The Week in Space and Physics

Climate change, global reforestation, Starliner delayed again and America's lack of space suits

Photo by Joanne Francis on Unsplash

To deny climate change is to deny basic physics. The roots of the problem lie in the Schrodinger equation, the fundamental equation of quantum mechanics. This law tells us how atoms and molecules behave - and crucially, how they absorb energy.

Carbon dioxide, as experimenters realised almost two centuries ago, absorbs infrared light. As it does, its atoms - one carbon, two oxygen - start to vibrate faster, warming the gas. Our planet, it turned out, emits a lot of energy in the form of infrared light. It is also surrounded by an atmosphere containing small amounts of carbon dioxide gas.

The result, logic dictates, is that the planet warms up slightly more than might otherwise be expected. The carbon dioxide in the atmosphere acts as a kind of blanket, absorbing heat from the surface and trapping in the air. The more carbon dioxide there is, the more the air warms up.

That is vital: without carbon dioxide our planet would be a frozen, lifeless rock. Its presence in the atmosphere heats the Earth enough for liquid water to fill the oceans and skies, and thus allows biology to thrive. The actual amount of carbon dioxide is not too important - what matters more is that levels are stable enough for life to adapt.

Fortunately, those levels have been stable for a long time. Over the last million years, at least, the level of carbon dioxide has fluctuated in a narrow band between 200 and 300 molecules out of every million in the air. Even that small range has had dramatic impacts on our planet: at the lower end, vast sheets of ice stretched across continents.

Today, however, carbon dioxide levels are well above 400 molecules per million. By the end of this century that number could be 600, or even 1000, if current trends continue. That represents a frightening end to a million years of climate stability.

What causes this change is beyond doubt. Our industrial civilization produces vast quantities of carbon dioxide, more than enough to upset the natural balance and result in a gradual increase in atmospheric levels. There is no escaping this conclusion, as the latest report from the Intergovernmental Panel on Climate Change (IPCC) makes clear.

Though many focus on the absolute level of carbon dioxide, and the warmer world that will result, the real problem is the speed of change. The world can adjust to changing carbon dioxide levels, as long as they happen slowly enough. In the distant past levels have been far, far higher - but shifts took place over millennia, not decades.

The rapid change we are inflicting on our planet is unprecedented. It is also deeply dangerous. The world has seen many climate disasters over the past few years, from floods in Europe and Asia, to fires in Australia and Brazil. These will become routine over the next few years, as will rising oceans and climate related famines and droughts.

As the latest IPCC report warns, many of the changes we are making will be hard, perhaps impossible, to reverse for centuries. Though many call the climate events of recent years extreme, in truth they represent a new normal. None of the recent years will stand out, compared to the weather of the years to come.

All of this, by the way, was predicted by one of the companies most responsible for the looming disaster. In 1982 an Exxon report forecast, with terrifying accuracy, the carbon dioxide levels of today. They knew what would happen, what they were doing, and did nothing to prevent it.

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Can Trees Save the Planet?

As the scale of the coming climate catastrophe becomes clear, governments are scrambling to find a solution. The most obvious approach - to cut the amount of carbon dioxide we produce - seems unworkable. Despite discussions lasting for decades, atmospheric levels continue to rise at an ever-faster pace.

Instead, many are turning to alternative approaches. Some suggest we deliberately modify the climate to cool the planet, instead of heating it. We could, perhaps, pump gases into the upper atmosphere to reflect the Sun’s energy or spark massive algal blooms to suck up vast amounts of carbon.

Those approaches, though, have potentially catastrophic drawbacks. Instead, a far simpler way has started to draw attention: planting trees. Trees soak up carbon dioxide as they grow, stashing it away in the form of wood. Plant a lot of trees, then, and we could soak up enough carbon dioxide to restore balance.

Though the idea sounds attractive, scientists are not yet fully convinced it can work. Trees take years to grow, take up a lot of space and may not be as effective at sucking up carbon dioxide as assumed. Research studies into the idea have drawn different conclusions on how effective and workable massive reforestation could be.

