The SLS rocket officially sits on the launch pad, preparing for the final test before the lunar mission

At 5:47 pm EST on March 17th, the doors of the Vehicle Assembly Building (VAB) of the Kennedy Space Center opened, and NASA was preparing to send the next batch of astronauts to the moon. The huge SLS rocket combined with the Orion spacecraft for the first time outdoors. Fully unveiled, slowly moving for 11 hours and settling into launch pad 39B at Kennedy Space Center.

The new generation of super-heavy launch vehicle “Space Launch System (SLS)” will be responsible for NASA’s most ambitious series of missions to date, one of which is this summer, the SLS rocket with a total length of more than 100 meters combined with the Orion spacecraft, will carry out a Artemis 1 (Artemis 1) is an unmanned mission to orbit the moon. After the Orion spacecraft is put into orbit, the spacecraft will not dock with the International Space Station but go directly to the moon, and finally enter the Earth-moon distance retrograde about 70,000 kilometers away from the lunar surface. Orbit (Distant Retrograde Orbit, DRO), orbiting the moon for 6 days and returning to Earth.

If the Artemis 1 mission is a success, the subsequent Artemis 2 mission will send astronauts to orbit the moon in the Orion spacecraft, and Artemis 3 will take astronauts to a foothold since 1972. The lunar surface (where SpaceX’s manned landing system will be involved in this mission).

In order to complete the Artemis 1 mission, the SLS rocket needs a lot of propulsion – the Block 1 version configuration will provide 8.8 million pounds of thrust at launch, about 8.8 million pounds more than the most powerful Saturn V rocket of the past. 15%.

At 4:15 a.m. ET on March 18, the complete SLS rocket arrived at Kennedy Space Center’s 39B launch pad, which will take a month to complete the wet exercise, including filling the storage tank with more than 700,000 gallons of cryogenic propellant (liquid hydrogen, liquid oxygen), start the countdown phase (but stop before ignition), then return to the aircraft assembly building to recheck any problems arising from the exercise process, and finally return to the launch pad a week before the official launch.

The debut is a key step toward a mission to the moon, testing the carrying capabilities of the world’s most powerful rocket (before Starships) and the Orion spacecraft. According to the test data generated by the wet exercise, which can help NASA to determine the final launch date more specifically, Artemis 1 is likely to be launched from May to July this year.


NASA develops space suits after canceling female astronaut spacewalk due to “insufficient clothing”

Although the speed of technological development has been quite rapid, when exploring the vast universe, human beings can only “cross the river by feeling the stones”.

In March 2019, everyone was looking forward to the success of the “All-Women Astronaut Spacewalk” program announced earlier by NASA. Originally scheduled for March 29, astronauts Anne McClain and Christina Koch will perform an extravehicular mission to replace a second set of batteries for a different power channel in the same area of ​​the space station.

However, NASA announced plans to adjust the battery shortly after, replacing the batteries by male astronauts Nick Hague and Christina Koch. More “all-female astronaut spacewalks” didn’t happen, NASA said, in part because of a shortage of spacesuits on the space station.

More precisely, there is a shortage of spacesuits that fit the astronaut size. The space station only has a medium-sized spacesuit. Although the spacesuit can be replaced, it may take up to 12 hours. In order to avoid mission delays, only one female astronaut has suitable equipment to perform the mission.

In fact, Anne McClain has performed extravehicular missions before, but the space environment is different from the earth environment. When McClain performed the space mission, she found that the medium space suit only fit, and she and Koch could only be replaced by male astronauts to complete the mission. Therefore, the high-profile “all-female astronaut spacewalk” failed due to insufficient equipment.

It was this mission that exposed spacesuit design problems. At present, female astronauts only account for 11%. Under the limited budget, the common sizes of space suits are large or extra large, and there are not many suitable for female astronauts. NASA is developing the next generation of space suits, and one of the focuses is to hope to accommodate a more diverse astronaut.

To make the concept a reality, NASA funds related projects through the NIAC (Innovative Advanced Concepts) program. Bonnie Dunbar “creates custom high-performance spacesuits for exploring Mars” is one of them. Aerospace engineering professor Dunbar, a former astronaut, envisions using digital analysis components, from digital scanning to digital design/analysis to robotic fabrication, as well as 3D printing.

If this hypothesis materializes, extravehicular activity (EVA) space suits can be rapidly designed and manufactured, and can be used by crew members in any gravity environment. And while in space, astronauts can also make or repair on-site. NASA’s vision for the NIAC program is that astronauts walk into a body scanner and in a few hours will be able to walk on Mars in space suits. I really hope that day comes soon.

Russia announced that it would no longer sell rocket engines to the United States, choking: go to the sky with a broom

Roscosmos has the latest threat to global space sanctions. Roscosmos President Dmitry Rogozin said it would no longer sell Russian-made rocket engines to the United States, adding that “go fly with something else, a broom or something.” While most U.S. rockets should be unaffected, it could still change the way cargo is delivered to the International Space Station.

Since the 1990s, most U.S. defense satellites have relied on Russian-made RD-180 rocket engines to power their launch into space. Resupply of fuel and thrusters for timed maneuvers to propel the International Space Station, and the latest no longer selling rocket engines to the United States, Roscosmos President Dmitry Rogozin added, “(Let them) go fly on broomsticks,” a threat that primarily affects Northrop Grumman, United States P. Grumman and United Launch Alliance (ULA).

