NASA Selects Boeing and SpaceX for Commercial Crew Contracts

Under the Commercial Crew Transportation Capability (CCtCap) contracts, the two companies will

continue development of spacecraft capable of transporting NASA astronauts to and from the International Space Station as early as 2017, ending the agency’s dependence on Russian Soyuz spacecraft.

The contracts cover the development and certification of the spacecraft, including at least one test flight with both NASA and commercial crewmembers on board. The awards also fund between two and six operational flights to the ISS, each carrying four astronauts, once NASA certifies each company’s vehicle. Unlike previous phases of NASA’s commercial crew program, which used funded Space Act Agreements that provided greater flexibility, the CCtCap awards are fixed-price contracts.

“This was not an easy choice,” NASA Administrator Charles Bolden said at the Sept. 16 announcement at the Kennedy Space Center, “but this is the best choice for NASA and the nation.”

Boeing will receive $4.2 billion to build the CST-100 spacecraft, which it has been working on since the initial phases of NASA’s commercial crew program in 2010. The spacecraft will be launched on a United Launch Alliance Atlas 5 rocket.

“Boeing has been part of every American human space flight program, and we’re honored that NASA has chosen us to continue that legacy,” John Elbon, Boeing vice president and general manager for space exploration said in a company press release. “The CST-100 offers NASA the most cost-effective, safe and innovative solution to U.S.-based access to low-Earth orbit.”

SpaceX will receive $2.6 billion to build its Dragon V2 spacecraft, an upgraded version of the Dragon spacecraft currently used to transport cargo to and from the ISS. Dragon V2 will launch on the company’s Falcon 9 v1.1 rocket. 

See more

Read More

Mission to Pluto Is Like a Next-Gen Voyager

Yesterday, a cosmic coincidence brought together two spacecraft. One, a veteran cosmic explorer, is hurtling

ever outward toward the hinterlands of the solar system. The curtain is still waiting to rise on the other, a relative youngster that will soon be stepping into the spotlight.

On August 25, the Pluto-destined New Horizons spacecraft crossed Neptune’s orbit — 25 years to the day after its elder sibling, Voyager 2, swooped in for a close look at the big, blue ice giant and its curious, geyser-spewing moon.

That cosmic collusion of events helps mark the passing of a torch from one generation of space explorers to another, scientists said during a press conference commemorating the occasion.

A quarter-century ago, Voyager 2 beamed the first good images of Neptune back to Earthly eyes. Now, of course, Neptune isn’t anywhere near where it was then. But that didn’t stop New Horizons from snapping a quick photo as it zoomed over Neptune’s invisible footsteps. From 4 billion kilometers away, the giant planet and its weird moon Triton appear as nothing more than a few tiny pixels, a bit brighter than the inky black background.

For many, exploring the Pluto system will be the modern equivalent of the Voyager mission, says New Horizons principal investigator Alan Stern.

“This is the first opportunity in a generation to really explore a new planetary system for the first time,” he said. “When I was growing up, we had the privilege of seeing the first orbiter at Mars, and the first landers. And then, the first missions to Jupiter, to Saturn and Uranus and Neptune. And they were enthralling. And they were mind-blowing in terms of the richness of nature. But there hasn’t been anything like this yet in a long time.”

I think it’s safe to say that the spotlight will be firmly fixed on New Horizons when it pulls up next to Pluto in July 2015 and sends those first detailed images of the dwarf planet back to Earth. It’ll be like sending a long-awaited interplanetary postcard to millions of people at once.

Pluto is the most farflung system we will have explored. That enormous distance means we know relatively little about the tiny planet, which is faint and hard to see, even for the most powerful telescopes. “Even with all of our modern technology, everything we know about the Pluto system today would probably fit on one piece of paper,” Stern said, gesturing to a regular old piece of paper.

The same could probably be said for several of the giant planets in the 1980s. Putting the issues of politics and funding aside, these are stories of discovery on the grandest scale, of visiting new worlds and revealing new vistas.

Erupting Ice

Take Neptune, for example. Until Voyager arrived in 1989, the planet was a small blue smear in the sky. But Voyager saw much more than that. Fragments of rings gracefully hugged the space near the planet’s equator. A storm the size of Earth left a large, dark blue blotch on the cerulean surface (the Great Dark Spot had disappeared by the time Hubble aimed its eye at Neptune five years later). Methane clouds high in Neptune’s atmosphere hovered in relief above the otherwise smooth, gassy world. “The planet also had the highest speed winds of any that we had seen in the solar system — over 1,000 milers per hour,” says Voyager project scientist Ed Stone. “We were surprised to find such an active atmosphere so far from the sun.”

