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-   -   X-37B, F9 landing video (http://www.oldrocketforum.com/showthread.php?t=16820)

blackshire 09-08-2017 01:00 AM

X-37B, F9 landing video
 
Hello All,

Today's successful launch (see: http://www.youtube.com/watch?time_c...1&v=9M6Zvi-fFv4 ) of one of Boeing's X-37B spaceplanes aboard a SpaceX Falcon 9 (the first time an X-37B has ridden aboard a Falcon 9) actually benefited somewhat from the USAF-required cutoff of coverage of the second stage's portion of the ascent:

While the coverage of the second stage stopped just after it separated, the on-board camera coverage of the first stage's "flip-over" maneuver, boost-back burn, coasting, re-entry burn, re-entry, landing burn, and touchdown were more extensive than what we usually see. The first stage's ascent was a pretty "lofted" one, for it didn't take long for it to "draw a bead" on Cape Canaveral from high above, as was shown by the camera mounted above the grid fins. The split-screen coverage of the final descent and touchdown at LZ-1 (Landing Zone 1) included a nice close-up of the landing with excellent natural lighting and sea & sky background. Also:

This video includes--beginning at about 6:26--a brief Boeing presentation about the X-37B, which includes inflight and landing views, some of which were shot from on-board during previous X-37B flights. One test (from the previous OTS-4 mission) that was highlighted was that of a new Hall Effect Thruster (a type of ion engine), which was mounted on the rear fuselage of the spaceplane, next to its rocket nozzle. Such an electric thruster could--like the ion drive of the atmosphere-skimming GOCE satellite (see: http://www.google.com/search?source...1k1.7PoeE4ni9wM )--enable the X-37B to operate as a satelloid, orbiting indefinitely at *constant* altitudes far lower than can unpowered satellites.

tbzep 09-08-2017 09:35 AM

I never get tired of those booster recoveries and the generally great HD footage of SpaceX missions.

blackshire 09-08-2017 10:17 AM

Quote:
Originally Posted by tbzep
I never get tired of those booster recoveries and the generally great HD footage of SpaceX missions.
Me either--the controlled release of so much energy can never become truly routine. This video (see: http://spaceflightnow.com/2017/09/0...37b-spaceplane/ ), taken from the press site, provides the odd contrasts between what is seen and heard. The launch begins in silence, but the flame is as bright as the Sun, and the sound--when it arrives several seconds after the vehicle is already well underway--is so overpowering and all-pervasive that covering one's ears makes no noticeable difference. Those extremes aren't conveyed by this video, but one aspect is--how the roar fades away into silence, while the vehicle is still visible (in person, it's a ringing silence, after one's eardrums have undergone such an acoustic assault, but the almost-eerie audio contrast is still there in the video).

Jerry Irvine 09-08-2017 06:25 PM

I have seen powered landings in person and up close. it is astounding. (Lunar Lander, 2 entrants)

blackshire 09-08-2017 08:47 PM

Quote:
Originally Posted by Jerry Irvine
I have seen powered landings in person and up close. it is astounding. (Lunar Lander, 2 entrants)
It's ironic that it's the failed attempts of those that get more media attention, but many if most of those who cover the prize attempts may not appreciate just how much is going on during the brief descents and successful landings, and:

If any of the landers can't hover (like the Falcon 9 first stage, whose thrust exceeds its weight when its tanks are so nearly empty), they have only one shot at "sticking" a successful landing, by utilizing their downward momentum against thrust in order to reach zero altitude and velocity ^gently^. But even if they *can* hover, it's still not easy, especially if there's any appreciable wind (New Shepard's booster can hover before touchdown, and Blue Origin had to write some sophisticated guidance software to enable it to compensate for winds aloft -and- surface winds). Also:

Even Surveyor 1, launched on Memorial Day, 1966, was given only a 1-in-10 chance of succeeding (NASA would have been satisfied if its radar had simply detected the Moon and triggered the spacecraft's descent sequence). This small hope diminished even more when one of its two low-gain antenna booms failed to extend after launch, as some engineers feared that its off-center mass might prevent the lander's control system from keeping the spacecraft stable during powered descent. JPL was very pleasantly surprised when the descent and landing not only succeeded, but went exactly as planned, and after touchdown even the stuck antenna boom was found to have finally deployed. (Many years ago, someone built a model rocket motor [motors] powered Surveyor scale model that made several successful rocket-braked landings until--like Surveyor 2--one of its three vernier retro-rockets failed to ignite, causing it to tumble and crash.) In addition:

The entrant landers in the various lunar lander prize competitions (see: http://www.google.com/search?source...1.A n5MmenajxE ) that can compensate for winds would be "over-qualified"--which is a *good* thing!--for lunar landings, where that factor isn't present.

Jerry Irvine 09-08-2017 09:46 PM

Quote:
Originally Posted by blackshire
Even Surveyor 1, launched on Memorial Day, 1966, was given only a 1-in-10 chance of succeeding (NASA would have been satisfied if its radar had simply detected the Moon and triggered the spacecraft's descent sequence). This small hope diminished even more when one of its two low-gain antenna booms failed to extend after launch, as some engineers feared that its off-center mass might prevent the lander's control system from keeping the spacecraft stable during powered descent. JPL was very pleasantly surprised
And that's the point.

blackshire 09-08-2017 10:13 PM

Quote:
Originally Posted by Jerry Irvine
And that's the point.
Yep--folks who don't follow this field closely aren't aware of how many things the landing radar, engine(s), and guidance computer must do each second, and all correctly, in order to reach a safe landing.

luke strawwalker 09-10-2017 07:46 PM

Thanks for posting that blackshire... I didn't even know they were launching, especially the X-37B again, and on a SpaceX Falcon 9 to boot!

One quibble with the coverage, though... what happened to the little blonde hottie who's emceed the last few SpaceX launches?? She's easy on the eyes and presents the information in a smooth, understandable way. Sorry but these "boy band rejects" that they have doing the announcing just stumble over themselves and don't do that well in their play-by-play announcing...

Yeah, I know, they're all SpaceX scientists and technicians and stuff, but they need to pick the better ones who are more attractive and have smoother delivery and more charisma IMHO... LOL:)

Later! OL J R :)

blackshire 09-10-2017 09:22 PM

Quote:
Originally Posted by luke strawwalker
Thanks for posting that blackshire... I didn't even know they were launching, especially the X-37B again, and on a SpaceX Falcon 9 to boot!

One quibble with the coverage, though... what happened to the little blonde hottie who's emceed the last few SpaceX launches?? She's easy on the eyes and presents the information in a smooth, understandable way. Sorry but these "boy band rejects" that they have doing the announcing just stumble over themselves and don't do that well in their play-by-play announcing...

Yeah, I know, they're all SpaceX scientists and technicians and stuff, but they need to pick the better ones who are more attractive and have smoother delivery and more charisma IMHO... LOL:)

Later! OL J R :)
You're welcome. I noticed that, too (and he also shaved off his beard). They may have decided to go with the reduced broadcast crew because the coverage would be brief, and because the payload has many secret features (its planned orbit, its experiments, what they'll be doing, etc.), and the banter between the usual 3 - 4 people involved might accidentally reveal something that the USAF would prefer to keep under wraps.

BigRIJoe 09-11-2017 05:45 AM

So why the launch vehicle switch for the X-37B?


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