Posted on by Anne Minard

Discovery Launch: Sixth Attempt a Charm?

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With just over four hours to go before launch, NASA is 80 percent optimistic that tonight’s Discovery launch will be a go — with the weather holding the only foreseeable wild card. Launch time is 7:43 p.m. local time (EDT) from the Cape Canaveral Air Force Station. 

Unfortunately for east coast skywatchers, a storm system that’s been dumping rain all weekend will obstruct a view of the launch that would otherwise be a beauty, as the shuttle will cruise northeast over the ocean nearly parallel to the shore. Without the clouds, the launch would have been visible as far west as the Appalachian Mountains, and as far north as the southern tip of Nova Scotia. 

But Florida’s weather is looking promising, partly cloudy (and 80 degrees at the time of this post) with an 80 percent chance of cooperating with the launch.

7:20 p.m. (EDT) update: With less than a half hour to go, daylight is fading under clear skies in Florida. Earlier, the weather forecast improved from 80 percent to 100 percent favorable for launch. NASA is reporting no problems.

The Discovery crew members are set to fly a new truss segment to the International Space Station and install the final set of power-generating solar arrays, boosting the station’s power capacity and paving the way for doubling the size of the ISS crew from three to six.

The Discovery crew has been bouncing between NASA’s Kennedy Space Center, in Florida, and the Johnson Space Center in Houston since late January; the first launch attempt was scheduled for early February. But four times, managers rescheduled the launch based on their concern following a hydrogen control valve malfunction on the shuttle Endeavour last fall. They wanted to rule out any similar glitches on Discovery.

Things were looking good for the fifth attempt on Wednesday — when skies would have been clear across much of the east coast — but a leak during refueling sent up another red flag. 

Understandably, this morning’s fueling was a bit tense. But for three hours beginning at 10:20 EDT, nearly 500,000 gallons of chilled liquid oxygen and hydrogen propellants flowed into Discovery’s external tank without incident. 

Two irregularities have been reported so far this afternoon: a bat was found clinging to Discovery’s external tank, and Launch Director Mike Leinbach sent a “red team” to launch pad 39A to manually correct a valve issue that caused a drop in helium pressure. 

Neither issue is expected to interfere with launch.

Stay tuned for updates, either to this post or a new one.

LEAD IMAGE CAPTION: NASA’s Discovery shuttle pictured under a full moon on Wednesday, when its fifth launch attempt was scrapped. Tonight marks the sixth. NASA/Bill Ingalls

Source: NASA

Posted on by Anne Minard

Earth Cyclones, Venus Vortices Have Much in Common

Scientists have spotted an S-shaped feature in the center of the vortices on Venus that looks familiar — because they’ve seen it in tropical cyclones on Earth.

Researchers from the United States and Europe spotted the feature using NASA’s Pioneer Venus Orbiter and The European Space Agency’s Venus Express. Their new discovery confirms that massive, swirling wind patterns have much in common where they have been found — on Venus, Saturn and Earth.

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At cloud top level, Venus’ entire atmosphere circles the planet in just about four Earth days, much faster than the solid planet does. Despite this “superrotation,” some dynamical and morphological similarities exist between the vortex organization in the atmospheres of Venus’s northern and southern hemispheres and tropical cyclones and hurricanes on Earth.

Organization of the Venus atmospheric circulation into two circumpolar vortices, one centered on each pole, was first deduced more than 30 years ago from Mariner 10 ultraviolet images. The S-shaped feature in the center of the vortices on Venus was first detected by the Pioneer Venus Orbiter near the northern pole and recently by Venus Express orbiter around the southern pole. It is also known to occur in Earth’s tropical cyclones.

Using an idealized nonlinear and nondivergent barotropic model, lead author Sanjay S. Limaye, of the University of Wisconsin-Madison, and his colleagues are proposing that these S-shaped features are the manifestations of barotropic instability. The feature can be simulated with a barotropic model and, like in the vortices on Venus and in tropical cyclones, it is found to be transient.

