Nancy Atkinson, Author at Universe Today

February 7, 2008December 26, 2015 by Nancy Atkinson

STS-122 Space Shuttle Mission Rockets to Space

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Defying a bleak weather forecast, space shuttle Atlantis rocketed into space on Thursday, February 7, on its way to the International Space Station with a new science laboratory. The STS-122 mission had been delayed by a faulty fuel sensor, and was originally scheduled to launch last December. But today there were no problems with the sensor during fueling and the shuttle lifted off flawlessly at 2:45 p.m. EST. On board is a seven member crew and the European Space Agency’s $1.9 billion Columbus science module, Europe’s main contribution to the ISS. Atlantis will rendezvous with the station on Saturday, Feb. 9. The launch came seven years to the day after Atlantis carried NASA’ science laboratory named Destiny to the space station.

“It was a pretty clean launch,” astronaut Jim Dutton radioed the shuttle crew from mission control following the launch. “We did see, at about MET 2:13 (two minutes and 13 seconds after launch) a few piece of debris, they think at least three, that came off inboard of the LO2 (liquid oxygen) feedline just aft of the starboard bipod leg. The debris assessment team indicated they didn’t identify an impact at the time and it’s obviously under evaluation.”

The crew of Atlantis will now check out its systems and inspect the heat shield while chasing down the space station. There will be three spacewalks during the flight so astronauts can attach the Columbus lab and connect its power and fluid lines.

Atlantis’ liftoff came despite concerns that a weather front would interfere with the launch. But the weather cooperated for an on-time launch.

Installing Columbus, named after the 15th-century Italian explorer, is the main task for the 121st space shuttle mission.

“Columbus has discovered a new world, and I think that with Columbus we are discovering a totally new world,” Jean Jacques Dordain, ESA’s director general, said after the launch.

Atlantis’ seven-member crew includes two Europeans, Germany’s Hans Schlegel and France’s Leopold Eyharts. US astronauts are Commander Steven Frick, pilot Alan Poindexter, and mission specialists Leland Melvin, Rex Walheim, and Stanley Love.

“It’s great to have two laboratories in space,” said Bill Gerstenmaier, NASAâ€™s associate administrator for space operations.

The mission is scheduled to last 11 days.

Original News Source: NASA Press Release

February 7, 2008December 26, 2015 by Nancy Atkinson

Another Asteroid Passes Close to Earth

On Tuesday, February 5, 2008 an SUV sized asteroid passed between the Earth and the moon. Asteroid 2008 CT1 came within 135,000 kilometers ( 84,000 miles) of Earth, only a third of the distance to the moon. The asteroid was discovered only two days before its close approach to Earth, spotted by the Lincoln Near Earth Asteroid Research (LINEAR) project, using robotic telescopes located at New Mexico’s White Sands Missile Range. The asteroid’s size is estimated between 8 – 15 meters.

While this asteroid seems small, we know that even small rocks can be devastating. Last September, a meteorite estimated at .2 – 2 meters wide created a crater 13 meters wide in Peru. The cause of the Tunguska Event of the early 20th Century is now believed to be a 35m rock that never even touched the ground. It’s believed that it exploded a few miles above the ground, creating a shockwave that devastated the landscape below.

2008 CT1 could possibly return to Earthâ€™s vicinity in 2041, although its orbit has not yet been well defined, so that prediction could change. It is also a possible Mercury impactor, since that that planet is very near the asteroidâ€™s currently calculated perihelion.

LINEAR uses a Ground-based Electro-Optical Deep Space Surveillance (GEODSS) telescope, and has detected over 3,000,000 asteroids since 1998, which is about 70% of the known near-Earth asteroids.

Original News Source: SLOOH Skylog

February 1, 2008December 26, 2015 by Nancy Atkinson

Memorial Service Honors Columbia Astronauts

Five years ago, family members of the STS-107 space shuttle crew were waiting at the Kennedy Space Center to hear the double sonic boom that would announce the arrival of the Columbia shuttle returning home from its mission to space. But the sonic booms never came; there was only silence. Today, at the Space Mirror Memorial at the NASA Kennedy Space Center, NASA officials, astronauts and families of the Columbia crew paid tribute to all astronauts who have lost their lives, and called for NASA to continue to learn from the tragedies.

