NASA Archives

August 3, 2007December 26, 2015 by Fraser Cain

The Origin Discovered for Saturn’s G Ring

When you look at Saturn, it’s easy to see the distinct rings, with dark bands in between them. For some of the rings, scientists think they know their sources: several of the planet’s moons are feeding particles into the rings. The planet’s mysterious G ring has had them puzzled since Cassini first arrived at Saturn in 2004. But now this ring is giving up its secrets.

The particles in Saturn’s G ring are confined to their position through gravitational interaction with Saturn’s moon Mimas. Micrometeoroids collide with the particles, and release even smaller, dust-sized particles. The plasma field generated by Saturn’s magnetic field sweeps through the cloud of particles, and pulls out the finest ones, creating the G ring.

This discovery will be published in the August 2nd issue of the journal Science, and was based on Cassini spacecraft observations in 2004 and 2005. The photos gathered by Cassini have been turned into movies, showcasing an entire orbital revolution. The G ring is revealed as a bright arc on the ring’s inner edge. To see the animation, click here.

Several of Saturn’s other rings are associated with a specific moon. For example, Enceladus’ geysers are supplying material for the E ring. And other moons sculpt and shape the rings, such as the effect that Prometheus and Pandora have on the F ring. But this isn’t the case for the G ring.

The latest Cassini images show that the ring stretches around Saturn like a bright arc 150 km wide, reaching about 1/6th around the planet. It contains about as much mass as a single ice rich moon 100 metres wide. It was seen several times during Cassini’s 2004 arrival at Saturn, but scientists hadn’t worked out where it came from until now.

Original Source:Cassini-Huygens News Release

August 1, 2007December 26, 2015 by Fraser Cain

Networking Across the Planets

I don’t know about your Internet connection, but I have enough trouble wiring up my home network. Imagine trying to connect together spacecraft orbiting millions of kilometres away into a serviceable network. That’s just what’s going to happen when NASA’s Phoenix Lander arrives at the Red Planet. In the spirit of cooperation, ESA’s Mars Express will be on hand to watch the Phoenix lander during its entry and landing phases of the mission.

If everything goes well, Phoenix will blast off from Cape Canaveral on August 4th, making its way to the Red Planet atop a Boeing Delta II rocket. It’ll then take several months to reach Mars, arriving in spring, 2008.

For missions to Mars, the most dangerous moment is the Entry Descent and Landing (EDL) phase, where the spacecraft plunges through the thin Martian atmosphere. Go too fast and you crash into the planet; too slow and you just skip off the atmosphere, and head off into space. For more information about why this is hard, check out this article.

With such a dangerous maneuver, it’s good to know there’ll be another set of eyes watching overhead. Mars Express will optimize its orbit over the next few months so that it’ll be keeping Phoenix directly in sight for the entire EDL phase. Mars Express is equipped with a special electronics package designed to communicate with landers on the surface of Mars. It was originally designed to communicate with Beagle 2, but it’ll be repurposed to talk to Phoenix.

If all goes well, Mars Express will receive regular updates from Phoenix through the decent and landing stages, and then over the lander’s anticipated 90-day lifespan. Let’s hope everything goes well, but if things go poorly, the spacecraft will be able to give mission controllers detailed information about how the lander went splat, so they can work out why. If only Beagle 2 had been so lucky.

Original Source:ESA News Release

July 30, 2007December 26, 2015 by Fraser Cain

Prototype Blended Wing Aircraft Tested

The flying wing is an old design, but NASA aerospace engineers think it might be just what the airline industry needs. As part of their research into this concept, the agency recently tested out the X-48B flying wing prototype. If this design matches the developers’ ambitions, it could usher in a new class of aircraft which would be quieter and use less fuel.

The remotely controlled 6.4 metre (21-foot) wingspan aircraft took off from NASA’s Dryden Flight Research Center on July 20th, 2007. It climbed to an altitude of 2,286 metres (7,500 feet), and then landed again 31 minutes later.