Recent studies, however, suggest that even if mass tree planting does not cool the planet overall, it would still have important local benefits. Climate models typically suggest that rainfall over Europe will fall in coming decades - which will raise the risk of drought and desertification around the Mediterranean.

Tree planting could counter this risk, and may even increase the amount of rainfall across Europe. That holds true even if the world warms up, suggesting that expanding forests would help fight some of the worst effects of climate change.

Reforestation may not be enough to save the world from climate change, then, but it can certainly help mitigate some of its worst effects. Governments should act now to encourage tree planting wherever possible.

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Starliner Delayed Again

Boeing’s reputation for reliable engineering has suffered badly over the past few years. Two notable incidents stand out: the worldwide grounding of the 737 MAX aircraft after two deadly crashes, and the 2019 failure of the new Starliner capsule to reach the International Space Station.

That failure was, Boeing believes, caused by bad software. An error in the onboard timekeeping system sent the capsule into the wrong orbit, making it impossible to reach the space station. Though Starliner then deorbited and landed successfully, additional bugs were spotted just two hours before re-entry. Had they not been found, the capsule may have burned up in the atmosphere.

That uncrewed flight was supposed to demonstrate the ability of Starliner to carry astronauts safely to the space station. Had Boeing succeeded, the capsule would now be in use for routine human spaceflight. As the failed, the company has instead spent almost two years trying to find and fix all the problems.

A second attempt at reaching the International Space Station was initially scheduled for July 30th. That was first delayed by the problems with Russia’s new Nauka module, and then further postponed after Boeing found issues with the capsule’s propulsion system.

Despite initially hoping to resolve the problems quickly, Boeing was forced to admit a fix will take much longer. Troubleshooters failed to either solve the issue or even understand why it happened in the first place. As a result, a more detailed examination is needed - which requires removing the capsule from the rocket.

That could leave NASA relying on SpaceX’s Dragon capsule for several more months, at least. The launchpad previously reserved for Starliner will now be reallocated to the NASA’s Lucy spacecraft, planned for launch in October. Docking space at the International Space Station is limited too, and an available slot may not open up until November.

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The Billion Dollar Space Suit

NASA’s ambitions to land on the Moon by 2024 have never been terribly realistic. Now, three years before the deadline, the space agency has finally admitted it will not meet the goal. The blame, they say, lies not with the untested rockets, nor with the unbuilt lunar landers. Instead, a lack of space suits is responsible.

That claim is somewhat laughable. Yes, NASA may not have appropriate attire for humans to walk on the Moon, but they also lack the ability to get there, or to come back. At the heart of the problem is funding: Congress has never agreed to fund NASA at the level needed to meet such an ambitious target.

That, coupled with endless delays on the yet-to-launch SLS rocket, means that 2024, or even 2025 is an almost impossible goal. NASA’s report does acknowledge some of this, and hints that the agency - at least its engineers - recognise the challenge. Lack of funding, technical problems and the coronavirus pandemic are all listed as key reasons for the delay in preparing the space suits.

The report also reveals the fantastic cost of the suits. NASA has already spent over four hundred million dollars on their development; another six hundred million could be spent before they are finally ready. According to one report, more than twenty-seven contractors are now involved in their design and production. That undoubtedly contributes to the cost and delays.

NASA now thinks the suits will be complete by April 2025, though that is only if everything goes to plan. Realistic dates for the completion of the SLS and the lunar landing system are probably even further in the future. Instead of blaming the space suits for a years’ delay, NASA would be better off admitting that 2028 is a more realistic goal.

China, meanwhile, seems to be pushing ahead with their own efforts to put astronauts on the Moon. Reports suggest that the country is now building its own landing system, capable of ferrying humans to the lunar surface. While details are still vague, it would fit in with China’s previously stated ambitions to land astronauts by the mid-2030s. America at least seems on track to beat that deadline.

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