Jets use fan blades, turbochargers do not. Turbochargers use impellers and are only compressors. Jets have different compression sections, burners (flame fronts) and actually make thrust.
First off, turbochargers make use of a turbine to drive the compressor.
Secondly, many of the early jets used centrifugal compressors (impeller).
Thirdly, several people have made small turbojets by grafting a combustion chamber between the compressor and turbine of an off the shelf turbocharger.
One of the reasons that GE got its start in jet engines (when the RAF was looking for an American company to work on jet engines) was because of their experience with turbochargers. GE also had a lot of experience with other turbomachinery which didn't hurt.
The grandparent did miss that England invented RADAR.
Yes and no. The US Naval Research Labs did some early work in the 1920's and Deak Parsons was working on the proximity fuze in the late 30's - which first saw use at Guadalcanal in early 1943. In addition, the US had many RADAR sets of domestic design operating in the VHF spectrum - including one operating on the north end of Oahu on the morning of Dec 7, 1941.
I mean one country (England) in Europe only invented the steam engine, locomotive,
Hmmm, lessee. Seem to recall that the first steam engine was built by a Greek named Hero, although the first useful one was built by Newcomen. The first self propelled vehicle was built by Cugnot of France, another Frenchman built the first steamboat (and that was acknowledged by Fulton). The first high pressure steam engines were built by Trevithick of England and Oliver Evans of the US. Trevithick also built the first steam locomotive. While the first locomotives in the US were imported from England, the US became a net exporter of steam locomotives by the mid-1830's. The first elecric locomotive (albeit model sized) was built by Thomas Davenport of Vermont in 1834.
the telephone
Huh? I would believe "The telegraph" (Wheatstone).
internal combustion
Funny, the names for the two most common ICE cycles are Otto and Diesel - sounds suspiciously German to me.
the jet engine
Which was devloped from turbocharger technology - ISTR was a Swiss development. The Swiss had a working gas turbine in 1940.
One thing you did leave out, the steam turbine was developed by an Englishman by the name of Parsons.
3. As for "America invented the Internet", sure Americans came up with some key parts of the Internet. However a lot of it is International in nature. The WWW, arguably the most visible part of the Internet, is a European creation.
A more accurate way of putting it is that the (TCP, UDP, etc)/IP was developed in the US, but the concept of an "internet" is not unique to TCP/IP. The major thrust in Europe on internetworking (say 1980 to early 1990's) was the OSI framework, which was still sputtering along as late as 1994 if not a bit later. Do you remember why OSI has fallen off the face of the earth?
As for the WWW, the original protocol was developed in Europe and based on a simplified version of SGML. It became popular only after the Mosaic browser was developed - and that work was done in Illinois.
1. The issue of contention seems to be the DNS roots, not the entirity of the Internet. It is an integral part, but by no means the only part.
Countries had a choice of going with TCP/IP or OSI and part of the bargain was that the DNS root servers were under US control (originally Jon Postel, then NSF/Network Solutions, now ICANN).
I'm just saying that keeping control of a fundamental worldwide technology/system is a bit silly.
Pretty much the same way that the kilogram standard is based in Paris and the 0 degree meridian goes through Greenwich?
Europe has been heavy contributors to networking in general since the early 1970s, and the internet since 1986 (the formation of RARE) (even before then, various national research projects contributed). So what if Europe wasn't involved in the initial formation of the internet?
A similar thing could be said about the metric system - the first proponent of a decimal measuring system was Thomas Jefferson (and he better suggestions to base the unit of length than what the French came up with). So doesn't the UN have the right to tell France that they have to give up the international standard for the kilogram? Doesn't it make sense that such an important artifact should be turned over to the UN? (Note: the kilogram is the last unit to be based on an artifact).
Would you say that nobody should have the right to control their own zoning laws except Iraq because the first known zoning laws were invented by the Babylonians?
I would certainly say the Iraqi's have the right to control their own zoning laws and that they should not give up that control because the UN finds them useful for other countries.
One question: What happened to OSI?
One of the reasons that TCP/IP triumphed over OSI was that the US government had a much more pragmatic attitude towards networking than the EU. I don't blame the Department of Commerce for not wanting the TCP/IP network goingthe way of OSI.
but buying a company that invented something and inventing something isn't the same thing.
