Commercial Hubble Repair

[Micahgtb]

Just a simple question. Can any currently planned commercial vehicle (with one or more launches) plan and complete a Hubble repair mission? I am looking forward to JWST as the next person but giving up such a still relevant instrument seems terrible to me. Any clues?

[Jorge]

Just a simple question. Can any currently planned commercial vehicle (with one or more launches) plan and complete a Hubble repair mission? I am looking forward to JWST as the next person but giving up such a still relevant instrument seems terrible to me. Any clues?

Hubble was outfitted with a passive LIDS interface and a set of laser retroreflectors during STS-125, so technically any of the commercial crew vehicles (Dragon, CST-100, Dream Chaser, and the Blue Origin vehicle) can rendezvous and dock with it.

Actually being able to perform a *useful* servicing mission is another matter. If any of the above vehicles can support standalone EVAs, that capability is certainly not being advertised yet. Only Dragon has any unpressurized cargo space for replacement instruments, and without a robotic arm, installation would be highly impractical.

In my opinion, an (as-yet unproposed) mission module would have to be developed and launched separately to provide said capabilities in order for any of these vehicles to perform a useful servicing mission.

[manboy]

Just a simple question. Can any currently planned commercial vehicle (with one or more launches) plan and complete a Hubble repair mission? I am looking forward to JWST as the next person but giving up such a still relevant instrument seems terrible to me. Any clues?

I'm not sure if any of the Commercial Crew vehicles support EVA.

[krytek]

There were rumors of a possible EVA and robotic arm capability for the Dream Chaser.

[manboy]

There were rumors of a possible EVA and robotic arm capability for the Dream Chaser.

Those weren't rumors. Mark Sirangelo was talking about possible future variants.

[corrodedNut]

I finally managed to convert this file. Its from 2010, so some things are obsolete. As you can see (pp.15-24), SpaceX has given servicing missions some thought.

[Garrett]

I finally managed to convert this file. Its from 2010, so some things are obsolete. As you can see (pp.15-24), SpaceX has given servicing missions some thought.

Thanks for that! Very interesting.

[Micahgtb]

I finally managed to convert this file. Its from 2010, so some things are obsolete. As you can see (pp.15-24), SpaceX has given servicing missions some thought.

Ya this was pretty much what I had in mind, glad to see someone has put some thought into it at least.

[adrianwyard]

As mentioned earlier SNC has said they intend Dream Chaser be used for servicing too, but I've not seen any details. Has anyone else?

To be honest I think Dragon probably has the upper hand here mainly due to the many options afforded by the trunk, but here are some wild speculations on DC as a servicing vehicle:

+ The DC's rear tunnel seems about the right size for a 1 person air lock. By contrast, Dragon needs to be depressurized/repressurized entirely for EVA.

+ As with Dragon, a robotic arm would be protected inside a canister on the upper DC surface. If the base of the arm was near the cockpit windows these would provide excellent visibility for grapple and support of the EVA crewmember. (The interior of the arm canister will need handles to allow EVA translation from the back of DC to the work site.)

+ If the arm canister doesn't disrupt the aerodynamics too much the arm can be returned for re-use (unlike with Dragon.)

So, basically the same as Dragon except you have crewmembers supporting the EVA inside a pressurized vehicle - as happens with ISS EVAs - rather than while in their own EVA gear.

[Micahgtb]

As mentioned earlier SNC has said they intend Dream Chaser be used for servicing too, but I've not seen any details. Has anyone else?

To be honest I think Dragon probably has the upper hand here mainly due to the many options afforded by the trunk, but here are some wild speculations on DC as a servicing vehicle:

+ The DC's rear tunnel seems about the right size for a 1 person air lock. By contrast, Dragon needs to be depressurized/repressurized entirely for EVA.

+ As with Dragon, a robotic arm would be protected inside a canister on the upper DC surface. If the base of the arm was near the cockpit windows these would provide excellent visibility for grapple and support of the EVA crewmember. (The interior of the arm canister will need handles to allow EVA translation from the back of DC to the work site.)

+ If the arm canister doesn't disrupt the aerodynamics too much the arm can be returned for re-use (unlike with Dragon.)

So, basically the same as Dragon except you have crewmembers supporting the EVA inside a pressurized vehicle - as happens with ISS EVAs - rather than while in their own EVA gear.

Right, but with DC where would the new and old instruments go?

[adrianwyard]

Right, but with DC where would the new and old instruments go?

It's a problem. That's where Dragon has the edge.

I initially thought that DC's Upper Stage fairing/adapter could be enlarged and converted into a Dragon-like trunk. Perhaps the aero-fairing would be jettisoned to save weight (like the Orion SM panels.) Unpressurized spares would be attached to this structure. If needed, solar panels could be attached here too.

The big problem with this is the OMS engines fire back into this area. Even speculative solutions to this sound nuts: Hinge the cargo structure to the side out of the way?

[docmordrid]

Right, but with DC where would the new and old instruments go?

Found these SpaecDev pics in my image collection, downloaded from the NASA CC pages. Low-res, but the idea comes through loud and clear.

Source: http://www.nasa.gov/offices/c3po/partners/spacedev/index.html

[Micahgtb]

Right, but with DC where would the new and old instruments go?

Found these SpaeDev pics in my image collection, downloaded from the NASA CC pages. Lor-es, but the idea comes through loud and clear.

Source: http://www.nasa.gov/offices/c3po/partners/spacedev/index.html

Yes it does! Any clue as to what the crew capacity would be with this configuration?

[docmordrid]

No clue. They're old images showing 4 engines vs. the current 2, and the long-gone  hybrid upper stage.

Still - I would think with a composite pressure vessel a cabin hatch and payload bay could be rapidly prototyped for a "Servicing Dream Chaser".

Rampant speculation:  2-4 seats, bulkhead with unpressurized cargo bay, a mini-MDA supplied arm & no rear docking adapter needed?