Evelyn Husband Thompson, wife of STS-107 commander Rick Husband said that each of the families are recalling what they went through five years ago in public or private ways. Families of Ilan Ramon and Willie McCool are in Israel for a memorial service there, while the families of Dave Brown, Laurel Clark, Mike Anderson and Kalpana Chawla are privately remembering the accident.

The astronauts were returning home from a successful flight when the shuttle broke up on re-entry.

Husband-Thompson, who remarried just three weeks ago said, “Life does go on, and even though we never know what life is going to bring us, there is hope for tomorrow.”

Eileen Collins, who commanded the STS-114 return to flight mission two years after the Columbia accident said that, personally, this was a difficult day for her, and that it was hard to describe the experiences of the past five years.

“I can’t properly put it into words, but our purpose here today is to honor and respect, remember and learn,” she said. Collins said that she has changed because of the accident, and now realizes that spaceflight is even more difficult and hazardous than she originally believed.

“Everyday requires constant attention to detail,” she said.

Remembering the crews of Columbia, Challenger, and Apollo 1, NASA Associate Administrator for Space Operations Bill Gerstenmaier said, “All astronauts who have sacrificed their lives are pioneers and role models who refused to shy away from seemingly impossible challenges.”

Gerstenmaier spoke frankly about loss and NASA’s mistakes.

“This is a tough time of year for our agency as we pause and remember the loss of our co-workers and friends, and the failure of our engineering design. We feel the deep ache of regret,” he said. “Our memories serve to dedicate ourselves to reducing the risks associated with the hostile environment in which we fly. We must continually challenge our assumptions and test our designs. Only with this attitude can we hope to not be surprised by another tragedy.”

NASA Adminstrator Mike Griffin said, “American’s don’t quit. We’ll never quit. But today we remind ourselves that not quiting can have high costs. Today, we celebrate the people who bore those costs and the people who remain behind them. We don’t forget, we never forget, we can’t forget, we won’t forget.”

Original News Source: NASA TV

February 1, 2008December 26, 2015 by Nancy Atkinson

Cassini Finds Patterns and Rhythm in Saturn’s Rings

Cassini has been orbiting around Saturn for almost four years, and amazingly, the spacecraft keeps discovering new and unexpected features about this world and its system of rings and moons. Recently, in two of Saturn’s rings, Cassini found orderly lines of densely grouped, boulder-size icy particles that extend outward across the rings like ripples from a rock dropped in a calm pond. Surprisingly, the distances between these ring particles stay relatively equal even though their velocities may change. This type of pattern is completely new, as normally, the distances between particles change with their velocity.

The pattern was detected when Cassini sent out three signals toward Earth. The signals crossed Saturn’s rings, and the frequencies were scattered from the passing ring particles. Once the signals were captured by Earth-based antennas of NASA’s Deep Space Network, Cassini scientists saw a regular pattern in the received signal frequencies.

“This particular feature is the smallest and most detailed of anything seen in Saturn’s rings so far,” said Cassini radio science team member Essam Marouf. “In the chaotic environment of the rings, to find such regularity in the most cramped areas is nothing short of amazing.” The regular structure can only be found in locations where particles are densely packed together, such as the B ring and the innermost part of the A ring. The signals were sent to capture a complete view of the rings.

The unexpected pattern within Saturn’s rings may give scientists some new ideas of what to expect from other similar planets and solar systems.

Scientists call this pattern of particles “enormously extended natural diffraction grating.” A diffraction grating has parallel lines like a picket fence; when light hits this fence, it separates according to wavelength, from ultraviolet to infrared light.

“The signals showed that the particle groups were arranged in an unexpectedly regular formation that had rhythm within the rings of Saturn,'” said Marouf. “Each particle is in its own orbit, and sometimes they collide and move apart as their velocities change. As a result, you have particles bunched together into dense groups that extend across the ring in harmony with each other.”

Original News Source: Cassini Press Release

February 1, 2008December 26, 2015 by Nancy Atkinson

“Across the Universe” Day for NASA and Beatles Fans

NASA will use its Deep Space Network to transmit a song across the universe. And fittingly, the song is “Across the Universe” by the Beatles. On Feb. 4 at 7 pm EST, the song will be beamed towards the North Star, Polaris, located 431 light years away from Earth, and will travel across the universe at 186,000 miles per second.

