Tag Archives: explosion

SpaceX rocket aced a landing, then exploded so hard it launched again for a bit

Luckily, nobody was injured and the company seems to be taking the events in good spirits.

Image credits Official SpaceX Photos / Flickr.

SpaceX is a company that’s definitely not afraid to take risks and try new things. And a natural part of such an approach is that things will often not go according to plan, and sometimes they fail spectacularly. Yesterday was one such day, after one of the company’s Starship rockets touched down in Texas.

Post-landing problems

SpaceX wants to make going to space cheap enough that it’s practical. A large part of that plan involves cutting down costs by making rockets reusable. They’re hard at work doing that.

So far, they’ve run into their fair share of trouble. Their approach involves using the rocket’s thrusters in flight to orient the craft upright before landing. Two of their previous test flights ended in fireballs though, because, while the rockets maneuvered as intended, they didn’t decelerate fast enough before touching down.

The test yesterday went much better than those two. It used a full-scale prototype of the rocket, which launched, traveled around 6 miles (10 kilometers), and then headed in for a landing. The maneuvers worked like a charm, and the craft flipped upright after descending close enough to the pad. “Third time’s the charm as the saying goes,” quipped SpaceX commentator John Insprucker, referring to the previous trials, as the rocket touched down successfully.

A few minutes later, however, the rocket would explode, briefly sending itself upon a new flight path.

SpaceX has not issued an official statement on the event yet, but CEO Elon Musk did comment on his personal Twitter account with good humor.

Technically speaking, it did. The first time.

It’s all good to make fun of a bad situation, but even considering that the rocket exploded after landing, this is quite the feat. SpaceX’s approach was under question given how the last two tests panned out, but yesterday’s shows that the plan was sound after all. Most importantly, nobody was injured, and rockets can be rebuilt. Even a result like this — which was arguably, ultimately, a failure — brings us one step closer to the days when rockets are reusable and don’t explode on the landing pad. Both extremely desirable traits, as the Spaceship is earmarked to ferry people to and from Mars for SpaceX.

“SpaceX team is doing great work! One day, the true measure of success will be that Starship flights are commonplace,” Musk added in a later tweet. It is not yet clear why the rocket exploded, but according to the Independent, “observers speculated that it was the result of a rough landing combined with a methane leak”.

NASA maps the devastation of Beirut blast from outer space

On August 4, disaster struck Beirut. A stockpile of 2,750 tons of ammonium nitrate, a chemical used as fertilizer or as an ingredient in bombs, suddenly exploded with a force twenty times greater than that of the GBU-43/B Massive Ordnance Air Blast (also known as the “Mother of All Bombs”), the most powerful non-nuclear weapon in the US arsenal.

At least 135 people were killed and more than 4,000 were injured by the massive explosion that produced a 3.3 magnitude earthquake, which was felt as far as Cyprus, around 240 kilometers (150 miles) away.

The toll of this devastation was recently analyzed by NASA scientists, in collaboration with colleagues from the ESA and Singapore, who employed satellite-derived synthetic aperture data to map the extent of the damage in the Lebanese capital.

NASA’s ARIA team, in collaboration with the Earth Observatory of Singapore, used satellite data to map the extent of likely damage following a massive explosion in Beirut. Credit: NASA/JPL-Caltech/Earth Observatory of Singapore/ESA.

Dark red pixels — each covering an area of 30 meters across — represent the most severe damage. These are typically clustered around the blast’s epicenter, the Port of Beirut. Orange pixels represent moderate damage while yellow pixels correspond to areas that sustained less damage.

The destruction in Beirut is thought to have left more than 300,000 people homeless at a time when the country is struggling both financially and politically.

Hopefully, maps such as this can help local authorities identify which areas have suffered the most damage and where people are most in need of assistance.

Underwater volcanoes can produce stadium-sized bubbles

An underwater volcano off the coast of Alaska has erupted more than 70 times over 9 months, producing a distinctive grumble before each eruption. The volcano also belched ungodly large gas bubbles.

Map of Bogoslof Volcano and two satellite images of the partially submerged summit and crater during the eruption. Image credits: Lyons et al / Nature.