United Launch Alliance is composed of Lockheed Martin Space Systems and Boeing Defense Space Security (BDS), which covers some rocket launch services of the US Department of Defense, NASA and other government agencies. ), Delta 2, Delta 4, etc.; Antares, assembled and launched by Northrop Grumman, which regularly sends cargo to the International Space Station for NASA, these rockets In the past, it relied on engines designed and produced by the Russian company NPO Energomash.

However, since the Crimea crisis in 2014, the United States has realized that it must stop buying Russian engines. Specifically, ULA partnered with Blue Origin in 2018 to develop the BE-4 engine, a replacement for the RD-180 engine. , ready for the next-generation Vulcan launch vehicle.

And ULA claims that all Russian-supplied engines are ready for active rockets, and the company’s Decatur, Alabama factory still has about two dozen RD-180 engines in stock, which can last the Optimus 5 launch vehicle by 2025. All tasks, so Roscosmos poses little threat to them, even if Russia does not help repair the RD-180 engine, ULA believes that they have accumulated rich experience and knowledge to solve the problem on their own.

But the Antares launch vehicle assembled by Northrop Grumman could be more affected. Russia had planned to hand over 12 more RD-181 engines between 2022 and 2024, and now the latest threat from Roscosmos may render the company’s rockets unable to fly and deliver cargo to the International Space Station.

However, SpaceX has risen globally with its own Falcon 9 rockets and engines, and local American companies such as Rocket Lab have also gained a firm foothold. Even without the help of Russia, the United States should not be too worried in the future.

Solar Orbiter captures massive prominence eruption, extending millions of kilometers into space

The sun has been very busy throughout February this year, and it is experiencing a series of eruptions, including the most dramatic eruption of a prominence captured by Solar Orbiter on February 15, the most powerful of the X-class flare category. Fortunately, the eruption was not pointed at Earth, but scientists warn that as the active area on the sun’s surface is about to face Earth, it is bound to see many significant flares.

A solar prominence is a fiery flow of tens of thousands of kilometers long above the surface of the sun’s magnetic field. It usually appears as a huge annular arch structure, which can last for hours, days, or even weeks, and can further trigger millions of miles into space. kilometer coronal mass ejection (CME).

According to the European Space Agency (ESA), the EUV full-Sun and high-resolution Imager (EUI) of the Solar Orbiter (SolO), jointly developed by ESA and NASA, was released on 2 The prominence was clearly observed on the other side of the sun on March 15, extending 5 times the radius of the sun, the largest prominence eruption ever observed in a single image, and the 2nd largest eruption since September 2017 Scale of the active region on the far side of the sun.

Luckily for us on Earth, the eruption occurred on the other side of the sun on February 15, but ESA and NASA predict that geomagnetic storms are likely in the coming days as active areas on the sun’s surface gradually turn towards us .

From the end of January to the beginning of February, it took several days for the material ejected by an M-class flare to reach the earth, triggering a mild geomagnetic storm that caused the crash of 40 Starlink satellites that SpaceX just launched. According to the SpaceWeatherLive website, which tracks solar activity, the entire sun is February erupted every day and also included 3 M-class flares (the second most intense): M1.4 on February 12, M1 on February 14, and M1.3 on February 15.

In addition to Solar Orbiter, other space missions are also watching the sun. For example, Solar Orbiter will soon cooperate with Parker Solar Probe to conduct joint observations during the latter’s arrival at perihelion.

New galaxy evolution model confirms that dark matter-free galaxies are not alien

In order to explain how to make the universe run smoothly, theories suggest that all galaxies should be filled with a large amount of dark matter. However, over the years, scientists have discovered several galaxies with almost no dark matter, which seriously challenges the rules of the universe. Fortunately, a group of teams recently identified how dark matter-free galaxies can survive in a universe that contains a lot of dark matter — the former has lost track of dark matter.

Although dark matter has always been invisible, there are many clues to guide the way. The first and earliest evidence is galaxies. Observational data show that the rotation speed of the outer side of the galaxy is faster than that expected by Newton’s gravity, indicating that there must be a huge amount of mass energy pulling the outer side of the galaxy to prevent the galaxy from falling apart. Since then, dark matter has gained a firm foothold and is difficult to separate from the galaxy. Models suggest that dark matter condenses into filaments and forms nodes at higher densities, which in turn attract visible matter to gather to form clusters of galaxies, which, because galaxies contain much dark matter, continue to merge to shape galaxy clusters today.

Therefore, it is difficult to understand that a galaxy does not contain dark matter.

However, in 2018, scientists encountered an extremely embarrassing moment: the discovery of a galaxy with almost no dark matter, called NGC 1052-DF2. Because NGC 1052-DF2 is located near a group of galaxies dominated by the large elliptical galaxy NGC 1052, the team suspected at the time that billions of years ago, the giant fledgling elliptical galaxy might have somehow caused NGC 1052-DF2 during its growth. Galaxies lack dark matter.

Another idea is that the galaxy NGC 1052-DF2 experienced a catastrophic event inside that wiped out all the gas and dark matter and prevented new stars from forming.

A year later, in 2019, another team discovered a second galaxy without dark matter, named NGC 1052-DF4 (DF4 for short), proving that NGC 1052-DF2 is not a special case, and there must be an unimaginable dark matter-free galaxy in the universe Galaxies are waiting to be excavated.