Former Beatle Paul McCartney thinks this is a great idea. “Send my love to the aliens,” he said in a message to NASA.

If there are any beings near Polaris, they’ll hear the song in about 431 years.

The song’s transmission will commemorate the 40th anniversary of the day The Beatles recorded the song, as well as the 50th anniversary of both NASA’s founding and the beginning days of the Beatles. Two other anniversaries also are being honored: The launch 50 years ago this week of Explorer 1, the first U.S. satellite, and the founding 45 years ago of the Deep Space Network, an international network of antennas that supports missions to explore the universe.

Feb. 4 has been declared “Across The Universe Day” by Beatles fans to commemorate the anniversaries. As part of the celebration, the public around the world has been invited to participate in the event by simultaneously playing the song at the same time as the transmission by NASA.

John Lennon’s widow, Yoko Ono, characterized the song’s transmission as a significant event. “I see that this is the beginning of the new age in which we will communicate with billions of planets across the universe,” she said.

Even though radio and television signals on Earth ‘leak’ out into space all the time, hopefully NASA can use this event to generate enthusiasm and promote awareness of its history, as well as its plans for future missions.

Additionally, this is a chance for the public to learn more about the Deep Space Network, NASA’s incredibly reliable system of radio antennas that is critical in supporting lunar and planetary exploration. The DSN is used for tracking of spacecraft, sending telemetry and commands, and for deep space navigation. Learn more about the DSN here.

Original News Source: NASA Press Release

January 31, 2008December 26, 2015 by Nancy Atkinson

50 Years Ago: Explorer 1

The launch of Sputnik in October 1957 changed the world overnight. And with the Soviet Union’s second successful launch of Sputnik 2 the following month, Americans were feeling a little left behind in the dust, especially after the US’s first satellite launch attempt with the Vanguard rocket exploded on the launchpad. But space pioneer Werner Von Braun, shown in this picture with JPL Director William Pickering and scientist James Van Allen, came through with his Jupiter C rocket that launched the US’s first satellite, Explorer 1, into space on January 31, 1958.

Explorer 1 was not all that big, with a length of 203 centimeters (80 inches), a diameter of 15.9 centimeters (6.25 inches), and a weight of 14 kilograms (30.8 pounds). But it did its job, which was, first and foremost, to reach orbit, and then return scientific information.

The Jet Propulsion Laboratory got the assignment of designing and building a scientific payload for the launch, which they accomplished in three months.

The primary science instrument on Explorer 1 was a cosmic ray detector designed to measure the radiation above the atmosphere. Dr. James Van Allen designed the experiment, which revealed a much lower cosmic ray count than expected. Van Allen theorized that the instrument may have been saturated by very strong radiation from a belt of charged particles trapped in space by Earth’s magnetic field. A subsequent launch by Explorer 3 two months later confirmed the existence of these radiation belts, which became known as the Van Allen Belts, in honor of their discoverer.

There were other scientific findings from Explorer 1 as well. Because of its symmetrical shape, Explorer 1 was used to help determine the upper atmospheric densities.

Two other instruments on board looked for micrometeorites in orbit: a micrometeorite detector and an acoustic microphone to detect the sound of an micrometeorite impact. The micrometeorite detector was made of a grid of electrical wires. A micrometeorite of about 10 microns would fracture a wire upon impact, destroy the electrical connection, and record the event. One or two of the wires were destroyed during launch. The equipment worked for about 60 days, but showed only one possible meteorite impact. Data from the acoustical sensor microphone were obtained only when an impact occurred while the satellite was over a ground recording station. However, over an 11-day period (February 1, 1958, to February 12, 1958), 145 impacts were recorded. The high impact rates on one portion of the orbit and the subsequent failures in the satellite’s electronic system were attributed to a meteor shower.

The batteries ran out on Explorer 1 on May 23, 1958 when the last signal was recorded. The US’s first satellite burned up in re-entry of the atmosphere in March of 1970.

