Pluto: Three possible models of Dwarf Planet ahead of New Horizons visit

Interior structure models assumed for Pluto.

Two space researchers, Amy Barr, with Brown University and Geoffrey Collins with Wheaton College, have published a paper in the journal Icarus in which they describe three possible interior models of the former planet Pluto.

They suggest the possibilities include: 

1. an undifferentiated rock/ice mixture, 
2. a differentiated rock/ice mixture, and an ocean covered with ice. 
3. The third possibility suggests the likelihood, they claim, of tectonic action on the dwarf planet.

Pluto

A close up view of the planet by space probe New Horizons due to arrive next year, should help clarify which scenario is most likely.

Amy Barr

Scientists believe that Pluto came to exist as it does today, in part due to a collision billions of years ago that led also to the formation of its moon Charon.

Charon

When celestial bodies collide, not only do they knock each other around, they produce heat—heat, the researchers suggest that could still be evident today.

Barr and Collins are leading towards a theory that suggests that shortly after impact, Pluto and Charon were much closer together, the gravity attraction between them would have caused both to be egg shaped.

As time passed, melted ice from the impact would have created an icy crust on top of an ocean on Pluto, and then, as Charon moved farther away, the attractive pull would have diminished, causing ice plates to form and crack against one another, a form of tectonics.

Geoffrey Collins

If that were the case, the two add, then in all likelihood, when New Horizons begins sending back images, they should see evidence of such tectonic action—plate edges thrust into the air, for example.

There's just one catch, Pluto circles the sun in an elliptical orbit, thus sometimes it's much closer to the sun than other times.

When near, it has a defined atmosphere, when far away however, its atmosphere actually freezes to its surface, something that could hide ridges in the ice and thus evidence of both tectonic activity and an ocean beneath the crust of ice.

New Horizons

Artist concept of New Horizons spacecraft.

Johns Hopkins University Applied Physics Laboratory (JHUAPL) /Southwest Research Institute (SwRI)

Since New Horizons will arrive during a time when its atmosphere is frozen to the surface, it might be difficult to determine which of the three proposed models actually describes the relationship between its exterior and interior.

Barr and Collins are optimistic that even in such a scenario, ridges should be apparent, proving that beneath Pluto's icy surface, lies an ocean, one that future researchers might one day sample.

More information: Tectonic Activity on Pluto After the Charon-Forming Impact, Icarus, Available online 4 April 2014. dx.doi.org/10.1016/j.icarus.2014.03.042 . Available on Arxiv: xxx.lanl.gov/abs/1403.6377

ISS Astronauts to conduct Three EVAs to repair Coolant Module

American astronauts will undertake a series of urgent spacewalks to repair a broken cooling line on the International Space Station.

NASA has announced that two American astronauts will move soon to replace a busted valve within an external pump module on one of the station's two coolant loops that shut down last week when it reached pre-set temperature limits.

The replacement will be undertaken during three spacewalks by the International Space Station (ISS) crew. The first is set for Saturday, followed by another on Monday and next Wednesday, on Christmas Day.

The spacewalks have directed NASA's attention away from the launch of the Cygnus-3 supply ship, which has been rescheduled for January 2014.

Orbital Sciences Corp.'s unmanned Cygnus cargo craft had been due for launch this week on Virginia's coast.

NASA was forced last week to reroute coolant systems when one of the station's coolant loops, Loop-A, automatically shut down due to a temperature fluctuation.

The ISS crew proceeded to move certain electrical systems over to the second loop, NASA reported.

The two coolant loops circulate ammonia to keep internal and external equipment cool.

"At no time was the crew or the station itself in any danger," NASA reported.

The space agency said that some non-critical systems were "powered down" as teams analyzed how the valve malfunctioned.

This is not the first time a coolant problem has hampered the ISS.

The ISS crew took an unscheduled spacewalk in May to inspect and fix a coolant leak in its power system. They installed a new cooling pump during a six-hour-long session.

That same coolant loop had a similar problem in November 2012, when an emergency spacewalk was needed to fix a leak.

Nasa Asteroid Capture: Three Possible Candidates Selected

This NASA artist's rendering obtained on May 31, 2013 shows what capturing an asteroid could look like. 

The US space agency has narrowed its hunt for an asteroid to capture to three, NASA said.

The asteroids fit the requirements of being between seven to 10 meters (yards) in size, and further study should be able to narrow the choice even more, scientists said at a conference in San Diego, California.

"We have two to three which we will characterize in the next year and if all goes well... those will be valid candidates that could be certified targets," said Paul Chodas, senior scientist at the NASA Near-Earth Object Program Office.

The plan is to send a robotic spacecraft to capture the asteroid and drag it into orbit around the Moon.

Once there, astronauts could visit the asteroid and take samples of it back to Earth for study.

The spacecraft used for travel there and back would be the Orion multi-purpose vehicle, which is being built but has not yet been used, as well as a new deep space rocket launcher.

The program aims to break new ground by increasing NASA capabilities beyond low Earth orbit, where the International Space Station circles the globe.

Paul Chodas

NASA has touted the planetary defense capabilities the project would build toward protecting the Earth from a potential hazardous asteroid collision, as well as the technology it would boost for future human missions to deep space.

President Barack Obama has proclaimed the project would be a key step on the way to sending humans to Mars by the 2030s.

Bill Gerstenmaier, associate administrator of NASA's Human Exploration and Operations Directorate, described the asteroid mission as "pretty compelling."

"If you think about grabbing an object in space and then manipulating it for our use and putting it into a destination where we could go back and routinely visit and let commercial companies go visit, I think that is a pretty compelling activity."

