Group items tagged

Those parts are on board the

SpaceX Dragon spacecraft

The spacewalk would take place April 22 — if Dragon gets there as planned on Wednesday

e Dragon is carrying a new spacesuit, components to fix an existing spacesuit, critical research experiments and food for the six crew members of Expedition 39.

The challenge, however, is making sure the station could be ready even if the primary multiplexer demultiplexer (MDM) fails before spacewalkers can make the backup replacement.

There are more than a dozen MDMs on station, but each one controls different functions

This primary MDM not only controls a robotics mobile transporter, but also radiators and a joint to move the station’s solar arrays, among other things.

. NASA needs to reposition the arrays when a vehicle approaches because plumes from the thrusters can put extra “loads” or electrical power on the system.

Luckily, the angle of the sun is such these days that the array can sit in the same spot for a while, at least two to three weeks

 NASA configured the station so that even if the primary computer fails, the array will automatically position correctly

NASA also will move a mobile transporter on station today so that the station’s robotic arm is ready to grasp the Dragon when it arrives, meaning that even if the primary computer fails the transporter will be in the right spot

If Dragon is delayed again, the next launch opportunity is April 18 and the spacewalk would be pushed back

There are at least two or three spare MDMs on station

the one needed for this particular spacewalk is inside the U.S. Destiny laboratory, which is handily right next to the S0 truss and spacesuit worksite.

In 240 BC, Eratosthenes, a Greek astronomer and mathematician, estimated the circumference of the earth. As the director of the great library of Alexandria, he read in a papyrus book that in Syene, approaching noon on the summer solstice, the longest day of the year, shadows of temple columns grew shorter. At noon, they were gone. The sun was directly overhead. However, a stick in Alexandria, far to the north, could cast a pronounced shadow. Thus, he realized that the surface of the Earth could not be flat. It must be curved. Not only that, but the greater the curvature, the greater the difference in the shadow lengths. By measurement on the ground and application of geometry, he calculated the circumference of the earth.

could help lay the foundation for the colonization of Mars,

its designers say

The MPX team

isn't suggesting that the 2020 Mars rover should

digging a hole with its robotic arm and planting seeds in the Red Planet's dirt.

the experiment would be entirely self-contained, eliminating the chance that Earth life could escape and perhaps get a foothold on Mars.

MPX would employ a clear "CubeSat" box

which would be affixed to the exterior of the 2020 rover

This box would hold Earth air and about 200 seeds of Arabidopsis, a small flowering plant that's commonly used in scientific research

The seeds would receive water when the rover touched down on Mars, and would then be allowed to grow for two weeks or so.

MPX would provide an organism-level test

how Earth life deals with the Red Planet's relatively high radiation levels and low gravity, which is about 40 percent as strong as that of Earth,

"It also would be the first multicellular organism to grow, live and die on another planet

A press release from his office said the presence of the private space company would boost jobs in the region

There’s little information on SpaceX’s website about what the Raptor engine is or specific development plans

Space News reports that it would be used for deep-space missions

SpaceX CEO Elon Musk has mentioned the engine previously when talking about Mars missions, according to multiple media reports

test the whole engine at Stennis

the first phase starts with the components

E-2 stand at Stennis is big enough for components, but we would need a bigger stand for the whole Raptor

reportedly hashing out a Space Act agreement to establish user fees and other parameters

Once that’s finished, the testing will begin, perhaps as early as next year

SpaceX currently does most of its rocket testing in Texas

most of the satellite will disintegrate in the atmosphere, some smaller parts are expected to reach Earth’s surface

GOCE satellite launched in March 2009 on a planned two-year mission to map the variations in Earth's gravity field.

