Thursday, 26 January 2017

Astronomy - Introducing WFIRST — NASA’s wider set of eyes on the universe

Astronomy - Introducing WFIRST — NASA’s wider set of eyes on the universe

WFIRST, the 2.4-metre aperture Wide Field Infrared Survey Telescope, is shown here in an artist's rendering. It will carry a Wide Field Instrument to provide astronomers with Hubble-quality images covering large swaths of the sky, and enabling several studies of cosmic evolution. Image credit: NASA/Goddard Space Flight Center/Conceptual Image Lab.
WFIRST, the 2.4-metre aperture Wide Field Infrared Survey Telescope, is shown here in an artist’s rendering. It will carry a Wide Field Instrument to provide astronomers with Hubble-quality images covering large swaths of the sky, and enabling several studies of cosmic evolution. Image credit: NASA/Goddard Space Flight Center/Conceptual Image Lab.
After years of preparatory studies, NASA is formally starting an astrophysics mission designed to help unlock the secrets of the universe — the Wide Field Infrared Survey Telescope (WFIRST).
With a view 100 times bigger than that of NASA’s Hubble Space Telescope, WFIRST will aid researchers in their efforts to unravel the secrets of dark energy and dark matter, and explore the evolution of the cosmos. It also will discover new worlds outside our solar system and advance the search for worlds that could be suitable for life.
NASA’s Agency Program Management Council, which evaluates the agency’s programs and projects on content, risk management and performance, made the decision to move forward with the mission on Wednesday.
The mission is led by NASA’s Goddard Space Flight Center in Greenbelt, Maryland. NASA’s Jet Propulsion Laboratory in Pasadena, California, will manage the mission’s 7.8-foot (2.4-metre) telescope and deliver the coronagraph, an instrument to help image and characterise planets around other stars. The Infrared Processing and Analysis Center (IPAC) at the California Institute of Technology in Pasadena will share science centre activities with the Space Telescope Science Institute in Baltimore, under Goddard leadership.
“WFIRST has the potential to open our eyes to the wonders of the universe, much the same way Hubble has,” said John Grunsfeld, astronaut and associate administrator of NASA’s Science Mission Directorate at Headquarters in Washington. “This mission uniquely combines the ability to discover and characterise planets beyond our own solar system with the sensitivity and optics to look wide and deep into the universe in a quest to unravel the mysteries of dark energy and dark matter.”
WFIRST is the agency’s next major astrophysics observatory, following the launch of the James Webb Space Telescope in 2018. The WFIRST observatory will survey large regions of the sky in near-infrared light to answer fundamental questions about the structure and evolution of the universe, and expand our knowledge of planets beyond our solar system — known as exoplanets.
It will carry a Wide Field Instrument for surveys, and a Coronagraph Instrument designed to block the glare of individual stars and reveal the faint light of planets orbiting around them. By blocking the light of the host star, the Coronagraph Instrument will enable detailed measurements of the chemical makeup of planetary atmospheres. Comparing these data across many worlds will allow scientists to better understand the origin and physics of these atmospheres, and search for chemical signs of environments suitable for life.
“WFIRST is designed to address science areas identified as top priorities by the astronomical community,” said Paul Hertz, director of NASA’s Astrophysics Division in Washington. “The Wide-Field Instrument will give the telescope the ability to capture a single image with the depth and quality of Hubble, but covering 100 times the area. The coronagraph will provide revolutionary science, capturing the faint, but direct images of distant gaseous worlds and super-Earths.”
The telescope’s sensitivity and wide view will enable a large-scale search for exoplanets by monitoring the brightness of millions of stars in the crowded central region of our galaxy. The survey will net thousands of new exoplanets similar in size and distance from their star as those in our own solar system, complementing the work started by NASA’s Kepler mission and the upcoming work of the Transiting Exoplanet Survey Satellite.
Employing multiple techniques, astronomers also will use WFIRST to track how dark energy and dark matter have affected the evolution of our universe. Dark energy is a mysterious, negative pressure that has been speeding up the expansion of the universe. Dark matter is invisible material that makes up most of the matter in our universe.
By measuring the distances of thousands of supernovae, astronomers can map in detail how cosmic expansion has increased with time. WFIRST also can precisely measure the shapes, positions and distances of millions of galaxies to track the distribution and growth of cosmic structures, including galaxy clusters and the dark matter accompanying them.
“In addition to its exciting capabilities for dark energy and exoplanets, WFIRST will provide a treasure trove of exquisite data for all astronomers,” said Neil Gehrels, WFIRST project scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This mission will survey the universe to find the most interesting objects out there.”
Twelve science investigation teams were recently selected by NASA to help optimise science returns for the mission. Olivier Doré of JPL leads one of the teams. His group will focus on cosmology and the best methods for WFIRST to measure and test the nature of dark energy.
WFIRST is slated to launch in the mid-2020s. The observatory will begin operations after travelling to a gravitational balance point known as Earth-Sun L2, which is located about one million miles from Earth in a direction directly opposite the Sun.

