YOU’RE standing in a colossal edifice, gawping upwards. Towering above your head are the 10 levels of platforms for working on rockets as they are built and readied for launch. One day this structure, the iconic Vehicle Assembly Building at Kennedy Space Center in Florida, will house the Space Launch System (SLS) rocket and Orion spacecraft for , due to launch in 2018.

It is one of the largest buildings in the world, covering an area of some 32,000 square metres and boasts more than 3.6 million cubic metres of space inside. It was built to house the assembly of Apollo/Saturn vehicles, but it has since been modified to support space shuttle operations.

NASA has installed four new platforms to give access to SLS and Orion as they are constructed within the building before launch – how this would look is shown in the mock-up below.

While the first of Orion’s flights propelled by the SLS will be made with no people on board, Exploration Mission 1 will blaze a trail for future missions to Mars. Orion will perch atop the SLS, the most powerful rocket in the world, on its three-week mission into deep space. During that time it will travel thousands of kilometres beyond the moon, before returning to Earth hotter and faster than any spacecraft before.

The hope is that the ship could one day shuttle four astronauts on the first human mission to the Red Planet.

This article appeared in print under the headline “Inside a rocket factory”

A gaseous tug-of-war flips galaxies from bright up-and-coming prospects to dim has-beens, a new simulation shows.

There are two types of galaxy in our universe: “blue” galaxies, which rapidly birth new stars, and “red and dead” galaxies, which have given up star formation. Once a galaxy has amassed a particular number of stars, it swiftly switches from blue to red. But what drove this abrupt shift has been a mystery.

Now, at the University of Durham, UK, and his colleagues have run simulations that show that critical number of stars is set by a delicate balancing act between how much gas comes into the galaxy, and how much can get out.

“Gas leaves a galaxy when its stars explode into supernovae, forming a hot, buoyant bubble of gas that is ejected from the galaxy like a helium balloon,” says Bower’s colleague at the Leiden Observatory in the Netherlands. “Gas enters that same galaxy via the draw of the supermassive black hole at its centre.”

Balancing act

In low-mass galaxies that are still crafting new stars, young stars and newly formed supernovae squeeze enough hot gas out of the galaxy that they balance out the rate at which the central black hole hauls new gas in.

But only cold gas can collapse to form new stars. The shift from blue to red occurs once galaxies become massive enough to grow a large halo of hot gas, heated up by the gravitational pull of the enlarging galaxy.

“The galaxy’s mass is tightly related to this halo, which is squeezed tightly together by gravity,” says Schaye. “This halo gets so hot as the galaxy gets heavier that it stops any gas bubbles from the supernovae leaving – sealing the galaxy shut from one side.”

The gas bubbles that once left the galaxy like helium balloons in the wind are now drawn to its centre, where they are absorbed by the supermassive black hole.

Big blow out

“The black hole grows rapidly and generates a lot of energy which can blow out the remaining cool gas”, completing the transition from blue to red, says Schaye.

The team hopes its findings can act as a springboard for further investigations into the life cycle of galaxies.

“There are always bigger and better simulations to be done to explore this area in more detail,” says Schaye. “Ultimately, we’d like to get closer to the action of where the black hole starts.”

“It’s too early to say for sure that this is absolutely what’s going on, but it’s very convincing,” says Andrew Pontzen at University College London. “There are other things out there that can strip away the gas used for star formation and hence shut off galaxy star formation, so in reality it could be a combination of these things. But I would put money on this effect contributing.”

Journal reference: arxiv.org/abs/1607.07445

The future looks dire for the English bulldog, one of the most popular – and illness-prone – dog breeds in the UK and US.

Among other problems, English bulldogs have difficulty breathing, moving and mating. These traits are a result of how we have selectively bred the dogs to promote characteristics like its shortened muzzle and stature. Decades of heavy inbreeding have caused further problems, including autoimmune diseases and allergies.

To see if these problems could be remedied in future generations by careful breeding, at University of California, Davis, and his team analysed the DNA of more than 100 English bulldogs to get a measure of how much genetic diversity still exists in the breed.

“I have been concerned for some time about the increasing incidence of heritable disorders in many pure breeds of dog,” says Pederson. “The bulldog is unarguably one of the most egregious examples of that trend.”

Lack of diversity

His team found an alarmingly low genetic diversity among the dogs. This means dog breeders are unlikely to be able to reverse the negative effects of extreme selection through careful matching of genetically different English bulldogs.