Another similarity between the observed features in the vortex circulations of Venus and in terrestrial hurricanes is the presence of transverse waves extending radially outward from the vortex centres. The lack of observations of such features in Earth’s polar vortices is suggestive that the dynamics of the Venus polar vortices may have more in common with hurricanes than their more direct terrestrial counterparts. 

Given the challenges in measuring the deep circulation of Venus’s atmosphere, the authors expect that the morphological similarities between vortices on Earth and Venus might help scientists better understand atmospheric superrotation on Venus and guide future observations.

IMAGE CAPTIONS: 1. The ‘eye of the hurricane’ on Venus, taken by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on board Venus Express. The yellow dot represents the south pole. Credit: ESA 2. An infrared satellite image of Hurricane Howard [1998], showing an S-shaped pattern in the low (warm) clouds in the tropical cyclone’s eye. Credit: Sanjay S. Limaye. 

Source: Geophysical Research Letters

Posted on by Anne Minard

New Horizons Spots Neptune’s Moon Triton

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New Horizons got a great shot of Neptune’s moon Triton last fall, as it was trucking toward Pluto and the Kuiper Belt. 

The mission was 2.33 billion miles (3.75 billion kilometers) from Neptune on Oct. 16, when its Long Range Reconnaissance Imager (LORRI) locked onto the planet and snapped away. The craft was following a programmed sequence of commands as part of its annual checkout. NASA released the image Thursday afternoon.

Mission scientists say the shot was good practice for imaging Pluto, which New Horizons will do in 2015. Neptune’s moon Triton and Pluto — the former planet retitled in 2006 as the ambassador to the Kuiper Belt — have much in common.

“Among the objects visited by spacecraft so far, Triton is by far the best analog of Pluto,” said New Horizons Principal Investigator Alan Stern. 

Triton is only slightly larger than Pluto, boasting a 1,700-mile (2,700-kilometers) diameter compared to Pluto’s 1,500-mile (2,400-kilometer) girth. Both objects have atmospheres primarily composed of nitrogen gas with a surface pressure only 1/70,000th of Earth’s, and comparably cold surface temperatures. Temperatures average -390 degrees F (-199 degrees C) on Triton and -370 degrees F (-188 degrees C) on Pluto. 

Triton is widely believed to have once been a member of the Kuiper Belt that was captured into orbit around Neptune, probably during a collision early in the solar system’s history. Pluto was the first Kuiper Belt object to be discovered.

Furthermore, “We wanted to test LORRI’s ability to measure a faint object near a much brighter one using a special tracking mode,” said New Horizons Project Scientist Hal Weaver, of Johns Hopkins University, “and the Neptune-Triton pair perfectly fit the bill.”

LORRI was operated in 4-by-4 format (the original pixels are binned in groups of 16), and the spacecraft was put into a special tracking mode to allow for longer exposure times to maximize its sensitivity.

Mission scientists also wanted to measure Triton itself, to follow up on observations made by the Voyager 2 spacecraft during its flyby of Neptune in 1989. Those images revealed evidence of cryovolcanic activity and cantaloupe-like terrain. New Horizons can observe Neptune and Triton at solar phase angles (the Sun-object-spacecraft angle) that are not possible to achieve from Earth-based facilities, yielding new insight into the properties of Titan’s surface and Neptune’s atmosphere.

New Horizons is currently in electronic hibernation, 1.2 billion miles (1.93 billion kilometers) from home, speeding away from the Sun at 38,520 miles (61,991 kilometers) per hour. LORRI will continue to observe the Neptune-Triton pair during annual checkouts until the Pluto encounter in 2015. 