I remember reading a short note about MS having only three original products:
#1 The original MS BASIC
#2 Multiplan
#3 Version 1 of Wndows [am not sure about this one]
Everything else was something they bought:
Flight Simulator: Sublogic
MS-DOS: Seattle Computer Products
C Compiler: Lattice
and the list goes on.
6. Having all files be "commands" in that if you double-click it examines the file (even if only the filename) and opens it with the correct program.
You obviously haven't seen HP's Visual User Environment (which is the basis for Common Desktop Environment) from ca 1990. One difference is the default action for double clicking on a data file brings up the text editor, unless the file had been associated with an action (look under ~/.dt/types) and that action could either be keyed to the "file" command or to the extension (it could be set up recognize a ".doc" file created by Island Write or a ".doc" files created by MS-Weird and invoke the appropriate application).
And don't get me started on people who think that Motif copied the Win95 theme.
but it could detect not only trace amounts of explosives
The beauty of NQR is that it is a bulk detector, not a trace detector. As several people have pointed out, it is easy to pick up explosive residues which could trigger trace detectors. You are correct in that NQR can determine explosive composition (e.g. RDX, PETN, etc).
Mod me down, but MS Office is rather near perfection.
While there are some aspects of MS-Office that are really refined, the UI for Word strikes me as being more broken the perfected. I was much happier with the UI on the old versions of Word for DOS - it was much nicer to use "keyboard only" than Word for Windoze.
Another big irritation with both MS-Word and OOo Writer is their treatment of everything on the document as being some kind of paragraph - where I find thinking in terms of frames (containers) to be much easier (e.g. Island Write - which also could be driven very nicely from the keyboard) for laying out pages. It makes more sense to me to be able to specify the frame size and location before inserting a picture, rather than having to resize and reposition the damn thing after inserting the picture/graphic/object in Word or Writer. (KWord is sort of getting there.)
I guess it was too much to point the users to the free MS Word Reader or create it in HTML format?
PDF is a closed format but has a freely available reader. How is this different than using a freely available MS Reader?
I can think of several reasons why PDF's are better than MS-Word files for posting laws on websites.
#1 PDF's are much harder to edit
#2 Viewers are available for a lot more platforms than MS-Word and there is at least one GPL'd viewer
#3 PDF's are much more backwards compatible than MS-Word files - a PDF created in the early 90's should still be readable a couple of decades from now - can the same be said of an MS-Word document written in the early 90's?
Some countries even use 16.67 cycles for their railway power.
Before the 1960's, the standard frequency for AC railroad electrifications in the US was 25 Hz.
Why the low frequency? Because it's harder to persuade a current to flow in a coil at high frequency {look up inductive reactance}
Not quite, the main incentive was that AC series motors (AKA universal motors) worked better at lower frequencies. A good reference is CERA Bulletin B-118, which is a reprint of Westinghouse articles on electrification.
The good news with Al is that the half-lives are pretty short. I would guess that your long term activation is from Mn-56 (both from activation of Mn-55 and (n,p) with Fe-56).
the levels near target chamber center can reach around ~5-10 mrem/hr
That's pretty hot - most places don't like Rad workers being exposed to more than 2 mrem/hr. The hottest place I've measured was 6-9 mrem/hr - holding the detector head tight against my chest about 3 hours after a stress test with Tc-99m.
Big problem with DD reactions is that the cross section is pretty darn small and they produce neutrons (albeit at lower enrgies than DT). As such, don't think you would even come close to break-even.
the mean free path of neutrons in lithium might be pretty big, but I don't know what the cross section of lithium is
I would guesstimate (don't have access to the 14 MeV cross section data for Lithium) the scattering cross section to be on the order of a couple of barns - which would imply a macroscopic cross section on the order of -say- 0.03cm^-1 (i.e. MFP on the order of 30cm). You would still have to have ports for the optics - which are going to get hammered something fierce.
It probably isn't as big as Halfnium or other "conventional" neutron absorbers.
Hafnium is a good absorber of thermal neutrons, not 14-MeV neutrons (for which Hydrogen is about the best you can do).
