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-   -   What "weed need" is a space mission! (https://www.mersenneforum.org/showthread.php?t=17609)

Uncwilly 2016-03-06 02:57

[QUOTE=only_human;428205]Found this clip out there. Dunno where it came from or anything else about it.
[url]https://m.youtube.com/watch?v=aARSV1GT1Ic[/url][/QUOTE]That is some joker reposting an earlier landing attempt:
[YOUTUBE]WcfJLNj6ujQ[/YOUTUBE]

chalsall 2016-03-07 20:56

[QUOTE=Uncwilly;428170]As hinted at in the broadcast, when the booster comes in for a landing, it shakes the drone ship and the drone ship loses satellite lock. This interrupts the feed. But then later, the data can be recovered from on-board sources.[/QUOTE]

I'm just vicariously observing here.

But would not a gyroscope stabilized antenna keep a fix?

only_human 2016-03-07 22:06

[QUOTE=chalsall;428316]I'm just vicariously observing here.

But would not a gyroscope stabilized antenna keep a fix?[/QUOTE]

This external thread is primarily wondering about keeping a satellite fix but there isn't anything definitive in it. It does indicate though that other tentative solutions have been previously suggested and negatively answered:
[url]https://news.ycombinator.com/item?id=11227481[/url]
[QUOTE]daeken 2 days ago

I do wonder why they don't have a separate small barge with a couple fiber runs between them, to do the comms (e.g. host the dish(es)). I guess it just isn't that important.
reply

dtparr 2 days ago

That was asked on the spacex sub-reddit. The response was something like "you underestimate the power of a Merlin" which I took to mean that a reasonable distance to avoid the effects is too far to reasonably run ship-to-ship cabling.[/QUOTE]

chalsall 2016-03-08 16:27

[QUOTE=only_human;428328]This external thread is primarily wondering about keeping a satellite fix but there isn't anything definitive in it.[/QUOTE]

Thanks for that additional information.

I do note that SpaceX always has a support ship a few kilometers away during landing attempts. In my mind it would be fairly trivial to have a unidirectional wireless link between the barge and the support ship; omnidirectional antenna on the barge and a high-gain directional antenna on the ship which could then uplink to a satellite.

I'm sure SpaceX have already thought of this (I doubt I could hold a candle to even their interns), but they probably have more important things to work on then simply satiating their geek fans' appetite for live video streams.... :smile:

only_human 2016-03-08 23:41

[QUOTE=chalsall;428424]Thanks for that additional information.

I do note that SpaceX always has a support ship a few kilometers away during landing attempts. In my mind it would be fairly trivial to have a unidirectional wireless link between the barge and the support ship; omnidirectional antenna on the barge and a high-gain directional antenna on the ship which could then uplink to a satellite.

I'm sure SpaceX have already thought of this (I doubt I could hold a candle to even their interns), but they probably have more important things to work on then simply satiating their geek fans' appetite for live video streams.... :smile:[/QUOTE]
I agree entirely that omnidirectional transmission to another site that does the actual uplink sounds feasible. As for SpaceX priorities, first and foremost is controlling messaging and perception which is very hard to do in the presence of live streaming. So they would like to capitalize on the launch enthusiast presence but not so much with the delivery of disaster porn.

only_human 2016-03-14 22:05

[URL="http://arstechnica.com/science/2016/03/with-todays-launch-europe-and-russia-seek-to-break-the-mars-curse/"]With today’s launch, Europe and Russia seek to break the Mars “curse”[/URL]
[QUOTE]The ExoMars program has been in various stages of planning since around the turn of the century. In 2008 NASA and the European Space Agency reached an agreement to share costs on the two missions, an orbiter and landers, that would both search for life and test technologies for a mission to return samples of Martian soil and rocks to Earth.

However, in February, 2012, President Obama's budget called for the cancellation of NASA's participation in the program to pay for the James Webb Space Telescope, which continued to run over its budget allocation. "Tough choices had to be made," NASA's administrator, Charles Bolden, said at the time about the agency's science budget.

At that point the European Space Agency turned to Russia, which has long wanted to return to Mars after a series of missions in the 1970s. The Russian Space Agency agreed to provide Proton rockets for both the 2016 and 2018 launches, as well as some scientific instruments for the 2016 orbiter. The Russians will also assist with the development of technology for the 2018 rover.