New galaxy evolution model unexpectedly confirms past inferences
Recently, the University of California, Irvine team originally wanted to model the evolution of galaxies, but the model unexpectedly produced 7 galaxies with almost no dark matter. The researchers then used the model to examine the evolution of these galaxies and found that at first, these galaxies had no dark matter. Dark matter galaxies are actually normal small galaxies, and dark matter also exists, but they are eventually stripped of dark matter due to mergers with larger nearby galaxies.

In short, these small galaxies were engulfed, but somehow reappeared on the other side with about half of the stars, but with all the gas and dark matter missing.

The theory confirms the team’s idea in 2018 that collisions between neighboring galaxies would trigger looting, leaving smaller galaxies with only a few stars and remnant dark matter left.

The University of California, Irvine team said that this also shows that the galaxies lacking dark matter should be more than the two discovered above, especially in the vicinity of massive galaxies. As many as 30% of the massive galaxies in the universe may have small galaxies without dark matter.

Astronomers are busy with new topics. The research paper was published in the journal Nature Astronomy.

The supermassive black hole of the M77 galaxy has always been blocked by dust in the past, and now the location is finally confirmed

At the center of the galaxy M77, some 47 million light-years from Earth, a supermassive black hole has finally been discovered hidden within a thick cloud of dust. Where the black hole hides in this dust cloud has been a mystery for decades, but scientists have now used detailed data from VLTI to measure the temperature at various points in the cloud to finally pinpoint the location of the supermassive black hole.

Active galactic nuclei (AGNs) are of various types, some emit radio waves and some don’t; some glow brightly in visible light, while others are softer, such as galaxy M77. Because there are so many subdivisions of appearance, astronomers introduced the AGN unified model, pointing out that although there are differences in active galactic nuclei, they all have the same basic structure: a supermassive black hole surrounded by a thick dust ring, all appearance differences in active galactic nuclei, It all depends on the different directions and angles from which we observe the black hole and the dust ring from the earth. If the dust ring is thick enough to block the black hole, the black hole can even be completely hidden under certain conditions.

Messier 77 (also known as M77, NGC 1068) is a barred spiral galaxy 47 million light-years from Earth and an active galaxy with an active galactic nucleus (AGN), but it is obscured by warm dust in the visible light band, and astronomical Questions remain about whether dust can completely hide a black hole, causing the AGN to be less bright than other AGNs in visible light.

Now thanks to the MATISSE instrument installed on the Very Large Telescope Interferometer (VLTI), the team of astronomer Gámez Rosas of Leiden University in the Netherlands has mapped the temperature change of the dust caused by the intense radiation of the black hole, not only finding the thick cosmic dust gas The ring also confirms the location of the supermassive black hole hidden in it, finally solving the problem of scientists for many years, and also providing important evidence to support the AGN unified model.

These findings may help determine the history of Sagittarius A*, the supermassive black hole at the center of the Milky Way, and analyze the interactions between active galactic nuclei and galaxies. The new paper was published in the journal Nature.

Goodbye, International Space Station?

On March 23, 2001, the Russian Mir space station fell after 15 years of operation, and its wreckage fell in the South Pacific; on March 4, 2011, after the launch of the US Earth observation satellite Glory, the launch vehicle failed and crashed into the South Pacific. ; On April 2, 2018, China’s Tiangong-1 space laboratory fell into the South Pacific; on December 27, 2021, the launch test of the Russian Angara-A5 heavy rocket failed, and the rocket debris fell into the South Pacific.

If you look more closely, you will find that the landing points of these aircraft are very uniform, all at 48°52.6′ south latitude and 123°23.6′ west longitude in the central South Pacific, which is about 2,685 kilometers away from any land. Such a special place naturally has its own name – the ocean is hard to reach, also known as “Nemo’s Point” (Latin for “no one”).

Nemo Point, the point on Earth’s surface that is furthest from land.

Point Nemo is recognized as a “spacecraft graveyard”. Since 1971, nearly 300 space debris has been received. The National Aeronautics and Space Administration (NASA) announced on December 31, 2021 that the International Space Station (ISS) will be officially decommissioned in 2031, after which the wreckage will be thrown here.

life extension
The all-powerful ISS is getting old. On November 2, 2000, NASA astronaut William Schaeffer and two Russian astronauts, Sergei Konstantinovich Krikalev and Yuri Gidzinko, aboard the “Soyuz TM-” 31″ The spacecraft arrived at the ISS and became the first astronauts. Here, they can watch the sun rise or set every 45 minutes.

Over the next 20 years, more than 200 astronauts from 19 countries have enjoyed the wonders, and used this stable microgravity environment stolen from space to conduct about 3,000 scientific researches, involving biology, physics, biomedicine, materials, earth and space. Science and many other fields: climate sensors verify climate models and provide information on changes in the Earth’s climate environment; space science instruments deepen human understanding of phenomena such as neutron stars and dark matter; ISS staff volunteer to be test subjects to record human life in a microgravity environment and work, etc.

Another special significance of the ISS lies in the in-depth cooperation between the United States and Russia in the space field. ISS is led by NASA and Roscosmos, and is joined by European, Japanese, Canadian, and Brazilian space agencies. The R&D team includes 25 space agencies around the world.

This is currently the largest man-made object in space, carrying more than 10 humans at the same time. However, with the accumulation of time, the ISS began to have frequent loopholes, ranging from the cooling system and oxygen system failure, to the loss of experimental subjects, broken windows, and toilet “strikes”.