High altitude clouds streak Neptune’s atmosphere. (NASA/JPL)

And then there was Neptune’s strange little moon, Triton. Before Voyager arrived, teams had no idea what they would find. Unlike some of the other outer planet moons, Triton was not formed in the same neighborhood as Neptune. Instead, it grew up far, far away, in a region known as the Kuiper Belt. That distant band of rocky objects is home to the likes of Pluto and its dwarfy brethren.

“Triton was captured by Neptune and probably had geologic activity early in its history. But we had no idea, really, what it was going to look like,” Stone says. “There were many surprises ahead for us.”

The flyby revealed an active world with strange surface features (dubbed “cantaloupe terrain”), fractures, icy lava and geysers strewing dark material across the moon’s bright polar cap. “Even at the most remote edges, we have an active, alive surface on this cold little moon,” Stone says.

Now, a new animation using re-processed images from Voyager recreates that early flyby.

Voyager 2 Encounter with Triton(Youtube)

Link

Read More

The Age of Comets

Whistling and moaning, a 50-mile-an-hour (80-kilometer-an-hour) wind whipped among the telescope

domes atop Kitt Peak. Just a few feet below, turning gray in the dusk, slid a river of clouds that had been rising and dropping all day. And high above, comet Hale-Bopp hung suspended like a feathery fishing lure, its tail curving off a bit, as if blown to the side by the punishing wind.

One by one, stars winked on in a darkening sky. In each of the telescope domes, teams of astronomers prayed that the wind would drop below 40 miles per hour (64 kilometers an hour), the point at which they'd be able to open the sliding doors and get back to work.

The sky turned indigo. Then black. Viewed from the summit, 6,873 feet (2,095 meters) above Arizona's Sonoran Desert, Hale-Bopp's bright dust tail, along with a dimmer, all but transparent blue one, seemed to grow by degrees. Among the brightest comets ever seen, Hale-Bopp had been visible for months from midtown Manhattan, of all places. But here, on a moonless night in the mountains in the desert, the length of Hale-Bopp's tail became visible—a wispy, delicate veil.

Along with eclipses, comets have been the most feared and admired sky spectacles of all. But while astronomers have been able to predict eclipses for thousands of years, only in the 1700s was a comet's return correctly predicted, by Edmond Halley.

Some comets swing around the sun every few years. Others, like Hale-Bopp, may take thousands of years. Most can be seen only with a telescope. But every once in a while—a few times a century, perhaps—an impressive one is visible to the naked eye. And in the past two years the world has witnessed not one but two of them.

Hyakutake in 1996 had one of the longest tails on record, stretching more than halfway across the sky; Hale-Bopp in 1997 had one of the most brilliant heads, nearly as bright as the star Sirius. Add the Jupiter crash of comet Shoemaker-Levy in 1994, Halley's most recent visit in 1986, vivid comet West in 1976, and the scientifically signifiant—if visually disappointing—Kohoutek in 1973-74, and you could say that we are indeed living in the age of comets.

Hovering in the most fragile of gravitational balances, a fleet of dirty, lumpy snowballs numbering in the trillions is barely held in orbit by the pull of the sun. They are stored in the Oort cloud, a huge, diffuse sphere of cometary nuclei in the far reaches of the solar system. Close to the sun, yet still beyond Neptune, circle what may well be their brethren, in a great disk called the Kuiper belt.

Comets are leftovers, scraps of material that didn't make it to planethood in the events creating our solar system. Once, many astronomers believe, the solar system was full of comet nuclei, chunks of ice and dust left over from the formation of the sun. Most clumped together to form planets, leaving a relative handful—averaging perhaps a few miles wide, with temperatures as low as minus 400 degrees Fahrenheit (minus 240 degrees Celsius)—as time capsules of the early solar system.

They orbit in a perpetual deep freeze until some subtle gravitational nudge upsets the delicate balance. Then the great fall begins. Imperceptibly at first, a snowball drifts toward the sun and steadily accelerates. As solar radiation heats the comet, the ice within sublimates, escaping as gas from vents at the surface. Sometimes jets of sublimating ice whirl off the rotating comet nucleus like a fireworks pinwheel. Dust trapped in the ice breaks free. Pushed back by the pressure of the sun's radiation, the dust streams out behind the comet in what appears as a fiery tail.

Rendezvous with a Comet (From youtube)

More...

