UT writer Steve Nerlich and I have collaborated for a couple of podcasts on the 365 Days of Astronomy podcast series where we talk about our favorite space shuttle missions. We actually did the first one last year, and decided to do an encore this year with the end of the space shuttle program upon us. Give us some love and have a listen:
And if anyone is interested in doing their own podcast on 365 Days of Astronomy and sharing your interests in space and astronomy, there are plenty of days available throughout the rest of the year. Find out more at this link.
A panoramic view of Earth taken from the ISS, with shuttle Atlantis docked to the station. Aurora Australis or the Southern Lights can be seen on Earth's horizon and a number of stars also are visible. Credit: NASA
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The STS-135 crew of space shuttle Atlantis and the Expedition 28 crew of the International Space Station were treated with great views of the Aurora Australis. Here’s one shot the crews photographed, showing a panoramic view of the station/shuttle complex along with several different astronomical beauties! The aurora shows up brightly, but what else is in the image? Looking closely –and southern hemisphere observers might recognize some objects better — but do you see the globular cluster Omega Centauri, the Coalsack Nebula and the Southern Cross? Anyone see anything else?
See below for another great aurora shot from the ISS, where the green glow shows up even better:
The Southern Lights or Aurora Australis as seen from the space station and space shuttle. Credit: NASA
These images were taken on Thursday during one of the “night” passes for the station/shuttle. The astronauts mentioned the aurora during media interviews on Friday. “We saw an incredible Southern Lights aurora,” said STS-135 pilot Doug Hurley. “It was the best one I’ve seen in my two spaceflights. It was just unbelievable, the view out the cupola.”
Delta IV Medium rocket thunders off of Cape Canaveral Air Force Stations Launch Complex 37B. Credit:: Alan Walters (awaltersphoto.com) for Universe Today.
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CAPE CANAVERAL, Fla. – The U.S. Air Force launched the GPS IIF-2 satellite into orbit Saturday (July 16) on a mission to enhance the country’s constellation of Global Positioning System satellites. The satellite was launched atop a Delta IV Medium 4, 2 rocket from Cape Canaveral Air Force Station’s Launch Complex 37B at 2:41 a.m. EDT. The Delta IV had been scheduled to launch two days prior but slipped one day due to a technical issue with the satellite and a second day when technicians were prevented from rolling the Mobile Service Tower or MST back because of weather.
The early-morning launch lit up the skies for miles around Florida's Space Coast and saw the second of twelve planned IIF satellites placed into orbit. Photo Credit: Jason Rhian
This morning’s launch
The rocket was provided by United Launch Alliance (ULA) and the company oversaw the liftoff. This configuration of the Delta IV Medium has two solid rocket boosters which are provided by Utah’s Alliant Techsystems (ATK). The boosters are required to provide the extra boost required to send the spacecraft into the correct orbit.
A United Launch Alliance Delta IV Medium rocket thunders off of Cape Canaveral Air Force Station's Launch Complex 37B. Photo Credit: Jason Rhian
Weather was the biggest concern for the launch, but when the clock reached zero the launch vehicle thundered off of the pad in a spectacle of sound and light. The weather turned out to be a non-issue with mostly clear moonlit skies and almost no breeze. Lightning could still be seen lighting up the Florida sky off in the distance – but the summer light show only served as a backdrop for the launch.
“This is an exciting time for ULA, we are happy to have launched our 52nd mission,” said United Launch Alliance Spokesman Chris Chavez. “We’re happy to support the U.S. Air Force along with our customer and partner Boeing – it was a great launch and a great morning.”
The pulse-line production method can be seen in this picture provided by Boeing. The satellite is moved through its various stations in a similar fashion as to how aircraft are produced. Photo Credit: Boeing
The satellite
Boeing is the prime contractor that provided the U.S. Air Force with the GPS satellite. The GPS IIF system is expected to provide next-generation performance to the GPS constellation of satellites. These abilities are considered to be vital to U.S. national security as well as maintaining the GPS constellation’s availability for civil, commercial and military requirements. The IIF is expected to provide enhanced capability and better performance.