LEAD IMAGE CAPTION: The top frame is a composite, full-frame (0.29° by  0.29°) LORRI image of Neptune taken Oct. 16, 2008, using an exposure time of 10 seconds and 4-by-4 pixel re-binning to achieve its highest possible sensitivity. The bottom frame is a twice-magnified view that more clearly shows the detection of Triton, Neptune’s largest moon. Neptune is the brightest object in the field and is saturated (on purpose) in this long exposure. Triton, which is about 16 arcsec east (celestial north is up, east is to the left) of Neptune, is approximately 180 times fainter.  All the other objects in the image are background field stars. The dark “tails” on the brightest objects are artifacts of the LORRI charge-coupled device (CCD); the effect is small but easily seen in this logarithmic intensity stretch. (Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

Source: NASA

Posted on by Anne Minard

Cassini Switches to Backup Thrusters

Cassini, fueled by plutonium (NASA)

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NASA’s Cassini spacecraft successfully switched to a backup set of propulsion thrusters late Wednesday, which will allow the long-lived machine to continue scoping out Saturn and its moons.

The swap was performed because of degradation in the performance of the primary thrusters, which had been in use since Cassini’s launch in 1997. This is only the second time in Cassini’s 11 years of flight that the engineering teams have gone to a backup system.

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This natural color view was created from images collected shortly after Cassini began its extended Equinox Mission in July 2008. Credit: NASA

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. Since its launch four years ago, the mission sent the Huygens probe to Saturn’s largest moon, Titan, and has yielded copious data about Saturn, its rings and its many moons.

The thrusters are used for making small corrections to the spacecraft’s course, for some attitude control functions, and for making angular momentum adjustments in the reaction wheels, which also are used for attitude control. The redundant set is an identical set of eight thrusters. Almost all Cassini engineering subsystems have redundant backup capability.

Cassini has successfully completed its original four-year planned tour of Saturn and is now in extended mission operations.

Sources: NASA, here and here.

Posted on by Nancy Atkinson

Watch Discovery Light Up the Night Sky

Shuttle Discovery on the launchpad. Credit: NASA/Bill Ingalls

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2nd UPDATE: (6:45 EDT) Mission managers have reset the launch of Discovery on STS-119 to no earlier than Sunday, March 15 at 7:43:38 p.m. EDT. Engineers will troubleshoot problems with a leaky hydrogen line.

UPDATE: (2:25 pm EDT) Launch scrub due to leak in hydrogen line while fueling. Rats! Latest news is that NASA will try again tomorrow to launch. The launch time has now been set for 8:54 pm EDT on Thursday, March 12.

Space shuttle Discovery will light up the night sky with a Wednesday Thursday Sunday evening launch, at 9:20 pm EDT (1:20 am GMT). 8:54 pd EDT (12:54 am GMT). 7:43 pm EDT (11:443 pm GMT). Mission managers have given the go-ahead for filling the external fuel tank with the super-cold propellants and the weather looks favorable, so things are looking good for an on-time launch. Night launches are always gorgeous to watch, and there are a plethora of ways to follow the launch. First and foremost, if you live along the Eastern coast of the United States, you may be able to see the shuttle rise from Earth with your own eyes! If the skies are clear in your area, look low in the sky at launch time, about 5 to 15 degrees above the horizon, depending on your viewing point. You’ll see a light moving quite fast, streaking across 90 degrees of azimuth in less than a minute.

Below is a list of the different webcasts and feeds that will be showing the launch live for those of us that don’t live on the US Eastern seaboard. Plus, I’ll be Twittering during pre-launch and launch if you want to join me.

Of course, the launch will be shown live on NASA TV. If NASA TV isn’t available in your area via cable or satellite, watch it on the web.

Spaceflightnow.com will be having a live webcast featuring Miles O’Brien, former astronaut LeRoy Chiao and David Waters starting at at 4:30 p.m. EDT (2030 GMT) Wednesday.

SpaceVidCast will also be showing a live feed, with interesting banter from their hosts, Cariann and Ben Higginbotham.

Commander Lee Archambault will lead Discovery’s crew of seven, along with Pilot Tony Antonelli, and Mission Specialists Joseph Acaba, John Phillips, Steve Swanson, Richard Arnold and Japan Aerospace Exploration Agency astronaut Koichi Wakata on mission STS-119 to the International Space Station.

