the same age as the rest of the solar system — about 4.5 billion years old.

In fact, the Galilean satellites are sometimes called a “mini solar system” since they formed from the leftovers of Jupiter similar to how Earth and other planets formed from gas and dust left over from the formation of our Sun. The similarities don’t end there. Each planet in the inner solar system is less dense than their inner neighbor — Mars is less dense than Earth, which is less dense than Venus, which is less dense than Mercury. The Galilean moons follow the same principle, being less dense the farther they are from Jupiter. The reduced density at greater distances is likely due to temperature: denser, rocky and metal material condenses out first, close to Jupiter or the Sun, while lighter-weight icy material only condenses out at larger distances where it is colder.

Distance from Jupiter also determines how much tidal heating the Galilean satellites experience — Io, closest to Jupiter, is heated so much that it is the most volcanically active body in the solar system, and it likely long ago drove off any water it had when it formed. Europa has a layer of ice and water on top of a rocky and metal interior, while Ganymede and Callisto actually have higher proportions of water ice and so lower densities.

Surface

Europa’s water-ice surface is crisscrossed by long, linear fractures. Based on the small number of observable craters, the surface of this moon appears to be no more than 40 to 90 million years old, which is youthful in geologic terms (the surface of Callisto, another of Jupiter’s moons, is estimated to be a few billion years old). Along Europa’s many fractures, and in splotchy patterns across its surface, is a reddish-brown material whose composition is not known for certain, but likely contains salts and sulfur compounds that have been mixed with the water ice and modified by radiation. This surface composition may hold clues to the moon’s potential as a habitable world.

NASA’s Galileo spacecraft explored the Jupiter system from 1995 to 2003 and made numerous flybys of Europa. Galileo revealed strange pits and domes that suggest Europa’s ice layer could be slowly churning, or convecting (cooler, denser ice sinks, while warmer less-dense ice rises) due to heat from below. Long, linear fractures are often only 1-2 kilometers wide but can extend for thousands of kilometers across Europa’s surface. Some of these fractures have built up into ridges hundreds of meters tall, while others appear to have pulled apart into wide bands of multiple parallel fractures. Galileo also found regions called “chaos terrain,” where broken, blocky landscapes were covered in mysterious reddish material. In 2011, scientists studying Galileo data proposed that chaos terrains could be places where the surface collapsed above lens-shaped lakes embedded within the ice.

Atmosphere

Europa has only a tenuous atmosphere of oxygen, but in 2013, NASA announced that researchers using the Hubble Space Telescope found evidence that Europa might be actively venting water into space. This would mean the moon is geologically active in the present day. If confirmed by follow-up observations, the plumes of water could be studied by future spacecraft similar to how the Cassini sampled the plume of Saturn’s moon Enceladus.

Magnetosphere

One of the most important measurements made by the Galileo mission showed how Jupiter’s magnetic field was disrupted in the space around Europa. The measurement strongly implied that a special type of magnetic field is being created (induced) within Europa by a deep layer of some electrically conductive fluid beneath the surface. Based on Europa’s icy composition, scientists think the most likely material to create this magnetic signature is a global ocean of salty water, and this magnetic field result is still the best evidence we have for the existence of an ocean on Europa.

EUROPA is an ocean world.

Space Shuttle Program

Parts of the Space ShuttleThe Space Shuttle Program of NASA was one of the turning points in the mankind’s quest for space. It made manned flight become more common by having reusable spacecraft that could be used for several missions again and again. Space Shuttle Program which had its first flight on April 12, 1961 was able to make going to space become commonplace and many civilians were also able to go to space due to the space shuttle program.

Between the first launch on April 12, 1981, and the final landing on July 21, 2011, NASA’s space shuttle fleet — Columbia, Challenger, Discovery, Atlantis and Endeavour — flew 135 missions, helped construct the International Space Station and inspired generations. NASA’s space shuttle fleet began setting records with its first launch on April 12, 1981 and continued to set high marks of achievement and endurance through 30 years of missions. Starting with Columbia and continuing with Challenger, Discovery, Atlantis and Endeavour, the spacecraft has carried people into orbit repeatedly, launched, recovered and repaired satellites, conducted cutting-edge research and built the largest structure in space, the International Space Station. The final space shuttle mission, STS-135, ended July 21, 2011 when Atlantis rolled to a stop at its home port, NASA’s Kennedy Space Center in Florida.

As humanity’s first reusable spacecraft, the space shuttle pushed the bounds of discovery ever farther, requiring not only advanced technologies but the tremendous effort of a vast workforce. Thousands of civil servants and contractors throughout NASA’s field centers and across the nation have demonstrated an unwavering commitment to mission success and the greater goal of space exploration.

Space Shuttle in Orbit

In July 2011, the space shuttle Atlantis touched down for the final time, ending the storied career of NASA’s fleet of space shuttles. The winged orbiters were NASA’s human spaceflight workhorses for 30 years and helped build the ISS, which celebrated its 20th anniversary of continuous human occupation last year.



 

Luna Moon Mission Program

 

Luna Moon MissionThe Luna moon mission program (from the Russian word Луна “Luna” meaning “Lunar” or “Moon”), occasionally called Lunik by western media, was a series of robotic spacecraft missions sent to the Moon by the Soviet Union between 1959 and 1976. Fifteen were successful, each designed as either an orbiter or lander, and accomplished many firsts in space exploration. They also performed many experiments, studying the Moon’s chemical composition, gravity, temperature, and radiation.

Twenty-four spacecraft were formally given the Luna designation, although more were launched. Those that failed to reach orbit were not publicly acknowledged at the time, and not assigned a Luna number. Those that failed in low Earth orbit were usually given Cosmos designations. The estimated cost of the Luna program in 1964 was US$6–10 billion.

Luna 1 (launched Jan. 2, 1959) was the first spacecraft to escape Earth’s gravity. It failed to impact the Moon as planned and became the first man-made object to go into orbit around the Sun. Luna 2 (launched Sept. 12, 1959) was the first spacecraft to strike the Moon, and Luna 3 (Oct. 4, 1959) made the first circumnavigation of the Moon and returned the first photographs of its far side. Luna 9 (Jan. 31, 1966) made the first successful lunar soft landing. Luna 16 (Sept. 12, 1970) was the first unmanned spacecraft to carry lunar soil samples back to Earth. Luna 17 (Nov. 10, 1970) soft-landed a robot vehicle, Lunokhod 1, for exploration. It also contained television equipment, by means of which it transmitted live pictures of several kilometres of the Moon’s surface. Luna 22 (May 29, 1974) orbited the Moon 2,842 times while conducting space research in its vicinity. Luna 24 (Aug. 9, 1976) returned with lunar soil samples taken from a depth of seven feet (about two metres) below the surface.


Seventeen of the 45 Luna missions were successful.

A few Luna missions won key victories in the space race between the United States and the former Soviet Union. Luna spacecraft were the first to impact and make a survivable landing on the Moon, photograph the far side of the Moon (never before seen by humans) and orbit the Moon.

Chinese Lunar Missions

Chinese Lunar MissionsThe Chinese Lunar Exploration Program (CLEP; Chinese: 中国探月; pinyin: Zhōngguó Tànyuè), also known as the Chang’e Project (Chinese: 嫦娥工程; pinyin: Cháng’é Gōngchéng) after the Chinese moon goddess Chang’e, is an ongoing series of robotic Moon missions by the China National Space Administration (CNSA). The program incorporates lunar orbiters, landers, rovers and sample return spacecraft, launched using Long March rockets. Launches and flights are monitored by a telemetry, tracking, and command (TT&C) system, which uses 50-meter (160-foot) radio antennas in Beijing and 40-meter (130-foot) antennas in Kunming, Shanghai, and Ürümqi to form a 3,000-kilometer (1,900-mile) VLBI antenna.A proprietary ground application system is responsible for downlink data reception.

The first spacecraft of the program, the Chang’e 1 lunar orbiter, was launched from Xichang Satellite Launch Center on 24 October 2007, having been delayed from the initial planned date of 17–19 April 2007. A second orbiter, Chang’e 2, was launched on 1 October 2010. Chang’e 3, which includes a lander and rover, was launched on 1 December 2013 and successfully soft-landed on the Moon on 14 December 2013. Chang’e 4, which includes a lander and rover, was launched on 7 December 2018 and landed on 3 January 2019 on the South Pole-Aitken Basin, on the far side of the Moon. A sample return mission, Chang’e 5, launched on 23 November 2020.

