Tag: shuttle
Vapor trails
Remembering Columbia
An evening pause: On this day eight years ago, the space shuttle Columbia broke up as it returned from orbit. Rather than watch that sad sight again, I’d rather remember the shuttle’s achievements. Watch this footage of Columbia’s first landing on April 14, 1981, which proved it was possible to glide powerless back from space and land safely on a runway. Though we as a nation might be abandoning this approach right now, future generations will use this as their standard way to return to Earth.
Several things to note as you watch the video. First, the shuttle’s angle of descent is extremely and frighteningly steep, until the very last moment. And every shuttle landing is like this. The shuttle is heavy, but it is still attempting to glide powerless to a landing. To do so it needs the thickness of the atmosphere combined with high speed to give it lift. Thus, it plows downward at a mucher higher speed and angle than any airplane, then quickly levels out at the last moment.
Secondly, this first landing did not have a drogue chute to slow the shuttle down. Rather than complicate things, they simply let the shuttle roll until it came to a stop.
Discovery rolls out to launch pad again
Discovery has once again rolled out to the launch pad for its final mission.
Discovery has once again rolled out to the launch pad for its final mission.
Challenger, 25 years later
Today is the 25th anniversary of the Challenger accident. There are innumerable links from many sources talking about the event, too many for me to list here. You can find most at this link on Jeff Foust’s website, spacetoday.net.
Though I think it is very important for us to remember and honor these events, I have become somewhat disenchanted with the modern American obsession with memorials and anniversaries. Rather than build a memorial, I’d much rather we focused entirely on building new spaceships, new space stations, and new lunar bases, while flying multi-year missions on ISS, all in preparation for exploring and colonizing the solar system.
If we actually made the solar system a place for humans to live in and explore, we would build a far better memorial to those who have sacrificed their lives for the sake of exploration. And I think these heroes would be far more pleased by that memorial than by a stone statue or emotional op-ed that describes their courage.
NASA sets final space shuttle mission for June 28
Though the money is not yet appropriated by Congress, NASA has set the date, June 28, for a third and final space shuttle mission.
Though the money is not yet appropriated by Congress, NASA has set the date, June 28, for a third and final space shuttle mission.
Injured astronaut replaced for next shuttle flight
NASA has named a replacement for astronaut Tim Kopra, who injured himself in a bicycle accident, for the next shuttle mission.
NASA has named a replacement for astronaut Tim Kopra, who injured himself in a bicycle accident, for the next shuttle mission.
Mark Kelly to decide in few weeks on shuttle command
The husband of Congresswoman Gabrielle Giffords, astronaut Mark Kelly, says he will decide in a few weeks whether to pull out as commander of Endeavour’s final mission.
The husband of Congresswoman Gabrielle Giffords, astronaut Mark Kelly, says he will decide in a few weeks whether to pull out as commander of Endeavour’s final mission.
Astronaut Tim Kopra, member of next shuttle crew, injured in bike mishap
The lead spacewalker for the next shuttle mission, the long-delayed last flight of Discovery, has apparently broken his hip in a bike accident. Key quote:
NASA does not train backup crews and a replacement, even a recently flown veteran, would need time to rehearse spacewalk scenarios and receive mission-specific training for Discovery’s flight. How long that might take, if required, and what impact it might have on the shuttle’s launch date is not yet known.
The lead spacewalker for the next shuttle mission, the long-delayed last flight of Discovery, has apparently broken his hip in a bike accident. Key quote:
NASA does not train backup crews and a replacement, even a recently flown veteran, would need time to rehearse spacewalk scenarios and receive mission-specific training for Discovery’s flight. How long that might take, if required, and what impact it might have on the shuttle’s launch date is not yet known.
NASA Names Backup Commander for Mark Kelly’s Shuttle Mission
NASA has named a backup to Endeavour’s commander Mark Kelly for the shuttle’s last flight, now set for launch on April 19. This is “to facilitate training for crew and support teams,” while Kelly focuses on the recovery of his wife, Congresswoman Gabrielle Giffords.
NASA has named a backup to Endeavour’s commander Mark Kelly for the shuttle’s last flight, now set for launch on April 19. This is “to facilitate training for crew and support teams,” while Kelly focuses on the recovery of his wife, Congresswoman Gabrielle Giffords.
NASA sets date for Discovery’s launch, Feb 24, confident tank problems are solved
NASA, confident that they have pinned down the cause of the cracks on the external tank, has set February 24 as the date for Discovery’s launch.
NASA, confident that they have pinned down the cause of the cracks on the external tank, has set February 24 as the date for Discovery’s launch.
Nelson suggests NASA might not get third shuttle flight
Not so good news: Nelson suggests NASA might not get a third shuttle flight.
Not so good news: Nelson suggests NASA might not get a third shuttle flight.
NASA expands work to boost tank strength
Good news: NASA decides to do more to strengthen the shuttle’s external tank.