Original News Source: Explorer 1

January 30, 2008December 26, 2015 by Nancy Atkinson

“Suits and Ties” Collaborate on Successful Space Station Repair

At the end of Wednesday’s successful spacewalk to change out a faulty motor on one of the International Space Station’s solar array positioning devices, the astronauts outside the ISS and flight controllers in Houston were congratulating each other on the group effort it took to pull off this particularly tricky and potentially dangerous repair job.

“You guys looked really good to us. Thanks for making it look so easy,” Mission Control in Houston radioed up to the spacewalkers after their seven-hour and 10 minutes EVA.

“Yeah,” said ISS astronaut Dan Tani. “And we did’t even have to put on a tie.”

This spacewalk really was a collaboration between the “suits and ties” at NASA. The suits — spacesuits, that is — were worn by astronauts Tani and Peggy Whitson. The ties were sported by the engineers and astronauts in Mission Control who planned the repair and guided the spacewalkers during the entire EVA.

Tani and Whitson were thanking one tie-wearing astronaut in particular. Tom Marshburn had practiced the choreography of the spacewalk in the Neutral Buoyancy Lab in Houston, and shared his insights with the spacewalkers. Usually astronauts get to practice their own EVA’s in the enormous pool that contains a mock-up of the ISS. But the Bearing Motor Roll Ring Module on the starboard solar array quit working in December when Whitson and Tani were already on board the station. So the plan and nuances of the EVA were tested in the pool by Marshburn and former ISS resident Suni Williams and relayed up to Tani and Whitson.

The spacewalk was especially hazardous because of the risk of electrical shock from 160 volts of electricity that flows through the arrays. For safety, Whitson and Tani waited until the International Space Station was on the dark side of Earth, giving them only 33 minute increments to complete their tasks. Whitson had to squeeze inside the station’s truss girder to swap out the 250 pound (113 kilograms) garbage can-sized motor.

The new motor successfully performed a 360-degree test spin during the spacewalk. It’s power-generating capabilities were tested successfully as well.

“Yay, it works!” exclaimed Whitson as she and Tani watched the solar wing turn. “Excellent, outstanding…isn’t that cool?”

The successful repair means the station should be able to generate enough power to support the new modules that will be brought on the next shuttle missions, the European Columbus science lab, and the Japanese Kibo labratory.

“Given the complexity of this spacewalk and the risks that we had to manage … we are exceptionally pleased with how things went,” flight director Kwatsi Alibaruho said after the EVA.

In addition to the motor repair, Whitson and Tani also performed another inspection of the station’s starboard Solar Alpha Rotary Joint, a 10-ft wide gear that keeps the solar wings pointing toward the sun The SARJ is not working and is contaminated with metal shavings. The spacewalkers evaluated damage from the debris and collected samples from areas previously unseen.

Alibaruho said the new debris samples will help determine what repairs will be done, perhaps later this year. NASA hopes to launch up to five shuttle flights to the ISS this year.

Wednesday’s EVA was the final planned spacewalk of the Expedition 16 mission and the 101st dedicated to space station assembly and maintenance. The spacewalk also marked the sixth career EVA’s for both Whitson and Tani.

So, there’s just one question for Dan Tani: Which is harder — donning a 280 lb spacesuit or tying a Windsor Knot?

Original News Source: NASA TV

January 30, 2008December 26, 2015 by Nancy Atkinson

A Young Star Grows Up

Remember when you were young and how Mom always told you to eat everything on your plate so you would get big? Well, there’s a young star heeding that advice about 2,600 light years from Earth in the constellation Monoceros. Known as MWC 147, this young stellar object is devouring everything on its “plate,” the disk of gas and dust that surrounds it. Astronomers are witnessing how this star is gaining mass, and is on its way to becoming an adult.

Using the Very Large Telescope Interferometer, ESO (European Organization for Astronomical Research in the Southern Hemisphere) astronomers have peered into the disc of material surrounding MWC 147, witnessing how the star gains its mass as it matures. This star is increasing in mass at a rate of seven millionths of a solar mass per year. Ah, these young stars. It seems like they grow up so fast these days.

MWC 147 is less than half a million years old. If our 4.6 billion year old Sun is considered to be middle-aged, MWC 147 would be a 1-day-old baby. This star is in the family of Herbig Ae/Be objects. These are stars that have a few times the mass of our Sun and are still forming, increasing in mass by swallowing material present in a surrounding disc.