Mission Chronology

Chang’e 1 – 2007 – Lunar Orbiter
Chang’e 2 – 2010 – Lunar Orbiter
Chang’e 3 – 2013 – Lunar Lander
Yutu – 2013 – Lunar Rover
Chang’e 5-T1 – 2014 – Test Vehicle
Queqiao – 2018 – Communications Relay Satellite
Chang’e 4 – 2018 – Lunar Farside Lander and Rover
Chang’e 5 – 2020 – Lunar Lander and Sample Return

Video on Lunar Sample Return from Change-5

Video on Landing on the Far Side of the Moon by Change-4

Salyut Space Station

Despite an array of problems, the first space station, Salyut 1, made important progress toward living and working in space long-term and paved the way for future space stations. Launched by the Soviet Union in 1971, the port orbited the Earth almost 3,000 times during its 175 days in space before it was intentionally crashed into the Pacific Ocean.

Shaped like a cylinder, Salyut 1 bore three pressurized compartments for astronauts and one unpressurized area containing the engines and control equipment. The station was about 65 feet (20 meters) long and 13 feet (4 meters) in diameter at its widest point. Two double sets of solar panels extended like wings on the exterior of the compartments at either end.

Salyut 1 Space StationSalyut 1 launched unmanned from the Soviet Union on April 19, 1971.  Two days later, Soyuz 10 lifted off, carrying a crew of three toward the space station with the intention of remaining in space for 30 days. The cosmonauts attempted to dock with Salyut 1, but although they were able to lock onto the station, a problem with the hatch kept them from being able to enter it. They returned home early and unsuccessful. During the re-entry process, a problem rendered the air supply of Soyuz 10 toxic, and one of the cosmonauts slipped into unconsciousness. All three survived with no long-term effects.

On June 6, Soyuz 11 transported cosmonauts Georgi Dobrovolski, Vladislav Vokov, and Viktor Patsayev to Salyut 1, where after three hours, they successfully docked with the station. They remained on board for 383 orbits in the course of just over three weeks, setting a new space endurance record. On June 16, smoke from a control panel caused the crew to consider abandoning the station, but the unit was switched off and the problem averted.

 


On October 11, 1971, the engines on Salyut 1 fired for the last time, bringing the space station into a lower orbit that would result in its eventual plunge into the Pacific Ocean. But despite its early death, Salyut 1 set the stage for stations to come after. The Soviets continued to put short-term stations into space for several years until they felt they were ready for a long-term project.

Lunar Gateway

The Lunar Gateway, or simply the Gateway, is a planned small space station in lunar orbit intended to serve as a solar-powered communication hub, science laboratory, short-term habitation module, and holding area for rovers and other robots. It is expected to play a major role in NASA’s Artemis program, after 2024. While the project is led by NASA, the Gateway is meant to be developed, serviced, and utilized in collaboration with commercial and international partners: Canada (CSA), Europe (ESA), and Japan (JAXA). It will serve as the staging point for both robotic and crewed exploration of the lunar south pole, and is the proposed staging point for NASA’s Deep Space Transport concept for transport to Mars.Formerly known as the Deep Space Gateway (DSG), the station was renamed Lunar Orbital Platform-Gateway (LOP-G) in NASA’s 2018 proposal for the 2019 United States federal budget.

Lunar Gateway to MoonThe Gateway will be an outpost orbiting the Moon that provides vital support for a sustainable, long-term human return to the lunar surface, as well as a staging point for deep space exploration. It is a critical component of NASA’s Artemis program.

The Gateway is a vital part of NASA’s deep space exploration plans, along with the Space Launch System (SLS) rocket, Orion spacecraft, and human landing system that will send astronauts to the Moon. Gaining new experiences on and around the Moon will prepare NASA to send the first humans to Mars in the coming years, and the Gateway will play a vital role in this process. It is a destination for astronaut expeditions and science investigations, as well as a port for deep space transportation such as landers en route to the lunar surface or spacecraft embarking to destinations beyond the Moon.

NASA has focused Gateway development on the initial critical elements required to support the 2024 landing – the Power and Propulsion Element, the Habitation and Logistics Outpost (HALO) and logistics capabilities.

Space Tourism

What is Space Tourism?

Space tourism is human space travel for recreational purposes. There are several different types of space tourism, including orbital, suborbital and lunar space tourism. To date, orbital space tourism has been performed only by the Russian Space Agency. Work also continues towards developing suborbital space tourism vehicles. This is being done by aerospace companies like Blue Origin and Virgin Galactic. In addition, SpaceX (an aerospace manufacturer) announced in 2018 that they are planning on sending space tourists, including Yusaku Maezawa, on a free-return trajectory around the Moon on the Starship.

