Tag Archives: engineering

Imaging the ground under the Greenland ice sheet

In a paper published today in Geophysical Research Letters of the American Geophysical Union, scientists describe how they have been able to produce remarkably detailed images of the ground buried almost a mile under the ice sheet of Greenland. These radar techniques are the same used in the past by spacecraft to image the hidden surface of Venus, only far more sophisticated.

The grooves on the surface of Greenland

This image from the paper compares the radar image of the Greenland surface (on the left) to an photograph of a known surface feature in the Northwest Territories of Canada, produced thousands of years ago by the giant icesheets of the last Ice Age. Both are at the same scale, about a third of a mile across, and are looking at the surface at an oblique angle of about 45 degrees. With the radar-produced image on the left, sunlight is simulated as coming from the right, with the elevation increasing as the colors go from green (lowest) to yellow to brown to purple (highest).

The long grooves, generally 30 to 100 feet deep and extending sometimes several miles, are produced as the icesheet slides across the ground. In the radar image, however, these grooves are slowly being ground out now.

It is the resolution of this technique that is so exciting. That they can look through ice almost a mile thick and resolve objects that are only tens of feet across tells me that someday it will be possible for spacecraft to map the smallest features on the surface of Venus or Titan. More exciting, this suggests that the technology will one day exist to even map the unknown surface of gas giants like Jupiter or Saturn, and do it in breathtaking detail.



A private science mission to an asteroid?

A proposal to revive a project to send a private science probe to an asteroid.

The original project, NEAP, was proposed back in 1997 by the late Jim Bensen of SpaceDev (now Sierra Nevada). Benson wanted to not only do research, but he planned to claim the asteroid as his property upon landing. Though his proposal never flew, it was clearly a forerunner to today’s resurgence of the private space industry, and in many ways kickstarted that resurgence.


Two old unused Soviet Almaz space stations sold to private company

Two old unused Soviet Almaz space stations have been sold to a private company and have arrived in their new home on the Isle of Man. Key quote:

The stations will be initially stored in Jurby, but there plans for research, testing and possible launch into orbit.

For those who do not know, the Almaz station was built in the 1970s by the Soviet Union to do manned military reconnaissance. Two manned Almaz stations were eventually flown, Salyut 3 and Salyut 5. The station hull itself became the fundamental module for all subsequent Soviet/Russian stations, including Mir and ISS.


Charles Bolden has come out of hiding

Today NASA administrator Charles Bolden spoke at the AIAA meeting in Orlando. According to Florida Today, he said two things of interest:

  • He is proud of the achievements of the shuttle program and is sad the program is ending.
  • He believes flying three more shuttle missions would be safe.

Considering that his administration has done nothing to save the program, and in fact has almost seemed eager to shut it down at times, his sadness seems incredibly insincere and self-serving.

As for his second comment about the shuttle’s safety, I wonder how he knows this, especially since his own engineers are currently struggling to pin down the root cause of the external tank cracks that have delayed the last flight of Discovery, and appear to be a chronic problem that needs to be fixed before any shuttle can once again fly.


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.”


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.


India’s geosynchronous rocket fails at launch

Bad news for India’s space program: It’s geosynchronous rocket, GSLV, failed today less than two minutes after launch. Key quote:

[The Indian Space Research Organization (ISRO)] has had a troubled past with GSLV, with only two of the seven launches so far claiming total success. Though ISRO claims that four launches had been successful, independent observers call at least two of them either failure or partial success. When it comes to launching its workhorse PSLV, ISRO has had 15 consecutive successes.


China Matches U.S. Space Launches for First Time

The new colonial movement: For the first time China has matched the U.S. in space launches. Note that though the above article implies it, the U.S. has quite often not been the yearly leader in launches, as Russia has often topped the list. Nonetheless, with China now becoming more competitive the future of space travel can only get bettter.


A Martian eclipse

The hubbub about this week’s lunar solstice eclipse was, from my perspective, mostly manufactured press blather. For those who had never seen a lunar eclipse, it was a spectacular experience, but there really was nothing scientifically or technically unique about the fact that it happened to occur on the solstice.

However, below is an eclipse that is definitely unique both technically and scientifically. Scientists using the Mars rover Opportunity have filmed an eclipse on Mars, showing the Martian moon Phobos crossing in front of the Sun. Consider the engineering accomplishment: not only did they need to be able to calculate exactly when this would happen at a very particular spot on the Martian surface, they had to have a camera there able to take the movie. And they had to operate it from Earth!


Electricity from wind plant so expensive no one will buy it

The electricity produced from a proposed wind plant will be so expensive the company can’t find customers. They do have one customer, however, but one wonders why:

In its 15-year deal, National Grid agreed to pay 18.7 cents per kilowatt hour for Cape Wind power beginning in 2013, with a 3.5 percent annual increase. The starting price is twice what National Grid pays today for power from fossil fuels, and regulators say the contract will add about 1.7 percent to its residential customers’ bills.

Read the whole article. It explains a lot about the failures of renewable energy, and how the efforts of the government and environmentalists to force it on us is misguided and downright foolish.


A team of explorers and scientists have today completed the first there-and-back crossing of Antarctica in wheeled vehicles.

A 10-man team of explorers and scientists today completed the first there-and-back crossing of the continent of Antarctica using wheeled vehicles. From the expedition blog:

We quickly took ourselves to the mess tent for some hot coffee and something which we had been craving for a while – Coca Cola. The feeling among the team was satisfaction and elation at what we had achieved and relief that the belt drive had held out! The first Expedition ever to travel coast to coast and back again, with the privilege of visiting the South Pole twice. We joked in the mess tent before deciding that we were not going to sleep and headed over to the Mechanic Area and back to the vehicles.

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