Shallow submarine volcanoes are difficult to study as they are often remote; this can make data acquisition difficult and costly. The interaction between magma and surface water is also complex. It can create violent explosions, but because these interactions are so inaccessible, researchers don’t really understand the entire process. Furthermore, these explosions can also pose risks to nearby ships and planes.

To better understand these processes, researchers installed low-frequency microphones around the Bogoslof volcano to better study this interaction — of course, they couldn’t install the microphones right next to the volcano, so they installed them 59 kilometers to the south.

| Infrasound signals from an explosive eruption of Bogoslof on 13 June 2017. Image credits: Lyons et al / Nature.

The volcano has been known for a long time. Its peak forms Bogoslof Island, an uninhabited island that barely rises above the water surface (but which hosts a thriving seal colony). The first known emergence of the island above sea level was recorded during an underwater eruption in 1796, and since then, the volcano has been steadily adding more surface to the island through new eruptions. The volcano’s eruptive belches have also been documented.

In July 1908, a medium-sized cutter called Albatross was cruising around the island when the sea began to swell. The account of this event reports that the sea bulged and bulged until it ruptured, releasing a terrifying plume of gas and steam. It was a dazzling display that few humans have witnessed, and it’s exactly what researchers wanted to study with the microphones: how big do these bubbles really get?

Schematic depiction of how a bubble forms around a submerged eruption — it all starts with gases coming inside the magma and ends with a bubble collapse. At some point, the bubble reaches its maximum radius; that’s when the pressure is lowest. Image credits: Lyons et al / Nature.

Shallow submerged explosions are often described as beginning with a swelling of the water surface, but these descriptions are qualitative in nature (“giant”, “huge”), not quantitative; researchers wanted to put some numbers on those adjectives but obviously, hanging around a volcano and waiting for it to erupt is not exactly a safe idea. Previous research has shown that smaller bubbles produce infrasound when they oscillate, and their size can be calculated based on these oscillations. This is where the microphones kicked in — they picked up the infrasound and based on this, enabled the researchers to calculate how big the bubbles were without actually seeing them.

You can actually hear the bubbles below. The audio has been adjusted for human ears and sped up 300x. Each of the spikes is a signal from a separate bubble.

via Wired.

According to the calculations, volcanic bubbles reached up to 750 feet (228 meters) across, with a volume of over 180 million cubic feet (5 million cubic meters) of gas. The size of the bubble depended on the radius of the crater and the depth at which the bubbles form.

“The range of initial bubble radii thus varies from the vent radius, 25m, to 200m, or slightly smaller than the approximate radius of the crater area around the time of the observed signals. In our model, large bubbles most probably formed at or near the vent in the base of the shallow submerged crater and thus the height of the submerged portion of the bubble is controlled by the depth of the water,” the study concludes.

The study has been published in Nature Geoscience.

Engines at MacGregor.

Experimental SpaceX engine explodes during trials, damaging the McGregor, Texas facilities

SpaceX’s McGregor facilities in Central Texas were rocked this Sunday as a Merlin engine exploded during testing. Two of the facility’s test bays were damaged, but nobody was harmed according to SpaceX.

Merlins.

Nine Merlin engines on the Falcon 9’s first stage.
Image credits SpaceX.

An explosion on Sunday (November 4) rocked SpaceX’s rocket-development facility at McGregor, Texas. The engine in question is being developed for the Block 5 version of SpaceX’s tried-and-true Falcon 9 craft. The explosion occurred before the engine was lit, during a procedure known as a LOX drop. The step involves pumping liquid oxygen through the engine to check for potential leaks, and an unknown event caused the liquid within the rocket to ignite.

Being an engine-in-development, the company is confident that its current launch manifest won’t be affected by the event. Three to four more launches are planned for this year (and the start of 2018), all of which will be powered by the Block 4 and an earlier version of the Merlin.

“All safety protocols were followed during the time of this incident,” said a company spokesman, John Taylor. “We are now conducting a thorough and fully transparent investigation of the root cause. SpaceX is committed to our current manifest, and we do not expect this to have any impact on our launch cadence.”

Nobody was hurt in the event, but it did damage the facility. SpaceX has three engine test stands in use at McGregor: one for the Merlin line of engines, one for the newer and more powerful Raptor, and one dedicated to upper-stage engines. Both bays of the Merlin stand were damaged. SpaceX said one of them should be up and running within a couple of days, while the other may require up to four weeks of repair works.

Engines at MacGregor.

Two SpaceX Merlin 1D engines on a test stand at the company’s facility in McGregor, Texas.
Image credits SpaceX.

If repairs on the first bay go as planned, the company should be able to continue “acceptance testing” for its Block 4 Merlin engines. This represents the penultimate test before a rocket is assembled, shipped to the launch site, and the entire booster undergoes a static fire test on the launch pad.

The Block 5 variant is expected to improve the Falcon 9’s overall performance, in particular making it simpler and faster to re-use. It’s also this variant that Elon Musk plans to use for commercial crew flights, the missions which will ferry NASA astronauts to the International Space Station.

Needless to say, SpaceX has a lot riding on the Block 5 working properly, and on time. A maiden flight hasn’t been announced but was widely expected to take place at some point in 2018. However, testing of the Block 5 Merlin engine will be suspended until the cause of that ignition is found and fixed. SpaceX anticipates that a full investigation into the incident will take several weeks, which may delay the debut.

Rare prediction: Star collision will be visible with the naked eye in 2022

Some scientists have made an unprecedented prediction, claiming that a pair of stars in the constellation Cygnus will collide approximately in 2022, creating an explosion so bright it will be visible to the naked eye.

The stars expected to merge are located in the Cygnus constellation. Image via NASA.

Calvin College professor Larry Molnar worked with his students and researchers from the Apache Point Observatory (Karen Kinemuchi) and the University of Wyoming (Henry Kobulnicky) to make an unprecedented claim. He and his team believe that two stars he is monitoring in the constellation Cygnus will merge and explode in 2022 (give or take a year), lighting up in the sky.

“It’s a one-in-a-million chance that you can predict an explosion,” Molnar said of his bold prognostication. “It’s never been done before.”

It will be a very dramatic change in the sky, as anyone can see it,” Calvin College astronomer Larry Molnar told National Geographic. “You won’t need a telescope to tell me in 2023 whether I was wrong or I was right.”

If it does happen, then you should see it easily without a telescope or any other specialized tools.

“It will be a very dramatic change in the sky, as anyone can see it. You won’t need a telescope to tell me in 2023 whether I was wrong or I was right,” Molnar said at the presentation, according to National Geographic.

The two stars, jointly called KIC 9832227, are located 1,800 light years away from Earth. Astronomers expect them to merge at some point but the exact time is hard to predict. Stellar collisions occur about once every 10,000 years and scientists have only recently been able to observe a stellar merger. If we will see the explosion in 2022, then this means that they have already exploded for 1795 years, but light from them hasn’t reached us already. As we can see them, the stars are quite close to one another. Daniel Van Noord, who also worked on the study, said they share an atmosphere together “like two peanuts sharing a single shell.”

It was actually Van Noord who started the study in 2013, when he realized that the star (as astronomers considered it then) was actually a binary system.

“He looked at how the color of the star correlated with brightness and determined it was definitely a binary,” said Molnar. “In fact, he discovered it was actually a contact binary, in which the two stars share a common atmosphere, like two peanuts sharing a single shell.”

“From there Dan determined a precise orbital period from Kinemuchi’s Kepler satellite data (just under 11 hours) and was surprised to discover that the period was slightly less than that shown by earlier data” Molnar continued.”

This reminded them of the work of Romuald Tylenda, who made similar observations of a star in 2008. The star system exhibited a similar behavior and then exploded – prompting Molnar to believe that the same thing will happen here. Extrapolating the data from Tylenda’s study they made the bold prediction and even set a date for it: 2022.

A red nova explosion like the one we might expect in 2022. Image via Space Telescope Science Institute

Whether or not this will happen, we should pay close attention, Molnar says, because this event will broaden our understanding of stars.

“Bottom line is we really think our merging star hypothesis should be taken seriously right now and we should be using the next few years to study this intensely so that if it does blow up we will know what led to that explosion,” he says.

The study is interesting because unlike most astronomical observations, which involve numerous team and expensive equipment, this study was low-scale and low-cost, which is why Molnar can afford to make such a risky prediction, as he himself says.

“Most big scientific projects are done in enormous groups with thousands of people and billions of dollars,” he said. “This project is just the opposite. It’s been done using a small telescope, with one professor and a few students looking for something that is not likely.”

“Nobody has ever predicted a nova explosion before. Why pay someone to do something that almost certainly won’t succeed? It’s a high-risk proposal. But at Calvin it’s only my risk, and I can use my work on interesting, open-ended questions to bring extra excitement into my classroom. Some projects still have an advantage when you don’t have as much time or money.”

Squished-booms: looking at the behavior of underwater explosions

Some things go boom, others don’t. The first category is definitely more fun.

Other things go boom in unusual places — these are arguably the best.
Image via Youtube / Slow Mo Guys.

A material explodes when it increases in volume rapidly and releases a lot of energy. The most usual energy storage used to create explosives is of the chemical kind, but explosives can be created using atomic, electrical, or mechanical sources. The characteristic boom or bang of an explosion is how your ears pick up on the “changing volume” part of the explosion, the shockwave. This is the force that lends explosions their destructive nature. The biggest part of an explosive’s energy is expended as light, heat, and work.

Not all explosions are made the same. The medium in which detonation takes place has a huge influence on the way the explosion and its shockwaves behave. And, while surface explosions are pretty ubiquitous in movies, underwater explosions aren’t — which is a shame, because they’re really pretty.

So let’s watch some

First thing first: explosions are inherently hard to enjoy properly — they’re ephemeral, gone in a flash of the eye.

That is, unless you film it thousands of times faster than the eye can see, which is exactly what the Slow Mo Guys did. They took a firecracker, set it alight, then submerged it in a fish tank to blow up — all under the watchful lens of a 120.000 fps high-speed camera. The resulting reel slows the detonations down enough for us to observe some basic principles of underwater explosions. I’ve taken the explosions and turned them into gifs below, but the whole video is pretty good and you should watch it.

Here are the firecrackers exploding.

Image via Youtube / Slow Mo Guys.

Underwater detonations spread out in the begging, creating a hollow sphere inside the liquid. This soon collapses in on itself, as water rushes to fill the gap.

Image via Youtube / Slow Mo Guys.

This happens for two reasons. One, water is much denser than air, so it’s a lot harder to push around. Then there’s the fact that water, unlike air, can’t be compressed. This is the same property that underpins hydraulic systems (incompressibility) and because of it, the firecracker has to act on the fluid as a whole. In essence, this means that it has to perform work on a much denser, much larger medium. This property is also used by SWAT teams and military personnel to breach doors in the form of water impulse charges — water here is used to direct the force of the blast evenly onto a surface.

A firecracker set off in normal conditions can propel gas and fragments a few meters away, but underwater the explosion has enough energy to expand only a few centimeters across.

In this gif, the detonation took place closer to the water’s surface and you can actually see the liquid pouring in on the collapsing bubble.

Image credits Youtube / Slow Mo Lab.

Apart from this shot, the video itself doesn’t add that much from the one above (the guy shooting it does have a necktie though). You can see it here.

The shockwaves

The gases released during detonation are then squashed by the liquid’s weight. This compression-explosion interplay can become quite lively, as the water compresses the gas as far as it can, then gets pushed back, and repeat. The collapse of the hollow bubble generates the first shock wave. Secondary shock waves are created as gas and water wrestle.

TheBackyardScientist can help explain with his liquid nitrogen bomb. He only shot with a 240 fps camera, so you can’t actually see the liquid being pushed during the explosion — but you can see the awesome gas-water play after it.

Here are some highlights.

Wub dub dub dub.
Image via Youtube / TheBackyardScientist.

Wub dub dub dub, the sequel.
Image via Youtube / TheBackyardScientist.

TBS conveniently placed some balloons around the point of detonation, to pick up on the shockwaves’ motions. As you can see, there’s a lot of motion going on throughout the fluid as the gas gets compressed then expands.

The surface

So this one will feature a nuke ’cause its the last part — why not go big?

https://www.youtube.com/watch?v=qDMUekfOR-E

As you can see, the highest point the water is thrown upwards lies directly above the point of detonation — the center point of the shockwave. If you pause the video or look at the thumbnail image you’ll see that the shape of the column of water being pushed upwards follows an exponential curve — not the round shape we saw in the bubbles.

 

SpaceX rocket explodes during satellite launch

SpaceX has suffered a serious setback after one of its rockets, carrying a $200 million communications satellite, exploded yesterday.

spacex explosion

The satellite was supposed to expand Facebook’s reach across Africa but never quite got to do that, after the Falcon 9 rocket carrying it blazed down in a massive fireball. The rocket exploded at 9:07 a.m. EDT (1307 GMT), and while SpaceX released a statement explaining the direct cause of explosion was, we don’t yet know the underlying cause.

“The anomaly originated around the upper-stage oxygen tank and occurred during propellant loading of the vehicle,” SpaceX representatives said in a statement. “Per standard operating procedure, all personnel were clear of the pad and there were no injuries. We are continuing to review the data to identify the root cause. Additional updates will be provided as they become available.”

This isn’t the first problem SpaceX has had with its Falcon 9 rockets. This is the second loss in the past 14 months, after another Falcon 9 broke down 3 minutes after launching in June 2015. Still, NASA has reiterated its confidence in SpaceX, saying that this can be treated like a lesson to be learned from.

“We remain confident in our commercial partners and firmly stand behind the successful 21st century launch complex that NASA, other federal agencies, and U.S. commercial companies are building on Florida’s Space Coast,” the space agency said. “Today’s incident — while it was not a NASA launch — is a reminder that spaceflight is an incredible challenge, but our partners learn from each success and setback.”

But not everyone is so confident. Several scientists and engineers have expressed worries regarding the SpaceX approach.

“SpaceX is running a punishing schedule,” said Scott Pace, the director of the Space Policy Institute at George Washington University and a former NASA official.

Pace also expressed concerns others were thinking about too – the potential of a human error.

“There is probably some human factor involved here. To what extent was human error part of this? And if so, why? Are you running your people too hard? What are your safety requirements?”

This could also jeopardize (to an extent) the ISS mission, as SpaceX was also scheduled to deliver cargo to the International Space Station. Again, NASA said they are fully prepared to deal with the situation.

“The situation at the Cape is being evaluated, and it’s too early to know whether the incident will affect the schedule for upcoming NASA-related SpaceX launches to the International Space Station. If there are SpaceX mission delays, other cargo spacecraft will be able to meet the station’s cargo needs, and supplies and research investigations are at good levels,” the NASA statement concluded.

For now, we await an official report on what happened and what the causes of the explosion are.

Artist's impression of supernova 1993J. Credit: Wikimedia Commons

Superluminous supernovas explode twice, create some of the most powerful magnets in the universe

Artist's impression of supernova 1993J.  Credit: Wikimedia Commons

Artist’s impression of supernova 1993J. Credit: Wikimedia Commons

When a star is ready to drop the curtain, it goes out with a bang — a supernova explosion. Sometimes, however, some stars blow up twice. Now, astronomers studying these rare and mysterious cosmic events say they’ve uncovered a link between these double explosions and another class of novas called superluminous supernovas.

Supernovae are basically stellar eruptions, triggered either by the gravitational collapse of a massive star, or by the sudden re-ignition of nuclear fusion in a degenerate star. They are amazing manifestations of energy – for brief moments, a supernova can outshine an entire galaxy, radiating as much energy as the Sun or any ordinary star is expected to emit over its entire lifespan, before fading after a few weeks or months. A typical supernova will also eject enough material to seed 7,000 Earths. The shock breakout immediately precedes the ‘big event’ and is essentially a massive flash of brightness.

Maybe the rarest class of supernovas, however, are the superluminous kind. These are up to 100 times brighter than the regular variety. They’re also very rare. Only 0.1% of supernovas are superluminous and only 30 have been caught by astronomers so far.

These mysterious cosmic bodies are the focus of research nowadays as astronomers try to piece the puzzle of their origin. We still don’t know a lot about them, but previous work seems to suggest superluminous supernovas blow up twice, something that British researchers seem to confirm in this new study.