The first GPS IIF satellite was launched in 2010. It is hoped that the pulse-line production method that is employed by Boeing will ensure that the IIF fleet is placed on orbit on schedule. This production method is very similar to how airplanes are developed. The process is named because satellites are moved from one work station to the next in a steady rhythm – similar to a pulse.
The GPS IIF-2 satellite will be utilized for both for civilian and military purposes. A new civilian L5 signal will assist with search and rescue missions, while the military will benefit from the satellite’s resistance to jamming. The satellite also has a reprogrammable processor that can receive uploads on-orbit. GPS IIF-2 has a design life of 12 years and it is hoped that it will provide long-term service will keeping operating costs low.
“The enhancements that the GPS IIF-2 satellite has should strengthen the constellation for many years to come,” said Boeing Spokesperson Angie Yoshimura.
Launch Complex 37B smolders after bearing the fury of the Delta IV Medium with its GPS payload. Photo Credit: Jason Rhian
For astronomers and physicists alike, the depths of space are a treasure trove that may provide us with the answers to some of the most profound questions of existence. Where we come from, how we came to be, how it all began, etc. However, observing deep space presents its share of challenges, not the least of which is visual accuracy.
In this case, scientists use what is known as Active Optics in order to compensate for external influences. The technique was first developed during the 1980s and relied on actively shaping a telescope’s mirrors to prevent deformation. This is necessary with telescopes that are in excess of 8 meters in diameter and have segmented mirrors.
Definition:
The name Active Optics refers to a system that keeps a mirror (usually the primary) in its optimal shape against all environmental factors. The technique corrects for distortion factors, such as gravity (at different telescope inclinations), wind, temperature changes, telescope axis deformation, and others.
The twin Keck telescopes shooting their laser guide stars into the heart of the Milky Way on a beautifully clear night on the summit on Mauna Kea. Credit: keckobservatory.org/Ethan
Adaptive Optics actively shapes a telescope’s mirrors to prevent deformation due to external influences (like wind, temperature, and mechanical stress) while keeping the telescope actively still and in its optimal shape. The technique has allowed for the construction of 8-meter telescopes and those with segmented mirrors.
Use in Astronomy:
Historically, a telescope’s mirrors have had to be very thick to hold their shape and to ensure accurate observations as they searched across the sky. However, this soon became unfeasible as the size and weight requirements became impractical. New generations of telescopes built since the 1980s have relied on very thin mirrors instead.
But since these were too thin to keep themselves in the correct shape, two methods were introduced to compensate. One was the use of actuators which would hold the mirrors rigid and in an optimal shape, the other was the use of small, segmented mirrors which would prevent most of the gravitational distortion that occur in large, thick mirrors.
The New Technology Telescope (NTT) pioneered the Active Optics. Credit: ESO/C.Madsen. Bacon
Other Applications:
In addition to astronomy, Active Optics is used for a number of other purposes as well. These include laser set-ups, where lenses and mirrors are used to steer the course of a focused beam. Interferometers, devices which are used to emit interfering electromagnetic waves, also relies on Active Optics.
These interferometers are used for the purposes of astronomy, quantum mechanics, nuclear physics, fiber optics, and other fields of scientific research. Active optics are also being investigated for use in X-ray imaging, where actively deformable grazing incidence mirrors would be employed.
Adaptive Optics:
Active Optics are not to be confused with Adaptive Optics, a technique that operates on a much shorter timescale to compensate for atmospheric effects. The influences that active optics compensate for (temperature, gravity) are intrinsically slower and have a larger amplitude in aberration.