We will be able to couple a ~3Kj heater pulse to the targets normally imploded on our current 30Kj 60 Terawatt system which currently holds the world record for neutron production at ~5X10^14 neutrons per pulse.
That's some serious neutron production - I'm assuming that's with a DT reaction (if it was a DD reaction, I'd be really impressed). You haven't said anything about activation - which is going to be significant with that many neutrons per pulse - especially with the 14 MeV neutrons produced by the DT reaction. At least the N-16 byproduct from the (n,p) reaction with O-16 has a short half-life, but there enough other reactions that you will need to let the system cool down after a pulse.
I was in a materials course (a "few" years ago) where Prof. Kulcinski of UofWisc came in to talk about the issues with fusion reactors. The one statistic that stood in my mind was that each atom in the first wall was expected to be knocked out of its lattice position an average of 10 times during the life of the first wall. That's why he is hot about the idea of using the D-He3 reaction - although his idea of mining the moon for He3 is far-fetched.
An amazing amount of shipping takes place on America's highways, something that in a lot of other countries is done by rail or what-have-you.
The percentage of freight traffic moving by rail in the US compares quite favorably to Europe. Each of the big boys of US railroading (UP, BNSF, CSX, NS) carries as many ton-miles of freight as all of Western Europe combined.
FWIW, the ISO cargo container's dimensions are defined in feet/inches due to the container being invented in north America.
Public transportation in the U.S. is abominable. A lot of that comes from the fact that much of the country was developed in a time when driving anywhere you wanted to go was a possibility, so things here tend to be very spread out, which makes efficient public transportation difficult to implement.
The US was investing heavily in public transportation systems prior to WW1. Investment stopped after WW1 because most state and municipal regulators were holding fares to pre-WW1 levels even though operting costs had doubled. This was also the same time that cars were becoming rapidly more affordable.
The Geode is extremely efficient. I'd have to look it up, but from memory I think it's like 7.5 watts. You could spend more running a nightlight. The drive will add some to that, but it'll definitely stay under 15w, and maybe under 10.
That's about what I remember from the spec sheet for the Soekris. Bear in mind that is the DC power input to the board and not the draw on the AC mains (which will be higher due to losses in the power supply). The Mac Mini idles around 10 to 11 watts from the AC mains, which would be about the same for the Soekris (assuming the Soekris is running off an effiecient supply).
This is not intended to belittle the Soekris. A dream set-up for firewall/mail server for me is a Soekris running off float charged batteries which would also supply power to the DSL modem and ethernet switch. Just don't see the point of converting AC to DC to charge batteries, then converting back to AC just so it can be converted back to DC. A DC-DC converter is smaller and a lot more efficient.
A Mac Mini just idling along uses about 10 to 11 watts from the AC mains (that's the total power draw) - a co-worker had a Mac Mini plugged into a wattmeter to measure power consumption in researching running the Mini on batteries (if this reminds you of a recent Slashdot article, it is because it was the very same Mini featured in that article).
Since you are already familiar with the Mac OS, the mini sounds like the most logical choice to me. I strongly doubt that a mini-itx will have as low of a draw as the Mini.
The original push for MRI (from Damadian) was to locate cancers - the main benefit is eliminating a lot of exploratory surgeries. In this case it eliminates the need for biopsies (which, from TFA, are rarely performed due to the risk). Very nice work.
This is an interesting application of magneto-immunoassay - using the change in magnetic properties to determine if there has been a reaction.
Yes, and for good reason. The reliability aspects of TCP would really mess up the packet timing necessary for proper functioning of NTP.
Reminds me of a conversation I had with our company IT guy about opening up the firewall to allow IPSEC traffic through. The first thing he wanted to know was "what port to open" - meaningless because IPSEC uses a different IP protocol than TCP (much the same way that UDP is separate from TCP). Should note that he is normally a fairly sharp and clueful guy.
The central theme of "Longitude" is knowing what time it is at a reference longitude (e.g. the time in Greenwich). For a ship, the only practical method prior to radio was having a very accurate and stable clock. (On land you use a telescope to measure the motions of the moons of Jupiter to determine the time in Paris - from the late 1700's on).