The ISS was originally designed to have a short lifespan of 15 years. In 2015, the U.S. and Russian aerospace departments signed an agreement to extend the life of the ISS from 2020 to 2024. In July 2020, NASA awarded Boeing a $916 million contract to support ISS life extension work until September 2024. Under the contract, Boeing provides engineering support services, resources and personnel for ISS activities and is responsible for managing the systems.

Seeing that the day of “retirement” is approaching, NASA issued a statement on December 31, 2021, announcing that the US government will support the operation of the International Space Station for another 6 years, and the retirement time will be extended to 2031. At the same time, it hopes to cooperate with Russia, Canada, Japan and Europe. Wait for international partners to continue working together until the end of the decade.

On February 1, NASA released the International Space Station Transition Report, which is regarded as the specific decommissioning plan for the ISS. However, compared with what was expected 6 years ago, there are many doubts about the extension of ISS’s retirement this time.

According to the “International Space Station Transition Report”, the technical life of the International Space Station is limited by the main structure, namely modules, radiators and trusses. Other systems such as power, environmental control and life support and communications can all be repaired or repaired in orbit. replace. According to a public interview with Vladimir Solovyov, the engineer in charge of the Russian part of the ISS, at least 80% of the infrastructure systems on the Russian part of the ISS have expired. The cargo compartment “Zalya” (one of the oldest modules of the ISS) 1) There are many small cracks on the surface, “with the passage of time, the cracks may expand.”

Russian Deputy Prime Minister Yuri Borisov also publicly stated that the ISS is seriously aging, and because the space station operation contract expires in 2024, Russia may withdraw from the project after 2025. However, Rogozin, general manager of Roscosmos, said that the overdue service of individual sections of the ISS is serious, but it is too early to end the project, and the specific plan after 2024 can be finalized after discussions with other partners. However, the “other partners” in his mouth have not reached a consensus on what to do with the ISS after 2024, and until 2022.

In addition to crashing or paying to maintain the ISS in low-Earth orbit, it has also been proposed that propulsion equipment can be used to push the ISS to outer space for reuse. From a dynamic point of view, this may not be impossible, but considering that the ISS’s radiation protection system is developed based on an orbit 400 kilometers above the ground, once the protective power of the thin atmosphere of thousands of kilometers in low-Earth orbit against cosmic rays is lost, the radiation intensity in the cabin will be high. There is no guarantee of astronaut survival. Considering the investment in reshaping the radiation protection system, the feasibility of the plan is almost zero.

Based on the above reasons, some people believe that the ISS is postponed until 2031 to retire, which is most likely to compete with China’s Tiangong Space Station. The Tiangong space station is expected to be completed around 2022, with a design life of 2032. Once the ISS crashes, it will be the only human space station. A one-year gap will at least make the current ISS partners hesitate when they turn around.

From hegemony to cooperation
Before the creation of space vehicles, people experienced the feeling of taking a spaceship to the sky in the 1911 paper. The process of manned spacecraft from launch to orbit is presented in detail, so people can see the magical effects of overweight and weightlessness on people, the strange performance of objects in weightlessness, and the fascinating views of the earth and sky at different heights.

The author of the paper, Konstantin Tsiolkovsky, later became the founder of modern astronautics. He was the first to demonstrate the possibility of using rockets for interstellar transportation, artificial earth satellites and low-Earth orbit stations.

“The earth is the cradle of mankind, but it is impossible for people to live in the cradle forever.” For hundreds of years, the famous saying of the father of aerospace has continued to inspire researchers in the field of aerospace.

More than 60 years later, the former Soviet Union launched the world’s first space station, “Salute 1”, and space exploration has entered a new journey. As of April 11, 1982, the former Soviet Union launched a total of 7 Salyut space stations. Huge aerospace laboratory.

The success of the Salyut space station helped the Soviet Union to expand its political prestige, and also pushed the US-Soviet space hegemony to a fever pitch.

The father of the Apollo program, Warner von Brown, proposed the concept of a wheel-shaped space station in 1956, thinking that this configuration could artificially create gravity. Two years after the successful launch of Salyut 1, the United States used the remaining materials of the Apollo program to develop the military background “Sky Lab” (Sky Lab). But due to a fuel docking error, Sky Lab fell into the atmosphere ahead of schedule on July 11, 1979.

On January 25, 1984, then-President Ronald Reagan directed NASA to develop a “permanently manned space station to be built within ten years.” NASA is determined to establish a space station consisting of three independent orbiting platforms for microgravity research, Earth and celestial observations. This is the Liberty space station. In order to control costs, the Liberty space station design has undergone several major revisions.

The former Soviet Union began building the Mir space station in 1986. This is the first truly modular space station for mankind. As the number of modules increases, the research and habitation capabilities will continue to improve, but the fate is largely independent of technological evolution. After the collapse of the former Soviet Union a few years later, the United States and Russia began to drastically cut their aerospace budgets.

In order to maintain the development of the aerospace field, and driven by political and economic factors, the space field has a tendency to shift from competition to cooperation.

In 1993, the United States had a big discussion about whether to let Russia join the space station. “In the post-Cold War era, space policy is foreign policy,” said Sagdiv, the former director of the Institute of Space Studies of the former Soviet Academy of Sciences who moved to the United States. He cited reasons why the United States should allow Russia to join the space station, including helping Russia maintain its national “space power” “The image is beneficial to win over Russian leaders, push Russian scientists beyond domestic work, and provide impetus for Russia to reduce the use of nuclear weapons. This is largely the reason why the U.S. government promotes aviation cooperation.