[Robotbeat]

I still think the hybrid engines are a sort of tacky solution that won't live that long once (if) DC actually starts flying.

[docmordrid]

A brace of SuperDraco's on either side would give it a kick in the gas, but that'll probably never happen.

[Robotbeat]

A brace of SuperDraco's on either side would give it a kick in the gas, but that'll probably never happen.

There are other aerospace companies out there besides SpaceX.

[docmordrid]

I know - but it's hypergolic and in the thrust range to be an abort motor. What are the other options?

[Robotbeat]

I know - but it's hypergolic and in the thrust range to be an abort motor. What are the other options?

http://www.astronautix.com/fam/stoiquid.htm

[Micahgtb]

I know - but it's hypergolic and in the thrust range to be an abort motor. What are the other options?

http://www.astronautix.com/fam/stoiquid.htm

Thanks for this website, didn't know it existed! Wonderful knowledge source.

[Robotbeat]

I know - but it's hypergolic and in the thrust range to be an abort motor. What are the other options?

http://www.astronautix.com/fam/stoiquid.htm

Thanks for this website, didn't know it existed! Wonderful knowledge source.

Just remember that it's not a primary source, so take its specific figures with a grain of salt. But yes, it's a very handy resource.

[go4mars]

I know - but it's hypergolic and in the thrust range to be an abort motor. What are the other options?

http://www.astronautix.com/fam/stoiquid.htm

Dracos and superdracos aren't on that list. 

[Prober]

this is really an off the wall idea.   

Only NASA could pull off the EVA's and repairs.   I had the good fortune to have some time avai to watch many hours of the last repair mission.  It so impressed me.

Wonder if "all" the hours video of the mission are available ?   IMHO, It was NASA, the Shuttle etc. at its best!

[adrianwyard]

Returning to speculation on a Cargo/Servicing Dream Chaser:

Given how old the attached graphic is, and how easy these things are to generate, we have to keep plenty of grains of salt handy. Nevertheless, Mark Sirangelo has said servicing is a mission for Dream Chaser so it's interesting to guess how this might work.

In a previous post I suggested an airlock could be installed in the rear tunnel, and the upper stage adapter could house servicing-related equipment. It turns out these ideas were considered for the HL-42 (42% larger than HL-20). See http://www.astronautix.com/craft/hl42.htm. For some reason it didn't bother them that the 'towed package' was back next to the OMS engines...

As far as DC goes, I've changed my mind on these. If we assume that this graphic is about right, and the pressure bulkhead can easily be moved forward to open up a mini cargo bay, here are some observations.

+ We now have a place to house the replacement parts uphill, the robotic arm can be safely placed within the bay, and the system has the ability to return parts.

+ Such a craft could only visit the ISS unmanned as the crew can't get to the rear hatch.

+ If built, this would be the only way to return unpressurized cargo from the ISS (although Dragon and HTV can bring it up.)

+ For EVA you'd probably just depressurize the (smaller) cabin area. If having an IVA crewmember in shirt-sleeves during the EVA was valuable, then you'd repressurize the cabin immediately, and have to depress/repressurize to get the EVA crew back in. While this is wasteful, the extra O2 would surely be less mass than an airlock.

+ Or, if the design was matured in time, Dream Chaser would be a great application for a suitport. http://en.wikipedia.org/wiki/Suitport

[go4mars]

+ If built, this would be the only way to return unpressurized cargo from the ISS (although Dragon and HTV can bring it up.)

What are some examples of unpressurized cargo they would like to send down?

[Jim]

Returning to speculation on a Cargo/Servicing Dream Chaser:

Given how old the attached graphic is, and how easy these things are to generate, we have to keep plenty of grains of salt handy. Nevertheless, Mark Sirangelo has said servicing is a mission for Dream Chaser so it's interesting to guess how this might work.

In a previous post I suggested an airlock could be installed in the rear tunnel, and the upper stage adapter could house servicing-related equipment. It turns out these ideas were considered for the HL-42 (42% larger than HL-20). See http://www.astronautix.com/craft/hl42.htm. For some reason it didn't bother them that the 'towed package' was back next to the OMS engines...

As far as DC goes, I've changed my mind on these. If we assume that this graphic is about right, and the pressure bulkhead can easily be moved forward to open up a mini cargo bay, here are some observations.

+ We now have a place to house the replacement parts uphill, the robotic arm can be safely placed within the bay, and the system has the ability to return parts.

+ Such a craft could only visit the ISS unmanned as the crew can't get to the rear hatch.

+ If built, this would be the only way to return unpressurized cargo from the ISS (although Dragon and HTV can bring it up.)

+ For EVA you'd probably just depressurize the (smaller) cabin area. If having an IVA crewmember in shirt-sleeves during the EVA was valuable, then you'd repressurize the cabin immediately, and have to depress/repressurize to get the EVA crew back in. While this is wasteful, the extra O2 would surely be less mass than an airlock.

+ Or, if the design was matured in time, Dream Chaser would be a great application for a suitport. http://en.wikipedia.org/wiki/Suitport

No need for an arm if it is unmanned.

Name a piece of unpressurized cargo that needs to be returned and can be returned by this?

It is null set or very small.

[jimvela]

The discussion of further manned servicing of Hubble is well and good, but is also very unlikely.

Before the final (Shuttle) servicing mission was re-instated, a considerable amount of effort was made towards planning an unmanned servicing and de-orbit prep mission.

Following the changes from the last servicing mission, it is now even more likely that *IF* any further mission to Hubble happens, it will be very much along the lines of the aborted plans for an unmanned servicing mission.

I know of at least two companies that have solid capabilities and mission designs that would allow an unmanned servicing mission with a high likelihood of success.

It wouldn't surprise me at all if at some point STScI could come up with enough funding and political support for a robotic mission, even with JWST  upcoming.  Particularly so if HST continues to hang on and operate suitably after JWST is launched.

[adrianwyard]

Jim, are you going to argue that there is never, ever, a need to bring back unpressurized cargo?

