Servicing Earth Satelites

SpaceNut · 2016-06-26 21:37:34

http://www.space.com/11135-satellite-re … ebris.html
http://ssco.gsfc.nasa.gov/rrm_refueling_task.html
http://www.space.com/8166-nasa-plans-re … ation.html

GW Johnson · 2016-06-28 15:46:02

Refueling satellites in GEO is a very worthy idea. As a "long term NASA goal", this is ridiculous: we already understand the Hubble Space Telescope refurbishment missions. So that NASA statement is BS at best.

Doing this in GEO requires a radiation shield solution, if done manned. It requires a very autonomous (and radiation-resistant) robot to do it unmanned. There are some deployable technology issues to resolve here. But it needs doing.

Too bad everything is tied up reprising Apollo with pork-barrel politics, ain't it?

GW

Last edited by GW Johnson (2016-06-28 15:46:49)

SpaceNut · 2016-06-30 21:41:04

As my second link indicates the only project on the books seems to be this on http://ssco.gsfc.nasa.gov/robotic_refue … ssion.html

It seems to be more of a demostration staging mission for prototyping rather than actual doing it for real for the fleet that circles us over head.

China announces success in technology to refuel satellites in orbit

GW Johnson · 2016-07-02 09:22:11

I couldn't get to the Chinese link. It failed repeatably to open.

The NASA link about the gear on ISS, seems to be more about trying to do wiring and plumbing in the clumsy spacesuits we use, than anything to do with actually transferring any propellants. It might apply to repairs made in space. It's a piece that needs doing, but the real solution lies in a far more supple space suit, and I think we all know that. NASA knows it, too, but politically cannot admit to it, because they're hog-tied to the existing suit makers, who do not want to attempt MCP, since they already know how to profit from full pressure suits.

The Russian transfers of thruster propellants are done without human intervention, I believe. That's the technology that could refuel satellites using storable thruster propellants. Our people witness this on ISS, but I don't see any US vehicles or equipment doing this. That's a real shortfall. So is transfer of gaseous ion thruster propellants.

The "biggie" is transfer of cryogenics. Spacex will have to master that to refuel its MCT in LEO for the trip to Mars, and again on Mars's surface for the trip home. Refueling on Mars is a space-suited-for-vacuum problem just like refueling in LEO. The difference is you actually have some footing stability on Mars.

GW

Last edited by GW Johnson (2016-07-02 18:53:44)

Tom Kalbfus · 2016-07-02 09:45:36

I think robots would be better to do this.

GW Johnson · 2016-07-02 18:55:16

May be. I dunno.

Sometimes I do think that if our robots were not quite as capable as they have turned out to be, that men might have gone further and done more in space.

GW

Tom Kalbfus · 2016-07-02 21:07:29

GW Johnson wrote:

May be. I dunno.
Sometimes I do think that if our robots were not quite as capable as they have turned out to be, that men might have gone further and done more in space.
GW

All you really need is robots that can be tele-operated like puppets, the intelligence in question is that of the operators, rather than a flesh and blood hand within a suited glove.

GW Johnson · 2016-07-03 13:51:53

I like tele-operated robots. It's a good idea, as long as the range is short enough to zero-out the speed-of-light delay. But, there will also always be those cases where only somebody on-site, up-close-and-personal, can respond to the unexpected adequately.

One has to be prepared and ready for both scenarios.

If you have the right kind of suit, and the right kind of work space, you don't even need the suit gloves on your hands, for up to about 30 minutes.

GW

Last edited by GW Johnson (2016-07-03 13:53:01)

SpaceNut · 2016-07-09 12:02:16

Well as I see that market the design of the service satelite is in the near billions for a long term device in orbit and we are going to launch it on something less than 200 million per device to go an survice that ailing satelite in orbit. Well thats cheaper than a new satelite and a 6 year waiting period for design to launch of it....

GW Johnson · 2016-07-09 13:20:21

I'm thinking the manned version of such a facility should comprise (1) a refuellable propulsion module or stage, (2) a habitable workspace about the size of the arm station of the shuttle, (3) a place to dock a crew transfer capsule, (4) and spaceframe in which to mount items securely for work, (5) something similar to the shuttle arm, (6) a very lightweight spaceframe surrounding the work space that is covered with reflective mylar sheet blankets and supports variable-power lighting, (7) some sort of storage space containing various propellants for various refuelling duties, (8) a solar electric power system, and (9) as a crew equipment item, a selection of full pressure and mechanical counterpressure spacesuits.

For the unmanned version, you need items (1), (4), (5), (6), (7), and (8). The arm is a tele-operated version controlled from the surface. Some tele-operated refuelling gear is also required, different for each of the resupply propellants.

The idea is to provide the shuttle bay facility without the shuttle itself. Add to it a very lightweight enclosure that is lightable to whatever level is desired. For the manned version, this not only eliminates shadows, but also bring workpieces up to near room temperature, so that thinner uninsulated pressure gloves may be used safely.

