Author Topic: Is Hubble servicing silly?  (Read 5842 times)

Offline Jim

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Re: Is Hubble servicing silly?
« Reply #20 on: 01/25/2007 05:37 PM »
I think Bob Thompson was using hindsight/revisonism in a lot of his testimonies.  NASA was making agreements with the DOD in 1985 to fly 8 missions a year, which was 1/3 of the total (24).  It was policy and documented, not hearsay.  And even  the NASA proposed flight rates were higher during Thompson's tenure

Offline joema

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Re: Is Hubble servicing silly?
« Reply #21 on: 01/25/2007 09:18 PM »
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Jim - 25/1/2007  12:37 PM

I think Bob Thompson was using hindsight/revisonism in a lot of his testimonies.  NASA was making agreements with the DOD in 1985 to fly 8 missions a year, which was 1/3 of the total (24).  It was policy and documented, not hearsay.  And even  the NASA proposed flight rates were higher during Thompson's tenure
Yes, don't mean to imply Thompson's statements were unassailable and definitive. However he was the top-ranking program manager over that period, and the above testimony was direct, not indirect from (say) a news agency or other intermediary.

There's a difference between discussed hypothetical flight rates and officially-planned flight rates. E.g, the Mathematica flight rates of 50 per year are often held up as something NASA committed to, when it was just a theoretical study by a 3rd party.

There's often talk about "NASA said they'd fly 20-50 times per year, and look what happened". However when you track down who said what, it's often a Popular Science article, or newspaper article quoting an unnamed or non-authoritative source. In some cases it was just "best guess" speculation back before the vehicle design was ever solidified (even before Phase A). In other cases the early projected flight rates assumed a five orbiter fleet and multiple launch sites, neither of which ever happened.

I'd be interested in seeing any definitive statement where a high-level NASA official committed to flying 20+ missions per year with a four orbiter fleet from a single launch site, and which was made after the final vehicle design was known.

Offline Jim

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Re: Is Hubble servicing silly?
« Reply #22 on: 01/25/2007 10:56 PM »
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joema - 25/1/2007  5:18 PM

I'd be interested in seeing any definitive statement where a high-level NASA official committed to flying 20+ missions per year with a four orbiter fleet from a single launch site, and which was made after the final vehicle design was known.

I was in the USAF shuttle program office in 1985 when the agreement for the 8 out of 24 flights was made.  This  included VAFB flights

Offline simonbp

Re: Is Hubble servicing silly?
« Reply #23 on: 01/25/2007 11:34 PM »
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Jim - 25/1/2007  5:56 PM

I was in the USAF shuttle program office in 1985 when the agreement for the 8 out of 24 flights was made.  This  included VAFB flights

One of the big things that Mike Mullane talks about in has book is the disconnect circa 1985 about the flight rate that NASA upper management expected and what was operationally possible (leading him to the conclusion that a shuttle disaster was almost inevitable during this time period). So, it makes sense that NASA HQ would have overcommitted to a flight rate that they couldn't actually sustain...

What would the Vanderburg flight rate have been? Was the on-pad processing slower or faster than KSC?

Simon ;)

Offline Jim

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Re: Is Hubble servicing silly?
« Reply #24 on: 01/25/2007 11:40 PM »
Vandenberg was around 4 a year with a surge to 6.   And it was much slower (stack on pad)

Offline joema

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Re: Is Hubble servicing silly?
« Reply #25 on: 01/26/2007 12:00 AM »
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Jim - 25/1/2007  5:56 PM
I was in the USAF shuttle program office in 1985 when the agreement for the 8 out of 24 flights was made.  This  included VAFB flights
Thanks, appreciate the insight.

Another interesting item Thompson mentioned was the maximum external tank production rate the Michoud facility could theoretically ramp up to was 24 per year. So that placed an absolute limit of 24 flights per year, no matter how many orbiters or launch sites existed.

Offline spaceflight101

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Re: Is Hubble servicing silly?
« Reply #26 on: 01/26/2007 08:00 PM »
The other valid question is "what are the costs of NOT servicing HST?" Indeed, there have been many who say that current ground-based tech renders the HST obsolete, so why even do it at all?

Launching a fleet of "disposables", as Jim has mentioned, actually makes sense, as long as you provide a means to de-orbit them. That way, every device you send up will be able to take advantage of the latest, greatest technological advances.

The earlier comment about the planned robotic service mission was correct. If Mike Fincke's glove had come off, instead of the high flow indication being caused by a faulty flowmeter, odds are that today the ISS would be abandoned in place. The risk-averse would have won.

