Damaged Tiles Aren’t a Risk to Endeavour

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With a detailed mock up in hand of the damaged region on the shuttle Endeavour’s underside, NASA engineers have been submitting the area to rigorous tests and computer simulations. Good news. From what they can tell so far, the spot probably isn’t a risk to the safety of shuttle during its reentry, and astronauts probably won’t even need to make repairs.

To perform their experiments, engineers created a duplicate of Endeavour’s damaged section, and then put it into an arc jet. This is a room-sized blowtorch that recreates the conditions of reentry on the shuttle’s tile system. Even though the temperature on the surface of the tiles reached 1090 degrees Celsius (2,000 degrees F), the temperature on the bottom of the gouge only peaked at 170 degrees Celsius (340 degrees F). This is below the limits set by NASA.

However, even if the temperatures remain within tolerance levels, NASA would also want to avoid any lengthy and expensive repairs to the shuttle on the ground, and might get the astronauts to make the repairs. John Shannon, the chairman of the mission management team said on Tuesday that he was “cautiously optimistic” that no on-orbit repairs would be necessary.

As a point of comparison, the suitcase sized chunk of foam that dislodged, and ultimately destroyed the space shuttle Columbia weighed 750 grams (1.67 pounds), while Endeavour’s fragment is thought to be about 100 grams (3.5 ounces). Columbia’s foam strike was on the leading edge of the wing, which experiences some of the hottest temperatures of reentry, while Endeavour’s was down near the landing gear, on a region which is much cooler.

And if you really want to get to know the gouge. Check out this amazing video from NASA that has turned the damaged section into a 3-D animation. You might question their assessment of the risks, but wow, they really know the damage.

NASA Mulls Orbital Shuttle Repair

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As it was approaching the International Space Station, the space shuttle Endeavour performed a back flip maneuver to expose its underside to the station residents. The astronauts captured high-resolution images of the shuttle’s underbelly, and uploaded them to NASA analysts to see how the shuttle fared during takeoff. Not well, apparently.

NASA engineers back on Earth are studying a gouge made in the shuttle’s protective tile system by a chunk of foam that fell during launch. The gouge was carefully measured by a laser and camera system attached to the shuttle’s robotic arm. The gash runs all the way through a tile on the underside of Endeavour, exposing bare metal. Engineers will perform a series of heat tests to understand the thermal properties of the damage. Tiles with a physical mockup of the damage will be exposed to similar conditions that Endeavour will face during reentry to understand the risks involved.

Once they understand the extent of the damage, and the potential risk to the shuttle, NASA will make a decision if and how the astronauts will repair the damage. They have three options: paint the section, screw in a protective plate, or fill the hole with a special protective goo.

Now, onto the actual mission. Their first spacewalk was on Saturday, August 11th. Rick Mastracchio and Dave Williams stepped outside to install the new starboard truss segment to the end of the International Space Station. Their entire trip outside lasted 6 hours and 17 minutes, and was hassle free, except for a computer shutdown in NASA’s Destiny laboratory. This forced backup computers to take over the operations of the module, but had no impact on the spacewalk.

The second spacewalk begins on Monday. This time, Mastracchio and Williams will step outside the station again, but this time to replace a broken gyroscope that the station uses to keep itself oriented. This spacewalk will also last approximately 6.5 hours. While the station can maintain its orientation with just two gyroscopes, it’s preferable to have all 4 working, to help spread the load of all the additional modules being added.

Source:NASA Status Report

Endeavour Reaches the Station

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The space shuttle Endeavour reached its orbital destination today, linking up with the International Space Station. The shuttle was piloted in by commander Scott Kelly, who aligned the docking ring in Endeavour‘s cargo bay to a port on the front of the Destiny laboratory module.

Just before the arrival, Kelly stopped the shuttle about 400 metres (1,300 feet) away from the station, and then slowly back-flipped, so that astronauts on board the station could take detailed photographs of the shuttle’s wings and belly. NASA engineers will then study these images to see if there was any damage to the shuttle’s heat tile system caused during launch – a few pieces of foam were seen falling during launch, but nothing too damaging.

Once the visual inspection was completed, the two vehicles connected at 2:02 pm EDT, and the station’s residents officially welcomed the visiting astronauts aboard. Station commander Fyodor Yurchikhin rang a ship’s bell on the station signifying their arrival; one of the traditions left over from the shuttle’s nautical heritage.

The astronauts will enter the station for the first time later this afternoon, after they’ve completed checking the two spacecraft’s connection for any pressure leaks. They will also begin transferring cargo, and prepare for the upcoming spacewalks and installation of the S5 truss.