Designed and built by Boeing’s Phantom Works, the X-48B was created to help engineers explore the flight dynamics of this aircraft shape. Instead of the traditional fuselage and wings, the X-48B looks just like flying wing, which blends smoothly into a wide, flat, tailless fuselage. The blend between the wing and fuselage gives the aircraft additional lift and less drag compared to a circular fuselage.

Powering the vehicle are three turbojet engines. These are 8.5% scale, which allow the aircraft to fly up to 3,000 metres (10,000 feet) altitude, and reach speeds of 220 kph (138 mph). The engines are mounted high up on the fuselage in the back, and making it both quieter inside, and on the ground.

NASA is planning 25 more test flights with the X-48B to gather data in low-speed maneuvers. Then they might use the prototype to see if it’s truly quiet and how it handles at transonic speeds.

Original Source: NASA News Release

July 26, 2007December 26, 2015 by Fraser Cain

Drunk Astronauts Were Allowed to Fly

Now this is a NASA scandal that I never saw coming. Apparently twice in the past, shuttle astronauts were permitted to fly, even though they had levels of alcohol in their system so high they posed a risk to the shuttle mission. What?!

Aviation Week is reporting that an independent 8-person panel was convened to study astronaut health after the arrest of former astronaut Lisa Nowak (I’m sure you remember this little incident). As part of their research, the panelists interviewed shuttle flight surgeons, and these details came to light. NASA is keeping the revelations, tight-lipped, but they have a press conference on Friday to discuss it further.

NASA will also release the fully document on Friday, which contains the findings of both the outside committee, as well as an internal panel. This external panel included Air Force experts in aerospace medicine and clinical psychiatry.

I suppose I can understand how astronauts might want to have a celebration with their friends and family before heading up into space. But considering the sacrifices they’ve already made to get to this point in their careers, and the stakes involved for any kind of failure on the mission, I’m amazed anyone drinks a sip of alcohol months before their scheduled flight. I’m also amazed that flight surgeons would permit astronauts to fly while intoxicated. I can just imagine the pressure they’re under to certify astronauts for flight.

Anyway, I suppose we’ll just to wait for the final report to see all the details. I’ll keep you posted.

Original Source: Aviation Week

July 19, 2007December 26, 2015 by Fraser Cain

Saturn’s 60th Moon Discovered

Saturn’s little system hit a big milestone this week with the announcement of its 60th moon. This new moon joins the crop of new satellites turned up by researchers poring through data sent back by NASA’s Cassini spacecraft.

The newly discovered moon first appeared as a faint dot in a series of images captured by Cassini on May 30. The discoverers, from Queen Mary, University of London, then went back through the vast library of Cassini images, verifying that they had found a new object.

Codenamed “Frank” for now, the new moon is only about 2 km (1.2 miles) across, and it’s mostly made of ice and rock. It’s located in between the orbits of Methone and Pallene.

This is the fifth new moon discovered by the Cassini imaging team.

Original Source: Cassini-Huygens News Release

July 16, 2007December 26, 2015 by Fraser Cain

Building an Engine that Can Throttle Down

Here on Earth, we’ve gotten used to the concept of a car’s accelerator pedal. Put it down a little, and the car accelerates slowly. Put the “pedal to the metal” and you’ll go faster. Imagine trying to park your car when you only have two choices: off and full speed. Developing a similar concept for a rocket is very difficult. Most rockets are designed to go at full blast, or nothing at all.

A variable acceleration rocket would tremendously useful for landing on the Moon. Instead of firing the landing rockets in short bursts, astronauts could throttle down for a nice smooth landing. But building an engine like this is harder than it sounds.

NASA researchers think they’ve got a prototype engine that should give the variable rate of acceleration astronauts are looking for. The newly developed Common Extensible Cryogenic Engine (CECE) is a variant on the RL10 engine that boosted the Surveyor robot landers to the Moon back in 1966-68. The RL10 is designed to only go full throttle, so adding the variable thrust was difficult.

The main problem is that changing the throttle affects how the whole engine functions. At low power, liquid hydrogen can slow and vapourize in the coolant lines. This might cause the engine to stall. During one test, the experimenters discovered that the engine “chugged”, vibrating 100 times a second. It turned out oxygen vapours were forming on the injector plate, inhibiting normal flow, causing the vibrations.