This facility is refuelled and resupplied (and crewed if applicable) for each mission, but otherwise stays permanently in orbit. The propulsion lets its go to the jobsite, then return to its orbital storage location.

We'll have to add radiation shielding to the manned version, for any missions above about altitude 900 miles. Those are getting into the lower van Allen belt.

GW

SpaceNut · 2016-07-09 19:30:59

I think a plasma shield created by magnetic field as we have been discussing this in the form of a modified RF field.

GW Johnson · 2016-07-10 14:10:24

That EM stuff is too far outside my experience and knowledge to judge. Has this been demonstrated in anything other than a science lab experiment?

GW

RobertDyck · 2016-07-11 00:20:21

Everything was a science lab experiment at one time. If you claim so-and-so was nothing but a science lab experiment, then we would still be using horse-drawn buggies. The mini-magnetosphere is based on Earth's magnetosphere. So it's already in use by nature on a very grand scale. The mini version has been demonstrated by science lab experiments at the University of Washington, and NASA Marshall Space Flight Center. Yup, we need to test/demonstrated it in space. I suggest a stand-alone satellite rather than anything at ISS. The truss structure and antennae and various things sticking out were not designed for the plasma of a mini-magnetosphere. And an effective test must be outside the Earth's magnetosphere, that means higher than the Van Allen belts. That's above 60,000 km.

GW Johnson · 2016-07-11 08:10:42

Hi RobertDyck:

My question about science lab status of the "mini-magnetosphere" relates to the timing of its availability: most things that we do in the science lab successfully require somewhere between 5 and 25 years to turn into a practical piece of equipment real people can use "in the field". When I say "science lab experiment", I'm talking about the initial feasibility demonstration.

I know very little about electromagnetics, so I know nothing about this mini-magnetosphere thing. But I have seen a lot of things taken from a feasibility experiment in the lab to a real device. That timeline I quoted is very real. It's not just one or two more experiments. It's fault detection, analysis, redesign, and retest. Multiple cycles.

I'm not saying such things cannot be done. Although, some have proven quite difficult, photosynthesis, for one. We haven't fully duplicated that piece of mother nature in the science lab, as near as I can tell from AAAS's journal. Controlled fusion is another; that's been worked on since I was a baby (and I am an oldster), without usable success (in the sense of a power-producing device) yet.

Once this mini-magnetosphere thing is ready for a flight test, why not start small and work up, but in a way that doesn't require multiple launches? Launch the thing into orbit with enough on-board propulsion to make about 3 or 4 big orbit changes, finally ending up higher than GEO to get outside the van Allen belts.

Start at the near edge of the Van Allen belts, and see if it deflects that stuff. Then fly higher and see if it deflects the most intense Van Allen belt stuff, which may more resemble solar flare stuff than GCR, if I understand correctly. Then fly outside the belts and see if it deflects the real GCR. It'll have to stay out there quite a while, as GCR varies on an 11 year time scale. And, there's the real solar flares, which hit unpredictably, but sometimes at extreme intensity.

That's about a decade's work with just one spacecraft experiment.

GW

Last edited by GW Johnson (2016-07-11 08:14:19)

SpaceNut · 2016-07-11 17:02:01

Sounds to me that this is a SEP demonstrator for propulsion to be able to change the obital altitudes and as well to be able to generate the power that is needed for the field as well..Some of the electric field was displayed in the deep space habitat and the remainder of the design info is in the mini megosphere topic. This is also simular to the electric propulsion of the q ship......which uses magnetic fields to alter the shape of space allowing it to move within the warping bubble.

RobertDyck · 2016-07-11 18:33:11

GW: Yes to everything. But from what I've read, we're ready to start the exact experiment you describe. It should be a stand-alone satellite. Not a deep space habitat, or anything for humans. Just a satellite to test/demonstrate the mini-magnetosphere. And since documents from University of Washington claim a basic mini-mag required 50kW of power, that will require a substantial solar array. Satellites for DirectTV etc currently are launched into GTO, and use SEP to move into GEO. So do the same thing for the manoeuvres you describe.

Design of the satellite could be interesting. The plasma is hot although very thin. You wouldn't be able to see it, or feel it, but standing within would probably result in gradual heating to become quite hot. And plasma will probably be corrosive. LEO has mono-atomic oxygen, so ISS and spacesuits have exteriors resistant to that. They currently use an outer layer of fabric that is PTFE fibre. But this satellite would require the solar panels either not interfere with the magnetic field, or work with it. That may require supporting structure made of something non-ferrous. But would aluminum alloy melt in the plasma? What if you can't make antenna from either steel or aluminum alloy? Cover the antenna behind a thermal blanket of PTFE?

Spectrolab (bought by Boeing Satellite Systems) currently make solar cells with a ceria doped coverslide. I had to look up what that means. Ceria is cerium dioxide: CeO2. Glass often has iron contaminants which tint it green. Ceria converts ferrous impurities to nearly colourless ferric oxides. So it makes the cover glass clear, allowing light to come through to the solar cell. But the important thing is "glass", which is scratch resistant and immune to corrosion from mono-atomic oxygen or thin plasma.

