Worried about disease viruses from Mars invading Earth

No one can be sure that the samples from Mars do not contain tiny creatures. If so, no one can claim that they are not harmful to the Earth.

In imagining sending humans to Mars in his 1973 book 'Cosmic Connection', Carl Sagan posed another problem besides cost and complexity. Life likely once existed on the red planet and could adversely affect humanity.

'There could be pathogens on Mars. If the organisms were introduced into the human environment, they could cause a biological disaster, a Martian plague," he wrote.

Scenarios where samples from outer space contain dangerous organisms are examples of 'reverse contamination', or the risk of material from another planet harming Earth's biosphere.

'The likelihood of such pathogens surviving is probably very small, but we cannot accept even a small risk at the expense of a billion lives,' Sagan wrote.

Scientists have long considered Sagan's warnings with hypotheses. But in the next decade, they will begin to take concrete actions to address the risks of reverse pollution, according to the New York Times.

The ground on Mars was captured by the Perseverance robot.

Special Mission

The US National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA) are preparing for a joint mission called Mars Sample Return. The Perseverance rover is collecting samples on the red planet and will return to Earth by another spacecraft.

Given concerns about retrograde contamination, NASA must act as if samples from Mars could cause another pandemic.

'Because it's not zero percent, we're doing due diligence to make sure there's no possibility of contamination,' Andrea Harrington, NASA's Mars specimen curator, said in a statement.

The agency plans to handle samples from Mars similar to how the Centers for Disease Control and Prevention (CDC) handles Ebola. Once the samples from Mars land on Earth, they must be kept in a structure called the 'Sample Receiving Facility'.

Mission experts say the structure must meet 'Biosafety Level 4' (BSL-4) standards. This means it has the ability to block the deadliest pathogens known to science.

Andrea Harrington, NASA's Mars Sample Curator.

At the same time, the structure must also be able to prevent matter on Earth from contaminating the sample from Mars. If the mission goes according to plan, the samples could land on Earth in the mid-2030s.

It will take a lot of time to build a facility that can safely house a Martian specimen. Construction may also face political or community challenges.

To date, there are no laboratories that meet NASA's requirements. As a result, a team of four scientists, including Dr. Harrington, toured some of the most dangerous facilities on the planet.

They call themselves 'NASA's RAMA Tiger Squad'. This nickname sounds like the name of a military reconnaissance group, but in reality it is just an acronym for the members of the group.

The team visited hotspots such as the US National Laboratory of Emerging Infectious Diseases in Boston, the US Army Medical Research Institute of Infectious Diseases in Maryland and CDC Building 18 in Atlanta.

In total, the team visited 18 dangerous disease treatment facilities, ultra-clean rooms, and equipment manufacturing sites for these two purposes. Members hope to find the right equipment for NASA's facilities to keep humanity as safe as possible.

Potential threat

'This will be the first mission to return a specimen from another planet to Earth. For the first time, another world will meet humans,' Harrington said.

There are many samples from around the Solar System that have been brought to Earth for study. Moon rocks and dust come from US, Soviet, and Chinese missions. Samples from two asteroids collected by Japan. Particles from the solar wind and comets were collected by the spacecraft.

However, material from Mars is considered by NASA to pose a 'significant' reverse pollutant risk. So the samples from this planet are in the legal category called 'Restriction to Earth'.

"We have to treat those samples as if they contained biohazardous materials," said Nick Benardini, a specialist in planetary protection at NASA. Dr. Benardini oversees policies and programs that try to prevent Earth's microbes from contaminating planets and satellites in the Solar System, and limit space material that harms Earth.

Image depicting the Mars Sample Return mission.

John Rummel, an expert who worked at NASA from 1987 to 2008, thinks it's right for the space agency to take risks, even if the proportions are very small and seem like a sci-fi movie.

'There are important unknowns regarding biology. Mars is a planet. We don't know how it works,' he said.

Part of Mars Sample Return's mission is to figure out how Mars works. This can't be done properly yet because scientists and research equipment can't get there yet.

NASA's Perseverance spacecraft arrives on Mars in 2021 and is collecting samples. These samples will be brought to a lander by autonomous robots or helicopter robots. The rocket then fires the sample vessel into Mars orbit, where the European-built spacecraft will 'catch' and fly back to Earth.