Being 6.6 times more massive than the Sun, however, MWC 147 will only live for about 35 million years, or to draw again the comparison with a person, about 100 days, instead of the 80 year equivalent of our Sun.

We’re still learning about the morphology of the inner environment of these young stars, and everything we can discover helps us to better understand how stars and their surrounding planets form.

The observations by the ESO astronomers show that the temperature changes in this area are much steeper than predicted by current models, indicating that most of the near-infrared emission emerges from hot material located very close to the star, within one or two times the Earth-Sun distance (1-2 AU). This also implies that dust cannot exist so close to the star, since the strong energy radiated by the star heats up and ultimately destroys the dust grains.

“We have performed detailed numerical simulations to understand these observations and reached the conclusion that we observe not only the outer dust disc, but also measure strong emission from a hot inner gaseous disc. This suggests that the disc is not a passive one, simply reprocessing the light from the star,” explained astronomer Stefan Kraus. “Instead, the disc is active, and we see the material, which is just transported from the outer disc parts towards the forming star.”

Also of note is the beautiful image of the region surrounding MWC 147, which I’ll post below. The number of stars in this image is incredible, and is reminiscent of the â€œgrains of sandâ€? comment by Carl Sagan. This is a wide field image taken by Stephane Guisard of ESO with a 200 mm lens.

Original News Source: ESO Press Release

January 29, 2008December 26, 2015 by Nancy Atkinson

Method to Test String Theory Proposed

Image of 10 dimensional super strings. Credit: PBS.

What is the universe made of? While general relativity does a good job providing insights into the Big Bang and the evolution of stars, galaxies and black holes, the theory doesn’t help much when it gets down to the small stuff. There are several theories about the basic, fundamental building blocks of all that exists. Some quantum physicists propose string theory as a theory of “everything,” that at the elemental heart of all matter lie tiny one-dimensional filaments called strings. Unfortunately, however, according to the theory, strings should be about a millionth of a billionth of a billionth of a billionth of a centimeter in length. Strings are way too small to see with current particle physics technology, so string theorists will have to come up with more clever methods to test the theory than just looking for the strings.

Well, one cosmologist has an idea. And it’s a really big idea.

Benjamin Wandelt, a professor of physics and astronomy at the University of Illinois says that ancient light from the beginnings of our universe was absorbed by neutral hydrogen atoms. By studying these atoms, certain predictions of string theory could be tested. Making the measurements, however, would require a gigantic array of radio telescopes to be built on Earth, in space or on the moon. And it would be really gigantic: Wandelt proposes an array of radio telescopes with a collective area of more than 1,000 square kilometers. Such an array could be built using current technology, Wandelt said, but would be prohibitively expensive.

So for now, both string theory and this method of testing are purely hypothetical.

According to Wandelt, what this huge array would be looking for are absorption features in the 21-centimeter spectrum of neutral hydrogen atoms.

“High-redshift, 21-centimeter observations provide a rare observational window in which to test string theory, constrain its parameters and show whether or not it makes sense to embed a type of inflation — called brane inflation– into string theory,” said Wandelt. “If we embed brane inflation into string theory, a network of cosmic strings is predicted to form. We can test this prediction by looking for the impact this cosmic string network would have on the density of neutral hydrogen in the universe.”

About 400,000 years after the Big Bang, the universe consisted of a thick shell of neutral hydrogen atoms (each composed of a single proton orbited by a single electron) illuminated by what became known as the cosmic microwave background.

Because neutral hydrogen atoms readily absorb electromagnetic radiation with a wavelength of 21 centimeters, the cosmic microwave background carries a signature of density perturbations in the hydrogen shell, which should be observable today, Wandelt said.

Cosmic strings are filaments of infinite length. Wandelt compared their composition to the boundaries of ice crystals in frozen water.

When water in a bowl begins to freeze, ice crystals will grow at different points in the bowl, with random orientations. When the ice crystals meet, they usually will not be aligned to one another. The boundary between two such misaligned crystals is called a discontinuity or a defect.