This discussion gradually deepened, and in this context, the ISS project was officially born.

On January 29, 1998, representatives of the United States, Russia, Japan, Canada and the participating countries of the European Space Agency signed the latest intergovernmental agreement on space station cooperation. According to the agreement, U.S.-Russian cooperation will be carried out in stages: the first step will be the landing of U.S. aerospace planes on the Mir space station that was operating in Russia at the time, followed by the joint construction of the space station by the United States and Russia, and finally the participation of U.S. allies in the construction of the international space station. space station.

Ten months after the agreement was signed, Russia launched the first module “Dawn” module in the orbit of the International Space Station. Three weeks later, the first U.S. segment, Unity, arrived via the Endeavour spacecraft, and ISS construction began. It took another 12 years for the entire ISS to be assembled.

The main structure of the ISS is integrated by the Soviet Union’s “Peace 2” and the US Space Station Liberty, which respectively extend to the Russian Orbital Segment (ROS) operated by Russia and the United States Orbital Segment (USOS) operated by the United States and other countries. It circles the earth 15.5 times a day and consists of 17 cabins, 10 trusses, 3 external loading platforms and 3 maintenance systems. There are two bathrooms, fitness facilities and a 360-degree external window inside. It is the largest satellite in low earth orbit. Compared to astronauts, the living space of the ISS is equivalent to the cabin of a Boeing 747 jumbo plane.

What is in heaven is also decided on earth
Under the common interests of the United States and Russia, the construction of the ISS is completed, and its fate is also affected by the relationship between the two countries. There are also many differences between the two countries on how to treat or deal with the ISS in the next decade. Russia has always been critical of the ISS. Rogozin has repeatedly criticized the United States for being “overly self-centered.” Shortly after NASA awarded Boeing with the lucrative contract in 2020, he said: “The United States is deviating from the ISS principle of mutual support. They see this as NATO, not an international project – with the United States there, everyone else has to help and pay.”

Russia hopes to focus on the construction of its own projects, intends to expand the on-orbit capability of the Russian module before the ISS is retired, and use the Proton and Soyuz carrier rockets to launch the Science multi-functional experimental module, the Mooring node module and the scientific power module, and consider waiting for the ISS to be retired. Later, the Russian independent space station ROSS was established based on part of the in-orbit module.

On September 2, 2021, Rogozin publicly stated that the ROSS deployment plan will be launched within 5 to 6 years, and the independent construction of the space station plan will be launched in 2025, and the first core module will be launched, which is expected to run around 2030. Of course Russia is also prepared. At the Global Space Exploration Conference held on June 15 of the same year, Rogozin said that Russia may also send astronauts to the Chinese space station in the future, and China and Russia are discussing the matter.

On January 13, TASS reported that Roscosmos and NASA were in talks to extend ISS operations until 2030. Rogozin said that the two sides have reached an agreement on the engineering support of the Zarya module, which will be continued by Russia after 2024.

America’s Last Thoughts on ISS – Help NASA Get Back Some Blood
The United States has promoted the commercialization of the ISS for many years, hoping that it will be completely run by private companies. “We want to maximize space station returns by 2030 while transitioning to commercial space destinations,” Robin Gattens, director of the ISS at NASA Headquarters, said on Jan. 31.

In addition to aging, another issue with the ISS is funding, according to NASA. Under the premise of extending the life of the space station, billions of dollars need to be frozen every year to keep the space station running. This is undoubtedly a huge expenditure. Once commercialized, NASA will be one of the commercial space station customers, at least spreading the cost of maintaining the space station.

In order to promote the commercialization of the ISS, NASA has been preparing for a long time. As early as the late 1990s, the ISS business development plan was formulated, and even a price list was listed, but there has been no substantial progress. In June 2019, NASA once again launched the ISS commercialization plan, including policy adjustments, reserving docking ports for commercial modules, and also issued a minimum long-term demand forecast for low-Earth orbit services to encourage private companies to invest.

On April 29 last year, NASA said that related companies are very interested in sending private visitors to the ISS, and the demand is so high that it even exceeds the capacity of the ISS. Using this as an excuse, NASA adjusted its pricing strategy for future private astronaut missions to the ISS, saying the new prices reflect the actual costs of supporting those missions and “reflect full compensation for the value of resources beyond the station’s baseline capabilities.” Probably similar to the abolition of official subsidies.

According to the original price policy in June 2019, ISS charges US$11,250 per person per day for life insurance and toilets, and US$22,500 per person per day for other crew supplies such as food and air. There are also some smaller fee items such as storage, electricity and data usage.

According to the new price policy, in addition to the cost of $88,000 to $164,000 per person per day, private astronauts will also pay $5.2 million for space station crew hours per mission and $4.8 million for mission integration and basic services.

However, the specific price is still negotiable. “Given the complexity and different plans of private astronaut missions, the value of compensation for the mission will also vary.”

As for the commercial operation rights of the ISS, NASA once selected two companies, Axiom Space and Bigelow Aerospace. Bigelow plans to use the resources of the International Space Station to carry out space tourism projects, while Axiom Space tries to use the gravity-free, ultra-clean environment of the International Space Station to produce special materials.