Artist’s impression of the European Extremly Large Telescope deploying lasers for adaptive optics. Credit: ESO/L. Calçada/N. Risinger
On the other hand, Adaptive Optics corrects for atmospheric distortions that affect the image. These corrections need to be much faster, but also have smaller amplitude. Because of this, adaptive optics uses smaller corrective mirrors (often the second, third or fourth mirror in a telescope).
President Barack Obama called out for pizza today and ending up talking with the crews of STS-135 and Expedition 28 on the International Space Station. Well, that was his story anyway, but he did talk with the crews, offering a challenge for commercial space companies, as well as remembering the first flight of cooperation between the US and the Soviet Union – the Apollo-Soyuz test project which launched 36 years ago today — and reiterating the challenge of sending humans to Mars.
The STS-135 crew brought a flag that was flown on STS-1, the first shuttle mission, up to the ISS. “We’ll present the flag to the space station crew and it will hopefully maintain a position of honor until the next vehicle launched from US soil brings US astronauts up to dock with the space station,” STS-135 commander Chris Ferguson told the president.
People have walked on the Moon. A lucky few. Most have readily shared their experience; some did so with a keen eye to making a personal profit. One who did not was Al Worden lunar command module pilot for Apollo 15. As he explains in his autobiographically styled book “Falling to Earth – An Apollo 15 Astronaut’s Journey to the Moon“, postal covers were much less than a tiny footnote to his accomplishments. Thankfully, this event is an equally tiny part of his enlightening book which takes the reader from a life on a farm in Michigan through to a Mississippi river boat ride.
Al Worden was the lunar command module pilot for Apollo 15, the fourth mission to land on the Moon and the first with a lunar rover. In answer to one of my unspoken questions, he writes that he preferred to remain flying in the command module while his crew members explored the area about Hadley Rille. They travelled only a few kilometres about the lunar module, while he orbited thousands of miles, often at a very low height. His descriptions about looking up at the mountains of the Moon and down at fields of cinder cones put the reader right there beside him.
While this book has some very eloquent and moving descriptions of the lunar surface and the surrounding star field, it is much like a biography. And, as put in the book, the few weeks in space were only a small fraction of Worden’s life. Much more happened and continues to happen. In a relaxed, open way, the reader gets swept along through his early years of growing hay, buying cars, attending college, training at West Point and general life in the air force. This time, while interesting, shows Worden’s life to be almost ordinary with very little indication of what was to come. Even his time with the air force appears to demonstrate a person with a natural bent toward mechanical items and a ready desire to do well.
Apparently this was sufficient, as Worden became part of the fifth tranche of astronauts. For the space minded, this is where the book becomes much more interesting. Here, the reader gets taken into the privileged astronaut club as a visceral member. Descriptions of pranks or gotchas abound, as well as joys of racing cars, buying new homes and keeping a family together. Not all were maintained, as the overall impression one gets is of an incredibly busy time filled with assessing, training and planning. Being a backup to Apollo 12, prime on Apollo 15 and temporary backup for Apollo 17, put a huge amount on Worden’s figurative plate. This book doesn’t gloss over the difficulties with its description of the end of Worden’s marriage, the accidental deaths of other astronauts and the constant need to ensure a successful mission. Nevertheless, the reader gets carried through this and joins Worden in the capsule as it journeys to the Moon and back again.
In a bit of a different tack, the book then sets upon a new course as it presents the postal cover issue. While obviously very important for the author to set the record straight, which he admirably does, it may seem to the reader that too much is made of it. The book says mea culpa but it also provides a background detailing the similar practices of other mission crew members and the specific actions of the author and his fellow crew. Fortunately, this is a brief portion of the book, but given that this event ruined the author’s career, the reader will understand the rational for its inclusion.
The remainder of the book is a very quick summary of Worden’s life after Apollo. While he stayed within NASA for awhile, he eventually retired, tried many opportunities and rebuilt a relationship with the astronaut corp that remains to this day. The final section has a most moving personal thought on why humankind explores, our need to continually advance into space and the effect of seeing the finite Earth floating in space. While occasionally the book has passages that feel like a transcribed log book, this section must have come completely from the author’s heart.
