Then again, it may not be:
…there were early claims by engineers and Ares I supporters that the test proved that that the Ares I rocket won’t shake violently during its ascent to orbit — as had been predicted — and that the shaking problem, called thrust oscillation, is no longer an issue for NASA.
But as the data is studied further, engineers and managers for NASA and ATK say those early conclusions are overstated.
NASA’s associate administrator for space operations, Bill Gerstenmaier, told NASA officials and contractors not to repeat the claims, especially to members of Congress, because, “That is not what the test showed.”
Picky, picky, picky. That mean old Gerst is such a party pooper.
Guys, it’s not possible to know how a motor will perform dynamically in free flight from a horizontal hold-down test. At best, they got some valid data to plug into the dynamics models, the latter of which they may or may not have confidence in (though the Ares I-X test will help to validate — or invalidate — them).
[Update a few minutes later]
“Rocketman” has similar thoughts:
Drawing good news conclusions from one test, pinned to the ground, is folly. Proposing Ares 1 as a tech development program for Ares V is also folly. And taking a crap shoot like Ares 1X is desperate folly. But, these are the kind of fool’s games that will be played from here to cancellation.
It will continue until the administration comes up with a policy. But like Afghanistan, it seems determined to continue to kick the can down the road for now. I don’t envy Administrator Bolden right now.
Hrm, NASA ignoring engineering facts about problems with solid rockets on manned launch vehicles. I’m sure this’ll go better than the last time this happened, right? Right?
See, after you remove the oscillation overthruster, all those problems go away!
Sigivald: no matter where you go, there you are.
So we’ve done a hold-down test which doesn’t prove anything because it’s the actual booster but the dynamics are all wrong, and we want to do a flight test of a different booster, which will also prove nothing.
On this basis, we plan to build the future of manned space flight in the US?
I used to think my kids might go to the moon. Now, I doubt my grandkids will…
All this test does — all it could have ever done — is provide a data point for the excitation source for the thrust oscillation issue. It says nothing about the dynamic response of the vehicle, in particular the second axial mode.
All launch vehicles behave “like tuning forks” in the sense that they all have multiple lightly damped bending and longitudinal vibration modes. Whether any given mode is problematic depends on the excitations near those specific frequencies. It takes an enormous amount of effort — analysis, simulation, test, and design — to get these vehicles to work just right. That’s why rocket scientists have the reputation they do….
BBB
> Ares I-X test will help to validate…
uhhhhh, no. Different propellant, 4 segments not 5 (different organ pipe), different ascent acceleration profile, different q bar at mach 1, different final velocity, different upper stage dynamics (the dummies only match cg). One of the few things that can be validated: 1) tower clearance at L/O…