Before the epidemic, Bigelow’s progress was far ahead. The BEAM module launched in 2016 has been connected to the actual use of the International Space Station, but the epidemic has hit Bigelow hard. It declared bankruptcy in the first half of 2020, and the ownership of the module was also transferred to NASA.

The Axiom project is progressing steadily, signing a separate agreement with NASA, and the agreement will begin at the end of 2024, Axiom will launch multiple modules to the ISS. These modules will eventually separate from the ISS to form civilian-operated “free-flying vehicles” in orbit. Axiom received approval for its maiden flight to the ISS on February 2, and could launch into space on March 30. The mission will carry three paying customers, each reportedly paying $55 million.

In December 2021, NASA awarded another $415 million to three companies (Blue Origin, Nanoracks and Northrop Grumman) to encourage them to build commercial space stations in Earth orbit.

According to the International Space Station Transition Report, NASA’s agreement with Blue Origin, Nanoracks, Northrop Grumman, and Axiom is the first of two phases of a transition program to stimulate the commercialization of low-Earth orbit destinations (CLD) in the 1930s. “The first phase is expected to last until 2025,” the report noted. “As for the second phase of the ISS’s transition to CLD, NASA intends to provide NASA crew members and other potential entrants with certification to use CLD at a later date and then purchase services from destination providers for crew use as needed.” This is to replicate NASA’s current proposal for private astronaut transportation to and from the ISS.

A big reason for the CLD program is the success of SpaceX. SpaceX has the only commercial space vehicle currently capable of transporting astronauts to and from the ISS, freeing NASA from the dilemma of relying on Russia to send astronauts to the ISS after it terminated the spacecraft program in 2011. NASA and SpaceX have been working together for several years.

In 2014, NASA had awarded two multi-billion-dollar contracts, one to veteran airline Boeing and the other to SpaceX. Since May 2020, SpaceX has completed multiple crewed round-trip orbital missions via the Falcon9 rocket and CrewDragon capsule. As for the Boeing manned spacecraft CST-100Starliner, it still needs to conduct an unmanned test flight before actually carrying astronauts.

How much money will the transition from the International Space Station to a commercial outpost really save NASA?

According to the report, “by 2031, savings are expected to be around $1.3 billion; by 2033 this will increase to $1.8 billion”. These funds will eventually go to NASA’s deep space exploration program. Some argue that no matter how successful the commercialization efforts end up being, NASA must maintain a presence in low-Earth orbit. After all, according to public data, the ISS in the United States costs more than $100 billion, and this money “can all come from taxpayers.”

General relativity re-verified with higher precision

The only known pair of pulsars has just revealed a wealth of unique cosmic insights.

Scientists have been observing the pair of pulsars, or pulsating neutron stars, for 16 years. The measurements confirmed Einstein’s theory of gravity, known as general relativity, to a new level of precision, physicists said in a paper published Dec. 13 in Physical Review X, and hinted at the The subtle effects of theory.

Pulsars are spinning dead stars composed of dense neutrons that appear to flicker as their beacon-like beams of radiation regularly sweep across Earth. Variations in the timing of these pulses can reveal the motion of the pulsar and the effects of general relativity. While physicists have discovered many individual pulsars, this is the only pair known to orbit each other. In 2003, the discovery of the double pulsar system J0737-3039 opened up a possible new way to test the general theory of relativity.

One of the pulsars spins about 44 times a second, while the other spins about every 2.8 seconds. The slower pulsar dimmed in 2008 because of a strange phenomenon in general relativity that spun its beam out of view. The researchers will continue to monitor the remaining visible pulsars, then combine the new data with the old observations to improve the precision of the measurements.

Here are five takeaways from the new study:

  1. Einstein was right in many ways.

With this pair of pulsar binaries, we can simultaneously perform five independent tests of general relativity to check whether various properties of the orbits match the predictions of Einstein’s theory. For example, researchers measure the rate at which the orbit’s ellipse rotates, or precesses, to see if it is as expected. It turns out that all parameters are in accordance with Einstein’s theory.

What’s more, Scott Ransom, an astrophysicist at the National Radio Astronomy Observatory in Charlottesville, Virginia, said, “Each individual test of general relativity has become so precise that … it must include general relativity. The higher-order effects of relativity to match the data.” This means the measurements are so precise that they hint at the subtle properties of gravity.

  1. Gravitational waves are draining energy.

The observations show that the pulsar’s orbit is shrinking. By measuring the time it took for the pulsars to complete their orbits each time, the researchers determined that the pair of pulsars shortened by about 7 millimeters per day.

That’s because pulsars excite gravitational waves as they orbit, which are ripples in space-time that vibrate outward and carry energy away. This apparent contraction was first detected in a galaxy with a pulsar and a neutron star in the 1970s, providing early evidence for the existence of gravitational waves. But the new results are 25 times more precise than previous measurements.

  1. Pulsars are losing mass.

There is also a subtle effect that will change this track. The pulsar gradually slows down over time, losing rotational energy. Because energy and mass are two sides of the same coin, that means faster pulsars lose about 8 million tons of mass per second.

“When I first realized this, I was really stunned,” Kramer said. “While it sounds like a lot, the mass loss only affects tiny adjustments to the orbit. Previously, scientists could Ignore this effect, because the change is very small. But orbital measurements are now accurate enough that it makes sense to take it into account.