Obama's 2014 budget for NASA asked for $100 million for the asteroid project, but the overall costs may be as high as $2 billion.

Bill Gerstenmaier

"It's a little different way than just a date and a destination. We are really good at just picking dates and destinations. But that's really hard in this budget environment where things are constrained and we have flat budgets, et cetera et cetera, to pull that off," said Gerstenmaier.

"It is not just a one-time thing. It actually feeds forward into the broader context of what we want to do with humans in space."

The launch could happen as early as 2017 or as late as 2019.

After launch of the robotic mission, the journey to the asteroid would take a year and a half, and the act of towing it toward the moon could take another three and a half years, NASA said.

The project would use a new fuel technology called solar electric propulsion.

"We are talking about engineering the solar system, in a way. We are talking about taking an asteroid which was once here, and then putting it into a useful orbit for our purposes," said Chodas.

"This is a very large idea here that we are talking about and I think it will reinvigorate interest in the space program," he said.

NASA Orion Space Capsule Lands With Two of Three Parachutes

The Orion capsule falls to Earth with parachutes deployed at Yuma Proving Ground, Arizona, on July 24, 2013.

Credit: NASA TV

NASA's Orion capsule, planned to be the space agency's next manned spaceship, safely landed during a flight test today (July 24) using just two of its three parachutes.

The test was the 10th in a series of maneuvers to check out Orion's parachute system, which will slow the vehicle down as it plummets through Earth's atmosphere on return trips from space.

Orion is designed to carry astronauts beyond low-Earth orbit to nearby asteroids, the moon, and eventually Mars.

The spacecraft is due to make its first test flight to space in 2014 in a mission called the Exploration Flight Test-1, and its initial crewed flight around 2021.

During today's flight test, an Orion prototype was dropped from a plane 35,000 feet (10,700 meters) over the U.S. Army's Yuma Proving Ground in southwestern Arizona.

It was the highest elevation that the capsule has been dropped from; previous tests saw mock Orion capsules released from a maximum of 25,000 feet (7,600 meters).

"The closer we can get to actual flight conditions, the more confidence we gain in the system," Chris Johnson, project manager for the Orion capsule parachute assembly system at NASA's Johnson Space Center in Houston, said in a statement.

"What we saw today — other than the failures we put in on purpose — is very similar to what Orion will look like coming back during Exploration Flight Test-1's Earth entry next year."

Orion is equipped with three parachutes to slow its fall, but is designed to need only two of them.

During today's test, engineers simulated the failure of one chute to confirm that the other two were adequate.

The team caused one parachute to fail during the descent to understand the effects of a chute pulling away in mid-flight.

"We wanted to know what would happen if a cable got hooked around a sharp edge and snapped off when the parachutes deployed," Stu McClung, Orion's landing and recovery system manager at Johnson, said in a statement.

"We don't think that would ever happen, but if it did, would it cause other failures? We want to know everything that could possibly go wrong, so that we can fix it before it does."

NASA SDO: FOUR X-class flares in 48 hours

These pictures from NASA's Solar Dynamics Observatory show the three of the Four X-class flares that the sun emitted in under 48 hours. 

The images show light with a wavelength of 131 angstroms, which is particularly good for showing solar flares and is typically colorised in teal. 

Credit: NASA/SDO

On Tuesday, it released the biggest solar flare of 2013 so far, an intense burst associated with a huge eruption of particles.

Also on May 13, 2013 the sun emitted a third significant solar flare in under 24 hours, peaking at 9:11 p.m.

This flare is classified as an X3.2 flare. This is the strongest X-class flare of 2013 so far, surpassing in strength the two X-class flares that occurred earlier in the 24-hour period.

The flare was also associated with a coronal mass ejection (CME). The CME began at 9:30 p.m. EDT and was not Earth-directed.

Experimental NASA research models show that the CME left the sun at approximately 1,400 miles per second, which is particularly fast for a CME.

The models suggest that it will catch up to the two CMEs associated with the earlier flares.

The merged cloud of solar material will pass by the Spitzer spacecraft and may give a glancing blow to the STEREO-B and Epoxi spacecraft.

Their mission operators have been notified. If warranted, operators can put spacecraft into safe mode to protect the instruments from solar material.

Ex-Soviet ICBM: SS18 'Satan' rocket launches three European micro-satellites

Ex-'Satan' rocket launches three European micro-satellites

A former Soviet SS-18 intercontinental missile lofted a trio of European micro-satellites into space on Wednesday, including a satellite to monitor the Sun's impact on climate change, France's National Centre for Space Studies (CNES) said.

The Russian-Ukrainian Dnepr lifted off at 1442 GMT from Yasny, southern Russia, the CNES said in a press release issued in Paris.

Its triple payload included a 150-kilo (330-pound) French satellite called Picard that will scrutinise the Sun for changes that could affect Earth's climate system.

More than 80 percent of current climate change is attributable to greenhouse gases that trap solar heat, leaving variations in solar output as the other big contributor.

Picard, named after a 17th-century French astronomer who investigated solar activity, will orbit at an altitude of 725 kilometres (453 miles), the CNES said.

It carries a telescope that will take images of the Sun in five wavelengths, and two other instruments to measure the Sun's energy output.

The other passengers aboard the Dnepr were the satellites Mango and Tango, under a Swedish Space Corporation project called Prisma.

They will test new sensors and navigation technologies designed to enable satellites to rendezvous or fly in formation in space.

The SS-18 was code-named "Satan" by NATO in the Cold War's heyday. In the 1990s, a number of the missiles were converted so that they could carry small civilian payloads into low Earth orbit.