Author: Robert Zimmerman

Shades of foam and failed o-rings?

10:23 pm

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.

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Continuing resolution likely into 2011

3:36 pm

The space war returns! The lame duck session of Congress is now expected to pass a continuing resolution that extends into next year, leaving the final decisions about the budget to the next Congress. This is very bad news for NASA and what’s left of the government space program.

Update: I should add that I’m not bothered in the slightest that this might happen. The money that the present Congress proposed giving to NASA will not make the exploration of the solar system possible, and in fact might hinder that exploration significantly under the weight of government regulation. It is time to cut the cord, and stop depending on the damn government to conquer the stars.

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The coming train wreck for Commercial Human Spaceflight

9:12 am

This post by retired NASA engineer Wayne Hale explains why it probably is a good idea if Congress cuts the subsidies for new commercial space: The coming train wreck for commercial human spaceflight. This is the key quote, where Hale describes the regulations NASA is requiring these new companies to meet:

The document runs a mind-numbing 260 pages of densely spaced requirements. Most disappointing, on pages 7 to 11 is a table of 74 additional requirements documents which must be followed, in whole or in part. Taken all together, there are thousands of requirement statements referenced in this document. And for every one NASA will require a potential commercial space flight provider to document, prove, and verify with massive amounts of paperwork and/or electronic forms.

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School Reverses Course After Ordering Student to Remove American Flag From Bike

5:03 pm

In a victory for free speech (from a battle that shouldn’t have been fought in the first place), a school has reversed course after ordering a 13-year-old student to remove the American flag from his bicycle because some students said they’d be offended. Key quote:

[School superintendent Edward] Paraz says the school . . . now will be shifting its focus to the students who complained. “In no way did we want to take that right away from Cody,” Paraz told Fox40 on Friday. “…We think we know who the instigators are that were trying to do that and we need to meet with their parents and those students to just kind of explain that this isn’t what we want to have.”

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Sinkholes on Mars

2:06 pm

Caver alert! Releases this week from both the Mars Express orbiter and the Mars Reconnaissance Orbiter show a variety of sinkholes and collapse features on Mars, which in turn suggest the possibility of underground passages.

First, there is this picture from Mars Express, showing the area called Phoenicis Lacus (Latin for Phoenix Lake).

Phoenicis Lacus

The large and long canyon in box 1 is actually a collapse feature, almost two miles deep and formed as this region was stretched, warped, and cracked by the powerful volcanic activity of the nearby giant volcanoes of the Tharsis plateau, including Olympus Mons, the solar system’s largest volcano. You can also see how this activity causes several sinkholes and craters in all three boxes to become elongated and distorted.

In places where the surface is deformed in this way on Earth, you often find tectonic caves, underground cracks produced as the ground is pulled apart. The large collapse feature suggests the possibility that there are voids below it.

Then there is this subimage from this release of Mars Reconnaissance Orbiter, showing the central peak and southern slope of an old crater in the Terra Sirenum region of the Martian southern hemisphere.

central crater peak

Down that south slope can be seen what look like fluvial-like flows. In the center of these flows as well as near the top of the peak are what appear to be a string of collapse features. Below is the close-up as indicated by the box above:

inset closeup of sinkholes

From the caption: “It is possible that these pits are evidence of subsurface piping or hydrothermal activity. Piping occurs when subsurface water flows through soil, takes some soil with it, and causes the overlying ground to collapse. These fluvial-like features and the connected pits may have formed during a late stage of crater formation when temperatures were suitable for liquid water.”

On Earth, this is one of the geological processes that forms sinkholes on the surface as well as caves underground. When cavers go out to look or dig for new caves, we often head for just this kind of string of sinkholes, as they are excellent evidence that an unentered cave lies hidden below, ripe for exploration.

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