 

Read More

What Is a Satellite?

A satellite is a moon, planet or machine that orbits a planet or star. For example, Earth is a satellite because it

Earth and the moon are examples of natural satellites. Thousands of artificial, or man-made, satellites orbit Earth. Some take pictures of the planet that help meteorologists predict weather and track hurricanes. Some take pictures of other planets, the sun, black holes, dark matter or faraway galaxies. These pictures help scientists better understand the solar system and universe.

Still other satellites are used mainly for communications, such as beaming TV signals and phone calls around the world. A group of more than 20 satellites make up the Global Positioning System, or GPS. If you have a GPS receiver, these satellites can help figure out your exact location.

Why Are Satellites Important?
The bird's-eye view that satellites have allows them to see large areas of Earth at one time. This ability means satellites can collect more data, more quickly, than instruments on the ground.

Satellites also can see into space better than telescopes at Earth's surface. That's because satellites fly above the clouds, dust and molecules in the atmosphere that can block the view from ground level.

Before satellites, TV signals didn't go very far. TV signals only travel in straight lines. So they would quickly trail off into space instead of following Earth's curve. Sometimes mountains or tall buildings would block them. Phone calls to faraway places were also a problem. Setting up telephone wires over long distances or underwater is difficult and costs a lot.

With satellites, TV signals and phone calls are sent upward to a satellite. Then, almost instantly, the satellite can send them back down to different locations on Earth.
 

orbits the sun. Likewise, the moon is a satellite because it orbits Earth. Usually, the word "satellite" refers to a machine that is launched into space and moves around Earth or another body in space.

What Are the Parts of a Satellite?
Satellites come in many shapes and sizes. But most have at least two parts in common - an antenna and a power source. The antenna sends and receives information, often to and from Earth. The power source can be a solar panel or battery. Solar panels make power by turning sunlight into electricity.

Many NASA satellites carry cameras and scientific sensors. Sometimes these instruments point toward Earth to gather information about its land, air and water. Other times they face toward space to collect data from the solar system and universe.

 

 

 

 Journey of a Satellite into Space (From youtube)

 

Learn more

Read More

NASA's MAVEN Spacecraft Makes Final Preparations For Mars

On Sept. 21, 2014, the Mars Atmosphere and Volatile Evolution spacecraft will complete roughly 10 months

of travel and enter orbit around the Red Planet.

The orbit-insertion maneuver will be carried out as the spacecraft approaches Mars, wrapping up an interplanetary journey of 442 million miles (711 million kilometers). Six thruster engines will fire briefly for a “settling” burn that damps out deviations in pointing. Then the six main engines will ignite two by two in quick succession and will burn for 33 minutes to slow the craft, allowing it to be captured in an elliptical orbit.

This milestone will mark the culmination of 11 years of concept and development for MAVEN, setting the stage for the mission’s science phase, which will investigate Mars as no other mission has.

“We’re the first mission devoted to observing the upper atmosphere of Mars and how it interacts with the sun and the solar wind,” said Bruce Jakosky, principal investigator for MAVEN at the University of Colorado in Boulder.

These observations will help scientists determine how much gas from Mars’ atmosphere has been lost to space throughout the planet’s history and which processes have driven that loss.

En route

Procedures to line up MAVEN for proper orbit insertion began shortly after MAVEN launched in November 2013. These included two trajectory-correction maneuvers, performed in December 2013 and February 2014.

Calibration of the mission’s three suites of science instruments – the Particles and Fields Package, the Remote Sensing Package and the Neutral Gas and Ion Mass Spectrometer – was completed during the cruise phase to Mars.

“Every day at Mars is gold,” said David Mitchell, MAVEN’s project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “The early checks of instrument and spacecraft systems during cruise phase enable us to move into the science collection phase shortly after MAVEN arrives at Mars.”

The voyage also gave the team an opportunity to take data on the interplanetary solar wind using the Fields and Particles Package.

Meanwhile, teams in California, Colorado and Maryland carried out rehearsals of the entire orbit insertion twice. The science team also performed a weeklong simulation of the planning and implementation required to obtain science data. Two months prior to arrival at Mars, all instruments were turned off, in preparation for orbit insertion.

Into orbit

During orbit insertion, MAVEN will be controlled by its on-board computers. By that time, the team will have uploaded the most up-to-date information about the spacecraft’s location, velocity and orientation. The insertion instructions will have been updated, and the fuel valves will be open, to warm the fuel to an operating temperature of about 77 to 79 degrees Fahrenheit (25 to 26 degrees Celsius).

