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NASA: Revolutionary Camera Recording Propulsion Data Completes Test (theverge.com)
An anonymous reader quotes a report from The Verge: NASA has created a camera that can film slow motion footage of booming rocket engines with higher dynamic range than ever before. It's called the High Dynamic Range Stereo X camera, or HiDyRS-X (PDF), and late last week the agency released some of its footage to the public for the first time. The three-minute clip shows the most recent test of one of the boosters for NASA's upcoming Space Launch System rocket in unprecedented detail. SLS will use two of these 17-story tall solid rocket boosters, each of which is capable of burning 5.5 tons of propellant per second to create 3.6 million pounds of thrust. The problem when it comes to filming tests like these (and eventually, launches) is that the plumes of fire they produce are extremely bright. This usually leaves camera operators with two choices. They can either expose the footage for the bright plume, which will leave everything else in the shot looking dark and underexposed. Or they can expose for everything else in the shot, which leaves the plume looking bright white and void of detail. The HiDyRS-X camera solves this problem because the camera can capture all of this detail in one shot, and it does this in a fairly clever way. Where regular high-speed cameras usually only captures video one exposure at a time, HiDyRS-X can capture multiple exposures at a time. NASA did however report some failures with the test: the camera's automatic timer failed to go off, thus failing to record the igniting of the rocket, and the pressure being generated from the booster knocked the camera's power source loose.
If it were affordable. It's not, particularly at the sort of budget levels on hand. So only rarely going to be used. So it'll never have economies of scale or the refinements (including safety) that come with having a long launch record.
Everyone tries to design missions to use it, though, to try to get buy-in to their plans, knowing that due to pressure in congress they want to find excuses to use SLS as much as possible, even if financially the option doesn't make sense. Example: I was reading some of the followup work on HAVOC the other day - HAVOC being an evolutionary approach for manned missions to Venus that a couple people at Langley have been promoting. Now, when I read their initial proposal, I could tell that clearly their call for SLS to launch the airship was way overkill. The entire hull (including the envelope) is 6455kg (and they call for the transfer stages and aeroshell to be launched separately). Throw all of the other mass of the airship (not counting the separately launched return rocket), such as propulsion, helium tanks for inflation, etc, and it's still only 25772kg. Obviously you don't need SLS to launch a 26 tonne payload to LEO. They describe it instead as being volume limited due to the volume of the fabric. They have something in the ballpark of 15k m surface area. They don't give their fabric thicknesses, but the heaviest Venus balloon fabric I've ever seen proposed on any mission was VALOR's, which is somewhere around 120um thick (most are much thinner than VALOR's). Using 120um as a baseline, with a perfect packing ratio, 15k m would take up 1,8 cubic meters. Multiply it by whatever factor you want to account for imperfect packing - you'll never come anywhere close to the need of SLS's 1100 cubic meter fairing.
In their followup, they pretty much confirmed this. They did a (very) small scale folding experiment, using the fabric they were proposing, at the thickness they were proposing. It fit into their accordingly scaled-down SLS fairing. Now, clearly, if you're scaling down your fairing volume and vehicle, but you're not scaling down your fabric thickness, then you're going to end up with something that takes up vastly more volume. Yet it still fit. So clearly they don't need anywhere near all that space**
** - Caveat: I don't know if they don't understand how blimps work or what, but they have no accounting for ballonets nor catenary curtains in any documents they've released that I've come across, nor do they compensate for the former with superpressure or phase change fluids, or the latter with a rigid keel or frame. Obviously ballonets and catenary curtains also are a source of mass and volume. But again, nowhere even close to mandating SLS.
This is hardly the only case I've seen like this. It seems like it's popular to try to baseline SLS into missions to try to get support for those missions. Whether or not SLS is actually needed. They know that they can always remove the SLS requirement if/when the system gets cancelled.
No, she's fine. My associate is vomiting for a totally unrelated reason.
SLS rocket 1.633*10^6 kg thrus
It has about as much chance as a mosquito on an elephant's back farting changing the speed/direction of the elephant.
Silence is a state of mime.
The most I've found so far is the short
Note that an HDR video camera is not in and of itself particularly "revolutionary and innovative", and there's no indication of how the NASA camera might differ from existing offerings (higher frame rate? better dynamic range? more "scientific-ness!"?). But when fighting for budget the more clickbait one's research generates the easier it is to convince a politician to fund it - so everything becomes "revolutionary." (This is the science and engineering PR version of the music industry's "loudness war.")
Anyway, revolutionary or not, the rocket is big and the pictures are pretty.
"Game Changing Comment Uses Disruptive Technologies Based On Emerging Advances To Bring Revolutionary Full Stack Vacuity To Slashdot."
The rocket is going one way. The fuel is going the other. The net change in angular momentum for Earth balances that of the rocket, itself, reaching _orbit_ at high angular velocities. When it returns to ground, in a similar orbital plane and is braked by any means, that change in angular momentum is returned by the braking.
Note that if the orbits are not from similar latitudes with correspondingly similar ground velocities of the Earth's own rotation, there can be _fascinating_ effects on the eccentricity of the Earth's rotation and even on Earth's precession. But those re not likely to be large enough, or consistently cumulative enough, to be noticeable in any way.