Updates SpaceX Falcon 9 F5 CRS SpX-2 through CRS SpX-12 Updates
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ADSWNJ
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Their RV work was awesome. The original malfunction left them 1.34 degrees off plane, and in front of the ISS instead of where they wanted to be - i.e. they wanted to be low and catching up on a tighter orbit.
They had enough spare dV to boost up over the ISS orbit and coast back on top. 16-17 hours before docking, they were in a 514.7km x 339.9km orbit (Ecc 0.012), sliding over the ISS 424.3km x 408.9km (Ecc 0.0011). So from when they got control again, they maneuvered this baby really aggressively to get to RV - in something like 12-15 orbits. Not bad given the positioning.
If you want to set up the scenario yourself with a DG, then here were the orbital elements as of 02-Mar-2013 20:00 UTC (note ... EQUATORIAL params, not ECLIPTIC, so set this first when you are entering the elements):
Dragon:
Epoch 56354.46794
SMa 6798.307 km
Ecc 0.0128598
Inc 51.7229
LAN 278.7012
LnP 47.8351
MnL 350.9223
ISS:
Epoch 56354.73753
SMa 6787.560 km
Ecc 0.0011338
Inc 51.6476
LAN 276.9964
LnP 248.1822
MnL 36.832
(For anyone who hasn't done this before ... Ctrl-F4 and select Scenario Editor. Select your ship, then EDIT. Select orbital Elements. Frame - set to ref. Equator (not Ecliptic). Enter the elements above. Apply. Done. Select the ISS. do the same.)
They had enough spare dV to boost up over the ISS orbit and coast back on top. 16-17 hours before docking, they were in a 514.7km x 339.9km orbit (Ecc 0.012), sliding over the ISS 424.3km x 408.9km (Ecc 0.0011). So from when they got control again, they maneuvered this baby really aggressively to get to RV - in something like 12-15 orbits. Not bad given the positioning.
If you want to set up the scenario yourself with a DG, then here were the orbital elements as of 02-Mar-2013 20:00 UTC (note ... EQUATORIAL params, not ECLIPTIC, so set this first when you are entering the elements):
Dragon:
Epoch 56354.46794
SMa 6798.307 km
Ecc 0.0128598
Inc 51.7229
LAN 278.7012
LnP 47.8351
MnL 350.9223
ISS:
Epoch 56354.73753
SMa 6787.560 km
Ecc 0.0011338
Inc 51.6476
LAN 276.9964
LnP 248.1822
MnL 36.832
(For anyone who hasn't done this before ... Ctrl-F4 and select Scenario Editor. Select your ship, then EDIT. Select orbital Elements. Frame - set to ref. Equator (not Ecliptic). Enter the elements above. Apply. Done. Select the ISS. do the same.)
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N_Molson
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Yes, 1.34° is quite a lot. But I'm not sure I get how the thruster problem has affected the Rinc ? Isn't the rocket task (well, even more the launch window) to let the spacecraft on the exact orbit ? Because the remaining Rinc has to be corrected on the plane intersection nodes anyway, and when matters little. The synchronisation issue is easier to get, if you don't fire the burn at the scheduled time, well the ISS won't wait for you. 
My thought is that they require more than 1° of relative inclination at orbital insertion in case something goes really wrong just to be sure that any dead upper stage or payload won't be precisely in the same orbital plane than the ISS. We'd have to check the STS and Soyuz inclination at MECO to verify that hypothesis of mine.
---------- Post added at 04:19 PM ---------- Previous post was at 04:01 PM ----------
Doing some quick back of the enveloppe calculation, I get 133 m/s delta-v required for a 1 degree plane change at the ISS altitude, and googling around I found that Dragon has at least a 200 m/s delta-v budget... that's cutting it close when we consider the deorbit burn, so it probably has more capability than what I found, so if anyone has better numbers please, share them
---------- Post added at 04:19 PM ---------- Previous post was at 04:01 PM ----------
Doing some quick back of the enveloppe calculation, I get 133 m/s delta-v required for a 1 degree plane change at the ISS altitude, and googling around I found that Dragon has at least a 200 m/s delta-v budget... that's cutting it close when we consider the deorbit burn, so it probably has more capability than what I found, so if anyone has better numbers please, share them
RGClark
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ADSWNJ
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Yes, 1.34° is quite a lot. But I'm not sure I get how the thruster problem has affected the Rinc ? Isn't the rocket task (well, even more the launch window) to let the spacecraft on the exact orbit ? Because the remaining Rinc has to be corrected on the plane intersection nodes anyway, and when matters little. The synchronisation issue is easier to get, if you don't fire the burn at the scheduled time, well the ISS won't wait for you.
Comments in another forum suggested that the delay of several hours on the coelliptic burn would make the RInc increase over time due to precession and drag, given the lower temporary stranded orbit of the Dragon relative to the ISS.
My speculation - I also suspect that they do not want an unmanned missile fired directly in line with the ISS, so there's probably a deliberate degree or so of RInc.
C3PO
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Yes, 1.34° is quite a lot. But I'm not sure I get how the thruster problem has affected the Rinc ? Isn't the rocket task (well, even more the launch window) to let the spacecraft on the exact orbit ? Because the remaining Rinc has to be corrected on the plane intersection nodes anyway, and when matters little. The synchronisation issue is easier to get, if you don't fire the burn at the scheduled time, well the ISS won't wait for you.
Non-spherical gravity.
Because the initial orbit was a lot more elliptic than ISS' orbit, the change in inclination is different from ISS. However the plane change is slightly "cheaper" because of the low PeR. Furthermore, because the Dragon was late to raise the orbit, it overtook the ISS. This means that it had to go to an orbit with a higher Sma then ISS, and non-spherical gravity will pull the RInc down again.
Kyle
Armchair Astronaut
I love the sound the F9 makes when the engines ignite, so unique sounding from other engines.
Of note it appears that CRS3 has been delayed to November 28th.
Of note it appears that CRS3 has been delayed to November 28th.
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MaverickSawyer
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Skeee-rrrrrrFOOOOOSH! :lol:
IronRain
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orb
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NewScientist: SpaceX glitch may be deemed secret under US arms laws:
And some nice high resolution pictures from NASA: 2Explore:
And some nice high resolution pictures from NASA: 2Explore:
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Kyle
Armchair Astronaut
SSRMS moving into position to grapple HRSGF from the trunk.
Kyle
Armchair Astronaut
Out of the trunk.
---------- Post added at 08:40 PM ---------- Previous post was at 08:28 PM ----------
Getting close.
---------- Post added at 08:40 PM ---------- Previous post was at 08:28 PM ----------
Getting close.
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Kyle
Armchair Astronaut
Don't think so, all the cams are from the SSRMS.
Kyle
Armchair Astronaut
@SpaceX : #Dragon's external cargo successfully removed from trunk today. First unpressurized cargo carried to station via @SpaceX!
Couldn't find anything, sorry.
Couldn't find anything, sorry.