The Discovery crew members will bring the S6 truss segment and install the final set of power-generating solar arrays to the International Space Station. The S6 truss will complete the backbone of the station and provide one-fourth of the total power needed to support a crew of six. It also will increase the surface area of the ISS to over an acre. The sunlight reflected from this surface area will make the ISS the 2nd brightest object in the night sky, after the moon. Here’s info on where and how to look for the ISS in the night sky.

Posted on by Nancy Atkinson

March Madness for Space Geeks

Have you ever looked on with envy at your office mates’ brackets and (illegal) betting pools for the NCAA basketball tournament but you don’t know the difference between a jump ball and a jump shot? Well, now there’s a bracket just for you: March Mission Madness. And it’s a showdown of epic proportions, plus it’s not even against the law to participate (as long as no money is changing hands!) With NASA’s March Mission Madness, you can enjoy intriguing matchups, story lines and buzzer beating drama. Beginning today, March 9th, NASA fans will be able to view the lineup of 64 NASA missions, learn about mission goals, and vote for your favorite missions, as well as predict which missions your fellow space geeks and nerds will vote for during this single elimination tournament. There will even by play-by-by commentary from Miles O’Brien and Keith Cowing. Sound like fun? Here’s how to participate:

How to Play

There are two ways to participate in the 2009 Mission Madness Tournament. First, visit the website, http://www.nasa.gov/missionmadness, from March 9th – 18th to learn which missions are competing head to head, print your bracket and make your predictions. You can print out as many brackets as you like to evaluate endless winning scenarios.

Second, return to the website and vote for your favorite missions during each round, starting on March 19. You are allowed to vote for your favorite missions as many times as you like, so be sure to support your favorite missions to help them advance deep into the tournament. As voting is completed for each round, the winning missions advance allowing you to see how your predictions compare to all of the voters.
Round one features 32 predetermined matchups. Each round consists of two days of online voting with the winning missions advancing in head to head competition. Fans will be able to vote for their favorite missions as many times as they like while polls are open, with the very first Mission Madness Championship Winner determined on April 8th, 2009.

Here’s the tournament schedule:

March 9th – 18th Brackets available on the web site with the head to head line-ups for each region.

March 19th – 20th Round 1 Voting

March 23rd – 24th Round 2 Voting

March 26th – 27th Sweet Sixteen Voting

March 30th – 31st Quarter Final Round Voting

April 2nd – 3rd Semi Final Round Voting

April 6th – 7th Final Round Voting

April 8th NASA EDGE names 2009 Mission Madness Winning Mission

Source: NASA

Posted on by Anne Minard

Success: Kepler Lifts Off to Look for Other Earths

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Kepler as it appeared moments prior to launch in Florida. Credit: NASA

NASA’s Kepler mission lifted off without a hitch just before 11 p.m. local time Friday from Cape Canaveral Air Force Station in Florida. 

The launch was a bit of a nail-biter, coming on the heels of last week’s failure of the Orbiting Carbon Observatory, which plummeted into the ocean when its fairing malfunctioned. But everything for the Kepler launch — from the weather to the countdown — went flawlessly. At five minutes to launch, Kepler’s rockets sent ribbons of smoke into Florida’s 65-degree Fahrenheit (18-degree Celsius) nighttime air under perfectly clear skies. With 30 seconds left, confirmation commands were exchanged with practiced precision. The casing (called the fairing) fell off with grace, and three minutes into the flight, the craft was cruising away from Earth at nearly 7,000 miles (11,265 kilometers) per hour. Each launch event happened within three seconds of its predicted time. 

Kepler’s engines shut down at 11:45 p.m. U.S. eastern time, and the craft achieved separation just before midnight, about 62 minutes after launch. Now, for the next three and a half years, Kepler will trail Earth in orbit and stare at a single patch of sky in the  Cygnus-Lyra region of the Milky Way.

