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Showing posts with label SPACE VEHICLES. Show all posts
Showing posts with label SPACE VEHICLES. Show all posts

Successful launch of NASA's Orion spacecraft heralds first step on journey to Mars

Written By Unknown on Friday, January 2, 2015 | 5:36 PM

The United Launch Alliance Delta IV Heavy rocket, with NASA's Orion spacecraft mounted atop, lifts off from Cape Canaveral Air Force Station's Space Launch Complex 37 at at 7:05 a.m. EST, Friday, Dec. 5. Credit: NASA/Bill Ingalls
NASA marked a critical step on the journey to Mars with its Orion spacecraft during a roaring liftoff into the dawn sky over eastern Florida on Friday, Dec. 5, 2014, aboard a Delta IV Heavy rocket.

Once on its way, the Orion spacecraft accomplished a series of milestones as it jettisoned a set of fairing panels around the service module before the launch abort system tower pulled itself away from the spacecraft as planned.

The spacecraft and second stage of the Delta IV rocket settled into an initial orbit about 17 minutes after liftoff. Flight controllers put Orion into a slow roll to keep its temperature controlled while the spacecraft flew through a 97-minute coast phase.

The cone-shaped spacecraft did not carry anyone inside its cabin but is designed to take astronauts farther into space than ever before in the future.

Orion's first flight test is expected to be one for the books: the first mission since Apollo to carry a spacecraft built for humans to deep space, the first time NASA's next-generation spacecraft is tested against the challenges of space, and the first operational test of a heat shield strong enough to protect against 4,000-degree temperatures.

From today's launch on a gigantic United Launch Alliance Delta IV Heavy from Florida to the expected splashdown under billowing parachutes, the mission will test many of the riskiest events Orion will see when it sends astronauts to an asteroid and onward toward Mars in the future.

"Orion is the exploration spacecraft for NASA, and paired with the Space Launch System, or SLS, rocket it will allow us to explore the solar system," said Mark Geyer, program manager of Orion, which is based at Johnson Space Center in Houston.

While the Delta IV Heavy will send Orion on its flight test, SLS will launch the spacecraft on future missions.

NASA's Orion program has arrived at a fulcrum point that will tell its designers and builders how it stacks up technically. It also will show that NASA is ready to take the next step on its journey into deep space -- and ultimately to Mars.

So even though Orion is poised for a mere 4 1/2-hour, two-orbit mission without anyone on board, the cone-shaped craft needs to perform its roster of tasks well, including an all-important descent through Earth's atmosphere and splashdown.

"Really, we're going to test the riskiest parts of the mission," Geyer said. "Ascent, entry and things like fairing separations, Launch Abort System jettison, the parachutes plus the navigation and guidance -- all those things are going to be tested. Plus we'll fly into deep 
space and test the radiation effects on those systems."

The flight test began at Space Launch Complex 37 at Cape Canaveral Air Force Station.

The second stage will ignite again about two hours into the flight to send Orion through the Van Allen radiation belts and to a peak altitude of 3,609 miles, some 15 times higher than the International Space Station. This is going to be a key point in the test flight as instruments inside Orion record the radiation doses inside the cabin -- critical data for mission planners considering the best way to safely send astronauts into deep space in the future. Orion's cameras will be turned off during its passes through the belts to protect them.

Three hours, 23 minutes into flight, the Orion crew module will fly on its own following separation from its service module and the Delta IV Heavy second stage. The spacecraft will be aimed at Earth's atmosphere and it will be up to Orion's onboard computers to set the spacecraft in the right position so its base heat shield can bear the brunt of the intense reentry heat.

Hitting the atmosphere at 20,000 mph four hours and 13 minutes after launch, Orion will encounter about 80 percent of the heat it would endure during a return from lunar orbit with astronauts aboard. Ground controllers will lose contact with Orion for 2 1/2 minutes during reentry when the spacecraft is surrounded by plasma. They should regain communications with the craft just before the forward bay cover is jettisoned in a process that will begin the parachute deployment. After about four hours, 23 minutes, Orion will be bobbing in the Pacific Ocean off the coast of Baja California as recovery forces move in.

Teams from NASA's Ground Systems Development and Operations Program based at Kennedy will work with U.S. Navy and Orion prime contractor Lockheed Martin personnel to bring the spacecraft into the well deck of the USS Anchorage, an amphibious ship with a protective enclosure that will allow Orion to basically float onboard without having to be lifted by a crane. A second ship, the USNS Salvor, also will be on hand as a backup.
Many aspects of the mission point to a future as ambitious as any time in NASA's 50-plus-year history.

With lessons learned from Orion's flight test, NASA can improve the spacecraft's design 
while building the first Space Launch System rocket, a heavy booster with enough power to send the next Orion to a distant retrograde orbit around the moon for Exploration Mission-
1. Following that, astronauts are gearing up to fly Orion on the second SLS rocket on a mission that will return astronauts to deep space for the first time in more than 40 years. 

These adventures will set NASA up for future human missions to an asteroid and even on the journey to Mars.

