There is no indication of any problem with the Atlantis gear, but NASA and United Space Alliance engineers may inspect the mechanism to assess the slower deployment of the right one.
psloss - 24/6/2007 7:52 PMNow that you mention it, I had heard the same thing in an old video I have downloaded from InsideKSC of KSC being prepped for hurricane Frances. In that video you could see that MLGs and NLG being retracted.
I found this link over there (with pix from Bill Hartenstein):
http://www.aviationweek.com/aw/blogs/space/index.jsp?plckController=Blog&plckBlogPage=BlogViewPost&newspaperUserId=04ce340e-4b63-4d23-9695-d49ab661f385&plckPostId=Blog%3a04ce340e-4b63-4d23-9695-d49ab661f385Post%3a9f5b1025-5de8-47b4-8ec3-fed2103e151a&plckScript=blogScript&plckElementId=blogDest
The blog post says in part:QuoteThere is no indication of any problem with the Atlantis gear, but NASA and United Space Alliance engineers may inspect the mechanism to assess the slower deployment of the right one.
ShuttleDiscovery - 24/6/2007 8:14 PMI believe it's Atlantis.
Is that MP3 of Atlantis' gear or another orbiter?
USFJoseph - 24/6/2007 10:15 PM
Which raises the question -- what if they don't lock into place? What is the plan? Glide as long as possible and make a belly landing? I suppose that's about all they can do with the decision basically being to glide or to put her down quickly...
OV-106 - 25/6/2007 2:43 AMAnd hit SSME#1.
This was the flight where the door fell off at launch.
ShuttleDiscovery - 24/6/2007 1:09 PM
Ok the right one was a little slower, but as long as they're down and locked by the time they hit the runway ;) then there isn't really much to be concerned about...
shuttlefan - 24/6/2007 8:22 PMQuoteShuttleDiscovery - 24/6/2007 1:09 PM
Ok the right one was a little slower, but as long as they're down and locked by the time they hit the runway ;) then there isn't really much to be concerned about...
But we have to wonder if the hardware is trying to tell them something. Remember what Ron Dittamore (Space Shuttle Program Manage at the time of STS-107), said about always listening to the hardware?
rdale - 24/6/2007 8:57 PM
What would the "hardware" be "saying" in this instance?
johng - 25/6/2007 10:08 AMOut of curiosity, which landings did you find? I was thinking of posting just the deploy sequence from the last handful of Edwards landings for illustrative purposes (and FWIW, I'm seeing the same thing as you).
You know, after I read this thread, I spent some time on youtube looking at landing videos and regardless of orbiter or mission, they all have some time lag between the two mains, with the right one deploying last. Looks like a non-event to me.
DaveS - 24/6/2007 1:11 PMI have attached an MP3 of the MLG doors slamming shut, where you can really hear the delay between the left and right doors being closed. There's a whopping 1.25 second difference between both doors, with the right MLG door closing first and the left door closing last.
If I'm not mistaken, the MLG and NLG are deployed entirely by gravity, and are incapable of retracting themselves. I don't have Dennis Jenkins' book in front of me, but I'm mostly certain that I've read that locking the gear in place and locking the doors shut is done entirely by workers. It wouldn't surprise me that there was a delay.
It makes some sense - why have the weight and complexity of all the hydraulics to retract the landing gear, when it will only ever need to be done while workers were swarming over the vehicle anyway?
It would seem reasonable for there to be a specification that defines the maximum allowable time from when gear deploy is signaled to receipt of signals that it is down and locked. This could be tested in the OPF (though without benefit of a ~200 knot wind).OV-106 - 24/6/2007 7:43 PM
The orbiter would not survive a belly landing. Glide slope and landing speeds are much steeper and higher, respectively. than a regular aircraft.
The gear have "thrusters" on them as well. This is what they are called but do not think of them as the rocket-type thrusters. They provide an extra push to extend the gear if necessary.
As for deploying the chute pre-touchdown, that would be a bad idea. The was concerns this was going to happen on STS-95 during approach the scenerios were not good as I recall. This was the flight where the door fell off at launch.
gordo - 1/7/2007 1:09 PMBailout, speculatively. This was discussed in e-mails during the mission and was then extensively reported after the disaster; here's Bill Harwood's story:
I wonder what were the thoughts going round the MCC when Columbia's telemetry intially reported 2 flat tyres on 107? "this could be an interesting landing?"
gordo - 1/7/2007 1:34 PMI shouldn't prolong this tangent unless it is disassociated with the unrelated observation that prompted this thread, but if you read the transcript in Harwood's story, they lost the tire pressure measurements (the measurements went off-scale low). Which isn't the same thing as a "flat."
thanks for these, very sobering
rkoenn - 4/7/2007 8:43 PMThanks.
I work mechanisms for NASA on OV-104 which includes the landing gear and tires. We actually own the mechanism and not the hydraulic systems. The delta between the left and right main gear was 1.2 seconds but I have heard nothing about any concerns with this.