Agamemnon
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Everything posted by Agamemnon
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Rosetta, Philae and Comet 67P/Churyumov-Gerasimenko.
Agamemnon replied to Vicomt's topic in Science & Spaceflight
now they supplied material to ptolemy and are measuring... that would mean that the whole science sequence was performed as planned (even if one of the experiments failed because of the shutter) -
Rosetta, Philae and Comet 67P/Churyumov-Gerasimenko.
Agamemnon replied to Vicomt's topic in Science & Spaceflight
they are commanding philae to rotate to have more sunlight... plus it seems, acc. to twitter, that the drilling was successful and the drill went down as expected -
Rosetta, Philae and Comet 67P/Churyumov-Gerasimenko.
Agamemnon replied to Vicomt's topic in Science & Spaceflight
they have signal to philae... currently transmitting telemetry and science data... -
Rosetta, Philae and Comet 67P/Churyumov-Gerasimenko.
Agamemnon replied to Vicomt's topic in Science & Spaceflight
from emily lakdawalla https://twitter.com/elakdawalla/status/533371448979890176 -
Rosetta, Philae and Comet 67P/Churyumov-Gerasimenko.
Agamemnon replied to Vicomt's topic in Science & Spaceflight
iirc, as they are done with all science (and primary objectives) they can get (resp. they will be if the drill worked and they will get data in the evening in the next comm window)... they will risk it and try to change the lander position to get more sunlight -
she wont stay one year on the iss... she just uses the fact that soyuz will be changed in the middle of the one year stay of kornienko/kelly for a new one and there will be one week window for a tourist (because of the direct handover)... and she pays 50 mil. for the week
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usually no tourists because of indirect handovers (just in exception cases, like the one year stay in 2015... with sarah brightman as a tourist)
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it is effiecient for a gas generator kerolox... not so much for a kerolox in general - eg. there is a staged combustion kerolox engine (routinely used today) optimised for high thrust (not for isp) and for use on first stages that has nearly the same isp as merlin 1d vac optimised for high isp (the engine is rd-180 with vac isp 338 s) there is an isp optimized kerolox engine used in soyuz 2-1b upper stage with isp 359 s (rd-0124)
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the reason being that it uses quite crappy upper stage engine - quite low specific impulse for an upper stage - for m1d vac it is only 340 s... and the more energetic orbit (gto, geo, escape) you are targeting the better isp is required or you are getting quite harsh payload penalties... ariane 5 or atlas 5 uses hydrolox upper stage engines with specific impulse around 440-450 s (btw - russian staged combustion kerolox upper stage engines have isp close to 360 s) so... using better upper stage engine would help (eg. ariane, atlas, delta)... using 3rd stage would help too (eg. proton)
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Rosetta, Philae and Comet 67P/Churyumov-Gerasimenko.
Agamemnon replied to Vicomt's topic in Science & Spaceflight
new image, from 1000 km http://blogs.esa.int/rosetta/2014/08/02/comet-at-1000-km/ -
ESA will film deadly reentry from inside of a space craft
Agamemnon replied to Sky_walker's topic in Science & Spaceflight
net 29th july -
ESA will film deadly reentry from inside of a space craft
Agamemnon replied to Sky_walker's topic in Science & Spaceflight
actually, the launch is 25th July, 01:41:04 utc edit: forget that... seems to be delayed by several days due to an issue with the second stage -
New SpaceX Falcon launch... finally?
Agamemnon replied to Streetwind's topic in Science & Spaceflight
from what i seen, it is pushed to 27th; because of the recent death of v.popovkin (former roscosmos head) -
Best propulsion method for a "low cost" SSTO?
Agamemnon replied to Exosphere's topic in Science & Spaceflight
what about sabre? atm the best shot, i guess -
actually... acc. to people on nsf, that is not true... the contract only says that they get paid as if they launch a new dragon every time... but they could launch a recycled one, if they are confident enough that it would work...
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Live Launch: Soyuz -> ISS
Agamemnon replied to Kerbin Dallas Multipass's topic in Science & Spaceflight
yes, they do edit: plus, they show the docking camera from the KURS docking system as well -
Live Launch: Soyuz -> ISS
Agamemnon replied to Kerbin Dallas Multipass's topic in Science & Spaceflight
real launchers do not coast.. they launch in one go and the engines shutdown occur in apoapsis usually... there is one exception - antares - and that is caused by the solid upper state -
Live Launch: Soyuz -> ISS
Agamemnon replied to Kerbin Dallas Multipass's topic in Science & Spaceflight
they are successfully in orbit... solar arrays and antenas deployed as planned -
Live Launch: Soyuz -> ISS
Agamemnon replied to Kerbin Dallas Multipass's topic in Science & Spaceflight
there is another section in soyuz - called orbital section - where they can go after soyuz is in orbit -
Live Launch: Soyuz -> ISS
Agamemnon replied to Kerbin Dallas Multipass's topic in Science & Spaceflight
there is one company (or two maybe, not really sure now) which takes tourists to these launches from baikonur -
Live Launch: Soyuz -> ISS
Agamemnon replied to Kerbin Dallas Multipass's topic in Science & Spaceflight
basically... it is not so simple... this shortened randezvous profile needs better (more precise) orbital insertion from the launcher and usually needs an iss maneuver to better align the orbit before the launch... the launch time/date needs to be more precise to correctly align the phase angles... etc and btw - during the two day profile the cosmo/astronauts can use the orbital part of the soyuz - provides additional space, some sleeping space, wc, etc... -
what you need on earth starts somewhere around 9000 m/s... ksc or baikonur needs more because of location (it also depends on launcher, trajectory, etc)
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Orbital Mechanics Textbooks - suggestions
Agamemnon replied to S4qFBxkFFg's topic in Science & Spaceflight
http://www.braeunig.us/space/orbmech.htm -
except spacex is not even in the competition at the moment... on the other hand - arianne 5 holds cca 50% of commercial gto market... competition is between arianne and proton for gto launches (most of commercial launches around the world are to the gto) don't believe everything what is said about spacex