What is Space Tourism?There are several options for space tourists. For example, Crouch et al. (2009) investigate the choice behaviour between four types of space tourism: high altitude jet fighter flights, atmospheric zero-gravity flights, short-duration suborbital flights, and longer duration orbital trips into space. Reddy et al. (2012) find the following motivational factors behind space tourism (in order of importance): vision of earth from space, weightlessness, high speed experience, unusual experience, and scientific contribution.

During the period from 2001 to 2009, 7 space tourists made 8 space flights aboard a Russian Soyuz spacecraft brokered by Space Adventures to the International Space Station. The publicized price was in the range of US$20–25 million per trip. Some space tourists have signed contracts with third parties to conduct certain research activities while in orbit. By 2007, space tourism was thought to be one of the earliest markets that would emerge for commercial spaceflight. Space Adventures is the only company that has sent paying passengers to space. In conjunction with the Federal Space Agency of the Russian Federation and Rocket and Space Corporation Energia, Space Adventures facilitated the flights for all of the world’s first private space explorers. The first three participants paid in excess of $20 million (USD) each for their 10-day visit to the ISS.

Russia halted orbital space tourism in 2010 due to the increase in the International Space Station crew size, using the seats for expedition crews that would previously have been sold to paying spaceflight participants. Orbital tourist flights were set to resume in 2015 but the one planned was postponed indefinitely and none have occurred since 2009.

On June 7, 2019, NASA announced that starting in 2020, the organization aims to start allowing private astronauts to go on the International Space Station, with the use of SpaceX’s Crew Dragon spacecraft and Boeing’s Starliner spacecraft for public astronauts, which is planned to be priced at 35,000 USD per day for one astronaut (not including the cost to get there).

Read more at https://en.wikipedia.org/wiki/Space_tourism

International Space Station ISS

International Space StationThe International Space Station is a modular space station in low Earth orbit. It is a multinational collaborative project involving five participating space agencies: NASA, Roscosmos, JAXA, ESA, and CSA. The ownership and use of the space station is established by intergovernmental treaties and agreements.

The station is divided into two sections: the Russian Orbital Segment (ROS), operated by Russia; and the United States Orbital Segment (USOS), which is shared by many nations. Roscosmos has endorsed the continued operation of ROS through 2024,having previously proposed using elements of the segment to construct a new Russian space station called OPSEK.The first ISS component was launched in 1998, and the first long-term residents arrived on 2 November 2000. The station has since been continuously occupied for 20 years and 32 days, the longest continuous human presence in low Earth orbit, having surpassed the previous record of 9 years and 357 days held by the Mir space station. The latest major pressurised module, Leonardo, was fitted in 2011 and an experimental inflatable space habitat was added in 2016. Development and assembly of the station continues, with several major new Russian elements scheduled for launch starting in 2020. As of December 2018, the station is expected to operate until 2030.

NASA Artemis Program

NASA is committed to landing American astronauts, including the first woman and the next man, on the Moon by 2024. Through the agency’s Artemis lunar exploration program, we will use innovative new technologies and systems to explore more of the Moon than ever before. We will collaborate with our commercial and international partners to establish sustainable missions by 2028. And then we will use what we learn on and around the Moon to take the next giant leap – sending astronauts to Mars.

What is the NASA Artemis Program?

What is NASA Artemis ProgramWhy Go to the Moon?

With the Artemis program we will:

  • Demonstrate new technologies, capabilities, and business approaches needed for future exploration including Mars
  • Establish American leadership and a strategic presence on the Moon while expanding our U.S. global economic impact
  • Broaden our commercial and international partnerships
  • Inspire a new generation and encourage careers in STEM

How Do We Get There?

NASA’s powerful new rocket, the Space Launch System (SLS), will send astronauts aboard the Orion spacecraft nearly a quarter million miles from Earth to lunar orbit. Astronauts will dock Orion at the Gateway and transfer to a human landing system for expeditions to the surface of the Moon. They will return to the orbital outpost to board Orion again before returning safely to Earth.

When Will We Get There?

Ahead of the human return, we will send a suite of science instruments and technology demonstrations to the lunar surface through commercial Moon deliveries beginning in 2021.

The agency will fly two missions around the Moon to test its deep space exploration systems. NASA is working toward launching Artemis I, an uncrewed flight to test the SLS and Orion spacecraft together, followed by the Artemis II mission, the first SLS and Orion test flight with crew. NASA will land astronauts on the Moon by 2024 on the Artemis III mission and about once a year thereafter.

Artemis Program