  1. We can know the direction of rotation of the pulsar, which hints at its origin.

By studying the timing of a pulsar as the light from a pulsar passes its companion star, scientists can tell which direction the faster pulsar is spinning. The results showed that the pulsar was spinning in the same direction as its orbit, providing clues to the formation of the pulsar binary.

The two pulsars began as neighboring stars exploded one after the other. Normally, when a star explodes, the remnants it leaves behind are washed away, breaking them apart. The faster pulsar spins in the same direction as its orbit, which means the explosion that formed the pulsar didn’t give it too much jolt, which helps explain how the binary system remains intact.

  1. We have a clue about the pulsar’s radius.

Gravitational effects are known to cause the orbit’s ellipse to precess, or rotate, about 17 degrees per year. But in the new study, a subtle tweak was involved. As the pulsar rotates, it acts like the twisting skirt of a whirling dancer, dragging the fabric of spacetime behind it, changing the precession.

This drag effect means that the faster pulsar must have a radius of less than 22 kilometers, an estimate that, if more precise in future work, could help reveal the origin of the extremely dense neutron star material that makes up the pulsar physical properties.

With a diameter of 250 million light-years, the interior is dark, how terrible is the Bode constellation?

We often say that the matter in the universe is uniformly distributed in all spaces after the big bang. With the passage of time, because of the imbalance between the expansion speed of the universe and the size relationship between celestial galaxies, its gravitational effect on matter is also unbalanced. It is different, so there are more blank spaces in the cosmic space.

But in general, the distribution of matter and galaxies in the cosmic space is relatively balanced, and there will be no particularly large deviations.

However, scientists have found a very large “hole” in the northeast direction of the Virgo galaxy in the northern sky. The hole is about 250 million light-years in diameter and about 700 million light-years away from Earth.

At this location, which is more than 2,500 times larger than the Milky Way’s 100,000 light-years, there are so few stars in it that it becomes a huge blank area, which scientists have named the “Boes Void”.

Boes Hollow
As one of the largest known voids in the universe, there are so few galaxies in the Boes Void that it is almost impossible to find a single galaxy until an average of 10 million light-years.

We can compare it like this: the diameter of the Milky Way is only about 1/2500 of that of the constellation Boe, and in terms of volume, the constellation Boo can hold tens of millions of galaxies. In this “small” Milky Way galaxy, there are 100-400 billion stars alone, but in this huge constellation Boes, scientists have discovered here in the more than ten years since its discovery in 1981 to 1997. The number of galaxies is less than 60. The gap is so large that Boes is sometimes referred to as the “super-void”.

According to the scientists’ calculation of the distribution of galaxies in other spaces, it is reasonable that there should be at least 2,000 galaxies in the constellation Boo, but the reality is quite rare, and the distances between them are quite far, on average, almost 2000 galaxies. 10 million light years. Why is the Shepherd’s seat so empty?

Because galaxies are too rare, there is a view that the original matter in the Boes constellation void may have been taken away by other surrounding matter with greater gravitational force in the early stage of its formation. Later, the universe expanded and the galaxies moved away faster than the speed of light. The Booness hole is naturally getting bigger and bigger.

From the distribution of some sparse galaxies, it has been suggested that the super-large void in Boes may be formed by the combination of multiple small voids. Others believe that the constellation of Boes is not empty and is filled with dark matter and dark energy.

The formation of cosmic voids
Scientists have discovered some (dark) blue regions from the microwave background radiation distribution map that studies the distribution of heat in the universe after the Big Bang. They are the “holes” of the energy-poor and extremely sparsely distributed universe.

There are not many “voids” in the universe, and Boes is just one of them. The largest cosmic void discovered by human beings is far more terrifying than the size of the constellation Shepherd. Its diameter can reach 1.8 billion light-years. It is simply an invincible giant, known as a “super void”.

These voids do not mean that they exist in a complete vacuum, but in terms of the total distribution of matter in the universe, the matter here is 20% or more less than that in other regions, and the density is extremely low. When there are voids in the universe, where no galaxies are found, there are naturally no stars, planets and other matter. Because no celestial body can exist independently of a galaxy.

That is, to some extent, we can understand the void of the universe as a dark region of “nothing”, including the Boes Void.

Maybe some people think that the gap between the galaxies is too big? Where did so many empty words come from?

According to scientists’ research on cosmic voids, about 10,000 galaxies have disappeared from the universe. The area where they were originally also lost energy due to the “invisibility” of matter, and gradually cooled to become the low temperature region of the universe. The blue part of the above-mentioned cosmic microwave background radiation map, the darker the color, the lower the temperature, there is almost no matter here.

But in this case, scientists also don’t know where these stars go, or why the galaxies are so far away from this area. It has been suggested that if dark matter is to be blamed, then the formation of voids may be related to the activity of dark matter.

So is there any other possibility besides dark matter? Some scientists have proposed another possibility: the expansion of advanced civilizations in the universe. How should this be understood?

What advanced civilization did?
Regarding the speculation and exploration of cosmic civilization, the world has never lacked reservations about advanced civilizations other than humans. After all, the universe currently has no boundaries for human beings, and it is not completely certain whether there will be civilizations that we do not know about.

According to the level of Kardashev civilization, civilization in the universe should have three major stages: planetary energy utilization, star system energy utilization, and (galaxy) parent galaxy energy utilization.

Based on this understanding, we can make a bold guess: Could the voids in the universe be caused by advanced civilizations that utilize the energy of other galaxies in the universe?