Astronomy - NASA resumes JWST vibration testing

Astronomy - NASA resumes JWST vibration testing

A clean tent is lowered over the James Webb Space Telescope, with its wings folded back in launch configuration, before the start of vibration testing in November. Credit: NASA/Chris Gunn
Vibration testing on the James Webb Space Telescope, the multibillion-dollar successor to Hubble, has resumed after engineers traced a problem that cropped up last month to a restraint holding part of the observatory’s giant segmented mirror in place for launch.
The quick diagnosis keeps JWST on track for launch in October 2018, and engineers still have several months of time reserved in the schedule leading up to launch late next year to handle any more unexpected problems.
In a status report posted to the JWST web site this week, NASA said numerous tests and analysis of data and modeling led engineers to attribute an anomaly during vibration testing Dec. 3 to “gapping,” or extremely small motions, in a launch restraint mechanism holding back the wings of the telescope’s primary mirror, which are folded and stowed to fit inside the rocket for liftoff, then unfurl once the observatory is in space.
Eric Smith, JWST’s program director at NASA Headquarters, said in an interview last month that accelerometers near the launch restraint mechanisms detected unexpected readings during vibration testing intended to ensure the telescope and its instruments can survive the shaking of launch.
“During what’s called proto-flight level testing — this is where you test it to a little bit more than you expect from the launch vehicle just to make sure you have safety margin — we noticed that two of the accelerometers were giving us readings of much higher acceleration than were predicted,” Smith told Spaceflight Now last month. “When the software that runs the shaker tables detected this, they properly shut everything down safely so the team would have the time to look at these data and try to figure out why we’re getting these readings.”
The James Webb Space Telescope’s primary mirrors and science instruments are seen inside a clean tent being mounted on a vibration table at Goddard. Credit: NASA/Chris Gunn
The vibration testing, which has now resumed, is being done on a special shaker table inside a clean room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. The testing includes the telescope’s primary mirror, made of 18 gold-coated beryllium segments, the optical support structure, and JWST’s science instrument bay.
“There was an accelerometer on each side near these wings — near the bottom, actually, of the wings — that picked this up,” Smith said last month. “That’s where the team is looking. What phenomena, or what physical devices or characteristics are the same on both sides of the telescope there? That helps you narrow down where you’re looking.”
NASA officials are working with Arianespace, which will launch JWST toward the L2 Lagrange point a million miles (1.5 kilometers) from Earth on a European Ariane 5 rocket, to “ensure that the vibration testing program will adequately test the Webb payload with the expected launch vibration environment,” the agency said in an update posted on the mission’s website.
The launcher is a major contribution to the JWST program by the European Space Agency, which also led the build of two of the observatory’s four main science instruments.
JWST is an infrared successor to NASA’s famed Hubble Space Telescope, promising previously unseen views of the proto-universe, the earliest galaxies and stars after the Big Bang, and data about the conditions on potentially habitable worlds orbiting other stars.
