SpaceX And/Or Rocketry In General

archae86
archae86
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Aye, there's the rub,

Aye, there's the rub, cost.

Not only is there the extra hardware to carry along, but also the extra fuel to boost that extra hardware, or in case of required performance exceeding the foregone margin, loss of payload/transfer injection speed capability.

I was intrigued by a little buried reference in the link I posted to a situation that for a particular flight SpaceX had a commitment to a minimum apogee on the transfer in which they placed the payload, but got extra credit for anything beyond the minimum up to a maximum (the most the customer found useful, or wanted to pay for, or ...). On that specific flight they still had go-juice remaining when they shut down because they had hit the maximum.

While he clearly supervises (apparently largely successfully) a good many detail guys, I have a feeling Elon Musk often functions well in big-picture mode. I think he is so firmly committed to the potential value of re-use that low-level details of eventual importance such as cost of checkout during the turnaround, fraction of components replaced, cost of extra durability built into components beyond that prudent for single-launch use, etc. may not have been subjected to the comprehensive laundering they would get in a more traditional operation. Maybe he is missing something important, but I am sure glad they are trying.

Mike Hewson
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RE: I was intrigued by a

Quote:
I was intrigued by a little buried reference in the link I posted to a situation that for a particular flight SpaceX had a commitment to a minimum apogee on the transfer in which they placed the payload, but got extra credit for anything beyond the minimum up to a maximum (the most the customer found useful, or wanted to pay for, or ...). On that specific flight they still had go-juice remaining when they shut down because they had hit the maximum.


Off the cuff : it may be the burn wasn't until empty for non commercial/contractual reasons. The 'transfer' orbit obtained was highly elliptical and further burn may have extended that, thus less helpful for later circularisation or timing related to a 'polite' insertion up at geostat level. Something like that. I'm only shooting the breeze.

Quote:
While he clearly supervises (apparently largely successfully) a good many detail guys, I have a feeling Elon Musk often functions well in big-picture mode. I think he is so firmly committed to the potential value of re-use that low-level details of eventual importance such as cost of checkout during the turnaround, fraction of components replaced, cost of extra durability built into components beyond that prudent for single-launch use, etc. may not have been subjected to the comprehensive laundering they would get in a more traditional operation. Maybe he is missing something important, but I am sure glad they are trying.


Mr Musk certainly is on a unique trajectory ! With aerospace you have to burn quite alot of R&D dollars, or if you like every launch has an R&D component like it or not. With reuse his 'figure of merit' as it were is that the fuel is ~ 1% of launch cost, so that suggests the ( simplistic/base-case ) logic that one is 'gifted' with a ~ 99% budget for the re-launch of that same hardware. If so the obvious question is how much/little do you spend of that ?

Even if he doesn't get to his expectations regarding a reuse strategy he will have certainly learnt why not. Again, best of luck.

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

mikey
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RE: Mr Musk certainly is

Quote:


Mr Musk certainly is on a unique trajectory ! With aerospace you have to burn quite alot of R&D dollars, or if you like every launch has an R&D component like it or not. With reuse his 'figure of merit' as it were is that the fuel is ~ 1% of launch cost, so that suggests the ( simplistic/base-case ) logic that one is 'gifted' with a ~ 99% budget for the re-launch of that same hardware. If so the obvious question is how much/little do you spend of that ?

Even if he doesn't get to his expectations regarding a reuse strategy he will have certainly learnt why not. Again, best of luck.

Cheers, Mike.

My thought would be the wear and tear on a reusable vehicle instead of a one time use vehicle, the construction being significantly more expensive for a multiple launch and recovery one. The inspectors needed would be critical too, no hung over lazy bums doing the checks! I hope it works for him, and I hope he can make money at it, but the very process could be against him. The US Government spent billions of dollars keeping their own fleet running and then gave up as it was unsustainable. They also spent billions on the SR71 and gave up on it too after 40 years, although space based telescopes could be much better than some plane flying around the skies.

David S
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RE: The US Government

Quote:
The US Government spent billions of dollars keeping their own fleet running and then gave up as it was unsustainable. They also spent billions on the SR71 and gave up on it too after 40 years, although space based telescopes could be much better than some plane flying around the skies.


I always thought the SR71 was a success at its primary purpose of spying on the Soviet Union.