As the miracle of the early space age wanes into history, we can benefit by reconsidering what it was all about. With a personal view as provided by Al Worden in his book “Falling to Earth – An Apollo 15 Astronaut’s Journey to the Moon“, the reader can go back to that time, relive some grand moments, and realize just how far humankind has advanced in the last few generations.
Space Shuttle Discovery moving to Vehicle Assembly Building Discovery is being processed for retirement and placed in storage on July 13 in the VAB before transport to permanent home at the Smithsonian Air & Space Museum. Credit: Ken Kremer
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Space Shuttle Discovery was briefly on public display on Wednesday July 13 as she emerged from the hanger at the Kennedy Space Center where she has been undergoing processing for retirement since her final landing on the STS-133 mission.
It was a rather stark and sad moment because Discovery looked almost naked and downtrodden – and there was no doubt that she would never again fly majestically to space because huge parts of the orbiter were totally absent.
Discovery was stripped bare of her three main engines and orbital maneuvering pods at the rear and she had a giant hole in the front, just behind the nose, that was covered in see through plastic sheeting that formerly housed her now missing forward thrusters. Without these essential components, Discovery cannot move 1 nanometer.
When the Space Shuttle is forcibly retired in about a week, America will have no capability to launch astronauts into space and to the International Space Station for many many years to come.
Discovery was pulled a quarter mile from the Orbiter Processing Facility (OPF) to the Vehicle Assembly Building (VAB) to make room for Space Shuttle Atlantis when she returns next week from the STS-135 mission, according to Stephanie Stilson, the flow manager for Discovery, in an interview with Universe Today.
Stephanie Stilson,NASA KSC flow manager for Discovery. Credit: Ken Kremer
STS-135 is the 135th and final mission of NASA’s 30 year long Space Shuttle Program.
NASA now only has control of two of the three shuttle OPF’s since one OPF has been handed over to an unnamed client, Stilson said.
Stilson is leading the NASA team responsible for safing all three Space Shuttle Orbiters. “We are removing the hypergolic fuel and other toxic residues to prepare the orbiters for display in the museums where they will be permanently housed.”
“The safing work on Discovery should be complete by February 2012,” Stilson told me. “NASA plans to transport Discovery to her permanent home at the Smithsonian Air and Space Museum on April 12, 2012, which coincides with the anniversary of the first shuttle launch on April 12, 1981.”
Discovery Photo Album by Ken Kremer
Discovery emerges from OPF 2 processing hanger. Credit: Ken Kremer
Discovery exits OPF 2 minus main engines. Credit: Ken Kremer
Discovery moves from OPF 2 to VAB. Credit: Ken Kremer
Discovery moves from OPF 2 to VAB. Credit: Ken Kremer
Discovery on public display on Wednesday July 13. Credit: Ken Kremer
Below Discovery’s wing. Credit: Ken Kremer
Gaping hole in Discovery - minus forward reaction control thruster. Credit: Ken Kremer
Rear view of Discovery beside VAB. Credit: Ken Kremer
Discovery entering the VAB. Credit: Ken Kremer
Discovery enters the VAB. Credit: Ken Kremer
Viewing Discovery from the 5th Floor of the VAB. Credit: Ken Kremer
Discovery parked on the ground floor of the VAB. Credit: Ken Kremer
Images of craters obtained by MDIS from orbit. Left: A simple, bowl-shaped crater 4.1 km in diameter crater located at 78.8ºN, 346.3ºE. Solar illumination is from the south. Right: A complex crater 51.5 km in diameter located at 2.3ºN, 121.4ºE. Illumination is from the east. Shadows cast on a crater interior can be used to estimate the depth of a crater floor below the surrounding rim.
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Getting to know a planet well is getting to know its surface features. Through measuring impact craters, planetary scientists are able to disclose information such as the origin and evolution of Mercury’s surface. We know it’s a matter of numbers, but just exactly how is it done when you can’t physically be there?