There is no urgent need for this now, but some day in the future I think it will be developed. If the need did arise soon, of the commercial crew vehicles, DC seems best suited to this because its pressurized crew module can be more easily shortened to open space for a cargo bay. And it's also the only vehicle where the addition of a suitport looks straightforward. Do I think this will actually happen? No, I do not.

And to state the obvious: when the Shuttle was flying we made use of the return ability several times. I'm sure others can list more than me, but from memory: pump modules, EVA tanks, MISSE experiments, Hubble instruments.

[adrianwyard]

Despite the back-and-forth my initial question on servicing (in the DC thread) remains unanswered:

SNC talk about the DC being well suited to satellite servicing. I can't really see how that's the case. If we're talking about the vehicles as specified for commercial crew, then Dragon seems to have the edge because the trunk could contain mission-specific servicing hardware...

[QuantumG]

Despite the back-and-forth my initial question on servicing (in the DC thread) remains unanswered:

SNC talk about the DC being well suited to satellite servicing. I can't really see how that's the case. If we're talking about the vehicles as specified for commercial crew, then Dragon seems to have the edge because the trunk could contain mission-specific servicing hardware...

Why do you assume they're saying Dragon isn't well suited to satellite servicing? It is possible for both vehicles to be suitable isn't it?

[Jim]

1.  Jim, are you going to argue that there is never, ever, a need to bring back unpressurized cargo?

2.  There is no urgent need for this now, but some day in the future I think it will be developed. If the need did arise soon, of the commercial crew vehicles, DC seems best suited to this because its pressurized crew module can be more easily shortened to open space for a cargo bay.

3 And to state the obvious: when the Shuttle was flying we made use of the return ability several times. I'm sure others can list more than me, but from memory: pump modules, EVA tanks, MISSE experiments, Hubble instruments.

1. No

2.  Just that DC is illsuited for the task.

3.  A very small percentage

Return hardware will become viable on RLV's not reusable spacecraft

[adrianwyard]

Why do you assume they're saying Dragon isn't well suited to satellite servicing? It is possible for both vehicles to be suitable isn't it?

I was just referring to the occasions SNC brags about the servicing capabilities of own vehicle and not the competition.

[oiorionsbelt]

1.  Jim, are you going to argue that there is never, ever, a need to bring back unpressurized cargo?

2.  There is no urgent need for this now, but some day in the future I think it will be developed. If the need did arise soon, of the commercial crew vehicles, DC seems best suited to this because its pressurized crew module can be more easily shortened to open space for a cargo bay.

3 And to state the obvious: when the Shuttle was flying we made use of the return ability several times. I'm sure others can list more than me, but from memory: pump modules, EVA tanks, MISSE experiments, Hubble instruments.

1. No

2.  Just that DC is illsuited for the task.

3.  A very small percentage

Return hardware will become viable on RLV's not reusable spacecraft

Bold mine:
This is an interesting statement.
Care to fill in any details or reasons?

[TomH]

If the mission is unmanned, what about an agreement with USAF to use X-37B?

[Jim]

Bold mine:
This is an interesting statement.
Care to fill in any details or reasons?

When RLV's become economical for launching hardware, it should be economical to return some too.

[RDoc]

When RLV's become economical for launching hardware, it should be economical to return some too.

It seems a bit unobvious that RLV's are a requirement or even particularly relevant. Given a reusable spacecraft, I'd think the marginal cost of returning hardware from orbit would be extremely low. After all, if you're already up there, why return empty handed?

[Robotbeat]

When RLV's become economical for launching hardware, it should be economical to return some too.

It seems a bit unobvious that RLV's are a requirement or even particularly relevant. Given a reusable spacecraft, I'd think the marginal cost of returning hardware from orbit would be extremely low. After all, if you're already up there, why return empty handed?

Because the cost of the return capability is that much more, since you have to pay to get that return capability into orbit.

[RDoc]

When RLV's become economical for launching hardware, it should be economical to return some too.

It seems a bit unobvious that RLV's are a requirement or even particularly relevant. Given a reusable spacecraft, I'd think the marginal cost of returning hardware from orbit would be extremely low. After all, if you're already up there, why return empty handed?

Because the cost of the return capability is that much more, since you have to pay to get that return capability into orbit.

The premise of the discussion is you have a reusable spacecraft to start with. Of course, I'm assuming that if the spacecraft is reusable, that it returns to Earth. It wouldn't apply to something like a GTO/GSO taxi, but I don't think that's what we're discussing.

Anyway, apart from SSTO, whether the launcher is reusable or not has nothing to do with the spacecraft being reusable. Depending on the mass/value tradeoff for a particular mission, it doesn't seem inconceivable that a RLV would be sacrificed to get a heavier mass into orbit. SpaceX estimates a 40% payload penalty for launcher reusability. The cost of reusing DragonLab vs not is roughly the weight of the parachute and having a ship go out to pick it up.
 

<snip>
Return hardware will become viable on RLV's not reusable spacecraft

[Robotbeat]

It does depend, because the ability to return equipment and the extra weight penalty to make that equipment repairable, etc, has to come out of a very expensive expendable launch vehicle of around $10,000/kg to orbit.

[RDoc]

It does depend, because the ability to return equipment and the extra weight penalty to make that equipment repairable, etc, has to come out of a very expensive expendable launch vehicle of around $10,000/kg to orbit.

Within the capability of the launcher, the marginal cost of a Kg to orbit is not anywhere near $10,000, it's probably closer to $200. Once you've launched the first 5000Kg, the next Kg is pretty cheap.

Notice that SpaceX prices their launches by the launch, not the Kg. That means that as long as the mass to orbit stays within the launcher capacity, the marginal cost of launching any return racks not already installed is zero.

For dirty laundry, it may still not be worth doing. For examining why a piece of life support equipment failed early, or getting back a protein synthesis lab to be modified and reflown, it's may very well be.

