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JWST repair?


r4pt0r

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I knew the James Webb Space Telescope was going to be at L2, but I only just realized that we might need to send up a few servicing missions, as we have for Hubble. What active service spacecraft do we have that can get there and return from that distance at present? is that a Soyuz operation? Or will that be up to Orion in the coming years?

Before I submitted this thread, I quick googled it to see if there was already an answer and came to this :https://www.quora.com/If-the-JWST-is-launched-but-needs-repairs-will-we-be-in-a-position-to-launch-a-repair-mission-given-that-it-will-be-placed-at-1-5-million-km-from-Earth Looks like repair is not an option?

I know next to nothing about realworld spacecraft so be gentle...

Edited by r4pt0r
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Isn't designed to be reparable... You need to put more things than a simple grapple fixture to repair it.

It probably would need a vehicle designed exclusively for the damage suffered in the JWST, and probably will be cheaper to make another JWST.

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11 hours ago, kunok said:

Isn't designed to be reparable... You need to put more things than a simple grapple fixture to repair it.

It probably would need a vehicle designed exclusively for the damage suffered in the JWST, and probably will be cheaper to make another JWST.

It was hoped for repair due to being so expensive.

BTW, you can grapple to the engine of the satellite- Vivisat does that.

12 hours ago, r4pt0r said:

I knew the James Webb Space Telescope was going to be at L2, but I only just realized that we might need to send up a few servicing missions, as we have for Hubble. What active service spacecraft do we have that can get there and return from that distance at present? is that a Soyuz operation? Or will that be up to Orion in the coming years?

Before I submitted this thread, I quick googled it to see if there was already an answer and came to this :https://www.quora.com/If-the-JWST-is-launched-but-needs-repairs-will-we-be-in-a-position-to-launch-a-repair-mission-given-that-it-will-be-placed-at-1-5-million-km-from-Earth Looks like repair is not an option?

I know next to nothing about realworld spacecraft so be gentle...

Speaking or Vivisat, you could probably modify it (after practicing on a lot of GEO sats) to add a arm or two, and a cargo bay, launch it on F9H, and move it to L2.

Either that, or modify Orion with a HAB and a unpressurized cargo bay (or dock to a modified Cygnus for that purpose), add an inflatable airlock, and attach to the JWST.

The former seems a lot cheaper and easier, don't you think?

I wonder if a Sun-Earth L2 space station serviced by SLS Orion would be worth it...

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17 hours ago, fredinno said:

BTW, you can grapple to the engine of the satellite- Vivisat does that.

They already are doing that? Doesn't look like that. I know another similar project, about using one modified adapter for two satellites of the ariane 5, as one of this satellite services, so they optimize the launch capabilities.

Yeah maneuvering can be an option but everything else not. Won't be the worst limitation of the mission the coolant? (I'm not sure at all)

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17 minutes ago, kunok said:

They already are doing that? Doesn't look like that. I know another similar project, about using one modified adapter for two satellites of the ariane 5, as one of this satellite services, so they optimize the launch capabilities.

OrbitalATK now have an order for satellite servicing from Envisat, and are building the servicing vehicle for 2018 launch; formerly this work was done under the Vivisat joint venture with US Space, but that was dissolved under dodgy circumstances just before the firm order was received. The actual vehicle is basically a small GSO sat with no comms payload and enhanced propulsion, based on their GEOstar bus. The modified Ariane launch adaptor project was the now defunct ConeXpress.

22 minutes ago, kunok said:

Yeah maneuvering can be an option but everything else not. Won't be the worst limitation of the mission the coolant? (I'm not sure at all)

JWST doesn't use consumable coolant, it's dependent on the sun shield for cooling.

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1 hour ago, kunok said:

They already are doing that? Doesn't look like that. I know another similar project, about using one modified adapter for two satellites of the ariane 5, as one of this satellite services, so they optimize the launch capabilities.