"To be able to even think about going to an asteroid and to be able to think about this kind of exploration, that's very exciting," Kennedy Space Center Director Bob Cabana said. "I think there's a genuine, positive atmosphere, and I don't think it's confined to just Kennedy. You go across all the NASA centers and I think the team is really excited about the future."
And while all that work is happening on the ground, astronauts on the International Space Station will continue the groundbreaking research that is already adding to humanity's understanding of everything from long-duration spaceflight to the continued experimentation on products and processes that improve life on Earth.

None of those plans has caused NASA or Lockheed Martin, which is operating this flight test, to look past the crucial steps needed to make this mission a success.

Lockheed Martin assembled the spacecraft in the high bay at the Operations and Checkout Building at NASA's Kennedy Space Center in Florida, a facility recently named for Neil Armstrong, first man to walk on the moon.

While the mission is expected to make a huge impact on the way the next Orion is built, many lessons from the buildup of this spacecraft are already being incorporated in the planning for the next one, Geyer said.

"This has shown it's a good design, it's a good mission and now it's time to go fly," Geyer said.

Source: NASA

Gecko grippers get a microgravity test flight

Written By Unknown on Monday, December 29, 2014 | 5:57 AM

Scientists at NASA's Jet Propulsion Laboratory in Pasadena, California, are working on adhesive gripping tools that could grapple objects such as orbital debris or defunct satellites that would otherwise be hard to handle.
Credit: Image courtesy of NASA/Jet Propulsion Laboratory
There are no garbage trucks equipped to leave the atmosphere and pick up debris floating around Earth. But what if we could send a robot to do the job?

Scientists at NASA's Jet Propulsion Laboratory in Pasadena, California, are working on adhesive gripping tools that could grapple objects such as orbital debris or defunct satellites that would otherwise be hard to handle.

The gecko gripper project was selected for a test flight through the Flight Opportunities Program of NASA's Space Technology Mission Directorate. As a test, researchers used the grippers in brief periods of weightlessness aboard NASA's C-9B parabolic flight aircraft in August.

"Orbital debris is a serious risk to spacecraft, including the International Space Station," said Aaron Parness, a JPL robotics researcher who is the principal investigator for the grippers. "This is definitely a problem we're going to have to deal with. Our system might one day contribute to a solution."

The gripping system developed by Parness and colleagues was inspired by geckos, lizards that cling to walls with ease. Geckos' feet have branching arrays of tiny hairs, the smallest of which are hundreds of times thinner than a human hair. This system of hairs can conform to a rough surface without a lot of force. Although researchers cannot make a perfect replica of the gecko foot, they have put "hair" structures on the adhesive pads of the grippers.

The synthetic hairs, also called stalks, are wedge-shaped and have a slanted, mushroom-shaped cap. When the gripping pad lightly touches part of an object, only the very tips of the hairs make contact with that surface.

"The stickiness of the grippers can be turned on and off, by changing the direction in which you pull the hairs," Parness said.

To get the gripper to stick to a surface, force is applied to the adhesive pad material in a manner that makes the hairs bend. This increases the real area of contact between the hairs and the surface, which corresponds to greater adhesion. When the force is relaxed and the hairs go back to being upright, this process turns off the stickiness.

A phenomenon called van der Waals forces, named for Nobel Prize-winning physicist Johannes Diderik van der Waals, explains the non-permanent stickiness of the grippers, as well as gecko feet. These temporary adhesive forces happen because electrons orbiting the nuclei of atoms are not evenly spaced, creating a slight electrical charge. Such forces persist even in extreme temperature, pressure and radiation conditions.

"The reliability of van der Waals forces, even in severe environments, makes them particularly useful for space applications," Parness said.

"The system could grapple objects in space that are spinning or tumbling, and would otherwise be hard to target," he said.

In the recent tests, the grippers were able to grapple a 20-pound cube as it floated. The grippers also were able to grapple a researcher wearing a vest made of spacecraft material panels, representing a 250-pound "object." 

Members of the research team held the device with adhesive pads during the test, but the eventual idea is to integrate the grippers into a robotic arm or leg.
In total, the grippers have been tested on more than 30 spacecraft surfaces at JPL. They also have been tested successfully in a JPL thermal vacuum chamber, with total vacuum conditions and temperatures of minus 76 degrees Fahrenheit (minus 60 degrees Celsius) to simulate the conditions of space. While Parness was in graduate school at Stanford University in Palo Alto, California, the grippers were tested separately in more than 30,000 cycles of "on" and "off," with the adhesive staying strong. Several prototypes have since been designed.
There are more than 21,000 pieces of orbital debris larger than 3.9 inches (10 centimeters) in Earth's orbit. The U.S. Space Surveillance Network routinely tracks these objects. In 2009, an accidental collision occurred between an operational communications satellite and a large piece of debris, destroying the satellite.

Besides grappling orbital debris, the grippers could help inspect spacecraft or assist small satellites in docking to the International Space Station. The grippers are another example of how technology drives exploration.
The California Institute of Technology manages JPL for NASA.

 
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