And so today's launch was neither the beginning nor the end of efforts by Europe and Russia to finally put a robust lander safely on the surface of Mars. It is but a step, with the bigger tests coming later this year with the Schiaparelli landing, and in 2018, when a highly capable rover tries to repeat this feat.[/QUOTE]

only_human 2016-03-18 01:17

[QUOTE=only_human;429122][URL="http://arstechnica.com/science/2016/03/with-todays-launch-europe-and-russia-seek-to-break-the-mars-curse/"]With today’s launch, Europe and Russia seek to break the Mars “curse”[/URL][/QUOTE]
The following launch video/quote is from a Google Plus post.
[QUOTE]
European Space Agency, ESA

We're still buzzing about the successful launch of #ExoMars on Monday, taking Europe all the way to Mars! Enjoy this replay of the ExoMars 2016 liftoff on a Proton-M rocket from Baikonur, Kazakhstan at 09:31 GMT on 14 March 2016.

Credit: ESA/Euronews
[url]https://youtu.be/wbSyvBICfGc[/url]
[YOUTUBE]wbSyvBICfGc[/YOUTUBE][/QUOTE]

Dubslow 2016-03-18 06:13

[QUOTE=only_human;429451]The following launch video/quote is from a Google Plus post.[/QUOTE]

What in the [STRIKE]blazys[/STRIKE]blazes is that red stuff at T+7? Appears to originate above the engines?

only_human 2016-03-18 06:50

[QUOTE=Dubslow;429475]What in the [STRIKE]blazys[/STRIKE]blazes is that red stuff at T+7? Appears to originate above the engines?[/QUOTE]
Maybe this:
[url]http://www.space.com/21820-russia-proton-rocket-explained-infographic.html[/url]
[QUOTE]The Proton-M carries UDMH fuel (unsymmetrical dimethylhydrazine) and N2O4 oxidizer (nitrogen tetroxide) in its main stages. [/QUOTE]
[url]http://www.astronautix.com/props/n2o4udmh.htm[/url]
[QUOTE]Nitrogen tetroxide (N2O4) has a characteristic reddish-brown colour in both liquid and gaseous phases.[/QUOTE]

Dubslow 2016-03-18 07:24

[QUOTE=only_human;429478]Maybe this:
[url]http://www.space.com/21820-russia-proton-rocket-explained-infographic.html[/url]

[url]http://www.astronautix.com/props/n2o4udmh.htm[/url][/QUOTE]

The first link contradicts the graphic it contains as to the fuel of the fourth stage (though I should think LH2 is rather more likely than RP-1 for a vacuum stage).

As for the N2O4, does that mean it was leaking somewhere from the Proton? The oxidizer certainly should not appear a) above the engines b) at all, since its entire purpose is to be combusted inside the engines. If it truly is the oxidizer, than some *serious* malfunction occurred on that launch.

...or not. As far as I can tell, it's a normal artifact of Proton M launches. How exceedingly strange. Some cursory googling hasn't revealed what exactly is going on.

only_human 2016-03-18 07:45

This might be possibly corroborative. It refers to another Proton launch:
[url]https://www.reddit.com/r/space/comments/2uel9b/ignition_and_lift_off_of_the_402nd_proton_rocket/?limit=500[/url]
[QUOTE]BosonTheClown 1 point 1 year ago
I'm curious...what was the brown stuff that started to leak out around the 33 second mark?

[–]YURI_FOR_THE_YURIGOD 1 point 1 year ago
possibly N2O4 vapor. Proton M uses that as fuel. Check [URL="http://www.nasa.gov/offices/oce/llis/llis_lib/pdf/1025088main_HypergolSpillsandFires.pdf"]this NASA doc[/URL] for some cases of spills of hypergolic fuels.
Go to page 20 of that pdf (page 13 by their own numbering) and look at the second picture. It's a N2O4 leak and the cloud looks like the one in the video.[/QUOTE]

[url]https://m.youtube.com/watch?v=OOwD1O8LzKI[/url]
[QUOTE]Published on Feb 1, 2015. A Russian rocket took a rare day time launch this afternoon, February 1st 2015 at 12:31 UTC from Kazachstan. The Proton-M on it's 402nd mission lofted the British Inmarsat 5-F2 satellite into orbit. Inmarsat 5-F2 is part of a planned three satellite fleet, with F1 having launched 2013, that will provide communications and internet over each of the 89 Ka-band transponders onboard.[/QUOTE]
[YOUTUBE]OOwD1O8LzKI[/YOUTUBE]

EDIT: The Nasa doc linked in the reddit quote presents a 404 error but this might be the document. These chemicals are nasty stuff.
[url]http://ntrs.nasa.gov/search.jsp?R=20090029348[/url]


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