“Everybody realizes this is very valuable space hardware, and you test like this because you don’t want to find this problem later,” Smith said.
Ground teams at Goddard visually and ultrasonically inspected the telescope after the vibration test anomaly, finding no damage.
According to Smith, actuators and restraints currently mounted on the telescope are ground test units, and were slated for replacement with flight-worthy versions before launch.
“What we’re learning now on this integration and test device … the lesson would be applied to the flight one that we put on later,” Smith said last month. “It could be just the strength with which these latching points hold, or how they’re precisely aligned when you put them together.”
Vibration testing recently resumed, NASA said, and shake checks on the telescope were completed in one of three axes over the weekend. The vibration test for the second axis was due to begin this week, officials said.
Engineers are verifying the telescope and instrument structures can withstand the shaking of launch in all three axes of motion. The vibration test in each axis takes about a week or 10 days, Smith said, and will be followed by testing to subject the telescope to the acoustic environment of launch, which will take less than a week.
Teams planned to run deployment tests on the telescope’s foldable wings before and after the vibration and acoustic tests at Goddard to make sure the critical deployment mechanisms are undamaged.
Precision checks of the curvature of the mirror segments, each about the size of a coffee table, after the shake and sound tests will verify the telescope’s optics are still up to the job. Alignment checks are also planned.
The telescope is buttoned up in launch configuration for the testing at Goddard. Its next stop will be NASA’s Johnson Space Center in Houston for a thermal vacuum test, which will expose the core of JWST to the extreme temperature it will encounter in space.
“Once we finish the vibration and acoustic testing, there’s about a month or so of data analysis to make sure that everything tested out properly, and then it would ship down to JSC,” Smith said.
The shipment to Houston could occur as soon as April.
From there, the observatory’s science section will travel to a Northrop Grumman facility in Redondo Beach, California, for attachment to the spacecraft bus and sunshield, which will supply power, communications, pointing and thermal control to the telescope.
The spacecraft will travel from Southern California through the Panama Canal to the Ariane 5 launch base in Kourou, French Guiana, in mid-2018 for fueling and final launch preparations.
Smith said the latest testing hiccup should have no impact on the October 2018 launch date.
Managers had about six months of slack in the schedule leading up to October 2018 before the vibration test anomaly halted activities more than a month. The vibration testing is in JWST’s “critical path,” meaning any delays eat into the program’s schedule reserve.
“While we will use some of the funded schedule reserve, this is not going to have any sort of budget impact for us,” Smith said. “We have sufficient reserves to handle this, and we still have the October 2018 launch date in our sights.”
“The project has been very good about managing their reserve, so we’ll begin to look at other places later on where we can get back some of that schedule reserve,” he said. “We will not skimp on the testing through because you don’t want to do something rash with your hardware. It has to compete testing, so we’ll do that, and then we’ll begin to look for savings further down the road.”