As far as if repairability adds mass, I'm doubtful that much equipment is put into orbit that can't be factory disassembled. Obviously there are expendables, but even for failed equipment that isn't going to be reused, it's sometimes very instructive to take a close look to see what happened. After all, if you can double the on orbit life, you don't have to fly so many.

[Mongo62]

Getting back to the original Hubble servicing question, would not the cheapest solution simply be to build and launch a Hubble clone (this time installing a correctly-figured main mirror) to replace the entire telescope?

I vaguely recall hearing about a report many years ago that concluded that for the expense of all the various Shuttle servicing missions, several Hubbles could have been built and launched on unmanned rockets (Atlas V?), and we would have ended up with a whole fleet of active telescopes.

[Jorge]

Getting back to the original Hubble servicing question, would not the cheapest solution simply be to build and launch a Hubble clone (this time installing a correctly-figured main mirror) to replace the entire telescope?

Back when HST SM-4 was cancelled, Johns Hopkins proposed using the SM-4 replacement instruments to build a new telescope called the Hubble Origins Probe, for about $1B:

http://www.pha.jhu.edu/hop/

Of course, it would be much more expensive to build HOP now since the SM-4 instruments flew on STS-125.

I vaguely recall hearing about a report many years ago that concluded that for the expense of all the various Shuttle servicing missions, several Hubbles could have been built and launched on unmanned rockets (Atlas V?), and we would have ended up with a whole fleet of active telescopes.

Perhaps in a narrow technical sense. But Hubble was politically tied to the shuttle; had it launched on an ELV with the same original flaws, most likely there would never have been a second one.

[go4mars]

Of course, it would be much more expensive to build HOP now since the SM-4 instruments flew on STS-125.

Thanks Jorge.  Just to clarify; Do you mean that an EELV launch and everything except the SM-4 instruments would be about a billion dollars today, but that re-making the SM-4 instruments (or their current equivalent) would be more than an additional billion dollars?  I didn't notice any $ breakdown in the link.   

[Jorge]

Of course, it would be much more expensive to build HOP now since the SM-4 instruments flew on STS-125.

Thanks Jorge.  Just to clarify; Do you mean that an EELV launch and everything except the SM-4 instruments would be about a billion dollars today, but that re-making the SM-4 instruments (or their current equivalent) would be more than an additional billion dollars?

I assume that the whole thing will be a lot more than $1B due to the need to build new instruments, and because the price of EELV has gone up. They assumed $130-150M for an Atlas V 521, for example.

  I didn't notice any $ breakdown in the link.   

You didn't look hard enough. There is a cost breakdown on slide 20 of the PowerPoint slideshow at the link.

[A_M_Swallow]

With a life expectancy of only a couple more years Commercial Space cannot get a manned capsule to the Hubble Space Telescope in time.

An unmanned repair mission requires development of automated repair robots.  There has been some money going into space robots but not a lot.  Consequently such missions are many years in the future.

Launching Hubble#2.  With a mass of 11,110 kg (24,500 lb) and orbital height of 559 km (347 miles) there are several launch vehicles that can lift its replacement.  In previous years the estimated cost of building a replacement satellite was about $1 billion which suggests a current cost of $2 billion to $3 billion.  The replies to a request for bid for launching a replacement using the current specification within about 3 years could be very interesting.

[QuantumG]

It's possible with the right amount of money.

If they really want it, Congress should just put the repair out to tender. NASA could act in a support role if the price is right. If the price comes back too high, that just shows exactly how much Congress really wanted it.

[Danderman]

With a life expectancy of only a couple more years Commercial Space cannot get a manned capsule to the Hubble Space Telescope in time.

Really?

[yg1968]

DC has the option of adding a manipulator arm and an airlock:

See this thread:
http://forum.nasaspaceflight.com/index.php?topic=26179.msg785232#msg785232

[grythumn]

With a life expectancy of only a couple more years Commercial Space cannot get a manned capsule to the Hubble Space Telescope in time.

Really?

Current EOM is set for end of december 2014. Most of the projected lifespans I see online say "at least 2013" or "at least 2014". Wikipedia says reentry is due between 2019 and 2032, but doesn't cite a source.

http://hubblesite.org/the_telescope//hubble_essentials/
http://sci.esa.int/science-e/www/area/index.cfm?fareaid=31

-R C

[Nomadd]

With a life expectancy of only a couple more years Commercial Space cannot get a manned capsule to the Hubble Space Telescope in time.

Nonsense. There's no reason to believe Hubble is anywhere close to ceasing that soon. It could be going till it's orbit decays, and even then, any booster designed to deorbit it could boost it's orbit if it's still in good shape. With the gyro problems corrected on the new and rebuilt models, new batteries and mostly new instruments, it could be operational 20 years from now.

[simonbp]

It's not the orbit that will decay on Hubble first; it's the gyros. Hubble uses CMGs exclusively for pointing, and they are in theory triple-redundant. However, they already have lost one since the last servicing...

And extented missions can mean different things. At the moment Hubble is fully funded to provide a lot of support to the astronomers who use it (including 50% of my time). It's not impossible that this will go away in the future, much like it already has for Kepler. If that happens, the desire in the community for a new UV/Optical telescope will be considerably louder.

As far as replacement, NASA is exploring the option of launching one of the two donated NRO sats as a UV/Optical successor to Hubble (with the other as WFIRST). It's all very nebulous at the moment, but some recent (two weeks ago) talks on the subject are here: http://www.princeton.edu/astro/news-events/public-events/new-telescope-meeting/program/NEW-Telescope-Meeting-Sept-2012-Program.pdf The presentaions from Gehrels, Kruk, and Scowen are especially relevant. Note that Kruk brings up the idea of putting NRO/WFIRST at GSO (rather than SEL2) to allow servicing.

[Danderman]

It would seem that a commercial servicing mission for HST could be very cost effective, if undertaken in the next 5 years or so. Yes, the Hubble gyros remain the Achilles' heel of the system, but Hubble has limped by in the past with less-than-nominal numbers of functioning gyros. I would bet real money that HST will be functional in 5 years' time.

