4 more years! Intelsat, Northrop Grumman extend satellite servicing contract Northrop Grumman has signed a four-year contract renewal with Intelsat to continue providing on-orbit extension services for satellites. The extension will result in the geosynchronous satellite IS-10-02 ultimately gaining another nine years of life thanks to Northrop Grumman's Mission Extension Vehicle (MEV) 2. MEV-1 is …
If Hubble and other sats have failing gyros or other pointing issues, can you keep a repair sat hooked onto the docking point and just (well, 'just') take over the attitude control from outside?
I know the masses are in the wrong places, and you'll need comms, and you might be in the way, but with sufficient cleverness, is it a goer?
That's an excellent idea. Clamp on an external unit with its own gyros and control the attitude with that. If/when the external unit's gyros fail, unclamp it and whack on another one. Each replacement unit can have its own de-orbit thruster too. You can keep a satellite pointing the right way forever!
First of all satellites are assembled by professional on earth with components made by robots.
A human space with the inconveniences of that suit and lack of gravity is very much at a disadvantage. They really cant do much compared to the people on earth. Its just a show to justify expensive space programs.
Th ebest the human can do is maybe replace some large component with a new one, they arent doing real tiny work.
Th ebest the human can do is maybe replace some large component with a new one, they arent doing real tiny work.
You sound to be perilously close to the well known logical fallacy false dichotomy. Just because they can't do tiny repairs doesn't mean that they can't do anything.
My post was actually tongue in cheek because what I described did exist for a while and it was used to service the Hubble Telescope five times.
The gyro precision is tiny, the large repair sat is never going to get the accuracy that Hubble or similar sats require for their work. Millionths of a degree accuracy vs prolly degree accuracy, its just not the same thing.
Take a look at docking procedures in space, they arent exactly mm perfect and you want the same to focus Hubble ?
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The following items have been performed on Hubble service missions, Clearly gyroscope replacement is feasible but nobody is saying it would be easy for a robot to do and lot of development still required,
The service mission meant astronauts hanging off the Canada arm and was incrediably difficult. There is a review of the last mission here. there is a point where they had to remove over 100 screws to get access. as luck whould have it they stripped the head of one of the screws holding on a hand rail. Solution with rip off the hand rail.
https://www.youtube.com/watch?v=xgbUbdC6kbo
BTW, Space Force have cooled off on the idea of on orbit space servicing and refueling. I am guessing with improved payload capacity, reduced lanch cost and increased frequency its easier to replace than repair. just like consumer electronics, lol Why try a difficult refuelling mission when you easily launch with extra propellant in the first place.
Service mission 1,
COSTAR, Corrective Optics Space Telescope Axial Replacement installed, replacing High Speed Photometer (HSP)
Wide Field Planetary Camera 2 (WFPC2) replaced Wide Field Planetary Camera (WFPC)
Solar Arrays replaced with Solar Arrays 2 (SA2)
Replacement of #1 Solar Array Drive Electronics (SADE)
Replace the #2 and #3 Rate Sensor Unit (two gyros each)
Replacement of two Gyro Electronic Control Units, which direct the RSUs
Replacement of eight electrical fuses
Installation of two new magnetometers
Installation of Goddard High Resolution Spectrograph Redundancy (GHRS) kit
Installation of two protective covers over original magnetometers
Service mission 2
A refurbished Fine Guidance Sensor — one of three essential instruments used to provide pointing information for the spacecraft, to keep it pointing on target, and to calculate celestial distances
A Solid State Recorder (SSR) to replace one of Hubble’s data recorders (an SSR is more flexible and can store 10 times more data)
A refurbished, spare Reaction Wheel Assembly — part of the Pointing Control Subsystem
Service mission 3
Space Telescope Imaging Spectrograph (STIS) replaced Faint Object Spectrometer (FOS)
Near Infrared Camera/Multi-Object Spectrometer (NICMOS) replaced Goddard High Resolution Spectrograph (GHRS)
Replacement of Fine Guidance Sensor #1 with modified spare with added capability for ground-controlled alignment corrections
Addition of an Optical Control Electronics Enhancement Kit (OCE-EK)
Replacement of #1 Engineering Science Tape Recorder (ESTR) with digital Solid State Recorder (SSR) and replacement of #2 ESTR with a spare ESTR unit
Replacement #1 of 4 Reaction Wheel Assemblies (RWA), with refurbished spare
Replacement of Data Interface Unit (DIU) #2 with modified and upgraded spare unit
Replacement of #2 Solar Array Drive Electronics (SADE) with refurbished unit
Replacement of more durable covers on Magnetic Sensing System (MSS)
Service Mission 3A
Replacement of all three Rate Sensing Units (RSUs), each of which contains two gyroscopes
Installation of new computer, 20 times faster with six times more memory than its predecessor
Replacement of original reel-to-reel data recorder with digital Solid State Recorder (SSR) which is faster, more reliable and can store 10 times as much data
Replacement of #2 of 3 Fine Guidance Sensors (FGS) with refurbished unit
Replacement of failed #2 of 2 S-Band Single Access Transmitter (SSAT) used to relay data to the ground
Installation six Voltage/Temperature Improvement Kits (VIKs) on wiring between Solar Arrays and each battery to control charging of Hubble's batteries
Installation of Shell/Shield Replacement Fabric (SSRF) over the original Multi-Layer Insulation on Hubble’s forward shell and light shield to add thermal protection
Installation of Handrail Covers around the handrails above the Fine Guidance Sensor bay to prevent possible contamination to the Aft Shroud area from flaking handrail paint
Fit New Outer Blanket Layers (NOBLs) on equipment Bay 1
Service Mission 3B
Installation of Advanced Camera for Surveys (ACS), replacing the Faint Object Camera (FOC)
Installation of NICMOS Cooling System (NCS) comprised of two components, the NICMOS Cryogenic Cooler (NCC) and the NCS radiator, to revive the NICMOS instrument
Replace Solar Arrays 2 (SA2) with smaller, more efficient Solar Arrays 3 (SA3)
Replace the #2 of three Rate Sensor Units (each RSU contains two gyros)
Replace #1 of four Reaction Wheel Assemblies (RWA), part of Hubble’s pointing control system, with a refurbished unit
Replace Power Control Unit (PCU) to take full advantage of additional power generated by the new solar arrays
Fit New Outer Blanket Layers (NOBLs) on Bays 1, 9 and 10
Service Mission 4
Replace Wide Field Planetary Camera 2 (WFPC2) with Wide Field Camera 3 (WFC3)
Remove the Corrective Optics Space Telescope Axial Replacement (COSTAR) and install the Cosmic Origins Spectrograph (COS) in its place
Repair the Space Telescope Imaging Spectrograph (STIS)
Repair the Advanced Camera for Surveys (ACS)
Replace gyroscopes
Replace one Fine Guidance Sensor (FGS)
Replace batteries
Install New Outer Blanket Layers (NOBL) on bays 5, 7 and 8
Install Soft Capture Mechanism (SCM)
Replace Science Instrument Control and Data Handling (SIC&DH) unit
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