“A lack of genetic diversity is bad for the dogs because it not only concentrates unhealthy traits, but also makes it increasingly more difficult to make further changes in a breed or to correct health problems that may have arisen over decades,” says Pedersen.

The growing demand for small, short-muzzled breeds like bulldogs and pugs in recent years has led to a rising number of amateur, inexperienced breeders supplying puppies.

Tom Lewis, a geneticist at UK charity the Kennel Club, suggests this may have contributed to a sharp rise in unhealthy traits. “Not all breeders are experienced or careful enough to be responsible with the traits they select for,” he says. “Some breeders simply don’t know when enough is enough.”

American hybrids

In an attempt to inject some healthy diversity back into the breed’s gene pool, Swiss breeders have begun crossing the English bulldog with a breed from the US, known as “The Olde English Bulldogge”.

Outbreeding in this way can be very beneficial to struggling breeds, as long as it’s done carefully, says Lewis. “Ultimately, it’s the safety of the animals that should come first.”

Such crossing may improve the breed’s health, but some breeders worry that this practice could mean that the true English bulldog is lost for good.

Journal reference: Canine Genetics and Epidemiology, DOI:

Read more: Have we turned dogs into lazy thinkers through domestication?

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Neolithic mortuary enclosures – Stoke Hammond, Buckinghamshire

Iron Age or Roman settlement – Gillsmere Sike, Cumbria

Medieval farm and post-medieval lime kiln – Shap, Cumbria

Read more: Race to save hidden treasures under threat from climate change

Male bees may have inadvertently been taking contraceptives – a possible factor in the alarming decline in bee populations across North America and Europe over the past 15 years.

Neonicotinoid pesticides, a controversial class of neurotoxins used in agriculture for pest control, significantly impairs the fertility of male honeybees, according to a new study.

These pesticides are still widely used in the US, while the European Commission is currently reviewing a temporary ban it imposed in 2013.

and colleagues from the Institute of Bee Health at the University of Bern, Switzerland, explored the effects of two popular neonicotinoids, thiamethoxam and clothianidin, on the sperm of male honey bees, also known as ‘drones’.

The team randomly assigned batches of drones from 20 bee colonies to either insecticide exposure or control groups, and then took semen samples from males once they had reached sexual maturity.

Drones exposed to the neonicotinoids at levels found in fields showed around 39 per cent less living sperm on average. On top of this, the mortality rate of the drones during the study was almost doubled when exposed to the pesticides.

Honey bee queens make a single mating flight from the nest to collect sperm from as many as 20 different males, which they store within a dedicated organ over their entire lifespan.

This is vital for the survival of the hive, as it equips the colony with the genetic diversity needed to resist disease, parasites and environmental challenges.

Game of drones

“The process of the queen’s mating flight is a one-time thing so it’s really important that she collects plenty of quality sperm,” says Straub. “If not, then worker bees in the hive will quickly sense that the queen is ineffective and kill her. We like to call it ‘game of drones’.”

Replacement of the queen is costly as it hinders the growth of the colony. And as replacing a queen can only occur at certain periods in the year, colonies can sometimes go for long periods without one, putting them in danger of collapse.

The insecticides may irreparably damage sperm DNA and hinder sperm motility via a process known as reactive oxidative stress, has previously been shown to impede sperm production in birds and humans. The exact process behind this is still not known.

“The presence of these chemicals could be one reason behind the struggling bee numbers we’ve seen over the past 15 years in the northern hemisphere,” says Straub. “We can’t be sure though yet because of the sheer number of different factors that affect bee populations – it’s unlikely just the pesticides at work in the wild.”

Christopher Connolly, at the University of Dundee, UK, fears neonicotinoids could be reintroduced into UK farming when the country leaves the European Union.

“There is a lot of evidence for the negative effects that these chemicals have on our vital pollinators, particularly bumble bees. Britain was one of the loudest voices to oppose the ban when it came in, so I’m terrified of the ecological consequences if they’re brought back.”

Paul Hetherington at campaign group Buglife, which has long lobbied against neonicotinoid usage in the UK, is more optimistic: “While the consequences could be serious if we fully exit the EU, it’s more likely that we’ll at least partially remain a part of the European Commission and so still have to abide by their agricultural regulations, as with other non-EU countries like Switzerland and Norway.”

Journal reference: Royal Society B: Biological Sciences, DOI: