Universe Today

April 4, 2013June 5, 2022 by Ken Kremer

How the Air Force and SpaceX Saved Dragon from Doom

This grappling of the SpaceX Dragon capsule on March 3, 2013 by the space station robotic arm nearly didn’t happen when a thruster failure just minutes after the March 1 liftoff nearly doomed the mission. Credit: NASA

The picture perfect docking of the SpaceX Dragon capsule to the International Space Station (ISS) on March 3 and the triumphant ocean splashdown last week on March 26 nearly weren’t to be – and it all goes back to a microscopic manufacturing mistake in the oxidizer tank check valves that no one noticed long before the vessel ever took flight.

Barely 11 minutes after I witnessed the spectacular March 1 blastoff of the Dragon atop the SpaceX Falcon 9 rocket from Cape Canaveral, Florida, everyone’s glee suddenly turned to disbelief and gloom with the alarming news from SpaceX Mission Control that contact had been lost.

I asked SpaceX CEO and founder Elon Musk to explain what caused the failure and how they saved the drifting, uncontrolled Dragon capsule from doom – just in the nick of time.

Applying the space version of the Heimlich maneuver turned out to be the key. But if you can’t talk to the patient – all is lost.

Right after spacecraft separation in low Earth orbit , a sudden and unexpected failure of the Dragon’s critical thrust pods had prevented three out of four from initializing and firing. The oxidizer pressure was low in three tanks. And the propulsion system is required to orient the craft for two way communication and to propel the Dragon to the orbiting lab complex.

So at first the outlook for the $133 million Dragon CRS-2 cargo resupply mission to the ISS appeared dire.

Then, SpaceX engineers and the U.S Air Force sprang into action and staged an amazing turnaround.

“The problem was a very tiny change to the check valves that serve the oxidizer tanks on Dragon.” Musk told Universe Today

“Three of the check valves were actually different from the prior check valves that had flown – in a very tiny way. Because of the tiny change they got stuck.”

Falcon 9 SpaceX CRS-2 launch on March 1, 2013 to the ISS – shot from the roof of the Vehicle Assembly Building. Credit: Ken Kremer/www.kenkremer.com

SpaceX engineers worked frantically to troubleshoot the thruster issues in an urgent bid to overcome the serious glitch and bring the crucial propulsion systems back on line.

“What we did was we were able to write some new software in real time and upload that to Dragon to build pressure upstream of the check valves and then released that pressure- to give it a kind of a kick,” Musk told me at a NASA media briefing.

“For the spacecraft you could call it kind of a Heimlich maneuver. Basically that got the valves unstuck and then they worked well”

“But we had difficulty communicating with the spacecraft because it was in free drift in orbit.”

“So we worked closely with the Air Force to get higher intensity, more powerful dishes to communicate with the spacecraft and upload the software to do the Heimlich pressure maneuver.”

Schematic of SpaceX Dragon. Credit: SpaceX

Just how concerned was Musk?

“Yes, definitely it was a worrying time,” Musk elaborated.

“It was a little frightening,” Musk had said right after the March 1 launch.

Later in the briefing Musk explained that there had been a small design change to the check valves by the supplier.

“The supplier had made mistakes that we didn’t catch,” said Musk. “You would need a magnifying glass to see the difference.”

SpaceX had run the new check valves through a series of low pressurization systems tests and they worked well and didn’t get stuck. But SpaceX had failed to run the functional tests at higher pressures.

“We’ll make sure we don’t repeat that error in the future,” Musk stated.

Musk added that SpaceX will revert to the old check valves and run tests to make sure this failure doesn’t happen again.

SpaceX, along with Orbital Sciences Corp, are both partnered with NASA’s Commercial Resupply Services program to replace the cargo up mass capability the US lost following the retirement of NASA’s space shuttle orbiters in 2011.

Orbital’s Antares rocket could blast off on its first test mission as early as April 17.

Of course the Dragon CRS-2 flight isn’t the first inflight space emergency, and surely won’t be the last either.

So, for some additional perspective on the history of reacting to unexpected emergencies in space on both human spaceflight and robotic science probes, Universe Today contacted noted space historian Roger Launius, of the Smithsonian National Air & Space Museum (NASM).

Roger provided these insights to Universe Today editor Nancy Atkinson – included here:

“There are many instances in the history of spaceflight in which the mission had difficulties that were overcome and it proved successful,” said Launius.

“Let’s start with Hubble Space Telescope which had a spherical aberration on its mirror and the first reports in 1990 were that it would be a total loss, but the engineers found workarounds that allowed it to be successful even before the December 1993 servicing mission by a shuttle crew that really turned it into a superb scientific instrument.”

“Then what about Galileo, the Jupiter probe, which had a problem with its high gain antenna. It never did fully deploy but the engineers found ways to overcome that problem with the communication system and the spacecraft turned into a stunning success.”

“If you want to feature human spaceflight let’s start with the 1999 shuttle flight with Eileen Collins as commander that had a shutdown of the SSMEs prematurely and it failed to reach its optimum orbit. It still completed virtually all of the mission requirements.”

“That says nothing about Apollo 13,… I could go on and on. In virtually every mission there has been something potentially damaging to the mission that has happened. Mostly the folks working the mission have planned for contingencies and implement them and the public rarely hears about it as it looks from the outside like a flawless operation.”

“Bottom line, the recovery of the Dragon capsule was not all that amazing. It was engineers in the space business doing what they do best,” said Launius.

Ken Kremer

…………….

Learn more about SpaceX, Antares, Curiosity and NASA missions at Ken’s upcoming lecture presentations:

April 20/21 : “Curiosity and the Search for Life on Mars – (in 3-D)”. Plus Orion, SpaceX, Antares, the Space Shuttle and more! NEAF Astronomy Forum, Suffern, NY

April 28: “Curiosity and the Search for Life on Mars – (in 3-D)”. Plus the Space Shuttle, SpaceX, Antares, Orion and more. Washington Crossing State Park, Titusville, NJ, 130 PM

SpaceX Falcon 9 rocket and Dragon capsule poised to blast off from Cape Canaveral Air Force Station, Florida on a commercial resupply mission to the ISS. Credit: Ken Kremer/www.kenkremer.com

April 3, 2013December 23, 2015 by Nancy Atkinson

Watch Curiosity’s Parachute Flap in the Martian Breeze

This sequence of seven images from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter shows wind-caused changes in the parachute of NASA's Mars Science Laboratory spacecraft as the chute lay on the Martian ground during months after its use in safe landing of the Curiosity rover. Image credit: NASA/JPL-Caltech/Univ. of Arizona.

How cool is this? An animation of seven images from the HiRISE camera on the Mars Reconnaissance Orbiter show a “flapping” of the parachute that allowed the Curiosity rover to descend safely through Mars atmosphere images. The chute, imaged as it lay on the ground following the rover’s safe landing, was blown about by the Martian breeze! The images were acquired by HiRISE between August 12, 2012 and January 13, 2013. The different images show distinct changes in the parachute, which is attached to the backshell that encompassed the rover during launch, flight and descent.

The HiRISE team explains the animation:

In the first four images there are only subtle changes, perhaps explained by differences in viewing and illumination geometry.

Sometime between September 8, 2012 and November 30, 2012, there was a major change in which the parachute extension to the southeast (lower right) was moved inward, so the parachute covers a smaller area. In the same time interval some of the dark ejecta around the backshell brightened, perhaps from deposition of airborne dust.

Another change happened between December 16, 2012 and January 13, 2013, when the parachute shifted a bit to the southeast. This type of motion may kick off dust and keep parachutes on the surface bright, to help explain why the parachute from Viking 1 (landed in 1976) remains detectable.

Here’s another version from UnmannedSpaceflight.com’s Doug Ellison:

The Mars Science Laboratory's parachute flaps in the wind on Mars. Images by the HiRISE camera on the Mars Reconnaissance Orbiter, animation by Doug Ellison. — The Mars Science Laboratory’s parachute flaps in the wind on Mars. Images by the HiRISE camera on the Mars Reconnaissance Orbiter, animation by Doug Ellison.

And here’s a look at how big the chute really is (note the people for scale):

MSL parachutte tested in a wind tunnel. Credit: JPL.

Source: HiRISE

April 3, 2013December 23, 2015 by Nancy Atkinson

New Meme Puts Space Robots in Their Place

@doug_ellison's contribution to the new 'Robot Shaming' Tumblr site.

Oh, those space robots. They don’t always do what we want them to do, but we love them anyway. If you need a fun diversion in your day, a new Tumblr site has arisen to call out the robots who have made mistakes. Called “Shaming Robots” it started innocently with an image posted of the engineering model of the Curiosity rover blaming the engineering Opportunity rover for messing up JPL’s Mars Yard. There’s now pages of shamed robots (both space and Earth-based). Submit your own if you have a robot you’d like to shame. You can also follow the fun discussion on Twitter at the hashtag #robotshaming.

Astronomer Alex Parker stared the 'Robot Shaming' meme with this image of the engineering model of Curiosity at JPL. — Astronomer Alex Parker stared the ‘Robot Shaming’ meme with this image of the engineering model of Curiosity at JPL.

April 3, 2013December 23, 2015 by Nancy Atkinson

NASA’s Great Observatories Provide a Sparkly New View of the Small Magellanic Cloud

A part of the Small Magellanic Cloud galaxy is dazzling in this new view from NASA's Great Observatories. The Small Magellanic Cloud, or SMC, is a small galaxy about 200,000 light-years way that orbits our own Milky Way spiral galaxy. Credit: NASA.

This is just pretty! NASA’s Great Observatories — the Hubble Space Telescope, the Chandra X-Ray Observatory and the Spitzer Infrared Telescope — have combined forces to create this new image of the Small Magellanic Cloud. The SMC is one of the Milky Way’s closest galactic neighbors. Even though it is a small, or so-called dwarf galaxy, the SMC is so bright that it is visible to the unaided eye from the Southern Hemisphere and near the equator.

What did it take to create this image? Let’s take a look at the images from each of the observatories:

The Small Magellenic Cloud in X-Ray from the Chandra X-Ray Observatory. Credit: NASA.

The Small Magellenic Cloud in infrared, from the Spitzer Infrared Telescope. Credit: NASA.

The Small Magellenic Cloud as seen in optical wavelengths from the Hubble Space Telescope. Credit: NASA.

The various colors represent wavelengths of light across a broad spectrum. X-rays from NASA’s Chandra X-ray Observatory are shown in purple; visible-light from NASA’s Hubble Space Telescope is colored red, green and blue; and infrared observations from NASA’s Spitzer Space Telescope are also represented in red.

The three telescopes highlight different aspects of this lively stellar community. Winds and radiation from massive stars located in the central, disco-ball-like cluster of stars, called NGC 602a, have swept away surrounding material, clearing an opening in the star-forming cloud.

Find out more at this page from Chandra, and this one from JPL.

April 3, 2013December 23, 2015 by Nancy Atkinson

Incredible Views: Comet PANSTARRS Meets the Andromeda Galaxy

Two objects 2.5 million lightyears apart... PanSTARRS & Andromeda. Credit and copyright: Brendan Alexander.

We warned you it was going to happen, and here’s visual proof! In this comet encounter of the extragalactic kind, Comet PanSTARRS and the Andromeda Galaxy met each other in the skies above Earth. This great image by Brendan Alexander in Ireland shows the spectacular view. He said it was “a difficult image to capture due to low cloud, the low altitude of the target and tracking issue. I hope to get the chance to improve on this!”

Here’s another image from UT reader Anna Morris:

Comet PANSTARRS and the Andromeda galaxy over Suffolk, England on April 2, 2013. This composite images shows the movement of the comet during the imaging session. Credit and copyright: Anna Morris.

Want to see this meetup for yourself? Tonight might be even better:

Comet PANSTARRS shown every three days as it moves across Andromeda, passing near the Andromeda Galaxy around April 3. You can use Cassiopeia to point you to Beta Andromedae and from there to the comet. The map shows the sky facing northwest about one hour after sunset. Comet and galaxy brightness are exaggerated for the sake of illustration. Stellarium

Did you capture this event, too? Let us know, or upload your images to our Flickr page.

April 3, 2013December 23, 2015 by Nancy Atkinson

Building the Alpha Magnetic Spectrometer: 16 Years in 3 Minutes

Endeavour approaches the International Space Station. Visible is the Alpha Magnetic Spectrometer in the payload bay. Credit: NASA

The Alpha Magnetic Spectrometer on board the International Space Station released its first results today (read about them here) after having been in space since 2011. But this particle physics experiment was years in the making. In just 3 minutes, you can watch 16 years of building, preparing, launching and activating this detector.

Below, watch another video from NASA that provides an overview of the AMS:

April 3, 2013December 23, 2015 by Tammy Plotner

Wrapping Around The Mystery Of Spiral Galaxy Arms

Credit: Thiago Ize & Chris Johnson (Scientific Computing and Imaging Institute)

How disk galaxies form their spiral arms have been puzzling astrophysicists for almost as long as they have been observing them. With time, they have come to two conclusions… either this structure is caused by differences in gravity sculpting the gas, dust and stars into this familiar shape, or its just a random occurrence which comes and goes with time.

Now researchers are beginning to wrap their conclusions around findings based on new supercomputer simulations – simulations which involve the motion of up to 100 million “stellar particles” that mimic gravitational and astrophysical forces which shape them into natural spiral structure. The research team from the University of Wisconsin-Madison and the Harvard-Smithsonian Center for Astrophysics are excited about these conclusions and report the simulations may hold the essential clues of how spiral arms are formed.

“We show for the first time that stellar spiral arms are not transient features, as claimed for several decades,” says UW-Madison astrophysicist Elena D’Onghia, who led the new research along with Harvard colleagues Mark Vogelsberger and Lars Hernquist.

“The spiral arms are self-perpetuating, persistent, and surprisingly long lived,” adds Vogelsberger.

When it comes to spiral structure, it’s probably the most widely occurring of universal shapes. Our own Milky Way galaxy is considered to be a spiral galaxy and around 70% of the galaxies near to us are also spiral structured. When we think in a broader sense, just how many things take on this common formation? Whisking up dust with a broom causes particles to swirl into a spiral shape… draining water invokes a swirling pattern… weather formations go spiral. It’s a universal happening and it happens for a reason. Apparently that reason is gravity and something to perturb it. In the case of a galaxy, it’s a giant molecular cloud – the star-forming regions. Introduced into the simulation, the clouds, says D’Onghia, a UW-Madison professor of astronomy, act as “perturbers” and are enough to not only initiate the formation of spiral arms but to sustain them indefinitely.

“We find they are forming spiral arms,” explains D’Onghia. “Past theory held the arms would go away with the perturbations removed, but we see that (once formed) the arms self-perpetuate, even when the perturbations are removed. It proves that once the arms are generated through these clouds, they can exist on their own through (the influence of) gravity, even in the extreme when the perturbations are no longer there.”

So, what of companion galaxies? Can spiral structure be caused by proximity? The new research also takes that into account and models for “stand alone” galaxies as well. However, that’s not all the study included. According to Vogelsberger and Hernquist, the new computer-generated simulations are focusing on clarifying observational data. They are taking a closer look at the high-density molecular clouds and the “gravitationally induced holes in space” which act as ” the mechanisms that drive the formation of the characteristic arms of spiral galaxies.”

Until then, we know spiral structure isn’t just a chance happening and – to wrap things up – it’s probably the most common form of galaxy in our Universe.

Original Story Source: Harvard-Smithsonian Center for Astrophysics.

April 3, 2013December 23, 2015 by Nancy Atkinson

Space Station Detector Finds Extra Antimatter in Space, Maybe Dark Matter

From its vantage point about 400 km above Earth on the International Space Station, the Alpha Magnetic Spectrometer collects data from primordial cosmic rays from space. Credit: NASA

The first results from the largest and most complex scientific instrument on board the International Space Station has provided tantalizing hints of nature’s best-kept particle secrets, but a definitive signal for dark matter remains elusive. While the AMS has spotted millions of particles of antimatter – with an anomalous spike in positrons — the researchers can’t yet rule out other explanations, such as nearby pulsars.

“These observations show the existence of new physical phenomena,” said AMS principal investigator Samuel Ting,” and whether from a particle physics or astrophysical origin requires more data. Over the coming months, AMS will be able to tell us conclusively whether these positrons are a signal for dark matter, or whether they have some other origin.”

The positron fraction measured by AMS. Credit: CERN.

The AMS was brought to the ISS in 2011 during the final flight of space shuttle Endeavour, the penultimate shuttle flight. The $2 billion experiment examines ten thousand cosmic-ray hits every minute, searching for clues into the fundamental nature of matter.

During the first 18 months of operation, the AMS collected of 25 billion events. It found an anomalous excess of positrons in the cosmic ray flux — 6.8 million are electrons or their antimatter counterpart, positrons.

The AMS found the ratio of positrons to electrons goes up at energies between 10 and 350 gigaelectronvolts, but Ting and his team said the rise is not sharp enough to conclusively attribute it to dark matter collisions. But they also found that the signal looks the same across all space, which would be expected if the signal was due to dark matter – the mysterious stuff that is thought to hold galaxies together and give the Universe its structure.

Additionally, the energies of these positrons suggest they might have been created when particles of dark matter collided and destroyed each other.

A screenshot from Ting's presentation at CERN on April 3, 2013. 'It took us 18 years to complete this result,' Ting said. — A screenshot from Ting’s presentation at CERN on April 3, 2013. ‘It took us 18 years to complete this result,’ Ting said.

The AMS results are consistent with the findings of previous telescopes, like the Fermi and PAMELA gamma-ray instruments, which also saw a similar rise, but Ting said the AMS results are more precise.

The results released today do not include the last 3 months of data, which have not yet been processed.

“As the most precise measurement of the cosmic ray positron flux to date, these results show clearly the power and capabilities of the AMS detector,” Ting said.

Cosmic rays are charged high-energy particles that permeate space. An excess of antimatter within the cosmic ray flux was first observed around two decades ago. The origin of the excess, however, remains unexplained. One possibility, predicted by a theory known as supersymmetry, is that positrons could be produced when two particles of dark matter collide and annihilate. Ting said that over the coming years, AMS will further refine the measurement’s precision, and clarify the behavior of the positron fraction at energies above 250 GeV.

Although having the AMS in space and away from Earth’s atmosphere – allowing the instruments to receive a constant barrage of high-energy particles — during the press briefing, Ting explained the difficulties of operating the AMS in space. “You can’t send a student to go out and fix it,” he quipped, but also added that the ISS’s solar arrays and the departure and arrival of the various spacecraft can have an effect on thermal fluctuations the sensitive equipment might detect. “You need to monitor and correct the data constantly or you are not getting accurate results,” he said.

Despite recording over 30 billion cosmic rays since AMS-2 was installed on the International Space Station in 2011, the Ting said the findings released today are based on only 10% of the readings the instrument will deliver over its lifetime.

Asked how much time he needs to explore the anomalous readings, Ting just said, “Slowly.” However, Ting will reportedly provide an update in July at the International Cosmic Ray Conference.

More info: CERN press release, the team’s paper: First Result from the Alpha Magnetic Spectrometer on the International Space Station: Precision Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5–350 GeV

April 3, 2013December 23, 2015 by Nancy Atkinson

Astrophotos: We Have Liftoff from the Sun!

A large prominence from the Sun, on April 1, 2013. Credit and copyright: Paul Andrew.

Here are three images showing large prominences recently lifting off from the Sun’s surface. Solar prominences are sheets or arcs of luminous gas emanating from the Sun’s surface. They can loop hundreds of thousands of kilometers into space. In the image below by noted Australian amatuer Monty Leventhal, he estimates the prominence he captured stretches 233,000 km! Against the Sun, prominences appear dark, but against the sky they appear brighter. Prominences are held above the Sun’s surface by strong magnetic fields and can sometimes last for long periods of time.

See more and varied views below:

A negative image of the Sun and large prominences on March 31, 2013. Credit and copyright: César Cantú.

This digital filtergram shows an active prominence on the SE limb of the Sun, stretching across for approximately 233,000 km on March 27, 2013. Credit and copyright: Monty Leventhal.

Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

April 3, 2013December 23, 2015 by Jason Major

How Big Are Galaxies?

Galaxy size comparison chart by astrophysicist Rhys Taylor

I’m going to refrain from the initial response that comes to mind… actually, no I won’t — they’re really, really, really big!!!!

</Kermit arms>

Ok, now that that’s out of the way check out this graphic by Arecibo astrophysicist Rhys Taylor, which neatly illustrates the relative sizes of 25 selected galaxies using images made from NASA and ESA observation missions… including a rendering of our own surprisingly mundane Milky Way at the center for comparison. (Warning: this chart may adversely affect any feelings of bigness you may have once held dear.) According to Taylor on his personal blog, Physicists of the Caribbean (because he ~~works~~ had worked at the Arecibo Observatory in Puerto Rico) “Type in ‘asteroid sizes’ into Google and you’ll quickly find a bunch of images comparing various asteroids, putting them all next to each at the same scale. The same goes for planets and stars. Yet the results for galaxies are useless. Not only do you not get any size comparisons, but scroll down even just a page and you get images of smartphones, for crying out loud.” So to remedy that marked dearth of galactic comparisons, Taylor made his own. Which, if you share my personal aesthetics, you’ll agree is quite nicely done.

“I tried to get a nice selection of well-known, interesting objects,” Taylor explains. “I was also a little limited in that I needed high-resolution images which completely mapped the full extent of each object… still, I think the final selection has a decent mix, and I reckon it was a productive use of a Saturday.” And even with the dramatic comparisons above, Taylor wasn’t able to accurately portray to scale one of the biggest — if not the biggest — galaxies in the observable universe: IC 1101.

For an idea of how we measure up to that behemoth, he made this graphic:

Galaxy sizes including IC 1101, the largest-known galaxy. Click for a zoomable version. (Credit: Rhys Taylor)

That big bright blur in the center? That’s IC 1101, the largest known galaxy — in this instance created by scaling up an image of M87, another supersized elliptical galaxy that just happens to be considerably closer to our own (and thus has had clearer images taken of it.) But the size is right — IC 1101 is gargantuan.

At an estimated 5.5 million light-years wide, over 50 Milky Ways could fit across it! And considering it takes our Solar System about 225 million years to complete a single revolution around the Milky Way… well… yeah. Galaxies are big. Really, really, really, really big!

</Kermit arms>

Now if you’ll pardon me, I need to go stop my head from spinning… Read this and more on Rhys Taylor’s blog here, and add Rhys to your awesome astronomy Google+ circles here. And you can find out more about IC 1101 in the video below from Tony Darnell, aka DeepAstronomy: