Month: September 2021

Once upon a time, the idea of ​​sending people to Mars seemed either a distant view or something out of science fiction. But with several space agencies and even commercial space companies planning missions in the next decade, the day humans will fly to Mars is fast approaching the point of realization. Before this can happen, several problems must first be resolved, including a variety of technical and human factors.

In any discussion about manned missions to Mars, there is always the question of whether or not we can mitigate the radiation threat. In a new study, an international team of space scientists looked at the question of whether particle radiation would be too great a threat and whether the radiation could be mitigated through careful timing. In the end, they found that a mission to Mars is feasible, but must not exceed four years.

The research was led by Mikhail Dobynde, a researcher from the Skolkovo Institute of Science and Technology and the Russian Academy of Sciences in Moscow. There were also members of the GFZ German Research Center for Geosciences at the Helmholtz Center Potsdam, the University of California Los Angeles (UCLA) and the Massachusetts Institute of Technology (MIT).

For their study, the team looked at the threat posed by the two main types of radiation sources: Solar Energetic Particles (SEP) and Galactic Cosmic Rays (GCR). The former consists of fast-moving protons, electrons and high-energy atomic nuclei that can have a negative effect on electronics and living tissue. The latter consist of the same series of high-energy particles, but come from outside the solar system and are attributed to supernovae.

The intensity of these two radiation sources depends on solar activity, with the SEP values ​​being the least intense during a solar minimum, but the GCR activity being the most increased. The opposite is also the case where GCR activity is lowest during solar maximum but SEP is elevated. To assess the threat posed by these sources, the team combined geophysical models that examined how particle radiation changes during the 11-year solar cycle.

These were combined with models of how the radiation affects human passengers (including various body organs) and their spacecraft. The team then ran a series of Monte Carlo simulations of radiation propagation that took into account 10 different types of SEP radiation and 28 types of fully ionized GCR elements. From this they determined that the best time for a mission on Mars is in the six to twelve months after the solar activity peaks (also known as the solar maximum).

At this point GCR activity is lowest and SEP begins to decrease from its highest intensity. The situation is slowly reversed over the next six and a half years, with GCR activity slowly increasing until it reaches its maximum intensity (which coincides with a solar minimum). Since the average flight time to Mars is around nine months, a manned return to Mars could be accomplished in less than two years.

NASA’s Orion spacecraft will propel astronauts further into space than ever before with a module based on Europe’s Automated Transfer Vehicles (ATV). Photo credit: NASA

Based on their findings, Dobynde and his colleagues determined that this would make the mission home before the radiation environment became too dangerous. But a mission that lasted up to four years would move them forward as they would be forced to return home amid higher GCR activity. Therefore, their modeling also showed that the spacecraft’s shielding would have to be relatively thick to ensure the health of the crew.

However, the same results also indicated that too thick a shield could actually increase the amount of secondary radiation to which the crew is exposed. This phenomenon, in which high-energy particles collide with the shield to create a cascade of secondary particles (also known as “particle showers”), has been studied in depth on board the International Space Station (ISS).

According to Yuri Shprits, head of space physics and space weather at GFZ’s Geosciences Research Center (and co-author of the paper), these results could be of great value to future mission planners. “This study shows that while space radiation imposes severe restrictions on the severity of the spacecraft and time of launch, and poses technological difficulties for manned missions to Mars, such a mission is feasible,” he said.

These considerations are vital as there are several plans to undertake regular missions to Mars in the near future. These include NASA and its moon-to-Mars mission architecture, China’s plans to send crews to Mars by 2033 (and set up a permanent research outpost there), and Elon Musk’s plan to bring payloads and crew members every two years with the SpaceX Starship and the Super heavy start to deploy vehicle.

Artist’s impression of Mars Base Camp in orbit around Mars. When missions to Mars begin, one of the biggest risks will be space radiation. Photo credit: Lockheed Martin

These are just a few of the visions for the exploration (and colonization of Mars) that have been articulated lately. With all of the robotic missions currently exploring the planet and the possibility of human exploration on the horizon, Mars is reappearing in the public eye. Since the Apollo era, Mars has been considered the “next big leap” that could lead to a new era, a revived space age!

The fact that Mars is the most habitable celestial body beyond Earth has also been a source of inspiration for scientists, mission planners, astronauts and futurologists alike. Despite the challenges getting there, there is currently no shortage of people willing to sign up for a one-way trip. For these adventurous souls, the prospect of the first groundbreaking on Mars – the next big “frontier” – has a certain romance.

It is particularly exciting, however, when realistic assessments show that these adventurous ideas can actually be implemented with the right preparations, technologies and mitigation strategies. When scientific facts and romance come together to make plans for the future, great things can happen!

Further reading: UCLA, Space Weather

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Guest contribution by Larry Hamlin

The California Coastal Commission has determined that the state must plan for at least a 3.5-foot rise in coastline sea level over the next 30 years.

This ridiculous rate of coastal sea level rise is 26 times higher than the rate of coastal sea level rise measured from NOAA tide gauges over the past 30 years at numerous coastal locations, including 7 locations with between 75 and 115 years of continuous NOAA was tide meter data on sea level rise on the coast, showing that these places average of only 1.6 inches of sea level rise on the coast in the next 30 years – not 3.5 feet!!

In addition, the long-term NOAA coastal measurement data measurements show that despite ridiculous, flawed, and erroneous claims, there has been no acceleration (rates of coastal sea level rise) in coastal sea level for the past 30 years (and more) through otherwise Climate alarm models that have been shown to be completely wrong on the basis of actual data measurements.