David

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Mike Hewson
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What eventually became the

What eventually became the SR71 was originally intended as a high-speed/long-range bomber interceptor ie. knock down nuke carrying bombers well way from target. ICBM's made that role ( and the bombers ) largely redundant. So the reconnaissance idea came up, and as this was after Mr Powers was shot down, there was still a perceived need to overfly. It wasn't until that role was well established that satellite imaging then became superior to it, so for a while at least the SR71 did give better information. It fell out of use mainly so as to not annoy countries overflown without consent.

But some critics would add that since imaging by all methods rather reduced the stance of hawks, because for instance the 'bomber gap' wasn't, then it's use could well have been curtailed for that reason. Eisenhower and Kennedy after him were quite critical of intelligence reports that upon reflection consistently tended toward over-estimate of threat. But then Castro put missiles in and it was back to business as usual ....

Having said that it is a gorgeous looking plane, a pinnacle of aerodynamic thinking, and a real door-slammer at throttle up. :-) :-)

Cheers, Mike.

( edit ) Initial spy satellites were one-shot/single-use eg. Corona. So when the film ran out it ejected and was picked up on the way down by a fair bit of rigamarole. They tried to keep one or more ready on the pad. The U2 could be re-used and indeed regularly overflew. Now when effective down links of image data from space was established then all that really mattered was having enough of them about in various orbits to enable any interesting part of the world to be inspected on short notice. Later on the optics really improved the detail. The Hubble was a failed KH-11 ...

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

TimeLord04
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RE: RE: The US

Quote:
Quote:
The US Government spent billions of dollars keeping their own fleet running and then gave up as it was unsustainable. They also spent billions on the SR71 and gave up on it too after 40 years, although space based telescopes could be much better than some plane flying around the skies.

I always thought the SR71 was a success at its primary purpose of spying on the Soviet Union.


That's the way I heard it. VERY much a success. Leaked like a sieve on the ground; but, at altitude and at speed, it sealed up. I heard she was retired because of advances in aviation. Air Force had theirs, and CIA had theirs. Both were retired.

She was one of my favorite planes.

TimeLord04
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Mike Hewson
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Yeah. It is so futuristic

Yeah. It is so futuristic looking but it is here now. Those awesome engines are pure raw power and the key to its function : 'In Thrust We Trust'. I think it is uncommon for anyone under major to get in one. Strap it on your back and go for a burst. If I wuz the wuler of the world I'd use it for daily commutes. :-)

NB. Probably the best book about it with amazing photography and first hand accounts by a pilot ( Major Brian Shul ) is Sled Driver, which I've seen but yet to get my own copy.

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

mikey
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RE: RE: RE: The US

Quote:
Quote:
Quote:
The US Government spent billions of dollars keeping their own fleet running and then gave up as it was unsustainable. They also spent billions on the SR71 and gave up on it too after 40 years, although space based telescopes could be much better than some plane flying around the skies.

I always thought the SR71 was a success at its primary purpose of spying on the Soviet Union.

That's the way I heard it. VERY much a success. Leaked like a sieve on the ground; but, at altitude and at speed, it sealed up. I heard she was retired because of advances in aviation. Air Force had theirs, and CIA had theirs. Both were retired.

She was one of my favorite planes.

Back in the early days of it flying, my friend, who just died, was working for the Air Force in SE Asia in one of those Countries the US was NOT really in, had to help figure out how to communicate with the SR71 going that fast. He said they had to send data to a point in the sky and let the plane fly into it, BUT you couldn't just send it endlessly because the 'enemy' would then try to intercept it. The key was to keep the data stream so compressed that nothing was lost as the plane was gone to the next spot so quickly. In effect he was one of the first people working on data compression, top secret stuff at the time. The data sent would include any mission changes as well as the coordinates of where to be to receive the next message. He had some stories of the plane, some of which he still couldn't fully talk about even 40 years later.

He was a wizard at network communications and, after his SR71 time, even helped setup Air Force One, several generations of the planes, and the Embassies of the US around the World for both secure and unsecure communications.

Mike Hewson
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Well I've just twigged who

Well I've just twigged who Thales is ie. the Vandenberg launch alleged for 21/03/15. That was quite likely to be military/classifed. As the only non-US company to have access to the non-spoof GPS channel, they will have many customers apart from the bleedin' obvious so who knows ....

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

archae86
archae86
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A new post at

A new post at spaceflightnow.com asserts that the next SpaceX launch is now firmed up to be a Dragon to ISS launching to a 1-second wide launch window at 4:33 p.m. EDT (2033 UTC) on April 13.

While I don't spot a mention of recovery attempt in this posting, my most recent information is that this specific mission planned an attempt.

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