Re: Death Sentence for the Hubble?
From: JATO (No-Canned-Ham)
Date: 03/19/05
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Date: Sat, 19 Mar 2005 05:00:20 GMT
On Sat, 19 Mar 2005 06:05:46 GMT, simberg.interglobal@org.trash (Rand
Simberg) wrote:
>On Sat, 19 Mar 2005 02:17:04 GMT, in a place far, far away, JATO
><jato<No-Canned-Ham>@jatobservatory.org> made the phosphor on my
>monitor glow in such a way as to indicate that:
>
>>>>But the good thing about the comsats is most of
>>>>them are insured. In some cases the companies are even paid for the lost
>>>>revenue the birds would have generated. As for as the billion $ plus spy
>>>>birds. That's your tax dollars going in the drink. Did you know that there
>>>>have been government birds prohibited from flying on the shuttle because
>>>>the probability of loss was to deemed to be to great?
>>>
>>>No. Mostly because it's not true.
>>
>>And you know this how? I have seen the contract for at least one of these
>>missions. It was prohibited from being launched on the shuttle. While the
>>reason was not printed in the contract, it was verbalized in no uncertain
>>terms, and this was not 20 years ago.
>
>Gee, maybe it was because commercial payloads have been bascially
>prohibited from launching on the Shuttle for almost twenty years?
>
Try and follow along here ok. I am not talking about commercial payloads
being prohibited.
>>>Most government "birds" go to orbits that can't be reached by the
>>>Shuttle.
>>>
>>It depends on the mission, there are a lot of government missions that
>>could be shuttle missions. If the satellites have apogee engines to raise
>>it's orbit, which most do, and meet the mass requirement then they can be
>>shuttle launched.
>
>Do you understand the concept of orbital planes?
Yes I do. Do you understand spacecraft?
>
>>>The rest go on other vehicles because they're cheaper, not because
>>>their reliability is better.
>>
>>I agree it is cheaper. that goes without saying. But the fact is there
>>have been missions that where not flown on the shuttle, and not because of
>>cost or orbit. It was for the reason mentioned above.
>
>Nope.
There is no point in getting involved in a pissing match here. I know what
I know. I have been involved in this business for 20+ years.
>
>>>>>On a reusable vehicle with engine out capability, you'd finish the mission,
>>>>>land the vehicle, then do inspections (possibly more) to find the root
>>>>>cause. You're much more likely to find *the* cause of the failure with a
>>>>>reusable vehicle than with an ELV that's too expensive to recover (if it's
>>>>>possible to recover intact at all).
>>>>
>>>>Why would a commercial business that has a payload to launch want to pay
>>>>for all the extra weight of a launch vehicle that is going to come back to
>>>>earth?
>>>
>>>One doesn't pay for the weight of a launch vehicle. One pays whatever
>>>the launch price is.
>>
>>Launching weight is not free.If doesn't matter if the weight is the launch
>>vehicle or the payload. The more weight then the thrust you need. The more
>>thrust, the more the cost. That thrust may come in the form of an SRB or
>>the primary rocket engine. In any case the customer pays. Which is why one
>>reasons why some launch cost more than others. If that where the case it
>>would cost no more to launch a Titan than a Delta 2.
>
>That entire paragraph is irrelevant, because the only issue to a
>customer is price. And cost is not price.
>
I really don't understand your logic. You can call it whatever you want. If
the weight goes up the cost of the launch goes up. That means the price of
the launch goes up. I suppose if your car dealer tells you the cost of
your new car is more than you originally figured, to you that means the
price didn't go up?
>>>>The extra weight would add a massive amount to the launch price.
>>>
>>>There is zero data, or theory, to support this statement. Launch
>>>prices are much more complicated than vehicle weight. That's one of
>>>the least significant factors, in fact.
>>
>>
>>If you think spacecraft mass/weight is not a prime factor for launch
>>vehicle selection and pricing you are sadly mistaken.
>
>I said nothing about vehicle selection.
Well you should have, because it is a factor. Weight and mass of the
payload is a direct factor in launch vehicle selection. When the spacecraft
is in the design stage and launch vehicle is selected, if the mass and
weight of the spacecraft increases during the design phase, the launch
vehicle configuration has to change. This cost money. In some cases as much
a million dollars per pound. Again if you think weight has no barring on
cost, pricing or whatever you want to call it, you are mistaken, period.
>
>>I see this on a
>>regular basis. When the weight of the spacecraft grows during the design
>>phase, people quickly become concerned about the cost impact of the added
>>weight for the selected launch vehicle.
>
>Only when it exceeds the capacity of that vehicle. Otherwise, it's a
>non issue.
You continue to believe that if you want to. The program managers, vehicle
engineers, orbital analysts, mass and property engineers and spacecraft
system engineers such as myself know better. You go tell the launch
vehicle provider your spacecraft has gained weight from it's original
specified weight, that was used to quote your original launch vehicle cost,
and see what happens. Even if that weight gain is still within the capacity
of the launch vehicle. If have seen unused wires from pre-fab'ed
connectors used on the spacecraft bus harness, trimmed to the shortest
length possible. The clippings were collected, put in bags and weighed. All
to save a few pounds of weight on the spacecraft. And the spacecraft was
not close to exceeding the launch vehicle's capacity. I'll say it again
weight is money, period.
-JATO
http://jatobservatory.org
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