[oiorionsbelt]

Could a booster for Hubble be fitted with CMGs to take over for the ones currently on Hubble?

[simonbp]

Could a booster for Hubble be fitted with CMGs to take over for the ones currently on Hubble?

Maybe, but if you were going to go to the trouble of adding a thruster/booster module to HST, you would want to add gyros to it anyway to make up for the longer spacecraft. Indeed, it may be better to treat the booster as a free flyer that only occasionally docks with HST for a reboost.

And replacing gyros is relatively simple compared to instruments; a basic manned Dragon could do it without any extra equipment. Replacing the instruments is where a crane/boom/arm/etc would come in.

[yg1968]

And replacing gyros is relatively simple compared to instruments; a basic manned Dragon could do it without any extra equipment. Replacing the instruments is where a crane/boom/arm/etc would come in.

You mean a Dragon with a robotic arm, right?

[baldusi]

And replacing gyros is relatively simple compared to instruments; a basic manned Dragon could do it without any extra equipment. Replacing the instruments is where a crane/boom/arm/etc would come in.

You mean a Dragon with a robotic arm, right?

Is it EVA capable?
I still think it's the wrong orbit and doing a non man rated space telescope is a better investment. Particularly given the NRO donation. But, if NASA gave the new CMG as GFE, it would be interesting what sort of bids they would get if they do a conceptual tender on a mission to swap the CMG. In a couple of years, if the Phoenix Program has done some significant advance, it might even use a COTS manipulator.
Clearly a Dragon mission should be able to be fully robotic. May be a DreamChaser too.

[watermod]

Could a Robonaut or Dextre in a craft perform a repair of Hubble and other large sats?

I could even envision a repair craft parked at ISS.  ISS eventually getting enough repair parts in in normal supply missions to make the repair.  At some point a tug/frame type craft borrows the appropriate robot from ISS, is loaded with the parts and heads off to Hubble to make the repair.  Old parts are returned to ISS and eventually go down as returns or on a trash and burn flight.

It seems that would make more sense then lofting repair platforms & maybe astronauts over and over.

[beancounter]

Why not simply build a replica and launch it on an F9 (cheapest launch vehicle).  Bet the cost would be less than a manned mission and you get a new HST to boot.  Also less risky and probably possible in the current timeframe.  If you're going to do a refurbishment mission, why not simply a new (same as) unit.

[Danderman]

Why not simply build a replica and launch it on an F9 (cheapest launch vehicle).  Bet the cost would be less than a manned mission and you get a new HST to boot.  Also less risky and probably possible in the current timeframe.  If you're going to do a refurbishment mission, why not simply a new (same as) unit.

A new telescope would be very expensive, and F9 cannot put Hubble in a 600 km orbit, nor is the payload fairing wide enough.

A single launch of a Dragon with a crew is sufficient to keep Hubble flying for many years, and Dragon can dock with HST using the LIDS that was attached to Hubble during the last servicing mission.

[Dappa]

Why not simply build a replica and launch it on an F9 (cheapest launch vehicle).  Bet the cost would be less than a manned mission and you get a new HST to boot.  Also less risky and probably possible in the current timeframe.  If you're going to do a refurbishment mission, why not simply a new (same as) unit.

On top of from Danderman's points, a Hubble replica assumes identical launch environments and load paths. These variables on F9 clearly differ from those on Shuttle, requiring an extensive redesign. But then it's no longer a replica.

[Danderman]

If NASA had an unlimited budget, building and flying a new telescope would be great.

But, in this world of fixed budgets, I believe that a "batteries and gyros" commercial mission to HST would be the most cost effective approach to maintaining our optical capability.

[Jim]

I believe that a "batteries and gyros" commercial mission to HST would be the most cost effective approach to maintaining our optical capability.

Not with the dragon.  It is ill-suited for such a task.

[Arb]

Not with the dragon.  It is ill-suited for such a task.

Why?

[Jim]

Not with the dragon.  It is ill-suited for such a task.

Why?

It is not made to handle EVA's

[jongoff]

Not with the dragon.  It is ill-suited for such a task.

Why?

It is not made to handle EVA's

Of the EVA related capabilities that Dragon lacks, which do you think are the biggest deals? Some sort of airlock? An RMS? Handholds of some sort? or something else? 

Just curious, because I know some companies trying to solve some of those issues....

~Jon

[Danderman]

Not with the dragon.  It is ill-suited for such a task.

Why?

It is not made to handle EVA's

Of the EVA related capabilities that Dragon lacks, which do you think are the biggest deals? Some sort of airlock? An RMS? Handholds of some sort? or something else? 

Just curious, because I know some companies trying to solve some of those issues....

~Jon

Well, either they need an airlock, or the avionics (and everything else in the cabin) need to be vacuum-rated.

If they have an RMS, they can mitigate the need for handholds on the Dragon capsule by putting the EVA crew in RMS foot restraints. Handholds on the trunk would still be a good idea, I think.

This is all true.

The question is whether these capabilities would cost more than alternates, including building a new HST or some sort of robotic repair mission.

[vulture4]

It's not the orbit that will decay on Hubble first; it's the gyros. Hubble uses CMGs exclusively for pointing, and they are in theory triple-redundant. However, they already have lost one since the last servicing...

And extented missions can mean different things. At the moment Hubble is fully funded to provide a lot of support to the astronomers who use it (including 50% of my time). It's not impossible that this will go away in the future, much like it already has for Kepler. If that happens, the desire in the community for a new UV/Optical telescope will be considerably louder.

As far as replacement, NASA is exploring the option of launching one of the two donated NRO sats as a UV/Optical successor to Hubble (with the other as WFIRST). It's all very nebulous at the moment, but some recent (two weeks ago) talks on the subject are here: http://www.princeton.edu/astro/news-events/public-events/new-telescope-meeting/program/NEW-Telescope-Meeting-Sept-2012-Program.pdf The presentaions from Gehrels, Kruk, and Scowen are especially relevant. Note that Kruk brings up the idea of putting NRO/WFIRST at GSO (rather than SEL2) to allow servicing.