It’s not ready for space yet, but CECE might eventually become part of the design of a future lunar lander. The astronauts returning to the Moon will be very appreciative.

Original Source:Science@NASA

July 12, 2007December 26, 2015 by Fraser Cain

Station’s New Oxygen Generation System Activated

Apparently astronauts want to breathe. In their mad quest for air, the astronauts on board the International Space Station activated the new US-built oxygen generation system, designed to assist the intermittent Russian Elektron system.

The new oxygen generation system (or OGS) was turned on for the first time on Wednesday. Although there were a few glitches in the beginning, it’s been running fine today, and should start producing oxygen later today.

The OGS is capable of producing between 5 and 9 kgs(12 and 20 pounds) of oxygen a day. That much won’t be needed today, with only three crew members on board the station, but it’ll be critical when it has the full complement of six astronauts on board.

One of the OGS’ advantages is that it uses a solid polymer to assist the electrolysis of water into hydrogen and oxygen. The Russian system uses a liquid called potassium hydroxide. It turns out that this liquid had flowed around inside the Elektron, and clogged up one of the hydrogen valves, disabling it.

Original Source: NASA News Release

July 3, 2007December 26, 2015 by Fraser Cain

NASA’s New Einstein Probes Office

Albert Einstein made enough predictions about the nature of gravity and relativity that NASA has dedicated a whole office and fleet of spacecraft to him. This week the space agency announced their new Einstein Probes Office, where they’ll be compiling evidence for the strangest stuff in the Universe: dark energy, black holes, and the cosmic microwave background radiation.

The Beyond Einstein program consists of 5 proposed spacecraft; two major spacecraft, and 3 smaller probes. The two major missions are already in the works, and include the Laser Interferometer Space Antenna (LISA), which will orbit the Sun and measure gravitational waves. Constellation-X will watch matter falling into supermassive black holes.

The smaller probes include missions to investigate the nature of dark energy, the physics of the Big Bang, and the distribution and types of black holes in the universe. NASA has already approved preliminary studies into some of these missions.

NASA and the U.S. Department of Energy have put together a committee to figure out which missions should be launched first, and will release their findings in September, 2007.

Original Source:NASA Goddard

June 26, 2007December 26, 2015 by Fraser Cain

Double Supernovae Discovered

Supernovae are rare events, only occurring once every 25-100 years in galaxy. So it came as a complete surprise when NASA’s Swift satellite turned up two supernovae going off at the same time in a galaxy – separated by only 16 days.

Until now, astronomers have never seen a supernova going off in the galaxy MCG +05-43-16, and then suddenly: kaboom kaboom. The twin supernovae have been categorized SN 2007ck and SN 2007co.

And they’re completely different events. The first, SN 2007ck, is a Type II supernova, where a star with many times the mass of our own Sun runs out of fuel and collapses catastrophically. This creates a black hole or neutron star, and blows the outer layers of the star into space.

The second, SN 2007co is a Type Ia event. This is where a white dwarf star steals material from a binary partner until it can’t hold any more material, and detonates in a massive blast.

This is a complete coincidence. The two events are separated by tens of thousands of light years of space. In fact, an astronomer in the galaxy might see the two events separated by thousands of years.

Original Source: NASA

June 22, 2007December 26, 2015 by Fraser Cain

Atlantis Home from STS-117

The space shuttle Atlantis touched down Friday afternoon after a successful mission servicing the International Space Station. Because of bad weather in Florida, the shuttle was delayed a day, and finally re-routed to Edwards Air Force Base in California. It touched down at 3:49 pm EDT.

Over the course of their 14-day mission in space, the astronaut crew installed the new S3/S4 truss to the station, and deployed the new solar wings. They also retracted an older solar array, and performed some other minor fixes.

One of the big concerns was a thermal blanket that dislodged during Atlantis‘ launch. The astronauts tucked the blanket back in during one the mission’s 4 spacewalks. Whether or not the repair was necessary, Atlantis returned through the Earth’s atmosphere without a problem.

The next mission, STS-118, is scheduled for August and will deliver the S5 truss segment to the station.

Original Source : NASA