But the flip side to the robotics is the experience that would have been gained by the experience. Instead of Moon and Mars-bound astronauts arriving at their destinations with days of assembly ahead of them, by mastering robotics (can anyone say ASIMO?) they would arrive to a warm bed, hot showers, and the sounds of "You've got mail" inside their preassembled, robotically flown habitats.

As far as the completion of the STS program goes, it will only be completed after the ISS is fully assembled with everything in the ISS building at KSC. An "incomplete" here is nothing but fodder for less-than-supportive Congressmen. "You want money for this new 'toy' when you never completed construction of the ISS?"

Failure to complete ISS is nothing short of group ADD. It will be completed. Period. The STS will fly as long as it's needed.

Sometimes it's not what you accomplish, it's what you learn from the experience. Hey, that sounds like a "random quote" candidate.

Offline Jim

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Re: Is Hubble servicing silly?
« Reply #27 on: 01/26/2007 08:09 PM »
Don't need to deorbit since they are at L2 or HEO

Offline joema

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Re: Is Hubble servicing silly?
« Reply #28 on: 01/26/2007 10:25 PM »
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spaceflight101 - 26/1/2007  3:00 PM...Indeed, there have been many who say that current ground-based tech renders the HST obsolete, so why even do it at all?...
It's true ground-based telescopes using adaptive optics and imaging optical interferometry can now surpass Hubble in a few areas, namely resolution over a narrow viewing angle and in the infrared.

It's also true continued progress in these areas will likely allow ground based telescopes to eventually surpass Hubble over a broad viewing angle and in the visual spectrum. However it's technically very challenging, and it will be several years -- maybe not be until 2015-2020 or so.

Based on that and since the Hubble replacement instruments are already built, the crew is already trained, the shuttle servicing mission isn't really much more dangerous than an ISS mission, why not go ahead and do it? From a cost standpoint it's very unlikely a replacement orbital telescope could be built and launched for the cost of a servicing mission.

With the servicing mission, Hubble will produce good science possibly until 2015-2020, about the time ground-based telescopes fully catch up, plus about the same time JWST is launched.

Offline spaceflight101

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Re: Is Hubble servicing silly?
« Reply #29 on: 01/26/2007 11:19 PM »
The entire rationale for Sean O'Keefe cancelling the HST-4 mission was that none of the CAIB's recommendations were foreseen to have been able to have been met *when he had to make the decision*.

Since that day, huge advances in on-orbit TPS repair, with the exception of Rigid Wrap, have been acceptably demonstrated. In the same vein, the folks on the ground have made quantum strides in reduction of ET foam shedding.

In March 2004, I wrote a letter expressing my belief that Sean had missed an opportunity. Instead of cancelling HST-4, I felt that he should have challenged NASA, saying "We have two years to get this done" (at that time, HST-4 had been scheduled for CY 2006).

That missive was posted on a blog, and Sean replied personally. He explained why he made the choices he had. Griffin, on the other hand, had much better choices, as well as having met the criteria established by the CAIB.

So, when the opportunity came about to add STS-125 to the manifest, it was not very difficult to choose to go.

HST is possibly a more visible symbol than the ISS, although the ISS is easier to see with the naked eye.

People excoriated Sean over his rationale, but I remembered what he had written as I walked the hallway that leads to the Administrator's office.

Offline Jorge

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RE: Is Hubble servicing silly?
« Reply #30 on: 01/27/2007 07:07 PM »
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joema - 25/1/2007  9:51 AM

The shuttle is already committed to about 21 more launches for ISS.

Actually fifteen, but that doesn't affect your point.

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The question is how much additional cost is entailed beyond this for the HST mission. NASA Administrator Mike Griffin says the entire HST mission will cost $900 million. http://www.space.com/news/061013_hubble_cost.html

Breakdown:

$500 million: keeping the SM-4 team together from 2004 to 2008 (presumably training, facilities, transportation, benefits, overhead)
$200 million: repair hardware (gyros, batteries, science instruments, etc)
$100 million: additional expendable shuttle hardware
$100 million: additional shuttle processing costs for one additional flight
=========================
Grand total: $900 million.

The $200 million for instruments is already spent, much of the $500 million for crew is already spent (some of which was for robotic servicing investigation).

Arguably the ET (from the "expendable shuttle hardware" line item) is already paid for as well.

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Another way to view it is not how much does flying the mission cost, but how much does NOT FLYING it save? Not flying the mission would save about $400 million ($200 million shuttle operational costs + roughly $12 million per month crew costs from now to 3Q2008 launch). More details on cost: http://www.spaceref.com/news/viewsr.html?pid=22474

The SM4 mission will do more than just fix HST; it will add greatly expanded capabilities and continue the mission life (conservatively) for 5 years, but possibly much longer. The most failure-prone components (gyros and batteries) weren't all replaced on the last mission; SM4 will replace them all. Given successful servicing, it's conceivable Hubble could be productive until 2015 or 2020 (depends on orbital decay and amount of reboost given by SM4).