Good news: NASA decides to do more to strengthen the shuttle’s external tank.
Space flight by Giffords’ husband may be in doubt
The shooting in Tucson might cause NASA to drop Congresswoman Giffords’ husband as commander of Endeavour’s last mission this spring.
The shooting in Tucson might cause NASA to drop Congresswoman Giffords’ husband as commander of Endeavour’s last mission this spring.
NASA rules out early February launch for shuttle Discovery
NASA management has once again delayed the launch of Discovery, pushing it back to late February in order to finish repairs to its external tank.
NASA management has once again delayed the launch of Discovery, pushing it back to late February in order to finish repairs to its external tank.
Root cause of tank cracks possibly found
NASA engineers think they might have found the root cause of the cracks that have been appearing on the shuttle external tank. The cracks appear on structural units called stringers. Key quote:
“Some material used for the stringers was found to be ‘mottled,’ with a different surface appearance than the standard material. Testing revealed this mottled material had lower fracture toughness than the nominal material and exhibited unstable crack growth. All of the cracks found during tanking as well as cracks fixed during manufacturing were located on stringers made with this mottled material.”
NASA engineers think they might have found the root cause of the cracks that have been appearing on the shuttle external tank. The cracks appear on structural units called stringers. Key quote:
“Some material used for the stringers was found to be ‘mottled,’ with a different surface appearance than the standard material. Testing revealed this mottled material had lower fracture toughness than the nominal material and exhibited unstable crack growth. All of the cracks found during tanking as well as cracks fixed during manufacturing were located on stringers made with this mottled material.”
Engineers considering repairs to shuttle tank
NASA engineers are considering giving Discovery’s external tank the equivalent of a girdle in order to keep it from developing more cracks during launch. Key quote:
If that decision is made, it is unlikely NASA could complete the work, repair the tank’s foam insulation and get Discovery back out to the launch pad in time to support a launch attempt during the next available window, which opens Feb. 3 and closes Feb. 10. Work to beef up all 108 stringers at the top of the intertank almost certainly would delay Discovery’s launch on a space station resupply mission to the next available window, which opens Feb. 27 and closes in early March.
NASA engineers are considering giving Discovery’s external tank the equivalent of a girdle in order to keep it from developing more cracks during launch. Key quote:
If that decision is made, it is unlikely NASA could complete the work, repair the tank’s foam insulation and get Discovery back out to the launch pad in time to support a launch attempt during the next available window, which opens Feb. 3 and closes Feb. 10. Work to beef up all 108 stringers at the top of the intertank almost certainly would delay Discovery’s launch on a space station resupply mission to the next available window, which opens Feb. 27 and closes in early March.
Discovery tank repairs ongoing
The repairs to the cracks on Discovery’s external tank continue, with the hope for a February 3 launch.
The repairs to the cracks on Discovery’s external tank continue, with the hope for a February 3 launch.
NASA Wraps Up X-ray Scans of external tank
Updated and bumped: The inspections reveal four additional cracks on Discovery’s external tank.
NASA engineers have finished a series of x-ray scans of Discovery’s external tank.
Updated and bumped: The inspections reveal four additional cracks on Discovery’s external tank.
NASA engineers have finished a series of x-ray scans of Discovery’s external tank.
Shuttle Tank test yields no initial clues to fuel tank cracks
The initial results from the tank test performed today on the shuttle external tank are as yet inconclusive.
The initial results from the tank test performed today on the shuttle external tank are as yet inconclusive.
Tank tests today for cause of cracks in shuttle external tank
NASA will be conducting tank tests today on the Discovery’s external tank in an effort to find the cause of the recently discovered cracks.
NASA will be conducting tank tests today on the Discovery’s external tank in an effort to find the cause of the recently discovered cracks.
Discovery launch delayed until February
It’s official: The launch of Discovery is delayed until February.
It’s official: The launch of Discovery is delayed until February.
Root cause of shuttle external tank cracks still not clear
Bad news for the space shuttle: The root cause of the cracks on Discovery’s external tank is still not identified.
Bad news for the space shuttle: The root cause of the cracks on Discovery’s external tank is still not identified.
NASA engineers struggle to analyze cause of cracks in tank
NASA engineers continue to struggle to analyze the cause of the cracks in Discovery’s external tank. Key quote:
Forty-three tanks have been constructed with the lighter alloy, requiring just more than 4,600 stringers. So far, 31 cracks have been found, including those on Discovery.
“All of those have been known assembly issues,” Shannon said of the previous cracks, which were traced to misalignments of the stringers as they were fastened to the tank or to mishandling in which the fragile stringers struck or were struck by other hardware. Discovery’s cracks were the first found and repaired at the launch pad using techniques previously employed only at the production plant.
The ongoing detective work is immune to schedule and budget pressure, according to Bill Gerstenmaier, NASA’s associate administrator for space operations.
