Last week AP and NasaWatch broke the news that engineers were worried Ares, the replacement for the shuttle, could shake itself to pieces in the first few minutes of flight. “They know it’s a real problem. This thing is going to shake apart the whole structure, and they’ve got to solve it,” AP was told by Paul Fischbeck, of Carnegie Mellon University, who analysed risks for NASA in the past.

According to AP, acceleration pulses from gas vortices in the solid rocket booster powering the Ares launcher match the natural frequencies of the motor’s combustion chamber. This kind of resonance is bad – as any physics student shown footage of the Tacoma Narrows Bridge can testify. I don’t know if this is quite the same thing as the pogo oscillations that plagued the Saturn V rockets, but it sounds similar and it’s worth noting that Ares is nicknamed ‘The Stick’.

Later, NasaWatch got hold of a NASA memo that seemed to show that the Ares launch had been delayed by 12 months (blog post, memo). However Griffin has denied this. His slightly tetchy denial is rather convoluted but he says this is not a delay but a “re-phasing” of milestones (NasaWatch blog post). Clear on that?

Image: artist’s rendition of an Ares I rocket on launch pad / NASA