Good points. Without funding to do research, instruments can do nothing.

Whether servicing Hubble is practical would depend on the total servicing mission cost. With the Shuttle servicing missions this was very high and periodic replacement might well have been less expensive.

But the original idea (in the late 70's) was for astronomy instruments to co-orbit near the Space Station (or be mounted on it (in vacuum) where possible). This would reduce design complexity, launch and servicing cost since instruments could be reached via EVA or docked with the station for servicing. Currently there is only the AMS and one camera inside the cupola for earth observation.

[jongoff]

Not with the dragon.  It is ill-suited for such a task.

Why?

It is not made to handle EVA's

Of the EVA related capabilities that Dragon lacks, which do you think are the biggest deals? Some sort of airlock? An RMS? Handholds of some sort? or something else? 

Just curious, because I know some companies trying to solve some of those issues....

~Jon

Well, either they need an airlock, or the avionics (and everything else in the cabin) need to be vacuum-rated.

If they have an RMS, they can mitigate the need for handholds on the Dragon capsule by putting the EVA crew in RMS foot restraints. Handholds on the trunk would still be a good idea, I think.

Cool. Those problems are potentially solvable. I was curious if there were any showstoppers I hadn't already been thinking about.

~Jon

[jongoff]

Not with the dragon.  It is ill-suited for such a task.

Why?

It is not made to handle EVA's

Of the EVA related capabilities that Dragon lacks, which do you think are the biggest deals? Some sort of airlock? An RMS? Handholds of some sort? or something else? 

Just curious, because I know some companies trying to solve some of those issues....

~Jon

Well, either they need an airlock, or the avionics (and everything else in the cabin) need to be vacuum-rated.

If they have an RMS, they can mitigate the need for handholds on the Dragon capsule by putting the EVA crew in RMS foot restraints. Handholds on the trunk would still be a good idea, I think.

This is all true.

The question is whether these capabilities would cost more than alternates, including building a new HST or some sort of robotic repair mission.

I guess a lot depends on how expensive a crew flight with Dragon actually ends up being. If it's closer to their current $130M for a cargo flight, then it could very well be possible to have some sort of an airlock module that you could bring up on the trunk, and a stowable RMS arm like what Altius is investigating with NASA LaRC that could attach that to the LIDS ring on the front of the Dragon after launch, for instance. My guess is that the marginal cost of adding those capabilities will be relatively small compared to the say ~$500M that SpaceX took to build Falcon 9 and Dragon...

So even if the hardware designs only got used once for this mission, I still think you'd be talking about a mission competitive with robotic servicing (unless you were just trying to deorbit Hubble) or a Hubble replacement. If you could amortize the development over multiple missions of different sorts, I think you'd be able to get the costs of the RMS and airlock system down into an even more competitive range.

~Jon

[robertross]

I can see a Hubble replacement mission following the same path as many other missions: cost creep where they develop new capabilities and/or incorporate new technologies to reduce mass/size & improved performance.

They have a working platform that will certainly fail at some point. Keeping existing capabilites (in this situation) offers the least risk (imo)

[Jim]

Not with the dragon.  It is ill-suited for such a task.

Why?

It is not made to handle EVA's

Of the EVA related capabilities that Dragon lacks, which do you think are the biggest deals? Some sort of airlock? An RMS? Handholds of some sort? or something else? 

Just curious, because I know some companies trying to solve some of those issues....

~Jon

Well, either they need an airlock, or the avionics (and everything else in the cabin) need to be vacuum-rated.

If they have an RMS, they can mitigate the need for handholds on the Dragon capsule by putting the EVA crew in RMS foot restraints. Handholds on the trunk would still be a good idea, I think.

Room for EMU's and support equipment.  Gases for repressurization.  Potentially hatch size.
Resign and requalify the avionics? 

[beancounter]

As I noted above, build a new one on the existing spec's.  If the f9 can't handle it, then the FH will likely be on line by then.  Currently there's no way of doing an EVA mission to the existing HST.
Some of you seem hung up on a refurbishment mission whilst ignoring all the practical issues.
Perhaps if you're so keen on it, you could work up a funding model along the following lines:
Base HST escalate to today's dollars assuming no specification changes.
LV cost
Integration, handling, support, etc, costs
Total Cost of new unit
versus
- well, how much do you suppose a full up refurbishment mission will cost since we have no vehicle currently capable of undertaking it?

[robertross]

As I noted above, build a new one on the existing spec's.  If the f9 can't handle it, then the FH will likely be on line by then.  Currently there's no way of doing an EVA mission to the existing HST.
Some of you seem hung up on a refurbishment mission whilst ignoring all the practical issues.
Perhaps if you're so keen on it, you could work up a funding model along the following lines:
Base HST escalate to today's dollars assuming no specification changes.
LV cost
Integration, handling, support, etc, costs
Total Cost of new unit
versus
- well, how much do you suppose a full up refurbishment mission will cost since we have no vehicle currently capable of undertaking it?

The problem which I have learned on this site, is that the original suppliers likely no longer exist, or no parts are no longer available, which means re-design & re-certification (likely).

One problem I thought of, of my thoughts on refurbishment, is that the SpaceX document (but it wouldn't matter which vehicle) shows a robotic arm for instrument replacement. That's fine, but you have to get those doors opened first, and then you have to close them; remember the fun they once had on an EVA?

A manned EVA might be the better bet (still).

[beancounter]

As I noted above, build a new one on the existing spec's.  If the f9 can't handle it, then the FH will likely be on line by then.  Currently there's no way of doing an EVA mission to the existing HST.
Some of you seem hung up on a refurbishment mission whilst ignoring all the practical issues.
Perhaps if you're so keen on it, you could work up a funding model along the following lines:
Base HST escalate to today's dollars assuming no specification changes.
LV cost
Integration, handling, support, etc, costs
Total Cost of new unit
versus
- well, how much do you suppose a full up refurbishment mission will cost since we have no vehicle currently capable of undertaking it?

