With Falcon Heavy, SpaceX staged an amazing launch – but what about the environmental impact?

Falcon Heavy lifts off on Tuesday 6 February. Image: Getty.

SpaceX has now launched the most powerful spacecraft since the Apollo era – the Falcon Heavy rocket – setting the bar for future space launches. The most important thing about this reusable spacecraft is that it can carry a payload equivalent to sending five double-decker London buses into space – which will be invaluable for future manned space exploration or in sending bigger satellites into orbit.

Falcon Heavy essentially comprises three previously tested rockets strapped together to create one giant spacecraft. The launch drew massive international audiences – but while it was an amazing event to witness, there are some important potential drawbacks that must be considered as we assess the impact of this mission on space exploration.

But let’s start by looking at some of the many positives. Falcon Heavy is capable of taking 68 tonnes of equipment into orbit close to the Earth. The current closest competitor is the Delta IV heavy which has a payload equivalent of 29 tonnes. So Falcon Heavy represents a big step forward in delivering ever larger satellites or manned missions out to explore our solar system. For the purposes of colonising Mars or the moon, this is a welcome and necessary development.

The launch itself, the views from the payload and the landing of the booster rockets can only be described as stunning. The chosen payload was a Tesla Roadster vehicle belonging to Space X founder and CEO Elon Musk – with a dummy named “Starman” sitting in the driver’s seat along with plenty of cameras.

This sort of launch spectacle gives a much needed public engagement boost to the space industry that has not been seen since the time of the space race in the 1960s. As a side effect this camera feed from the payload also provided yet another proof that the Earth is not flat – a subject about which Musk has previously been vocal.

The fact that this is a fully reusable rocket is also an exciting development. While vehicles such as the Space Shuttle have been reusable, their launch vehicles have not. That means their launches resulted in a lot of rocket boosters and main fuel tanks either burning up in the atmosphere or sitting on the bottom of the ocean (some are recovered).

This recovery massively reduces the launch cost for both exploration and scientific discovery. The Falcon Heavy has been promoted as providing a cost of roughly $1,300 per kg of payload, while the space shuttle cost approximately $60,000 per kg. The impact this price drop has for innovative new space products and research is groundbreaking. The rocket boosters on this test flight had a controlled and breathtakingly simultaneous landing onto the launch pad.


Environmental impact

So what could possibly be wrong with this groundbreaking test flight? While visually appealing, cheaper and a major technological advancement, what about the environmental impact? The rocket is reusable, which means cutting down the resources required for the metal body of the rocket. However, the mass of most rockets are more than 95 per cent fuel. Building bigger rockets with bigger payloads means more fuel is used for each launch. The current fuel for Falcon Heavy is RP-1 (a refined kerosene) and liquid oxygen, which creates a lot of carbon dioxide when burnt.

The amount of kerosene in three Falcon 9 rockets is roughly 440 tonnes and RP-1 has a 34 per cent carbon content. This amount of carbon is a drop in the ocean compared to global industrial emissions as a whole, but if the SpaceX’s plan for a rocket launch every two weeks comes to fruition, this amount of carbon (approximately 4,000 tonnes per year) will rapidly become a bigger problem.

Space hazards

The car test payload is also something of an issue. The vehicle has been scheduled to head towards Mars, but what has not been made clear is what is going to happen to it afterwards. Every modern space mission is required to think about clearing up after itself. In the cases of planetary or lunar satellites this inevitably results in either a controlled burn-up in the atmosphere, or a direct impact with the body they orbit.

Space debris is rapidly becoming one of the biggest problems we face – there are more than 150m objects that need tracking to ensure as few collisions with working spacecraft as possible. The result of any impact or degradation of the car near Mars could start creating debris at the red planet, meaning that the pollution of another planet has already begun.

Space Junk. Image: David Shikomba/Wikipedia/creative commons.

However, current reports suggest that the rocket may have overshot its trajectory, meaning the vehicle will head towards the asteroid belt rather than Mars. This is probably going to mean a collision is inevitable. The scattering of tiny fragments of an electric vehicle is, at minimum, pollution – and at worst, a safety hazard for future missions. Where these fragments end up will be hard to predict – and hence troublesome for future satellite launches to Mars, Saturn or Jupiter. The debris could be drawn by the gravity of Mars, asteroids or even swept away with the solar wind.

What is also unclear is whether the car was built in a perfect clean room. If not there is the risk that bacteria from Earth may spread through the solar system after a collision. This would be extremely serious, given that we are currently planning to search for life on neighbouring bodies such as Mars and Jupiter’s moon Europa. If microorganisms were found there we may never know whether they actually came from Earth in the first place.

The ConversationOf course, these issues don’t affect my sense of excitement and wonder at watching the amazing launch. The potential advantages of this large-scale rocket are incredible, but private space firms must also be aware that the potential negative impacts (both in space and on Earth) are just as large.