Cosmic strings are defects in space. String theory predicts that a network of strings were produced in the early universe, but this has not been detected so far. Cosmic strings produce fluctuations in the gas density through which they move, a signature of which Wandelt says will be imprinted on the 21-centimeter radiation.

Like the cosmic microwave background, the cosmological 21-centimeter radiation has been stretched as the universe has expanded. Today, this relic radiation has a wavelength closer to 21 meters, putting it in the long-wavelength radio portion of the electromagnetic spectrum.

If such an enormous array were eventually constructed, measurements of perturbations in the density of neutral hydrogen atoms could also reveal the value of string tension, a fundamental parameter in string theory, Wandelt said. “And that would tell us about the energy scale at which quantum gravity begins to become important.”

But questions remain about the validity of this experiment. Also, could the array somehow be “shrunk” to search only a small area of the 21-centimeter radiation? Or possibily, could an instrument similar to WMAP (Wilkinson Microwave Anisotropy Probe) be constructed to look at the entire sky for this radiation?

Wandelt and graduate student Rishi Khatri describe their proposed test in a paper accepted for publication in the journal Physical Review Letters, and the paper is not yet available for public review.

Original News Source: University of Illinois Press Release

January 29, 2008December 26, 2015 by Nancy Atkinson

Tricky January 30 Spacewalk to Repair ISS Solar Array

Space station astronauts will conduct a spacewalk on January 30 to replace a faulty positioning motor at base of the station’s two starboard solar arrays. ISS Expedition 16 commander Peggy Whitson and flight engineer Dan Tani will change out the motor in hopes of regaining more power-generating ability of the orbiting laboratory’s expansive solar wings. But the astronauts will have to work fast, since they can only work on the electricity-producing arrays when the sun isn’t shining on them. That only allows 33 minute increments of time to conduct the repairs.

Because of the faulty motor, the solar arrays have been unable to track the sun continuously since early December, when the joint motor suffered a series of electrical shorts. In an earlier spacewalk, Tani and Whitson surveyed the damage and ruled out meteorite damage to the motor. Without the repair, the space station would have enough power to make it through at least the next shuttle mission, currently scheduled for a Feb. 7 launch, but not much further said Kirk Shireman, NASA’s ISS deputy program manager.

If the Wednesday spacewalk is successful, the ISS will have power to last through the planned arrival of a massive Japanese laboratory in April and into the summer, Shireman added.

The broken motor controls a beta gimbal joint that pivots one of the station’s two starboard solar wings to face the sun. NASA hopes replacing the whole motor, a garbage-can sized device that weighs about 250 pounds (113 kilograms), with a backup will fix the problem. The replacement motor was already on board the station, brought up on an earlier flight.

For safety reasons, the astronauts can only work while orbiting on the night side of Earth. If the sun was shining on the solar panels while Whitson and Tani were working on the joint, they would be at risk of shocks due to the high power levels surging through the arrays. They will only have about 33 minutes of total â€œshadeâ€? at a time to conduct their work. If they can’t replace the motor during one night side pass, they’ll have to wait and finish their task on the next pass. The station continuously orbits the Earth every 90 minutes.

NASA officials said the repair is possible to do in one 33 minute segment, but only if everything goes as planned. Since the damage only occurred recently, Whitson and Tani have not rehearsed the spacewalk in the Neutral Buoyancy Lab in Houston, a giant swimming pool where astronauts train for spacewalks. However, other astronauts on the ground have rehearsed the repair and shared their insights with the astronauts on board the ISS.

Wednesday’s EVA will be the sixth career spacewalk for both Whitson and Tani, and the fifth for the station’s Expedition 16 crew.

This spacewalk is unrelated to on-going analysis of problems with a massive Solar Alpha Rotary joint on the right side of the station’s main power truss that is needed to turn outboard arrays to track the sun. Astronauts discovered metal shavings in the gear’s attached metal ring during past spacewalks, and engineers do not yet understand the cause of the unusual erosion. Whitson and Tani will take another look at the 10-foot (3-meter) wide gear if they have extra time during Wednesday’s excursion, mission managers said.

NASA will broadcast the Expedition 16 crew’s fifth spacewalk live on NASA TV beginning at 4:00 a.m. EST (0900 GMT) on Jan. 30.

Original News Source: NASA TV, Space.com