The spacecraft consumed fuel at a much lower rate than expected, however, allowing GOCE to continue gathering data far beyond its expected lifespan

the most accurate gravity data ever available to scientists

provided enough data to complete its mission objective: to determine how many of the 100 billion stars in our galaxy have potentially habitable planets

Based on a statistical analysis

astronomers now estimate that one in five stars like the sun have planets about the size of Earth and a surface temperature conducive to life.

nearly 20 years since the discovery of the first extrasolar planet around a normal star

Since then we have learned that most stars have planets of some size and that Earth-size planets are relatively common in close-in orbits that are too hot for life

Earth-size planets in Earth-size orbits are not necessarily hospitable to life, even if they orbit in the habitable zone of a star where the temperature is not too hot and not too cold

thick atmospheres, making it so hot at the surface that DNA-like molecules would not survive

rocky surfaces that could harbor liquid water suitable for living organisms

Last week,

provided hope that many such planets actually are rocky

NASA launched the Kepler space telescope in 2009 to look for planets that cross in front of, or transit, their stars, which causes a slight diminution – about one hundredth of one percent – in the star's brightness

150,000 stars photographed every 30 minutes for four years

reported more than 3,000 planet candidates

the Keck Telescopes in Hawaii

help them determine each star's true brightness and calculate the diameter of each transiting planet, with an emphasis on Earth-diameter planets.

The team's definition of habitable is that a planet receives between four times and one-quarter the amount of light that Earth receives from the sun

Independently

focused on the 42,000 stars that are like the sun or slightly cooler and smaller, and found 603 candidate planets orbiting them

Only 10 of these were Earth-size, that is, one to two times the diameter of Earth and orbiting their star at a distance where they are heated to lukewarm temperatures suitable for life

Accounting for missed planets, as well as the fact that only a small fraction of planets are oriented so that they cross in front of their host star as seen from Earth, allowed them to estimate that 22 percent of all sun-like stars in the galaxy have Earth-size planets in their habitable zones.

All of the potentially habitable planets found in their survey are around K stars, which are cooler and slightly smaller than the sun

analysis shows that the result for K stars can be extrapolated to G stars like the sun

who are also deaf, signed up for the project just as the national Science Foundation funded the research

The team tested their system during a field trip visit to the Jean Messieu School for the deaf

Research from one of the tests revealed that the signer should be displayed in the center of the lens

deaf participants could look straight through the signer as they focused on a planetarium show.

This was particularly surprising for researchers as they believed that deaf students would prefer to have a video displayed at the top, as Google Glass normally presents itself

Researchers hope that with further studies, this tool can also be used for literary guidance

One idea is when you're reading a book and come across a word that you don't understand, you point at it, push a button to take a picture

A trio of parachutes will then unfurl to slow it down for a splashdown in the Pacific Ocean

Orion is NASA’s next generation human rated vehicle now under development to replace the now retired space shuttle

“The Orion heat shield is the largest of its kind ever built. Its wider than the Apollo and Mars Science Lab heat shields,” Todd Sullivan

heat shield senior manager

The heat shield measures 16.5 feet in diameter

It is constructed from a single seamless piece of Avcoat ablator

The ablative material will wear away as it heats up during the capsules atmospheric re-entry thereby preventing the 4000 degree F heat from being transferred to the rest of the capsule

The Delta IV Heavy is the only rocket with sufficient thrust to launch the Orion EFT-1 capsule and its attached upper stage to its intended orbit of 3600 miles altitude above Earth

15 times higher than the International Space Station (ISS) and farther than any human spacecraft has journeyed in 40 years

At the conclusion of the two-orbit, four- hour EFT-1 flight, the detached Orion capsule plunges back and re-enters the Earth’s atmosphere at 20,000 MPH (32,000 kilometers per hour).

“That’s about 80% of the reentry speed experienced by the Apollo capsule after returning from the Apollo moon landing missions,” Scott Wilson, NASA’s Orion Manager of Production Operations

The big reason to get to those high speeds during EFT-1 is to be able to test out the thermal protection system

Numerous sensors and instrumentation have been specially installed on the EFT-1 heat shield and the back shell tiles to collect measurements of things like temperatures, pressures and stresses during the extreme conditions of atmospheric reentry

data gathered during the

flight will aid in confirming. or refuting, design decisions and computer models as the program moves forward to the first flight

in late 2017 on the EM-1 mission and more human crewed missions thereafter

The mission required the spacecraft to leave the Earth/moon system and orbit around the sun instead

After encounters with comet Giacobini-Zinner in 1985 and the famous Halley’s comet in 1986 and the study of CME’s from the sun in 1991, the “plug” was pulled in the spacecraft on 5 May 1997