If all goes well, the spacecraft will need no further commands from the ground. The important exception is that final trajectory corrections could be made, if needed, 24 hours or 6 hours prior to insertion. That would only happen, however, if the navigation team concluded that the spacecraft was coming in at too low of an altitude.

Otherwise, during the last 24 hours, the spacecraft will carry out preprogrammed procedures to make all systems as “quiet” as possible, which is the safest condition for orbit insertion. These steps include automatically executing a new version of the fault protection, which will tell the craft how to react to an on-board component anomaly leading up to or during orbit insertion.

In addition, the spacecraft will have to reorient itself so that the thrusters are pointed in the correct direction for the burn. In this final orientation, MAVEN’s high-gain antenna, which is used for most communication with the spacecraft, will point away from Earth. During that period, MAVEN’s low-gain antenna will be used for limited communication capacity at a reduced data rate.

At last, the insertion will begin. For the next 33 minutes, the craft will burn more than half the fuel onboard as it enters an orbit 236 miles (380 kilometers) above the northern pole.

Three minutes after the engines turn off, the MAVEN computers will reinstate the normal safeguards, reorient the spacecraft to point the high-gain antenna toward Earth, and reestablish normal communications. At that point, MAVEN will transmit the data obtained during the insertion back to Earth, along with information on the state of the spacecraft, and the MAVEN team will learn if everything worked properly.

“Then, there will be a sigh of relief,” said Carlos Gomez-Rosa, MAVEN mission and science operations manager at Goddard.

Later, the team will upload new instructions for the science portion of the mission, as well as turn on and check out the science instruments.

New view of Mars

The team will perform six maneuvers to move the spacecraft from its insertion orbit into the four-and-a-half-hour orbit that will be used to gather science data.

This science orbit will be elliptical, with the spacecraft flying about 90 miles (approximately 150 kilometers) above the surface at periapsis, or closest point, in the orbit to “sniff” the upper atmosphere. At apoapsis, the farthest point from the surface, MAVEN will pull back 3,900 miles (roughly 6,300 kilometers) to observe the entire atmosphere.

With each pass, MAVEN will make measurements of the composition, structure and escape of atmospheric gases.

“MAVEN’s orbit through the tenuous top of the atmosphere will be unique among Mars missions,” said Jakosky. “We’ll get a new perspective on the planet and the history of the Martian climate, liquid water and planetary habitability by microbes.”

Izumi Hansen and Elizabeth Zubritsky
NASA's Goddard Space Flight Center
Link

Read More

Waht is the satellite??

In the context of spaceflight, a satellite is an artificial object which has been intentionally placed into orbit. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon.

The world's first artificial satellite, the Sputnik 1, was launched by the Soviet Union in 1957. Since then, thousands of satellites have been launched into orbit around the Earth. Some satellites, notably space stations, have been launched in parts and assembled in orbit. Artificial satellites originate from more than 50 countries and have used the satellite launching capabilities of ten nations. A few hundred satellites are currently operational, whereas thousands of unused satellites and satellite fragments orbit the Earth as space debris. A few space probes have been placed into orbit around other bodies and become artificial satellites to the Moon, Mercury, Venus, Mars, Jupiter, Saturn, Vesta, Eros, and the Sun.

Satellites are used for a large number of purposes. Common types include military and civilian Earth observation satellites, communications satellites, navigation satellites, weather satellites, and research satellites. Space stations and human spacecraft in orbit are also satellites. Satellite orbits vary greatly, depending on the purpose of the satellite, and are classified in a number of ways. Well-known (overlapping) classes include low Earth orbit, polar orbit, and geostationary orbit.

About 6,600 satellites have been launched. The latest estimates are that 3,600 remain in orbit.^[1] Of those, about 1,000 are operational;^[2][3] the rest have lived out their useful lives and are part of the space debris. Approximately 500 operational satellites are in low-Earth orbit, 50 are in medium-Earth orbit (at 20,000 km), the rest are in geostationary orbit (at 36,000 km).^[4]

Satellites are propelled by rockets to their orbits. Usually the launch vehicle itself is a rocket lifting off from a launch pad on land. In a minority of cases satellites are launched at sea (from a submarine or a mobile maritime platform) or aboard a plane (see air launch to orbit).

Satellites are usually semi-independent computer-controlled systems. Satellite subsystems attend many tasks, such as power generation, thermal control, telemetry, attitude control and orbit control.

Read more...

Read More