Using the Gran Telescopio Canarias, a telescope in Spain’s Canary Islands, astronomers spotted one of this rare gems in 2014. The superluminous supernova called DES14X3taz is located 6.4 billion light-years from Earth. The scientists were lucky enough to catch the explosion as it unfolded, and tracked its temperature for months. What they found was that after an initial spike of brightness, the supernova cooled off, only to turn the lights on much brighter some time later.

This graph shows the evolution of the apparent brightness of the new supernova. You can notice the initial peak, which rapidly drops for a couple of days. The brightness increases again for a double bang. Credit: Mathew Smith.

This graph shows the evolution of the apparent brightness of the new supernova. You can notice the initial peak, which rapidly drops for a couple of days. The brightness increases again for a double bang. Credit: Mathew Smith.

This initial spike of the dying star which had a mass 200 times greater than the sun was likely due to the ejection of a huge bubble of material. As this bubble grew to tremendous size, the material rapidly cooled. What was most remarkable, however, was that following the initial spike of brightness the star gave birth to a magnetar.

Though it sounds like a magnetic centaur, a magnetar is, in fact, a type of neutron star — the collapsed core of the star following the nova event. Magnetars are among the most powerful magnets in the Universe. In this particular case, the creation of the magnetar triggered the second, much more powerful supernova event because it heated the bubble of matter initially expelled into outer space.

Mathew Smith, an astrophysicist at the University of Southampton in England, one of the lead authors of the study, peered through existing literature and databases and found this sort of double-peak events are very common among superluminous supernovas. The two may be intrinsically connected, the researchers conclude.

“What we have managed to observe, which is completely new” said Smith, “is that before the major explosion there is a shorter, less luminous outburst, which we can pick out because it is followed by a dip in the light curve, and which lasts just a few days.”

“The hunt is now on to find these events early and really tie down what causes them,” Smith said. “Fingers crossed we find some more.”

Japan in more trouble after an explosion at a nuclear plant

The earthquake that occured yesterday near the coast of Japan, the 4th most powerful earthquake ever to be recorded, is causing even more problems, after the direct damage, the aftershocks, the tsunamis, and the fire tsunamis; this time, things can get way, way bigger and worse, and the disaster toll keeps rising.

An explosion at a nuclear power plant destroyed a nuclear power station created fears that the a disastrous meltdown could happen, which would definitely cause a huge number of human casualties not only in Japan, but in neighbouring areas as well. The explosion was caused by the earthquake and the tsunamis that devastated Japan, and caused (by now) an estimated number of 1300 deaths, already.

The Fukushima Dai-ichi plant, the one in case, caused worries that led to an immediate evacuation of all the workers and people in the area, but experts have yet to find out what lies behind this explosion.

“We are now trying to analyze what is behind the explosion,” said government spokesman Yukio Edano, stressing that people should quickly evacuate a six-mile (10-kilometer) radius. “We ask everyone to take action to secure safety.”

The trouble began after the 8.9 magnitude earthquake and the tsunamis it created knocked out all electricity from the area. Other disturbing news is that the Kyodo news agency said rail operators lost contact with four trains yesterday, and still haven’t found them today. Japan has also declared states of emergency for five other nuclear reactors, all of which are in danger of exploding after they lost their cooling ability.

‘Fossil’ fireballs found from supernovae

The US-Japan Sukazu observatory reported the finding of some never-before seen embers from the high temperature fireballs that immediately follower the supernovae explosions. Even after thousands of years in which they haven’t been exposed to any heat source, gas within these stellar wrecks is 10.000 hotter than the Sun’s surface.

supernova_sn2006gy

“This is the first evidence of a new type of supernova remnant — one that was heated right after the explosion,” said Hiroya Yamaguchi at the Institute of Physical and Chemical Research in Japan.

cosm_supernova2_large

Supernovae usually cool off quickly, due to the massive expansion that follows the explosion; after that it basically sweeps stellar gas and during the following thousands of years, starts to heat up again. In this studied supernova from the Jellyfish Nebula they also found some structures that raise questions.

“These structures indicate the presence of a large amount of silicon and sulfur atoms from which all electrons have been stripped away,” Yamaguchi said. These “naked” nuclei produce X-rays as they recapture their lost electrons.