The problem which I have learned on this site, is that the original suppliers likely no longer exist, or no parts are no longer available, which means re-design & re-certification (likely).

One problem I thought of, of my thoughts on refurbishment, is that the SpaceX document (but it wouldn't matter which vehicle) shows a robotic arm for instrument replacement. That's fine, but you have to get those doors opened first, and then you have to close them; remember the fun they once had on an EVA?

A manned EVA might be the better bet (still).

Yes but with no current vehicles capable of such a mission, manned or otherwise, how much would it cost to develop that capability versus simply building and launching a new one.  I take the point on suppliers etc, but I think that would be less of an effort compared with the vehicle, manned mission.

It's all blowing in the wind speculation anyway.  Unless I see some numbers either way, then the whole things mute.  And besides which, there's no funding for either of these options.

[Danderman]

I guess a lot depends on how expensive a crew flight with Dragon actually ends up being. If it's closer to their current $130M for a cargo flight, then it could very well be possible to have some sort of an airlock module that you could bring up on the trunk,

Herein lies the rub.

An "airlock module" would have to mate with the Dragon via the nose docking adapter (as opposed to somehow attaching to the side hatch), and the nose docking adapter would be occupied by the Hubble docking system. 

The only way around this would be to stow the airlock module in the Dragon trunk, and then somehow re-position it to the front of Dragon, where it would then serve as the interface between Dragon and HST. The RMS required for all those maneuvers would be extremely expensive to develop.

It would be much cheaper to vacuum-rate the Dragon interior avionics.

[QuantumG]

Or put a hatch in the heat shield.

PICA-X is a seamed ablative anyway.

.. and that's assuming you actually want to throw away your airlock before reentry.. otherwise just add an egress hatch to the side of the Dragon and make the airlock internal.

[A_M_Swallow]

I guess a lot depends on how expensive a crew flight with Dragon actually ends up being. If it's closer to their current $130M for a cargo flight, then it could very well be possible to have some sort of an airlock module that you could bring up on the trunk,

Herein lies the rub.

An "airlock module" would have to mate with the Dragon via the nose docking adapter (as opposed to somehow attaching to the side hatch), and the nose docking adapter would be occupied by the Hubble docking system. 

The only way around this would be to stow the airlock module in the Dragon trunk, and then somehow re-position it to the front of Dragon, where it would then serve as the interface between Dragon and HST. The RMS required for all those maneuvers would be extremely expensive to develop.

It would be much cheaper to vacuum-rate the Dragon interior avionics.

Jongoff's firm makes RMS.

To move the docking module the RMS may have to act as a foot.  A pair could be needed.

[Jim]

It would be much cheaper to vacuum-rate the Dragon interior avionics.

A. that is only one of many issues.
B.  Cheaper does not enter into the conversation.  It may not even be feasible to do.

[jongoff]

Herein lies the rub.

An "airlock module" would have to mate with the Dragon via the nose docking adapter (as opposed to somehow attaching to the side hatch), and the nose docking adapter would be occupied by the Hubble docking system. 

The only way around this would be to stow the airlock module in the Dragon trunk, and then somehow re-position it to the front of Dragon, where it would then serve as the interface between Dragon and HST.

Yes, if you did it that way, the airlock module would need an NDS/LIDS on both ends. If you did it that way. There are other ways it could be done of course. And making a docking adapter that could attach to a side hatch isn't entirely out of the question either.

The RMS required for all those maneuvers would be extremely expensive to develop.

It would be much cheaper to vacuum-rate the Dragon interior avionics.

I'm always impressed by the certainty levels expressed by people on this forum.

~Jon

[jongoff]

Or put a hatch in the heat shield.

PICA-X is a seamed ablative anyway.

.. and that's assuming you actually want to throw away your airlock before reentry.. otherwise just add an egress hatch to the side of the Dragon and make the airlock internal.

That's actually not a bad idea. From talking with some former SpaceX alums they mentioned that making structural modifications to Dragon was something they looked at a lot, and something that sounded relatively straightforward.  That said, it would probably be preferable to find a modification that could be done as an add-on "kit" to existing Dragons. Maybe an inflatable airlock that could be attached internally to the side hatch during the mission, but could be removed and stowed before reentry? It's a direction I hadn't really been thinking, to be honest.

~Jon

[jongoff]

I guess a lot depends on how expensive a crew flight with Dragon actually ends up being. If it's closer to their current $130M for a cargo flight, then it could very well be possible to have some sort of an airlock module that you could bring up on the trunk,

Herein lies the rub.

An "airlock module" would have to mate with the Dragon via the nose docking adapter (as opposed to somehow attaching to the side hatch), and the nose docking adapter would be occupied by the Hubble docking system. 

The only way around this would be to stow the airlock module in the Dragon trunk, and then somehow re-position it to the front of Dragon, where it would then serve as the interface between Dragon and HST. The RMS required for all those maneuvers would be extremely expensive to develop.

It would be much cheaper to vacuum-rate the Dragon interior avionics.

Jongoff's firm makes RMS.

To move the docking module the RMS may have to act as a foot.  A pair could be needed.

Well, to be fair, we're *starting* to *develop* RMS systems...we've got a ways to go before we're actually making flight versions you could just buy.

~Jon

[simonbp]

Why would you need an airlock?

Also for reference for a large HST ORU, the Fine Guidance Sensor (re)installed on SM-4 was 478 pounds and dimensions 5.5 x 4 x 2 feet. That's the kind of thing that would require some mechanical assistance for the astronauts.

[Danderman]

The RMS required for all those maneuvers would be extremely expensive to develop.

It would be much cheaper to vacuum-rate the Dragon interior avionics.

I'm always impressed by the certainty levels expressed by people on this forum.