Wiring would have to be insulated with Teflon. That leaves structure. What would the backing and structure of the solar arrays be made of?

SpaceNut · 2016-07-11 18:59:35

40% Efficient Solar Cells: They Are Being Used Back On Earth

first layer of Spectrolab's record-breaking triple-junction cell is composed of gallium indium phosphide, which converts short-wavelength portions of the spectrum, such as blue and UV. The second layer, made of gallium arsenide, captures the middle part of the spectrum. The third germanium layer does a good job with IR light.

Hot new solar cell System converts solar heat into usable light, increasing device’s overall efficiency. New Solar Cell Breaks Efficiency Ceiling, Theory Goes Out Window....

GW Johnson · 2016-07-12 10:11:29

These are the lab feasibility demonstrations that I wrote about in another posting. Those are remarkable ideas and efficiencies, indeed.

Now what has to be demonstrated with them is twofold: (1) can these devices be made to function at the sizes we need (around 2 inches dimension per cell), and (2) how long will these materials survive working that effectively at real field condition?

I like the idea of using SEP to move the test satellite around for the demonstration, because that demonstrates SEP as well. The protection field it generates does not have to enclose all of the vehicle. That might possibly confer some sort of design advantage for this vehicle.

GW

SpaceNut · 2017-01-15 09:47:07

"Robotic Servicing of Geosynchronous Satellites (RSGS) Program Overview"

Now for the hands

"Near Real-Time State Models: a Foundational Technology for Space Automation and Robotics"

SpaceNut · 2021-05-09 18:52:45

Mission Extension Vehicles succeed as Northrop Grumman works on future servicing/debris clean-up craft

With the successful docking of Mission Extension Vehicle 2, or MEV-2, to the Intelsat 10-02 satellite last month, Northrop Grumman not only repeated the task of successfully attaching one of their MEV spacecraft to a functioning satellite but also successfully proved the ability to grab a still-transmitting telecommunications satellite without disrupting service.
The success of both MEV-1 and -2 has led to an increasing interest in the use of those crafts after their current five-year missions with their present satellites are complete. Meanwhile, Northrop Grumman has already begun work on the next generations of remote, on-orbit servicing and debris clean-up vehicles.

Mars_B4_Moon · 2021-05-30 16:51:47

ESA request proposals for in-orbit servicing

https://rocketrundown.com/esa-request-p … servicing/

In addition to ESA’s attempts to stimulate the in-orbit servicing industry, the agency is also pursuing the world’s first attempt to remove debris from orbit.

SpaceNut · 2021-08-27 13:29:21

Astroscale successfully demos in-space capture-and-release system to clear orbital debris

when its space junk removal demo satellite that’s currently in orbit successfully captured and released a client spacecraft using a magnetic system.
The End-of-Life Services by Astroscale-demonstration (ELSA-d) mission was launched in March, with the goal of validating the company’s orbital debris removal tech. The demonstrator package, which was sent up on a Soyuz rocket that launched from Kazakhstan, included two separate spacecraft: a “servicer” designed to remove space junk, and a “client” that poses as said space junk.

8a092b8493746b9c4b8ae9b1208be9f5

Mars_B4_Moon · 2022-03-25 09:54:56

Northrop Grumman says customers are ‘lined up’ for on-orbit satellite servicing

https://spacenews.com/northrop-grumman- … g-vehicle/

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#26 2016-06-26 21:37:34

Re: Servicing Earth Satelites

#27 2016-06-28 15:46:02

Re: Servicing Earth Satelites

#28 2016-06-30 21:41:04

Re: Servicing Earth Satelites

#29 2016-07-02 09:22:11

Re: Servicing Earth Satelites

#30 2016-07-02 09:45:36

Re: Servicing Earth Satelites

#31 2016-07-02 18:55:16

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#32 2016-07-02 21:07:29

Re: Servicing Earth Satelites

#33 2016-07-03 13:51:53

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#34 2016-07-09 12:02:16

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#35 2016-07-09 13:20:21

Re: Servicing Earth Satelites

#36 2016-07-09 19:30:59

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#37 2016-07-10 14:10:24

Re: Servicing Earth Satelites

#38 2016-07-11 00:20:21

Re: Servicing Earth Satelites

#39 2016-07-11 08:10:42

Re: Servicing Earth Satelites

#40 2016-07-11 17:02:01

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#41 2016-07-11 18:33:11

Re: Servicing Earth Satelites

#42 2016-07-11 18:59:35

Re: Servicing Earth Satelites

#43 2016-07-12 10:11:29

Re: Servicing Earth Satelites

#44 2017-01-15 09:47:07

Re: Servicing Earth Satelites

#45 2021-05-09 18:52:45

Re: Servicing Earth Satelites

#46 2021-05-30 16:51:47

Re: Servicing Earth Satelites

#47 2021-08-27 13:29:21

Re: Servicing Earth Satelites

#48 2022-03-25 09:54:56

Re: Servicing Earth Satelites

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