According to the plan, in 2033, the specimens will land in the Utah Training and Test Area. Scientists can then study them with laboratory equipment.

Tech challenge

The job of the RAMA team is to find a way to turn the risk of pollution into an opportunity. Their goal is to learn about super clean rooms and what the space agency might have to invent.

The team visited seven high-level isolation laboratories in the US, UK, and Singapore, and ultra-clean space labs in Japan and Europe. The group also visited manufacturers of laboratory equipment.

The biggest technological challenge is that the specimen receiving facility must serve two purposes.

'Earth must not touch the specimen, and the specimen must not touch the Earth,' said Michael Meyer, the lead researcher of the Mars Exploration Program.

The storage room must ensure that substances on Earth do not contaminate the Martian specimen, to avoid the experiment giving false results. At the same time, the storage room must also keep the Martian material inside, not letting it escape into the atmosphere.

Clean rooms require positive air pressure, which means that the pressure inside is higher than the pressure outside. Therefore, the air always circulates from the inside to the outside.

However, high-level isolation rooms work in the opposite way. They maintain a lower air pressure inside than outside. Matter particles can fly in but not out.

Illustration of the robots used in the mission.

NASA needs positive pressure space to keep samples clean, and negative pressure to keep samples from leaking out. It is very difficult to integrate those conditions into the same space. It requires an innovative room structure and sophisticated ventilation system.

No lab on Earth has done it at the scale Mars Sample Return claims.

'We're not surprised this doesn't exist,' Dr Harrington said.

The best the RAMA team can do is observe how the labs work and hopefully determine the best combination.

Inside the BSL-4 laboratories, High Efficiency Air Filters (HEPA) are ubiquitous. The team studied disinfection methods, such as using Hydrogen Peroxide (H2O2) to destroy surface contaminants. However, the team still has to find the right way to disinfect the alien matter.

'Research to understand sterilization, in the case of these samples, is underway,' Dr Harrington said.

Structurally, the floors, ceilings, and walls of the receiving facility can be epoxy coated, as BSL-4 and cleanrooms typically do. The isolation room European scientists used to build self-propelled vehicles uses stainless steel walls. Both materials could serve NASA's dual purpose.

The RAMA team also looked at the equipment scientists use to manipulate the Martian samples, allowing for precise material handling without direct contact. Scientists have been remotely studying substances in pure nitrogen environments, providing NASA with an option to consider.

Matters arising

Many existing laboratories are too small for the size of the mission required. Door size also has a significant effect on the entry of equipment.

Equipment brought into BSL-4 rooms will not be allowed to go out, and will even have to be destroyed. Therefore, the room will have less instrumentation than a normal laboratory. Meanwhile, Mars Sample Return requires a lot of sophisticated scientific equipment.

The research team presented several options to NASA. The agency may renovate an existing BSL-4 laboratory or construct a separate laboratory. NASA is also considering a number of other options, such as building a more affordable modular high-level isolation room.

The team's investigation found that building a research site could take eight to 12 years, well past the time it takes for a specimen to return to Earth. Therefore, team members recommended that NASA should come up with a plan as soon as possible.

Part of the reason to speed things up is that there will almost certainly be failures. The labs that the RAMA team visited faced a series of regulatory, financial and construction problems.

Perseverance rover and Ingenuity helicopter on Mars.

The team determined the delay would pose a 'significant risk' to the Mars Sample Return mission. The sample receipt process will be more complicated due to the paperwork involved.

NASA wants the project to comply with its own planetary protection policy, as well as its own additional policies. The sample receiving facility is also subject to approval under the National Environmental Policy Act.

In addition, spacecraft and facilities will face Presidential Directive 25 on National Security. This directive regulates scientific and technological experiments that can have a major impact on the environment.

Interaction with the public is key to the success of the project. Dr. Rummel believes that transparency will get the support of the people, ensuring accountability and safety for the project.

NASA's investment in building a safe facility can lead to unexpected results.

'There will be very interesting technical challenges. That could bring more benefits to humanity, beyond what the Martian sample can bring," said Scott Hanton, Lab Manager editor.