Astronomy - China sets November launch for lunar sample return mission

Astronomy - China sets November launch for lunar sample return mission

File photo of the moon seen from the International Space Station. Credit: NASA
China plans to launch a robotic mission to return samples from the lunar surface, the first such mission in four decades, in November on top of the country’s new heavy-lift Long March 5 rocket, according to state media reports.
The government-run Xinhua news agency said the mission, which has been scheduled for launch in 2017 for some time, is on track for liftoff from the Wenchang space center on Hainan Island in November, citing sources at the China Aerospace Science and Technology Corp.
The Chang’e 5 mission will attempt to retrieve the first lunar surface samples for return to Earth since the Soviet Union’s robotic Luna 24 mission in August 1976.
The eight-ton (8.2-metric-ton) spacecraft will launch on a Long March 5 rocket, one of the most powerful boosters currently in service. The Long March 5 made a successful maiden flight last November.
Chang’e 5 will touch down on the moon, gather samples for delivery into a capsule on top of a small rocket, and the ascent vehicle will blast off to dock with a return module loitering in lunar orbit.
The return capsule, protected by a heat shield, will separate from the Chang’e 5 carrier craft on the trip back to Earth for a high-speed atmospheric re-entry and parachute-assisted landing. Scientists and recovery teams will be on standby to pick up the samples after the mission, which is expected to last several weeks.
A demonstrator probe launched by China in 2014 validated the technologies needed for a re-entry at interplanetary speeds. China’s crew-carrying Shenzhou capsules come down at slower speeds and encounter less extreme heating when returning to Earth from orbit several hundred miles up.
“The development of Chang’e-5 has entered the end of its flight model phase, and relevant work is proceeding smoothly, according to CASC,” Xinhua reported.
The November test launch of China’s heavy-lift Long March 5 rocket was successful. Credit: Xinhua
China’s unpiloted moon missions began in 2007 with the launch of Chang’e 1, the country’s first lunar orbiter. The Chang’e 2 orbiter followed with a launch in 2010, and that spacecraft departed the moon’s vicinity after completing its primary mapping mission, conducting China’s first flyby of an asteroid in December 2012.
The Chang’e 3 lander took off in December 2013 and made a soft touchdown in the moon’s Mare Imbrium region, deploying a mobile rover that spent several weeks driving across the surface.
The Chang’e missions are named for a moon goddess in Chinese mythology.
Future Chinese lunar projects include Chang’e 4, a copy of the Chang’e 3 lander and rover, which will attempt the first-ever landing on the far side of the moon in 2018. China is developing a deep space communications satellite to relay commands and science data data between ground controllers and Chang’e 4, which will be out of reach of ground-based antennas after landing.
A duplicate of the Chang’e 5 sample return craft, tentatively dubbed Chang’e 6, could try for a rock retrieval mission on the far side of the moon in the early 2020s, assuming the near-side sample return goes well, Chinese officials said last year.
Chinese officials are discussing the possibility of sending astronauts to the moon, but the country’s near-term human spaceflight program has emphasized the construction of a permanently-occupied space station in Earth orbit, with completion of the outpost expected by 2022.
China is also developing a Mars rover to launch in 2020 on the nation’s first robotic expedition to another planet.

Wednesday, 25 January 2017

Horoscope for Thursday, the 26th January 2017

26th January 2017 Daily Horoscope

Meditation - Super-Charge Me: Going Deeper with Yogananda's Energization Exercises

Super-Charge Me: Going Deeper with Yogananda's Energization Exercises

Congratulations! You've made it through the first half of the 30-day challenge.

The next two challenges relate to outward practices that help us go deeper in meditation.

Group practice of the Energization Exercises during a pilgrimage to India in 2012.

Challenge #6

In 1920, Paramhansa Yogananda created the Energization Exercises, a series of 39 exercises that help us to be more aware of and learn to control the energy in our bodies.

If you already know these exercises, today's challenge is toread this article, A Dance of Devotion, and choose at least one of its suggestions to bring into your practice.

If the energization exercises are new to you, today's challenge is to learn the sample practices in this article and do them before each meditation.

Don't Know the Exercises, but Want to Learn Them?

The Energization Exercises are Yogananda's unique contribution to yoga, a cornerstone of the path of Kriya Yoga that he presented, and improve the effectiveness of other meditation techniques.

The best way to learn them is in person, but the Lessons in Meditation online course and the iPhone and iPad app are excellent substitutes when learning them in person is not an option.

Going Deeper with Energization

Some Helpful Tips for Energization
by Kalidas Hansen

Here are a few points that help to keep me practicing the exercises and having fun in the process.

30-Day Energization Challenge
by Nayaswami Gyandev

If you already know the Energization Exercises, this is your ticket to greater results. And if you’re new to them, you’ll get all the instruction you need to make this powerful practice a part of your daily life.