The newly equipped Station-to-Shuttle power transfer system will get its first test this afternoon as well. This system will reroute power from the station’s electrical system to the visiting shuttle. If this works properly, the shuttle mission will probably be extended from 11 days to 14, and the astronauts will perform an additional spacewalk.

Original Source: NASA News Release

Endeavour is Off to the Space Station

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Thanks to the improved weather, the space shuttle Endeavour blasted off from Florida’s Cape Canaveral on Wednesday right on schedule, at 2236 UTC (6:36 pm EDT). Within minutes, the shuttle had released its solid rocket boosters and external fuel tank, and was drifting right on target towards Friday’s encounter with the International Space Station.

Mission STS-118 has begun.

Over the course of the next 11-14 days, Endeavour will link up with the station and transfer over a cargo hold full of food, water, air, fuel, equipment, and experiments. It’s also carrying a starboard truss section that astronauts will bolt onto the station’s backbone, enhancing its size and capacity.

Once the shuttle docks, the astronauts will carry out a series of 3 spacewalks to connect the truss, and replace one of the station’s gyroscopes. They’ll also install an external stowage platform. An additional 4th spacewalk is also a possibility, to attach a new camera boom that future missions could use to inspect their spacecraft for damage to heat tiles. That’s what would extend the mission from 11 to 14 days.

This is the first time that Endeavour has launched since the Columbia disaster killed 7 astronauts back in 2003. NASA has taken the time to give the shuttle a complete overhaul, upgrading almost every part of the orbiter. It’s also been equipped with a new gadget that will let it connect to the International Space Station’s power grid conserving its own batteries, and allowing it to operate longer.

Original Source: NASA News Release

Endeavour Cabin is Leaking Air

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Here’s another little bit of NASA bad news; let’s heap it on with the rest. Shuttle workers are trying to track down the source of an air leak on the space shuttle Endeavour that’s above acceptable limits. The problem was first discovered a few days ago, and engineers thought they’d tracked down the faulty nut. But even after tightening that nut, the cabin was still losing pressure.

This is a problem since Endeavour is supposed to blast off for the International Space Station at 7:02 pm EDT on August 7th. If they can’t trace the leak down quickly, it’ll push the mission back in an already crowded launch schedule.

If everything does go smoothly, Endeavour’s STS-118 mission will deliver cargo, spare parts and a new truss segment to the International Space Station.

Station’s New Oxygen Generation System Activated

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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

European Space Robot Tested Underwater

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Normally I wouldn’t bring this kind of thing to your attention, but this is just the craziest thing: meet Eurobot. The photo attached to this story really doesn’t do it justice. You’ve got to check out the original ESA news release, with a video of Eurobot crawling around a mockup of a space station. It’s hypnotic.

All right, I’m getting ahead of myself. Time for details.

Eurobot is a multi-jointed, three-armed robot being developed by ESA. At some point down the road, it’ll be lofted to the International Space Station, where it’ll crawl around the exterior of the station performing various fix-it jobs; the dangerous and mundane stuff currently done by humans.

Although astronauts will still be needed to complete extravehicular spacewalks, an assistant like Eurobot could do the initial preparatory work, transfer tools and equipment, and help clean up when the work’s done. There’s a shortage of astronaut time, so any way to make the job run more efficiently would be greatly appreciated.

So this week, a prototype robotic assistant was tested out in a weightless environment. Not space, but a gigantic pool where astronauts train to perform tasks in weightlessness. Eurobot crawled around a mockup of the space station, and engineers were able to put it through its paces. It even interacted with a human astronaut, passing him tools and helping out.

Like I said, though, you’ve really got to see the video.

Original Source:ESA

Computer Glitch Hits the Station Hard

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Computers on board the International Space Station crashed this morning, shutting down its orientation, water and oxygen supply. The 10 astronauts on board both the station and the visiting space shuttle Atlantis are in no immediate risk, but the glitch could push back Atlantis’ mission a day or more.

The Russian-built computer controlling these services went down for unknown reasons over the night. Officials in the US and Russia think it might have been caused by something electrical, and not a computer software problem. Flight controllers in Moscow were able to regain partial communications with the computer, and some of their functionality was brought back online.

The crew got quite a scare for a few hours, though. A malfunctioning fire alarm went off in the Russian Zarya module, but there was no indication of fire or smoke in the module.

In the worst-case scenario, the three crewmembers of the space station will have to evacuate, returning to Earth early, but the station has a 56-day oxygen supply left, so there’s no panic.

Atlantis has been using its thrusters to keep the station oriented until the problem can be solved.

Original Source: NASA Status report