NASA engineers continue to struggle to analyze the cause of the cracks in Discovery’s external tank. Key quote:
Forty-three tanks have been constructed with the lighter alloy, requiring just more than 4,600 stringers. So far, 31 cracks have been found, including those on Discovery.
“All of those have been known assembly issues,” Shannon said of the previous cracks, which were traced to misalignments of the stringers as they were fastened to the tank or to mishandling in which the fragile stringers struck or were struck by other hardware. Discovery’s cracks were the first found and repaired at the launch pad using techniques previously employed only at the production plant.
The ongoing detective work is immune to schedule and budget pressure, according to Bill Gerstenmaier, NASA’s associate administrator for space operations.
Discovery’s launch delayed until December 17 at the earliest
Discovery’s launch delayed until December 17 at the earliest. Key quote:
Shannon said that one of the concerns was that another major crack might liberate a piece of insulating foam large enough to damage Discovery, as happened during the January 2003 liftoff of Columbia. A suitcase-sized chunk of foam punched a hole in Columbia’s wing, dooming the ship and her crew of seven astronauts when they reentered the atmosphere.
Shannon said that teams were also examining the possibility that the tanks have been flying with undetected cracks for years.
Cracks became more common after the 1998 debut of “super-lightweight” tanks built with a more brittle aluminum-lithium alloy. Since then, 29 cracks in stringers making up the ribbed “intertank” section that separates liquid hydrogen and oxygen tanks have been found and repaired in 18 tanks, including Discovery’s and a tank scheduled for use by the shuttle Atlantis next summer.
Discovery’s launch delayed until December 17 at the earliest. Key quote:
Shannon said that one of the concerns was that another major crack might liberate a piece of insulating foam large enough to damage Discovery, as happened during the January 2003 liftoff of Columbia. A suitcase-sized chunk of foam punched a hole in Columbia’s wing, dooming the ship and her crew of seven astronauts when they reentered the atmosphere.
Shannon said that teams were also examining the possibility that the tanks have been flying with undetected cracks for years.
Cracks became more common after the 1998 debut of “super-lightweight” tanks built with a more brittle aluminum-lithium alloy. Since then, 29 cracks in stringers making up the ribbed “intertank” section that separates liquid hydrogen and oxygen tanks have been found and repaired in 18 tanks, including Discovery’s and a tank scheduled for use by the shuttle Atlantis next summer.
Update of Discovery’s launch status
An update of Discovery’s launch status, including possible launch dates.
An update of Discovery’s launch status, including possible launch dates.
Shuttle launch no earlier than December 3
NASA managers have once again delayed the launch of Discovery, now set for no earlier than December 3.
NASA managers have once again delayed the launch of Discovery, now set for no earlier than December 3.
Reviewing the flight rationale for Discovery’s launch
NASA management is reviewing the “flight rationale” for Discovery’s next mission, considering the cracks in the external tank. Key quote:
Troubleshooters are assessing the structural integrity of the tank and its foam insulation to develop the necessary flight rationale, or justification, for proceeding with another launch as early as Nov. 30.
NASA management is reviewing the “flight rationale” for Discovery’s next mission, considering the cracks in the external tank. Key quote:
Troubleshooters are assessing the structural integrity of the tank and its foam insulation to develop the necessary flight rationale, or justification, for proceeding with another launch as early as Nov. 30.
Shades of foam and failed o-rings?
A fourth crack has been found on Discovery’s external tank. How this will affect Discovery’s November 30 launch remains unknown. There will a briefing on Monday to discuss the status of the schedule. This quote however gives me the willies:
External tank crack repairs are not unusual. Some 29 stringer cracks were found in 18 previous tanks, according to an official familiar with their history. Four have now been found in Discovery’s tank, ET-137, and three were found in a tank scheduled for use by the shuttle Atlantis next summer, ET-138. Doublers were used in 23 repairs.
There is a saying that we always fight the last war. After the Challenger accident NASA made great effort to prevent another o-ring failure in the solid rocket boosters, and ignored the foam falling from the external tank. After the Columbia accident, NASA then made great effort to prevent another piece of foam from hitting an orbiter.
Unfortunately, it appears that NASA may now be ignoring this crack problem. Even though they have been able to repair past cracks, for this many cracks to occur this often should cause alarm bells to ring throughout the agency, forcing a look at the problem in toto. Instead, it appears management has been making catch-as-catch-can repairs.
What makes this situation even more difficult is the factory that makes the external tanks has shut down. No new tanks are available. Thus, there are not many options for flying these last few shuttle missions except by using the already existing tanks, and repairing them as needed.
Like I said, this is beginning to give me the willies.
Third crack found on Discovery’s external tank shell
A third crack has been found on Discovery’s external tank shell.
A third crack has been found on Discovery’s external tank shell.
Leaking vent line attachment disassembled, apparent seal problem found
Engineers have apparently found the cause of the leak in the hydrogen fuel line to Discovery’s external tank.
Engineers have apparently found the cause of the leak in the hydrogen fuel line to Discovery’s external tank.