Kepler fires the imagination, as it could finally address the age-old question of whether we Earthlings are alone. William Borucki, NASA’s principal investigator for Kepler science, spoke about the mission at a recent NASA press conference and said if Kepler spies Earth-like planets in the habitable zones of other stars, “life may well be common throughout our universe. If on the other hand we don’t find any, that will be another profound discovery. In fact it will mean there will be no Star Trek.”

The $500 million Kepler mission will spend three and a half years surveying more than 100,000 sun-like stars in Cygnus-Lyra.  Its telescope is specially designed to detect the periodic dimming of stars that planets cause as they pass by. 

By staring at one large patch of sky for the duration of its lifetime, Kepler will be able to watch planets periodically transit their stars over multiple cycles, allowing astronomers to confirm the presence of planets and use the Hubble and Spitzer space telescopes, along with ground-based telescopes, to characterize their atmospheres and orbits. Earth-size planets in habitable zones would theoretically take about a year to complete one orbit, so Kepler will monitor those stars for at least three years to confirm the planets’ presence.

Astronomers estimate that if even one percent of stars host Earth-like planets, there would be a million Earths in the Milky Way alone. If that’s true, hundreds of Earths should exist in Kepler’s target population of 100,000 stars.

Posted on by Anne Minard

Finally, It’s Go Time for Discovery Launch

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After four delays in a month’s time, NASA’s Discovery shuttle will finally depart the Kennedy Space Center at 9:20 p.m. local time on Wednesday, March 11. 

Discovery’s STS-119 mission will carry two new solar array wings, which will increase the station’s solar power capacity so it might support a larger crew. Launch was initially set for early February, but managers were worried following a malfunction of hydrogen control valves on the shuttle Endeavour last fall. They wanted to rule out any similar glitches on Discovery.

Discovery’s launch date was announced following a flight readiness review earlier today. During the meeting, top NASA and contractor managers assessed the risks associated with the mission and determined the shuttle’s equipment, support systems and procedures are ready.

On the resolution of the shuttle’s flow control valve issue, John Shannon, Space Shuttle Program manager said, “This is one of those problems requiring a lot of work. It was a little premature before today. The signs were there that we were safe, but the teams went off and came up with definitive data to prove it.”

Mike Leinbach, Space Shuttle launch director, added that from a processing standpoint, the shuttle is in good shape. “It feels good to be here with a firm launch date. I saw a lot of people after the meeting and the mood is really upbeat,” he said.

The launch countdown clock will begin at the T-43 hour mark at 7 p.m. on Sunday. Also on Sunday, Discovery’s astronauts are scheduled fly from their home base in Houston, arriving in arriving in Florida by mid-afternoon.

Source: NASA

Posted on by Anne Minard

Spirit Backslides on Plateau Climb, Must Go Around

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Spirit is taking the long way around a low plateau called “Home Plate,” after loose soil at the edge blocked the shortest route south for the upcoming Martian summer and following winter. The rover has begun a trek skirting at least partway around the plateau instead of directly over it.

NASA officials say even a circuitous route to the destinations chosen for Spirit will be much shorter than the overland expedition the rover’s twin, Opportunity, is making on the opposite side of Mars. And they’re pointing out that Spirit has gotten a jump on its summer science plans, examining a silica-rich outcrop that adds information about a long-ago environment that had hot water or steam.

The view from "Home Plate" Plateau, where Spirit spent the winter.
The view from "Home Plate" Plateau, where Spirit spent the winter.

Both of NASA’s Mars Exploration Rovers landed on Mars in 2004 for what were originally planned as three-month missions.

Spirit spent 2008 on the northern edge of Home Plate, a flat-topped deposit about the size of a baseball field, composed of hardened ash and rising about 1.5 meters (5 feet) above the ground around it. There, the north-facing tilt positioned Spirit’s solar arrays to catch enough sunshine for the rover to survive the six-month-long Martian winter.