~Jon

I should have mentioned that RMS operations around HST would be extremely expensive to develop.

As for vacuum-rating the interior of Dragon, the Apollo Command Module gives us some experience.

[Jim]

As for vacuum-rating the interior of Dragon, the Apollo Command Module gives us some experience.

Experience is not the issue.  Apollo was designed from the beginning for vacuum operations.  It used purposed designed avionics and not COTS boxes.  It had cold plates and plumbing for heat removal. And you just don't take an existing box and stick it on a cold plate.

So you propose a complete redesign of the Dragon avionics for a one off mission?

[jongoff]

I should have mentioned that RMS operations around HST would be extremely expensive to develop.

Why?

~Jon

[Zed_Noir]

Can an airlock be install internally in the Dragon? Maybe like a column from the nose hatch to the floor of the internal pressure vessel with internal storage alcoves for EVA gear. This idea will of course reduce seats in the Dragon to 3 or 4. 

What would be the size of the crew require for a HST service mission in  the Dragon?

[Chandonn]

Bdtter idea: carry an airlock module or modified trunk airlock with NDS at both ends and a hatch for EVA on the side.  Just leave it docked to Hubble after the mission for future servicing ops.

[wolfpack]

Doesn't all of this talk presume that there is money on the ground for continued Hubble operation? Isn't JWST draining the budget for space telescopes?

Hubble has done its job. Shame we couldn't bring it back and put it in the NASM, but things are what they are.

[mduncan36]

Bdtter idea: carry an airlock module or modified trunk airlock with NDS at both ends and a hatch for EVA on the side.  Just leave it docked to Hubble after the mission for future servicing ops.

I can only imagine what that would do to the fine pointing on Hubble. It's a very precise scientific instrument and not a space station.

I'd love to keep Hubble in operation but all of these ideas involve using tools that aren't well suited for the purpose and would require a lot of work (= money) to do the job. When it gets to the point that the mission would cost a substantial portion of a Hubble replacement then why bother? This is especially the case when congress has barely avoided cutting the funds for the JWST. Noble effort but I don't see any way to make it happen.

[Danderman]

I should have mentioned that RMS operations around HST would be extremely expensive to develop.

Why?

~Jon

Developing translation paths for the RMS to operate around HST will be a major issue. NASA will not want the RMS to impinge on Hubble.

[jongoff]

I should have mentioned that RMS operations around HST would be extremely expensive to develop.

Why?

~Jon

Developing translation paths for the RMS to operate around HST will be a major issue. NASA will not want the RMS to impinge on Hubble.

This isn't the 1980s, robotic path planning isn't *that* hard...especially if you have a hyperdextrous RMS.

~Jon

[simonbp]

Doesn't all of this talk presume that there is money on the ground for continued Hubble operation? Isn't JWST draining the budget for space telescopes?

Sort of; it's more the case that the Space Telescope Science Institute (STSI) which operates HST and will operate JWST is so focused on JWST that they are not pursuing extra Hubble funding as vigorously as possible. Most of the money that's spent on Hubble these days is for Research & Analysis, i.e. support for those at Universities actually doing science with Hubble. Engineering ground costs are pretty minimal.

Hubble has done its job.

Hardly; Hubble is still massively oversubscribed and even the most experienced users have to really fight for time. Here is a list of the current observing programs:

http://www.stsci.edu/hst/proposing/exp_abstract-catalogs/Cycle20-Abstract-Catalog.pdf

Hubble will not have done its job until a genuine UV/VIS replacement is launched. That may or may not be cheaper than another servicing mission, but it has to happen eventually.

[Danderman]

I should have mentioned that RMS operations around HST would be extremely expensive to develop.

Why?

~Jon

Developing translation paths for the RMS to operate around HST will be a major issue. NASA will not want the RMS to impinge on Hubble.

This isn't the 1980s, robotic path planning isn't *that* hard...especially if you have a hyperdextrous RMS.

~Jon

I really wish that were true where NASA is concerned.

[Jim]

I really wish that were true where NASA is concerned.

And where your source of this claim?

[Star One]

Doesn't all of this talk presume that there is money on the ground for continued Hubble operation? Isn't JWST draining the budget for space telescopes?

Sort of; it's more the case that the Space Telescope Science Institute (STSI) which operates HST and will operate JWST is so focused on JWST that they are not pursuing extra Hubble funding as vigorously as possible. Most of the money that's spent on Hubble these days is for Research & Analysis, i.e. support for those at Universities actually doing science with Hubble. Engineering ground costs are pretty minimal.

Hubble has done its job.

Hardly; Hubble is still massively oversubscribed and even the most experienced users have to really fight for time. Here is a list of the current observing programs:

http://www.stsci.edu/hst/proposing/exp_abstract-catalogs/Cycle20-Abstract-Catalog.pdf

Hubble will not have done its job until a genuine UV/VIS replacement is launched. That may or may not be cheaper than another servicing mission, but it has to happen eventually.

What a sinkhole of time & money JWST is, just how many other projects has it caused to be cancelled or never to get off the ground because of how over budget and behind schedule this thing is.

I would rather see another service mission on Hubble and the use of these two former NRO telescopes, as even with all that it would not surprise me if it costed less than the remaining cost of JWST.

[Danderman]

I really wish that were true where NASA is concerned.

And where your source of this claim?

Experience.

[as58]

Most of the money that's spent on Hubble these days is for Research & Analysis, i.e. support for those at Universities actually doing science with Hubble. Engineering ground costs are pretty minimal.

Are you sure? That's not what I've heard, and it doesn't seem to agree with what was written in the latest Senior Review.

[Jim]

I really wish that were true where NASA is concerned.

And where your source of this claim?

Experience.

No, from your posts, you haven't dealt with payload bay type payloads or EVA ops for quite awhile

[oldAtlas_Eguy]

NASA is getting ~$98M to operate the HST.

http://www.govbudgets.com/program/Science/Astrophysics/Cosmic_Origins/