Yeah maneuvering can be an option but everything else not. Won't be the worst limitation of the mission the coolant? (I'm not sure at all)

Pardon my grammar. WILL.

In 2 years.

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7 hours ago, Kryten said:

OrbitalATK now have an order for satellite servicing from Envisat, and are building the servicing vehicle for 2018 launch; formerly this work was done under the Vivisat joint venture with US Space, but that was dissolved under dodgy circumstances just before the firm order was received. The actual vehicle is basically a small GSO sat with no comms payload and enhanced propulsion, based on their GEOstar bus. The modified Ariane launch adaptor project was the now defunct ConeXpress.

JWST doesn't use consumable coolant, it's dependent on the sun shield for cooling.

Yes, the Orbital plan is pretty simple and might work for jwst too, you grab the rocket engine on jwst and then use the service satellite for reaction wheel and rcs. 
Problem with jwst is that it has an huge sunshade on one side and the telescope on the other side, it might be hard to connect to. 
On the other hand this would be an far simpler solution than an jwst replacement. 

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On 5/11/2016 at 6:28 PM, magnemoe said:

Yes, the Orbital plan is pretty simple and might work for jwst too, you grab the rocket engine on jwst and then use the service satellite for reaction wheel and rcs. 
Problem with jwst is that it has an huge sunshade on one side and the telescope on the other side, it might be hard to connect to. 
On the other hand this would be an far simpler solution than an jwst replacement. 

Can the Sunsheild be retracted back? That might be needed for a potential repair.

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Ultimately the idea of a repair mission to James Webb would depend on how worth it it would be to do so in the first place, given that the mission would mostly comprise of one time use hardware, procedures, and so on. With James Webb not being designed as Hubble was, to repair it would require development time and resources that, depending on the kind of repairs Webb might need, may end up costing just as much as rebuilding the whole thing altogether.

Other things to consider is the simple fact that if James Webb goes up in 2018 as planned, it will sit up there broken until at least 2021 when we're finally sending astronauts up with Orion. It also has to be stated that, much like the SLS rocket that would both launch it and inevitably be called on to help service it, Webb has had development issues. Given everything and the general climate, if Webb launches and it ends up a failure, no one might be willing to even fund a rescue in the first place.

But, grown up pessimist talk aside, the idea of repairing it would still be pretty complicated. One because you would in fact need a specialized device to either capture or otherwise restrain the satellite in one position while you work, and two because by design most of what might go wrong with it will require taking the thing apart in order to fix. If you have to dismantle the sun shield, what might that do to the instruments?

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JWST was supposed to be equipped with an IDA docking adapter, "just in case" (it might have been deleted), but includes no other provisions for repair. You can't open it up, take parts off. There are no hand rails for astronauts to move around it, there are thrusters that need to be disabled, there are parts that are likely to be damaged if you touched them by accident. It's a very delicate instrument that isn't designed to be tampered with.

A JWST repair mission would be dangerous (if manned) and would be likely to do more harm than good.

Edited by Nibb31
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Hubble was designed with Shuttle launch in mind, so clearly they could've taken the satellite half-disassembled then assemble it in space later. Servicing is just a small step ahead.

JWST, on the other hand, isn't designed with space assembly in mind. Practically what Nibb said.

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6 hours ago, Nibb31 said:

A JWST repair mission would be dangerous (if manned) and would be likely to do more harm than good.

Lets see getting on a metal can filled with reductant and oxidant within feet of each othe, igniting this and hurling oneself to 8000 m/s, the flying around in a zone of other objects traveling at you at up to 5600 m/s and you little vessel occasionally gets hit............is some how not dangerous, the return vehical is a brick throuwn into a furnace with flames 4000 degrees, and at the end this plastoc thing plops out before you slam into the ground and this is somehow not dangerous, but going to L2 is..........

Difficult to plan, maybe, sonce you are behind the earth it blocks solar sotms to some degree. The other issue is time and survival but the Orion as designed should be able to handle it. If its got a docking handle handles can be attached. 

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