Size, shape and structure of craters is the common bond that most solar system bodies share. By understanding the physics of how they were made, researchers are able to draw conclusions through modeling. Their laboratory impact experiments and numerical simulations make judging crater qualities doable on a planetary scale. To further refine their results, it is then compared against known data for new, as well as eroded, craters. This information then gives us a clearer idea of surface properties, such as mineral deposits, soil composition, ice deposits, proportions and more. Checking out shapes and sizes on Mercury with observations obtained by the MESSENGER spacecraft are just the beginning.
Why is a Mercury crater investigation so important? Maybe because its surface gravitational acceleration (3.7 m/s2) is nearly identical to that at Mars. In this case, gravity plays an important role as the “transition diameter” is affected. According to the study, “Simple craters tend to be bowl shaped, whereas complex craters have terraced walls and can contain a central peak. If gravity were the dominant factor controlling the transition diameter, one would expect that this diameter would be similar on Mercury and Mars.” These transition diameters observed on Mercury are important because they give us clues to the Martian crust. Their differences could mean a weaker surface due to near-surface water ice.
An example complex crater on Mercury, ~ 55 km in diameter and centered near 63.5°N, -139ºE, that has been imaged by MDIS (left) and profiled by MLA (right). A slightly larger complex crater lies along the MLA profile to the south.
The Mercury Laser Altimeter (MLA) and the Mercury Dual Imaging System (MDIS) are hard at work providing the photo data needed to study cratering. We’re now able to get an inside look at central peaks, walls, floors and slopes. In addition, we’re getting a concise measurement of diameters. As with the Moon, researchers can make assessments as to depth by measuring the shadows. While MLA cannot always be used for these types of measurements, these fresh insights are furthering our understanding of crater properties – both on Mercury and across all holey bodies in our solar system.
I know I mentioned that I was on Google+ a couple of days ago, but I just wanted to give you another reminder. Since I did that post, Pamela and I did a live recording of Astronomy Cast during a Google+ Hangout. I’ve also done Hangouts with Phil Plait, Chris Pirillo, Adrian West, Jon Voisey, Jay Cross, and other Universe Today friends, writers and supporters. I’ve been trying to coordinate at least a Hangout a day right now, figuring things out; it’s been a lot of fun. If you’re looking for an invite to Google+, just send me an email at [email protected], and I’ll get you hooked up.
A pulsar located about 1,600 light years from Earth.
Originally discovered by the Fermi Gamma Ray Space Telescope in 2009, Pulsar PSR J0357 had a bit of a surprise for astronomers when NASA’s Chandra X-ray Observatory turned an eye its way. Even though it might be 1,600 light years from Earth and half a million years old, it would appear this object has a cosmic sense of humor. Stretching across 4.2 light years is an enormous tail…
Viewable only at X-ray wavelengths, this incredible cosmic contrail is the longest ever associated with a so-called “rotation- powered” pulsar. Unlike other pulsars, J0357 gets its power from energy depletion as the spin rate decreases. But where did the plumage come from? According to the Chandra data, it may be an emission from energetic particles in the pulsar wind produced while turning around magnetic field lines. While artifacts of this type have been noted before, they’re classed as bow-shocks generated by the supersonic motion of pulsars through space. From there, the wind pulls the particles along behind it as the pulsar passes through interstellar gas.
But Pulsar PSR J0357 isn’t exactly fitting into a neat a tidy category…
According to data taken from Fermi, J0357 is only losing a small amount of energy as its spin rate slows. This means it shouldn’t be producing a particle wind of such proportions. Another anachronism is the placement of the bright portions of the tail – not anywhere near where bow-shocks are associated with pulsars.
“Further observations with Chandra could help test this bow-shock interpretation.” says the Chandra team. “If the pulsar is seen moving in the opposite direction from that of the tail, this would support the bow-shock idea.”
