Author Topic: LIVE: STS-116 - Flight Day 11 - Undocking (Read 42326 times)

Johnny Rönnberg · « **Reply #100 on:** 12/19/2006 10:25 pm »

Discovery in space.

Speedracer · « **Reply #101 on:** 12/19/2006 10:26 pm »

Just saw them pass over my location. At closest approach, I could barely make out two dots. Very cool!

lcs · « **Reply #102 on:** 12/19/2006 10:29 pm »

From Norfolk they were about 25 deg. above the horizon. Naked eye looked like a slightly elongated star. With 7x binoculars two clear equally bright stars.

TJL · « **Reply #103 on:** 12/19/2006 10:32 pm »

Just saw both Discovery and ISS as they flew over Long Island, New York...about 39 degrees above horizon. With binoculars you can make both of them out very clear.

marsguy · « **Reply #104 on:** 12/19/2006 10:55 pm »

Saw Discovery and ISS fly overhead a little while ago. Amazing that I was clearly able to see two dots with as simple binoculars as I had. I think I also may have seen the OMS/RCS firing.

Chris Bergin · « **Reply #105 on:** 12/19/2006 10:59 pm »

Sep rate now 18.5 ft per sec. Coming up on the third burn.

Jorge · « **Reply #106 on:** 12/19/2006 11:23 pm »

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Flightstar - 19/12/2006 4:24 PM

The crew get too much credit for carrying out the flyarouds and RPMs. The orbiter carries it out. The crew simply flick a few switches.

Nope, that is incorrect. The orbiter flies rotation (roll, pitch, yaw) based on crew inputs to the UNIV PTG display, but the crew hand-flies translation (X, Y, Z) using the aft THC. The orbiter computers are incapable of doing this; they can only perform "canned" translations.

For the RPM, they manually fly to set up the proper start conditions (Node 1 within 5 degrees of center on the ODS C/L camera, rdot between -0.2 and -0.3 at 600 ft, xdot between zero and 0.1), but are hands-off during the RPM. For the initial separation, they ramp up the rdot to 0.15, then 0.2, while maintaining the docking target within the 8 degree separation corridor. For the flyaround, they maintain range between 600 and 700 while keeping the ISS CG within the ODS C/L camera field of view.
--
JRF

Chris Bergin · « **Reply #107 on:** 12/19/2006 11:24 pm »

ISS just a dot now:

Avron · « **Reply #108 on:** 12/19/2006 11:25 pm »

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eeergo - 19/12/2006 6:06 PM

While feeling wordlessly amazed by the images, I was thinking...

How does this maneuver work? Still learning orbital mechanics... I figured that maybe they caused some extra velocity in the zenith direction by firing the thrusters, along with some velocity in the aft direction... and because of not having enough orbital velocity to achieve a higher orbit, they fall slowly again. Or do they continously fire the thrusters to control the maneuver? I didn't see any plume though... What I can't grasp is why the shuttle is always properly oriented with respect to their movement...

Maybe this should go in the Q&A section, but it seemed on the point right now... however, feel free to change its place, Chris

orbital mechanics are not signiifact with this close proximity

mkirk · « **Reply #109 on:** 12/19/2006 11:30 pm »

Quote

Flightstar - 19/12/2006 4:24 PM

The crew get too much credit for carrying out the flyarouds and RPMs. The orbiter carries it out. The crew simply flick a few switches.

Normally you and I are on the same wavelength but not this time.

I don’t really have time right now to go into all the reasons why that is a highly inaccurate assessment of what takes place, but Docking and Undocking are far more complex than that and the phases that require manual control definitely require a certain amount of finesse.

If you don’t know what you are doing you can start inducing rates on the vehicle that will ruin your day and get you hurt real fast!

The fact that it looks so easy is a testiment to the training involved!!!!!!!!!!!

Mark Kirkman

psloss · « **Reply #110 on:** 12/19/2006 11:31 pm »

Coming up on the Sep 3 burn...

psloss · « **Reply #111 on:** 12/19/2006 11:33 pm »

Good burn, nice video of ignition.

Chris Bergin · « **Reply #112 on:** 12/19/2006 11:35 pm »

Good job (how many times has that been said on this mission!)

Avron · « **Reply #113 on:** 12/19/2006 11:36 pm »

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psloss - 19/12/2006 7:16 PM

Good burn, nice video of ignition.

things sure did "jump"

psloss · « **Reply #114 on:** 12/19/2006 11:57 pm »

Thought I heard Nick Patrick call down asking about what video replays the ground wants to see...

psloss · « **Reply #115 on:** 12/19/2006 11:59 pm »

Here comes video from the ctr line camera...

Chris Bergin · « **Reply #116 on:** 12/20/2006 12:02 am »

Meanwhile, they are seperated by 41 miles.

ZeeNL · « **Reply #117 on:** 12/20/2006 12:05 am »

Quick question: Due to what force does the orbiter separate from the ISS? I imagine it can't be a spring force in the docking ring, because the docking port is not in line with the CG of the orbiter. Hmm, the commentator just said that it were indeed the springs

Next question: it must induce a slight rotation then, at what distance from the ISS can they use the RCS system?

collectSPACE · « **Reply #118 on:** 12/20/2006 12:20 am »

Same drill as the past few days, any questions for the imminent briefing?

ZeeNL · « **Reply #119 on:** 12/20/2006 12:22 am »

Ok, question: in the very unlikely event they can't get the orbiter down on one of the three landing sites on Friday, what will the plan be?