Ian Whittaker, Lecturer, Nottingham Trent University.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

Self-driving cars may be safe – but they could still prevent walkable, liveable communities

A self-driving car, driving itself. Image: Grendelkhan/Flickr/creative commons.

Almost exactly a decade ago, I was cycling in a bike lane when a car hit me from behind. Luckily, I suffered only a couple bruised ribs and some road rash. But ever since, I have felt my pulse rise when I hear a car coming up behind my bike.

As self-driving cars roll out, they’re already being billed as making me – and millions of American cyclists, pedestrians and vehicle passengers – safer.

As a driver and a cyclist, I initially welcomed the idea of self-driving cars that could detect nearby people and be programmed not to hit them, making the streets safer for everyone. Autonomous vehicles also seemed to provide attractive ways to use roads more efficiently and reduce the need for parking in our communities. People are certainly talking about how self-driving cars could help build more sustainable, livable, walkable and bikable communities.

But as an urban planner and transportation scholar who, like most people in my field, has paid close attention to the discussion around driverless cars, I have come to understand that autonomous vehicles will not complement modern urban planning goals of building people-centered communities. In fact, I think they’re mutually exclusive: we can have a world of safe, efficient, driverless cars, or we can have a world where people can walk, bike and take transit in high-quality, human-scaled communities.

Changing humans’ behavior

These days, with human-driven cars all over the place, I choose my riding routes and behavior carefully: I much prefer to ride on low-speed traffic, low-traffic roads, buffered bike lanes or off-street bike paths whenever possible, even if it means going substantially out of my way. That’s because I’m scared of what a human driver – through error, ignorance, inattention or even malice – might do to me on tougher roads.

But in a hypothetical future in which all cars are autonomous, maybe I’ll make different choices? So long as I’m confident self-driving cars will at least try to avoid killing me on my bike, I’ll take the most direct route to my destination, on roads that I consider much too dangerous to ride on today. I won’t need to worry about drivers because the technology will protect me.

Driverless cars will level the playing field: I’ll finally be able to ride where I am comfortable in a lane, rather than in the gutter – and pedal at a comfortable speed for myself rather than racing to keep up with, or get out of the way of, other riders or vehicles. I can even see riding with my kids on roads, instead of driving somewhere safe to ride like a park. (Of course, this is all still assuming driverless cars will eventually figure out how to avoid killing cyclists.)

To bikers and people interested in vibrant communities, this sounds great. I’m sure I won’t be the only cyclist who makes these choices. But that actually becomes a problem.

The tragedy of the commons

In the midsize midwestern college town I call home, estimates suggest about 4,000 people commute by bike. That might not sound like many, but consider the traffic backups that would result if even just a few hundred cyclists went out at rush hour and rode at leisurely speeds on the half-dozen arterial roads in my city.

Technology optimists might suggest that driverless cars will be able to pass cyclists more safely and efficiently. They might also be directed to use other roads that are less clogged, though that carries its own risks.

But what happens if it’s a lovely spring afternoon and all those 4,000 bike commuters are riding, in addition to a few thousand kids and teenagers running, riding or skating down my local roads? Some might even try to disrupt the flow of traffic by walking back and forth in the road or even just standing and texting, confident the cars will not hit them. It’s easy to see how good driverless cars will enable people to enjoy those previously terrifying streets, but it also demonstrates that safety for people and efficiency for cars can’t happen at the same time.


People versus cars

It’s not hard to imagine a situation where driverless cars can’t get anywhere efficiently – except late at night or early in the morning. That’s the sort of problem policy scholars enjoy working on, trying to engineer ways for people and technology to get along better.


One proposed solution would put cars and bicycles on different areas of the streets, or transform certain streets into “autonomous only” thoroughfares. But I question the logic of undertaking massive road-building projects when many cities today struggle to afford basic maintenance of their existing streets.

An alternative could be to simply make new rules governing how people should behave around autonomous vehicles. Similar rules exist already: Bikes aren’t allowed on most freeways, and jaywalking is illegal across most of the U.S.

Regulating people instead of cars would be cheaper than designing and building new streets. It would also help work around some of the technical problems of teaching driverless cars to avoid every possible danger – or even just learning to recognize bicycles in the first place.

However, telling people what they can and can’t do in the streets raises a key problem. In vibrant communities, roads are public property, which everyone can use for transportation, of course – but also for commerce, civil discourse and even civil disobedience. Most of the U.S., however, appears to have implicitly decided that streets are primarily for moving cars quickly from one place to another.

There might be an argument for driverless cars in rural areas, or for intercity travel, but in cities, if driverless cars merely replace human-driven vehicles, then communities won’t change much, or they may become even more car-dependent. If people choose to prioritise road safety over all other factors, that will shift how people use roads, sidewalks and other public ways. But then autonomous vehicles will never be particularly efficient or convenient.

The Conversation

Daniel Piatkowski, Assistant Professor of Community and Regional Planning, University of Nebraska-Lincoln

This article is republished from The Conversation under a Creative Commons license. Read the original article.