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Satellite Servicing Demonstration

The Hubble Servicing Project goes to work
on other Satellites
(Page 7)

Page 6 is here.

Continued On-Orbit Ops (Gas Valve Panel)
In March 2012, we started our first significant operations in space by checking out the tools and their cameras as well as releasing launch locks and cutting wire.  The long wait since launch was to load in the new software and scripts into the Space Station computer to be able to manipulate our hardware.


The overall layout of the Dextre robot facing our hardware.  Our RRM module
is located on the ELC-4 exterior platform.


Photo of Dextre's end-effector (OTCM) approaching one of the tools,
ready to grasp and power it up.

The tool cameras have been a special worry of mine since I designed their interface circuitry in 2010.  The Dextre robot video input is required for the sync to be clamped to zero volts, while normal cameras have a capacitive coupled output.  This makes the two incompatible.  In addition, I was unable to allocate much space to any circuitry to fix this problem since it had to fit into the tool.  The circuit I came up with is very compact, and worked well for all the tests on the ground and at the ISIL facility at the Johnson Space Center.  However, this was at only two separate occasions, all of our tests on the ground were by commercial monitors, which is not similar to the Dextre circuits.

In addition, we are the first users of the Dextre OTCM video inputs since it was launched, and no post-launch test was performed on this hardware.  

So when the day, hour and minute came for the cameras to be powered on, I was quite nervous about what we might see.  When the image below popped up, there was a big cheer at our control center.  We were all relieved as without cameras, our mission would not be possible.


This is the first image from the tool cameras that we saw.  There was a big
celebration of this success.

The other unusual aspect of the two tool cameras is how we select which one to send to the ground.  Dextre OTCM input can only accept one input, and I decided to not use the more complex 1553 computer interface to select the camera.  Instead, I designed a magnetic latching circuit that toggles between the cameras on each power cycle to the tool.


Once the tool was retrieved, Dextre is ready to go to work.
This is the Multi-Function Tool that will be used to
release the launch locks from the various parts.

The first task to be done was to release the launch locks.  These mechanisms lock down the movable parts of the system so that they do not get loose during the violent shaking of the Shuttle launch.  We use the bolt driver in the Multi Function Tool for that.


Shot of us in the 'front row' of the GSSCC control center.


Mike Oetken (mechanical lead) showing the proper use of the Project Manager
console: getting us lunch and dinner 8-).

While we follow the space robot in our control room, we also have staff in our robotics lab following along with a ground duplicate of RRM.  They can then try solutions with the ground robot to give the operators at the Johnson Space Center ideas and things to try.

In the image below, the top left screen is the graphical simulator that shows an overall view of the robot and Space Station.  The next four on the far wall show the four video feeds from station.  There are two ops stations in the middle of the room, the one facing away is for the robot operator (Joe Easley in the blue shirt).  He is facing many of the same screens we see in our control room.  Sitting to his back is the lead tools expert on console.  On the far right, you can see the robot, and not seen is the RRM simulator we brought to the Kennedy Space Center for the press events.  It is an accurate duplicate of the one in space.


While we work in the control center, other staff work in our robotics lab
in case of problems encountered in space.

Finally after years of waiting, and days of tool checkout and launch lock release, we finally got down to the first 'real' task.  This is to cut wire.  This wire is commonly used to tie down and lock down rotating caps and bolts so that they do not vibrate loose.  

To perform these operations, the tool is on the end of Dextre, whose arms are about 11 feet in length.  This in turn is on the SSRMS, which is about 60 foot long, and then mounted on the long Space Station truss.  It was not known if this long path would lead to too much inaccuracy and floppiness to perform intricate tasks such as cutting wire.  Prior to our mission, some thought it could not be done.

It turned out that it was not a problem, and we were able to cut two instances of wire very successfully.


Sequence of images from the cutting of the wire on the Ambient Cap.
left: approaching the wire.  middle: about to cut the wire, right: wire is cut.


To celebrate the successful on-orbit ops, we had a cookout one day, and
the chef was Ray Bietry (electrical systems).

Article on this activity from nasaspaceflight.com.

Press release by Ecliptic, who furnished the
core of the tool cameras.

On June 20 2012, we had our second round of operations and the conclusion of the Coolant Valve Panel work started in March.  In the image below, you see the Multi-Function Tool (ends at the black part with the small white dots) holding the T-Valve Adapter (TVA).  This in turn holds a T-Valve (aluminum block shaped object with tubes coming out and the green ring).  The valve was previously successfully removed from the task board that sits on the 'top' of RRM.  

In the image below, we are translating over to stow the TVA, and the amazing sight is to see the T-Valve gently loosely bobbing around.  It is mesmerizing to see it loose and with the Earth going by in the background.

t-valve removal in space
T-Valve removal in space.  Note the Earth and the Station Solar Array below.

NASA.gov article on this second activity.

After years of preparation, we finally performed the main event which are the refueling tasks over the course of six days in January 2013.

cutting wire on the safety cap
Image of the Wire Cutter Tool (WCT) about to cut the wire on the
Tertiary Cap (visible in the top part of the image).

approaching with safety cap adapter
Once the wire is cut, we approach with the adapter to remove the Tertiary Cap.

cap removed
Picture after.  The Safety Cap is now exposed.
The next step is to now cut the two wires exposed.  One holds the
Safety Cap closed, and the second is for the Actuation
Nut.  This latter is the 'handle' of the refueling valve.

sc wire cut
Close-up of cutting the wire on the Safety Cap.

about to mate onto pv1
We now finally have the EVR Nozzle Tool, which has the fuel hose, about to
be mated onto the fuel valve.  All preparations are finally in place to refuel.


Refueling ends with this scene, the removal of the nozzle tool from the
refueling valve.  What resulted was the most amazing sight of this mission.
Although we expected some small amount of alcohol release, I was very
surprised by how the release occurred.  It came as a splash, and then the
alcohol lingered longer in vacuum than I expected.

RRM team
The team in the control room for the main refueling task.

Spaceflightnow.com article

NASA Links:

Press release 

Web story 

Video (Very brief cameo at 5:20)

The final round of on-orbit operations for Phase 1 took place over five days during early May 2013.  This is where we took care of the lowest priority "Tertiary" tasks.

Doug view of tool capture
We use several cameras on Space Station but also have this CG tool (called "Doug") that we can create any virtual view we want.  On the left you see RRM with its tools, and on the right you see Dextre about to grap the Wire Cutter Tool (WCT).

Dextre opening flap of MLI.
Picture to culminate Tertiary tasks.  You can see the 65 foot long SSRMS, holding the 15' Dextre, holding our robotic tools, peeling open the demo flap of Multi-Layer Insulation (MLI).  Pretty cool picture in my opinion.

On-orbit view of RRM in IMAX movie.
In Spring 2016, the IMAX project released a preview of their movie "A Beautiful Planet"
About 30 seconds into this preview, you can see RRM in the right of the image.
(left most of the three rectangles in the right).

RRM removal
On March 5 2017 RRM was removed from its perch viewing the Earth after six years in space.  It burned up along with the CRS-X capsule later that month (RRM is bottom most box in the image).  You can see that ELC-4 payload Site 3 is empty.

SAGE install
SAGE III (frame shaped object was installed into the location formerly occupied by RRM.
The latter is just half in frame at the bottom of the image.

The original RRM mission ended in March 2017, but it continues with RRM3 (future blog).

In addition, work on satellite servicing continues on the Flex Hose Investigation page.
(includes my flight on the Zero Gravity plane).

Links

Page 1 of Satellite Servicing

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