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Author
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Topic: Shuttle landing gear deployment after SCA ferry
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Hart Sastrowardoyo
Member Posts: 3445
From: Toms River, NJ
Registered: Aug 2000
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posted 05-17-2008 11:28 PM
   
Here's a thought. The SCA lands with the shuttle. The shuttle is hoisted up, the SCA is backed away, and then the shuttle is lowered to the ground to be towed to be processed.The question is, who lowers the landing gear prior to the shuttle being towed? Is there someone in the shuttle cockpit after the SCA lands (and thus, said person is also hoisted into the air since they're in the shuttle) or is there someone in the shuttle cockpit during the whole SCA ferry flight, in case the SCA has to jettison the shuttle? |
Robert Pearlman
Editor Posts: 42988
From: Houston, TX
Registered: Nov 1999
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posted 05-18-2008 12:30 AM
In fact, neither; the gear is hydraulically deployed (or retracted, in the case of mating) from beneath the orbiter, as is also done in the VAB before mating with the external tank and solid rocket boosters.  
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Jay Chladek
Member Posts: 2272
From: Bellevue, NE, USA
Registered: Aug 2007
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posted 05-18-2008 01:11 AM
Do they have the ability to retract hydraulically? I understood that a shuttle can't do a self retract of its own gear since the retraction mechanisms were left out of the design to save weight. So ground crews have to winch the gear and doors closed when they raise a shuttle for attachment to an SCA or rolling over to the VAB to mate it with the ET and SRBs.As for jettison of an orbiter from an SCA, to my knowledge that can not be done by a ferrying SCA at all since they don't utilize explosive bolts on the struts anymore like they did during the Enterprise ALT tests. Since nobody rides the orbiter on ferry flights, if a jettison were possible, more then likely the orbiter would end up taking off the tail of the SCA in the process and both would crash. A fair amount of airspeed had to be built up by the SCA during the ALT tests in a shallow dive before Enterprise was cut loose on its free flights. The crew of the 747 during the ALT tests did have a bailout option in the form of a bailout shaft (sort of like a laundry chute) that lead from the upper deck of the 747 just behind the cockpit to underneath the fuselage in front of the wings. Before bailing out, explosive charges would blow some of the passenger windows to equalize air pressure inside the plane before the flight crew went down the escape shaft. I don't know if this system is still onboard the SCA aircraft though as I don't think the ferry crews wear parachutes for their flights since they have done these trips so often. Plus, at least two weather aircraft scout out many miles in front of the projected flightpath of an SCA to locate any potential trouble spots in the form of rain clouds or clear air turbulence and there are plenty of divert fields available and scouted out ahead of time should a mechanical problem occur. |
Robert Pearlman
Editor Posts: 42988
From: Houston, TX
Registered: Nov 1999
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posted 05-18-2008 01:43 AM
quote:
Originally posted by Jay Chladek:
Do they have the ability to retract hydraulically?
From the Space Shuttle News Reference: For retraction, each gear is hydraulically rotated forward and up during ground operations until it engages an uplock hook for each gear in its respective wheel well. The uplock hook locks onto a roller on each strut. Mechanical linkage driven by each landing gear mechanically closes the respective landing gear doors. |
Ben
Member Posts: 1896
From: Cape Canaveral, FL
Registered: May 2000
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posted 05-18-2008 10:41 AM
Although they did in the early program, the landing gear since around 1990 is retracted for flight in the OPF before being rolled over for mate. |
OV-105
Member Posts: 816
From: Ridgecrest, CA
Registered: Sep 2000
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posted 05-18-2008 09:10 PM
Check out The Dream Is Alive. They have a shot of them shutting the nose gear doors in the VAB before STS-41D. Once that shuttles were not going to be launched from Vandenberg AFB they sent the OTS to KSC and changed the Orbiter Maintnace and Modifcation Facility (OMMF) into the 3rd OPF. The MDM device went to Air Force Plant 42 so that they would not have to overland the orbiter from Edwards. The last shuttle to go overland was Columbia in 1985 before STS-61C flight after her OMD after STS-9. |
divemaster
Member Posts: 1376
From: ridgefield, ct
Registered: May 2002
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posted 05-18-2008 10:40 PM
And all this time I thought they just called AAA. |
Hart Sastrowardoyo
Member Posts: 3445
From: Toms River, NJ
Registered: Aug 2000
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posted 05-19-2008 07:32 AM
quote:
Originally posted by OV-105:
Check out The Dream Is Alive. They have a shot of them shutting the nose gear doors in the VAB before STS-41D.
I remember that shot, them shutting the landing gear doors with what looked like broom handles. I just couldn't figure out how they deployed the landing gear, whether it was somebody pushing a button in the cockpit, or somebody on the ground pushing a button somewhere on the outside of the shuttle.... |
Jay Chladek
Member Posts: 2272
From: Bellevue, NE, USA
Registered: Aug 2007
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posted 05-19-2008 09:22 AM
They still use the broom handles at Edwards at least. The STS-114 photo scrapbook by Dennis Jenkins has a few shots of Discovery having its gear bays closed up after its return the Edwards and the technicians are using broom handles to do the job. |
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