Posted on 12/18/2006 7:38:17 AM PST by NormsRevenge
So damn cool. They earned their pay today, no doubt about it. In March, there will be revised flight rules out the wazoo.
With it half folded, they could have just plucked it off and put it on P5.
Nope. The CG would exceed the SSRMS loading abilities, and too bulky to manuever into position.
Maybe...not sure I am convinced. What is the mass of P6?
I don't have that number, but I know you can't manipulate P6 without the arrays furled or jettisoned. The Robotics ops are untenable, if only because the geometry leaves you with hardware collisions.
Trust me - an the retract had to occur, or a jettison.
hmmmm.
Mass of P6 = 15,824 Kg = 16 Metric tons
Wha?
NASA has a geometric model of the ISS, but I can't get it from here - my primary PC is in for repairs, so I am freeping from my "dust box." So I will have to wait, until I can go look. Darn.
I see that the SSRMS is capable of handling large payloads of up to 116,000 kg, so the mass is not a major factor.
No, but the geometry may well be - can't tell from here. Also, torque likely is - it has to be translated 90 degrees, then rotated 90, then translated 90 again, while being moved out to the end of P5.
The arrays themselves have movement constraints, as well, and there is risk (or certainty!) of breaking them if in their extended state during assembly.
Imagine carrying two flat pieces of thin cardboard each longer than your body and trying to walk through the rooms of your house. Imagine the cardboard was very expensive and your house was full of expensive items adorning every countertop and table. Would you hold the boards straight out to your sides, or would you try to tuck them under your arms?
SSRMS may still be able to take the torque, if rotated exceedingly slowly.
Well, depends on how likely it was that the cardboard wuold never be usable again, and what it would cost to get replacement cardboard into orbit, if such were even possible, and what, on the space station, will be unusable, if the P6 panels can never be extended again (or are the panel assemblies replaceable in orbit?) (I imagine that is fun). Clearly, the bulk of the mass is the truss, not the panels, so if they are replacable, that changes things.
P6 Panel extension - pretty likely, though no guarantees.
P6 Replacement - We have a spare, so we can jettison the current ones if need be and replace.
Speaking of jettison, it's easier to drop the arrays fron the port side of ISS than from the nadir (top) position, where they are now. Everyone is much happier with the prospect of jettison if we get P6 installed on P5.
Oh, as for ISS reuasability without P6 panels, we just gained 50% more power with P4, so losing P6 is a static situation for now.
"reuasability" should be "usability"
Is the half of P6 that is still extended, still in use?
Nope. Powered down for the moment.
I gotta run, y'all have a good night.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.