I talked to Farenthold about this a few months ago, but I actually see SLS/Orion as a bigger and more dangerous waste of funds, because unlike a test stand that will almost certainly never be used, they have the vague appearance of utility to those who don’t understand the program, and will be harder to kill.
10 thoughts on “NASA’s Drift”
Comments are closed.
I haven’t done much outside research, and the first few pages of google searches on this test stand all point to various versions of the linked story, so forgive my ignorance as I say this: I’m still unable to wrap my head around how one tests a rocket engine “in a sealed vacuum chamber” in a way that also allows exhaust gases to escape. How exactly does that work? Is the test only about the structure of the rocket body in a vacuum while the engine runs? How does that test the bell housing and rest of the engine behavior in a vacuum?
And, how many live exospheric tests could be run with the kind of money spent on this test stand (the final amount, not the original 33%-of-final budgeted amount)?
Glad to see that the local union guys are just as fiscally principled as the “conservative” people they elect to Congress…
I guess if it’s big enough, and you don’t burn it too long, it will remain enough of a vacuum to get the performance data.
They evacuate the chamber with a steam ejector, which exhausts directly to the atmosphere. The exhaust from the rocket gets pumped out the same way, and even enhances the ejector effect.
One can do altitude testing cheaply, without a steam ejector, just by putting the engine in a duct that’s open at one end, and using the engine exhaust to pump the duct down. But starting in a vacuum requires something to create a vacuum. (Using the engine-pumped diffuser method also usually results in the engine being damaged or destroyed when the air re-enters the duct — rapidly).
What is mind boggling is that they felt the need to build a new stand, rather than reactivate the AEDC J-4 test cell. J-4 was built to do vacuum testing of engines up to 1.5 million pounds thrust, and could run for hours off of the facility’s central steam-driven vacuum plant. Of course, it might have cost more to reactivate J-4 than the original estimate on A-3, but history shows that it wouldn’t go anywhere near what they actually spent on A-3.
Coupla technical points that may help. That test stand like most such is supposed to use steam generators to run ejector pumps to dynamically pull pressure down while the test motor is firing. So, the hatch they install the test motor through needs to be sealed, but the overall test enclosure, not so much. (Never trust a general reporter not to miss obscure technical points.)
And the big thing they’d be testing is, does the motor light reliably in vacuum? The lack of back pressure can make a difference.
(One thing they can’t practically ground-test is, will coasting in near zero G also affect the motor startup? Though I shouldn’t say that too loudly – imagine the current behemoth test rig mounted on an appropriately-sized drop tower, on another few hundred millions of taxpayer NASA money. Yes, at some point it’s easier to just fly the damn thing.)
Studies had found that when NASA projects ran way late or way over budget, the agency rarely took the hard step of killing them.
In NASA’s defense, often as is the case with this particular white elephant, the reason “killing” is usually such a hard step for NASA is “Congress”.
$350M is nothing, infinitesimal, compared to the amount already wasted and ultimately will be wasted on SLS. In reality, this might be the most expensive means ever devised to demolish a launch pad. Time will tell, regrettably. Has anyone calculated the explosive force of an SLS “launch anomaly” in A-bomb equivalents?
This is another poster child but ultimately the problem always boils down to letting politicians do their thing. Are we ever going to address that problem? We could start in January, but I’m not holding my breath.
“Its congressional overseers tended to view NASA first as a means to deliver pork back home, and second as a means to deliver Americans into space.”
I’m not even sure “a means to deliver Americans into space” is in second place now.
Perhaps third or fourth. Kind of.
Well certainly NASA must first prove that it employs people on the ground and as a close second priority that it is safe… That surely would put “delivery” into a distant 3rd place, no?
If it is a vacuum chamber test facility it should still have its uses. I mean SpaceX will probably need to test their planned 2nd stage engines somewhere and other space launch companies might find it useful. I think Constellation had much worse waste of money than this.