These idiotic plans by the Commission to mandate a minimum of 3.5 feet (or worse as the report suggests below) over the next 30 years threatens to impose massive bureaucracy and waste trillions of dollars in unnecessary spending and the economy of the State endangering viability.

NOAA coastal sea level rise tide level data for California, as shown below with data from San Diego and San Francisco, shows a constant rise in territorial sea level (no rise in sea level rise over time) of only about 2 mm / year in these locations, no 35.5mm / year as prescribed by the Coastal Commission bureaucracy.

The California Coastal Commission is simply out of control and operates in a completely incompetent manner based on its reliance on unscientific and purely speculative, alarmist propaganda of the Coastal Sea Level Rise Climate Model, while keeping measured, consistent and tremendously lower coastal sea level rates completely ignored and obscured Ascension that represents more than 100 years of California history.

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The International Space Station (ISS) seems to be showing its age. Or at least the older modules that have been in space since 1998. According to a high-ranking Russian space official, cosmonauts on board the ISS discovered new cracks in the Functional Cargo Block (FCB) module. Zarya (“dawn”). These cracks were found in seven of the module’s twenty windows and could eventually threaten the entire station.

The Zarya module was the first component launched for the International Space Station ISS. While funding was provided through a NASA subcontract with Boeing and the module is part of the U.S. section, the module itself was provided by the State Research and Manufacturing Center for Research and Production (KhSC) in Russia (a subsidiary of Energia Rocket and Space Corporation ) and Roscosmos was responsible for the introduction in 1998.

Zarya was also responsible for providing electrical energy, storage, propulsion and guidance of the ISS during the initial assembly phase. Unfortunately, after twenty-three years in space (and twenty-one in continuous operation), the module begins to suffer from its structural problems. And in space, the worst structural problem imaginable is finding cracks in the fuselage.

The Russian cargo module Zarya in orbit before integration into the ISS. Photo credit: NASA

The news on this matter came from Vladimir Soloviev, the general designer of Energia RSC – which designed and built all modules in the Russian segment. As Soloviev told the Russian news agency RIA Novosti:

“Superficial cracks were found in some places on the Zarya module. This is bad and indicates that the cracks will spread over time … In this context, we have introduced a new method of measuring the deflection of glass. They can of course be covered with sealed covers, but what’s the point of flying at the train station without a window? ”

Soloviev didn’t say whether or not the rifts pose a decompression stop, but he previously said that much of the ISS’s equipment is aging and at risk of experiencing an “avalanche” of failures beyond 2025. The operating license was extended to 2030 and funding was secured until the end of 2025. However, recent engineering issues lead some to conclude that the ISS may not last as long.

In September 2019, the crew of Expedition 63 registered a drop in internal pressure and spent the next year locating the source. The leak was ultimately traced back to the intermediate chamber of the Russian Zvezda module, which was repaired by March 2020. While this leak did not threaten either the station or the crew, another leak was later identified that was quenched – but not fully repaired.

Image of the ISS in orbit. Photo credit: NASA

Back in January, Soloviev reported that the leak caused a pressure drop of 0.4 millimeters of mercury per day. In terms of air pressure, 760mm is the same as the atmospheric pressure here on earth at sea level – or 101,325 Pascal (Pa). This results in a pressure loss of 0.005 Pascal (0.0005%) per day, which requires that the station is supplied with reserves that are both present on the ISS and are transported from the earth.

Last month, the ISS also suffered a software bug that resulted in the Nauka module’s engines being accidentally re-ignited a few hours after docking. This was responsible for temporarily driving the ISS out of position, forcing the Orbital Flight Test-2 (OFT-2) mission to be delayed. Last month, Roskosmos also reported a further drop in air pressure in the Zvezda service module.

Roscosmos has pledged to remain a partner in the ISS program through 2024 and has signaled that they may be ready to expand their participation beyond that. However, Russia has also expressed interest in building its own orbital space station to replace the ISS from 2025. Last year Russia said it would not sign the Artemis Agreement, which obliges it to participate in NASA’s Artemis program.

According to statements made at the time, Russia’s refusal was based on the fact that the agreements were “too US-centered” and political, but also deviated from the spirit of cooperation embodied in the ISS program. Russia has since announced a new partnership with China to create an International Lunar Research Station (ILRS), followed by the release of a roadmap and timeline for development – the International Lunar Research Station (ILRS) Guide for Partnership.

It’s sad to admit, but the days of the ISS are numbered. This certainly seems to be the consensus among NASA, Roscosmos, and the thirteen other member states that have participated in the ISS since its inception. But in its twenty-one years of continuous operation, the station has enabled all kinds of scientific research, experimentation, and breakthroughs.

As the only dedicated microgravity research environment, the ISS has enabled experiments in areas from astronomy and astrobiology to materials science, space weather and medicine. In addition to space agencies, commercial establishments, research institutes and universities have also managed to benefit from its continued operation. Above all, the station has repeatedly served as a means of promoting cooperation between nations and space programs.

Knowing that the ISS has not been around for long (so to speak) and is likely to be replaced by multiple space stations owned and operated by competing power blocs is certainly daunting. But before the ISS reaches the end of its service and leaves its orbit, hopefully those who helped make it a reality will find a way to keep alive the spirit of collaboration it embodies.

Further reading: Reuters, RIA

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