It seems highly unlikely a new space telescope with capability superior to the refurbished Hubble could be built and launched for $400 million.

Agreed. Johns Hopkins produced a proposal for a Hubble Origins Probe (HOP) that would be launched on an ELV and replace HST. (See http://www.pha.jhu.edu/hop/). It would have used available HST spare hardware (including the SM-04 hardware) and cost between $700M-$1B. That cost includes launch, and on the surface looks competitive with the shuttle servicing mission. However, the HOP cost estimate does not include HST operations costs or the costs of the already-built SM-04 hardware like the shuttle estimate does.
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Offline Jorge

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RE: Is Hubble servicing silly?
« Reply #31 on: 01/27/2007 07:21 PM »
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vda - 25/1/2007  10:10 AM

You din't take in account that additional STS flight will mean that STS program will last longer = will eat NASA budget longer. It's not like "STS will be shut down on the exact date, set in stone".

That may have been the case under O'Keefe, but Griffin does consider September 30, 2010 to be an exact date, set in stone. Any STS flights not flown by then will not be flown, if he's still the administrator.

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It will be shut down when ISS is completed (for some definition of the word "complete"). With STS servicing, it becomes "STS will be shut down when ISS is completed AND HST is serviced".

And why do you think the definition of "complete" will remain static? The real, practical definition of "ISS assembly complete" is really "whatever configuration ISS happens to be in when the last shuttle lands."

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This makes your conclusion "not flying the mission would save about $400 million" incorrect, I think. It will save more.

Not really. If Griffin is still in charge, the cost of flying HST SM-04 will not be the monetary cost of extending STS ops a few months beyond the end of FY10. Rather, it will be the opportunity cost of not flying the ISS Contingency Logistic Flights (CLFs) at the end of the manifest that will be displaced.

(In the current manifest, 132/20A (Node 3 + Cupola) is sandwiched in between the two CLFs, but I believe that if push comes to shove, 131/ULF-4 and 133/ULF-5 will be cancelled before 132/20A.)
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Offline Jorge

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Re: Is Hubble servicing silly?
« Reply #32 on: 01/27/2007 07:24 PM »
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paulhbell07 - 25/1/2007  10:24 AM

I know that it's going to come down sometime, so why not put a module on the bottom of the telescope to boost it away from earth, I am sure this could be done on SM4.

Not enough time to design, build, and certify such a module. However, HST SM-04 will facilitate a future deorbit module by attaching corner-cube retroreflectors to HST's base. NASA is required to provide a controlled deorbit for HST due to international liability concerns.
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Offline Jorge

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Re: Is Hubble servicing silly?
« Reply #33 on: 01/27/2007 07:27 PM »
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joema - 25/1/2007  4:18 PM

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Jim - 25/1/2007  12:37 PM

I think Bob Thompson was using hindsight/revisonism in a lot of his testimonies.  NASA was making agreements with the DOD in 1985 to fly 8 missions a year, which was 1/3 of the total (24).  It was policy and documented, not hearsay.  And even  the NASA proposed flight rates were higher during Thompson's tenure
Yes, don't mean to imply Thompson's statements were unassailable and definitive. However he was the top-ranking program manager over that period, and the above testimony was direct, not indirect from (say) a news agency or other intermediary.

His statements are contradicted by documentation from the period. Jenkins (3rd ed) quotes some of those documents, and the 4th ed will likely address the issue directly.
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Offline Jorge

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Re: Is Hubble servicing silly?
« Reply #34 on: 01/27/2007 07:34 PM »
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joema - 26/1/2007  5:25 PM

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spaceflight101 - 26/1/2007  3:00 PM...Indeed, there have been many who say that current ground-based tech renders the HST obsolete, so why even do it at all?...
It's true ground-based telescopes using adaptive optics and imaging optical interferometry can now surpass Hubble in a few areas, namely resolution over a narrow viewing angle and in the infrared.

It's also true continued progress in these areas will likely allow ground based telescopes to eventually surpass Hubble over a broad viewing angle and in the visual spectrum. However it's technically very challenging, and it will be several years -- maybe not be until 2015-2020 or so.

And it's also true that HST has capabilities in the UV spectrum that no ground-based telescope can *ever* match. (And if a ground-based telescope ever *does* match it, that would be really bad news for us, since it means that the Earth's atmosphere is no longer filtering UV and we're all dead from sunburn...)
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