SpaceX And/Or Rocketry In General

Anonymous

Double clicking on the image

Double clicking on the image shows the extend of damage incurred. The heat from that engine really did a job on it. Also the zoomed image shows 3~4 men on the platform which gives a better perspective on its size.

archae86
archae86
Joined: 6 Dec 05
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Hohum. Today's SpaceX launch

Hohum. Today's SpaceX launch for Thales/Turkmenistan was nice and boring. The only excitement I noticed was the question of whether the weather rules would allow a launch sometime in the window. They had a 90-minute window, and did a weather delay of somewhat over 40 minutes.

No recovery attempt today--the mission needed too much punch to leave sufficient to spare for that.

Anonymous

I had to go out around launch

I had to go out around launch time and saw people standing outside looking northward. The ceiling was low so I thought it would be postponed. Wrong again.

Anonymous

I see where the latest

I see where the latest resupply effort from Russia has run into a major snag. The supply capsule is spinning out of control. They are awaiting the next ground station contact to see if this problem can be corrected. If not then the ISS will have to conserve until another mission is scheduled. The video of the Soyuz is always impressive. It certainly has been a work horse.

archae86
archae86
Joined: 6 Dec 05
Posts: 3157
Credit: 7228984895
RAC: 1134685

RE: Soyuz is always

Quote:
Soyuz is always impressive. It certainly has been a work horse.


The amazing thing about that booster is that it is a very close descendant of the original Soviet ICBM (then carrying an R-7 designation). I don't know how similar the internals are these days, but I don't think this is just "branding" as for example the current Atlas does not much resemble the ICBM progenitor, and Delta really just seems to be a brand. I believe the R-7 to current Soyuz path is pretty direct.

Certainly the left nine boosters in the top picture on this Soviet/Russian rockets page look might similar from ground up to at least halfway.

I recall that General Groves was appalled that his pet scientists at one point thought they did not know the required mass of fissile material to better than an order of magnitude. But construction needed to start, so the Oak Ridge gaseous diffusion plant got built "big enough", perhaps just in case.

Maybe the enormous (for an ICBM) R-7 has a similar history, as the designers may not have had a very clear fix on how rapidly they could shrink the size for a given yield, and the politicians may not have settled on what yield they would consider to be enough.

Anonymous

The Russians declared the

The Russians declared the resupply capsule a loss. Its current orbit will decay and it will plunge back into the atmosphere where it is expected to be completely consumed.

Events like this remind me of just how difficult a Mars mission will be. ISS resupply is not new but things can and do go wrong. I am definitely sitting out the Mars thingy.

Mike Hewson
Mike Hewson
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Joined: 1 Dec 05
Posts: 6591
Credit: 319349659
RAC: 425093

RE: RE: Soyuz is always

Quote:
Quote:
Soyuz is always impressive. It certainly has been a work horse.

The amazing thing about that booster is that it is a very close descendant of the original Soviet ICBM (then carrying an R-7 designation). I don't know how similar the internals are these days, but I don't think this is just "branding" as for example the current Atlas does not much resemble the ICBM progenitor, and Delta really just seems to be a brand. I believe the R-7 to current Soyuz path is pretty direct.r

Certainly the left nine boosters in the top picture on this Soviet/Russian rockets page look might similar from ground up to at least halfway.

I recall that General Groves was appalled that his pet scientists at one point thought they did not know the required mass of fissile material to better than an order of magnitude. But construction needed to start, so the Oak Ridge gaseous diffusion plant got built "big enough", perhaps just in case.

Maybe the enormous (for an ICBM) R-7 has a similar history, as the designers may not have had a very clear fix on how rapidly they could shrink the size for a given yield, and the politicians may not have settled on what yield they would consider to be enough.


That's right. One upper limit was over 100kg of uranium to get it to go, and that by throwing two sub-critical halves together. Hence one idea was to deliver the bomb via a ship that would take out a coastal target. In a sense the world would be rather a different place now if that were true*. Anyway, that led to the compressive implosion approach to achieve higher than natural metal density which also suited plutonium better, and you could start with much less.

I think the general Russian approach at the time was along "quantity has a quality all it's own" ie. brute force. In that regard Soyuz has nearly always delivered really well, so it would be of interest to see what happened this time.

Cheers, Mike.

* I say that because the behaviour is not linear. If uranium's nuclear cross section to neutron capture was less ie. that being the cause of why more fissile material was needed to get a chain reaction going, then that also implies that a larger volume of metal ( assume density constant ) will offer less solid angle to hit any given nucleus across the device. So for a pure fission mechanism the yield will scale rather more poorly than linear. [ The logic here is indeed similiar to the detection of reflected radio power when discussing radar echoes.] It would disintegrate & disperse well before giving full opportunity to chain react much of the otherwise fissionable material. That would then punt through to the fusion bomb design for which the fission bomb is a trigger. So that's about the size of the Ivy Mike test ( the scale down after that was going from tritium to lithium deuteride ). All in all I don't think that a thermonuclear device the size of a block of flats has the same deliverability. Likewise if uranium did have the cross section of thorium say, then power reactors would be far safer also.

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

... and my other CPU is a Ryzen 5950X :-) Blaise Pascal

Anonymous

New competition on the

New competition on the horizon: Blue Origin

[Edit] Oops another hydraulic failure. Hmm, this seems vaguely familiar. Nice flight though.

Mike Hewson
Mike Hewson
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Joined: 1 Dec 05
Posts: 6591
Credit: 319349659
RAC: 425093

Well, from the videos of the

Well, from the videos of the flight it looks good. Nice flame that H2/LOX. Max speed was about 800m/sec ie. ~ 10% of orbital requirement. So I guess the commercial loads will need a rather bigger kicker. FWIW :

gradatim ferociter = by degrees, ferociously

Examining the payload invite page indicates an offer of brief microgravity to researchers where that would useful. Presumably you could buy a slot within the larger module, power etc provided. Possibly even go up yourself later on to supervise an experiment.

I'll bet you any money that Professor Bob* won't be sending up any of his graduate students to do that ! :-)

Cheers, Mike.

* the generic university research/thesis supervisor, but more in the flavor of the Pointy Haired Boss from Dilbert.

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

... and my other CPU is a Ryzen 5950X :-) Blaise Pascal

Anonymous

RE: Well, from the videos

Quote:
Well, from the videos of the flight it looks good. Nice flame that H2/LOX. Max speed was about 800m/sec ie. ~ 10% of orbital requirement. So I guess the commercial loads will need a rather bigger kicker. FWIW :

I just saw a newer/better video. Your comment on the flame is spot on. The new video shows initial ignition being "far less violent" then most launches and the flight tracking shows a very "gentle" almost invisible "flame". Interesting engine.

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