In order to better develop their own civilization, these advanced civilizations take, store, utilize and consume the energy of the galaxy, leaving only a void with nothing. When the energy of the nearby galaxy is completely absorbed, the advanced civilization will The range of galactic energy sources will continue to increase, and the voids will become larger and larger.

Such speculation is not completely unreasonable, but it is a bit exaggerated. The energy utilization of a star system is exaggerated enough. How advanced civilization must it consume tens of millions of galaxy energy? According to this consumption, how long will the galaxy energy in the universe be enough for these civilizations to consume?

Obviously, not many people agree with this view.

Other astronomers believe that these cold regions of space are evidence of cosmic cycles. It’s just that the theory of cosmic circulation is still in the stage of speculation and confirmation, and which view is more informative, we have to wait for more astronomical observations.

Do parallel universes exist? More than 80 years ago, a cat gave the answer

Whether it’s science fiction or science fiction movies, the coolest concept is traveling through time and space. Because based on common sense, everything is always developing towards the future, and no matter how fast or slow the passage of time, there is only one direction.

As sci-fi fans, many people dream of being able to travel through time and space, some hope to travel to the past, and some to the future.

The future is uncertain, and it is theoretically feasible to travel to the future. If we can drive a spacecraft to fly at a speed close to the speed of light, or orbit a black hole at a close distance, and by these two methods, we can delay the passage of time in our space-time region, and theoretically we can travel to the future.

The past has already happened, and if we can really travel to the past on the same timeline, then it is possible to change the present. The most famous is the grandmother paradox. If you go back to the past and accidentally harm your young grandmother, your father will not be born, so how did you come and travel back to the past to cause the accident? Wouldn’t that be a contradiction! The act of traveling back into the past breaks the law of causality.

However, parallel universes can solve this contradiction. According to the idea of ​​parallel universes, if you travel back in time and accidentally kill your young grandmother, that change will create a new branch of time, splitting off a parallel universe from that point in time. With the concept of a parallel universe, there is no need to worry about changing the past and affecting the future during the travel process, because this change will only generate new time branches, and the old timeline will not be affected.

According to this assumption, not long after the birth of the universe, there will be almost infinite parallel universes.

When it comes to parallel universes, the concept was born not from the time travel paradox, but from quantum mechanics. This goes back to a cat more than 80 years ago. The owner of this cat is the famous physicist Schrödinger, so this cat is also called “Schrödinger’s cat”.

Schrödinger, as the founder of wave mechanics in quantum mechanics, proposed the thought experiment “Schrödinger’s cat” in 1935. The purpose is to make people feel how weird the Copenhagen interpretation of quantum mechanics is, so as to attack the incompleteness of the Copenhagen interpretation.

The Copenhagen School believes that the quantum world is inherently uncertain, and that the properties of the system can only be described by probabilities, and the measurement behavior will have an impact on the system, and the set of probabilities is reduced to one of all possibilities. Scientists use wave functions to describe the properties of quantum systems, so this situation is also known as wave function collapse.

Schrödinger said that if a cat is kept in an airtight container containing a small amount of radium and the highly toxic cyanide, there is a chance that the radium decays and controls an electronic switch. If the radium decayed, it would trigger the mechanism to break the bottle containing the cyanide, and the cat would die; if the radium did not decay, the cat would still be alive.

According to quantum mechanics, radioactive radium is in a superposition of both decayed and non-decayed states. According to this principle, the cat in the airtight container should also be in a superimposed state of dead cat and live cat, which is the “Schrödinger’s cat” that is both dead and alive. The cat’s life and death status is determined only when we open the container.

For traditional physicists, this is inconceivable, and living and dying defies logic. They argue that the cat’s outcome is doomed before the container is opened: life or death. Just because the container wasn’t opened for observation, we’re not sure about the cat’s life or death.

It is well known that microscopic matter has wave-particle duality, and before observation, particle and wave properties are in a superposition state. According to the Copenhagen School of Quantum Mechanics, before opening the container, Schrödinger’s cat is in a state of superposition of life and death. Once the observation behavior is involved, this superposition state will be disturbed and manifested as one of the eigenstates.

This thought experiment cleverly moved the quantum phenomena in the microscopic world to the macroscopic world with a cat. It is one of the very classic thought experiments in the history of science. In fact, the reason for this bizarre result is that quantum superposition states are not suitable for macroscopic large objects.

Since the cat’s state of life is unknown before the container is opened, and there are two states, then perhaps there should also be two different worlds, one where the cat is alive and the other where the cat is dead . Based on this idea, the concept of parallel universes was derived.

In the 1950s, physicist Hugh Everett proposed the many-worlds interpretation of quantum mechanics and believed that there is no wave function collapse at all, and that cats and dead cats actually exist in two parallel universes.

According to this theory, everything that could have happened in the past and in the future either actually happened or will happen, but they all happened in other universes and have nothing to do with our universe. If there are really many parallel universes, then there must be another me in some parallel universes, but their lives are different.

All things have a beginning and an end. Physicists believe that there must be a proto-universe, and other parallel universes are constantly differentiated on this basis. These parallel universes coexist, and there will be no connection between the newly differentiated parallel universe and the original parallel universe, and they exist independently of each other.

Thinking about that cat gave birth to perhaps the most daring conjecture in the field of physics-parallel universe. Just for its existence, scientists can only discuss it from a theoretical level. However, there is a big problem with this theory. Will the universe really make such a big change for the life and death of a cat?