The scientists and engineers who operate the rovers chose as 2009 destinations a steep mound called “Von Braun” and an irregular, 45-meter-wide (150-foot-wide) bowl called “Goddard.” These side-by-side features offer a promising area to examine while energy is adequate during the Martian summer. They’ll also provide the next north-facing winter haven beginning in late 2009. Von Braun and Goddard intrigue scientists as sites where Spirit may find more evidence about an explosive mix of water and volcanism in the area’s distant past. They are side-by-side, about 200 meters, or yards, south of where Spirit is now.

It’s mid-spring now in the southern hemisphere of Mars. The Sun has climbed higher in the sky over Spirit in recent weeks.

The rover team tried to drive Spirit onto Home Plate, heading south toward Von Braun and Goddard. They tried this first from partway up the slope where the rover had spent the winter. Only five of the six wheels on Spirit have been able to rotate since the right-front wheel stopped working in 2006. With five-wheel drive, Spirit couldn’t climb the slope. In January and February, Spirit descended from Home Plate and drove eastward about 15 meters (about 50 feet) toward a less steep on-ramp. Spinning wheels in loose soil led the rover team to choose another option.

“Spirit could not make progress in the last two attempts to get up onto Home Plate,” said rover project manager John Callas of NASA’s Jet Propulsion Laboratory in Pasadena, California. “Alternatively, we are driving Spirit around Home Plate to the east. Spirit will have to go around a couple of small ridges that extend to the northeast, and then see whether a route east of Home Plate looks traversable. If that route proves not to be traversable, a route around the west side of Home Plate is still an option.”

During the drive eastward just north of Home Plate in January, Spirit stopped to use tools on its robotic arm to examine a nodular, heavily eroded outcrop dubbed “Stapledon,” which had caught the eye of rover-team scientist Steve Ruff when he looked at images and infrared spectra Spirit took from its winter position.

“It looked like the material east of Home Plate that we found to be rich in silica,” said Ruff, of Arizona State University in Tempe. “The silica story around Home Plate is the most important finding of the Spirit mission so far with regard to habitability. Silica this concentrated forms around hot springs or steam vents, and both of those are favorable environments for life on Earth.”

Sure enough, Spirit’s alpha particle X-ray spectrometer found Stapledon to be rich in silica, too. Researchers plan to use Spirit’s thermal emission spectrometer and panoramic camera to check for more silica-rich outcrops on the route to Von Braun and Goddard. However, the team has set a priority to make good progress toward those destinations. Winds cleaned some dust off Spirit’s solar panels on Feb. 6 and Feb. 14, resulting in a combined increase of about 20 percent in the amount of power available to the rover.

Oppy, meanwhile, shows signs of increased friction in its right-front wheel. The team is driving the rover backwards for a few sols, a technique that has helped in similar situations in the past, apparently by redistributing lubricant in the wheel. Opportunity’s major destination is Endeavour Crater, about 22 kilometers (14 miles) in diameter and still about 12 kilometers (7 miles) away to the southeast. Opportunity has been driving south instead of directly toward Endurance, to swing around an area where loose soil appears deep enough to potentially entrap the rover.

Source: NASA

Posted on by Nancy Atkinson

Public Wants Hubble to Study Hugging Galaxies

The winner: Arp 274. Credit: NASA

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NASA asked the public to vote on where they want the Hubble Space Telescope to be pointed in the “Hubble, You Decide” contest. Nearly 140,000 votes were cast online to help decide. And the winner is: a pair of interacting galaxies that look like they are hugging. Called Arp 274 (from the Arp Atlas of Peculiar Galaxies) these two galaxies won over five other celestial candidates. The Hubble observations will be taken during the International Year of Astronomy’s “100 Hours of Astronomy,” taking place April 2 – 5. The full-color galaxy image will be released publicly during that time.

Drawn together by their gravity, the two galaxies are starting to interact. The spiral shapes of these galaxies are mostly intact, but evidence can be seen of the gravitational distortions they are creating within each other. When galaxies interact and merge together, the gas clouds inside them often form tremendous numbers of new stars.

According to NASA: “The new picture of Arp 274 promises to reveal intriguing never-before-seen details in the galactic grand slam.”

We’ll be sure to post the image when it is released.

Source: Hubblesite