A few decades later, the railroads needed an accurate source of time for dispatching trains by time-table. Fortunately, the electric telegraph came into being not long after the railroads to allow signaling of time and then dispatching (prodding of Charles Minot of the Erie RR in 1851). By the late 1870's, the northeast US had an electric time service (the ball dropped on Times Square on New Year's Eve probably descends from the time balls used to indicate 12 noon).
With the advent of clocks being set by telegraphic signals, there came a need for a means of keeping all of the clocks in synch - and lots of patent applications were filed for means of assuring or improving synchronization. There is speculation that seeing all these patent applications caused one Swiss patent examiner to muse on the nature of time. The examiner being a young Albert Einstein.
One of the first topics covered in books on astrodynamics or planetary motion (e.g. "Astronomical Algorithms" by Meeus) is - time. In this case talking about the difference between UTC, TDT (TAI) and GPS time.
The Science Channel was rerunning old Science TV shows, one of which was "The 21st Century" with Walter Cronkite from the late 1960s.
I remember that show with great fondness.
Along those lines, Disney's "Tomorrowland" DVD has some wonderful productions from the 1950's - including one about getting to Mars and back, which I remember first seeing in 1962.
If you think about it - we're still traveling about the same speed that we were in the late 1950's - no passenger plane significantly faster than the 707 (air travel now is generally slower than it was in the early 1970's), max speed on the freeways about the same (though average speed up in non-congested areas), trains generally slower in the US (although faster in many other parts of the world). The fastest production plane first flew in 1962.
And for space... What ever became of the follow-ons to the Saturn V? (examples would include an uprate S-V and the Nova).
Slashdot Mirror
First off, turbochargers make use of a turbine to drive the compressor.
Secondly, many of the early jets used centrifugal compressors (impeller).
Thirdly, several people have made small turbojets by grafting a combustion chamber between the compressor and turbine of an off the shelf turbocharger.
One of the reasons that GE got its start in jet engines (when the RAF was looking for an American company to work on jet engines) was because of their experience with turbochargers. GE also had a lot of experience with other turbomachinery which didn't hurt.
The grandparent did miss that England invented RADAR.
Yes and no. The US Naval Research Labs did some early work in the 1920's and Deak Parsons was working on the proximity fuze in the late 30's - which first saw use at Guadalcanal in early 1943. In addition, the US had many RADAR sets of domestic design operating in the VHF spectrum - including one operating on the north end of Oahu on the morning of Dec 7, 1941.
Hmmm, lessee. Seem to recall that the first steam engine was built by a Greek named Hero, although the first useful one was built by Newcomen. The first self propelled vehicle was built by Cugnot of France, another Frenchman built the first steamboat (and that was acknowledged by Fulton). The first high pressure steam engines were built by Trevithick of England and Oliver Evans of the US. Trevithick also built the first steam locomotive. While the first locomotives in the US were imported from England, the US became a net exporter of steam locomotives by the mid-1830's. The first elecric locomotive (albeit model sized) was built by Thomas Davenport of Vermont in 1834.
the telephone
Huh? I would believe "The telegraph" (Wheatstone).
internal combustion
Funny, the names for the two most common ICE cycles are Otto and Diesel - sounds suspiciously German to me.
the jet engine
Which was devloped from turbocharger technology - ISTR was a Swiss development. The Swiss had a working gas turbine in 1940.
One thing you did leave out, the steam turbine was developed by an Englishman by the name of Parsons.
A more accurate way of putting it is that the (TCP, UDP, etc)/IP was developed in the US, but the concept of an "internet" is not unique to TCP/IP. The major thrust in Europe on internetworking (say 1980 to early 1990's) was the OSI framework, which was still sputtering along as late as 1994 if not a bit later. Do you remember why OSI has fallen off the face of the earth?
As for the WWW, the original protocol was developed in Europe and based on a simplified version of SGML. It became popular only after the Mosaic browser was developed - and that work was done in Illinois.
Countries had a choice of going with TCP/IP or OSI and part of the bargain was that the DNS root servers were under US control (originally Jon Postel, then NSF/Network Solutions, now ICANN).
Pretty much the same way that the kilogram standard is based in Paris and the 0 degree meridian goes through Greenwich?
A similar thing could be said about the metric system - the first proponent of a decimal measuring system was Thomas Jefferson (and he better suggestions to base the unit of length than what the French came up with). So doesn't the UN have the right to tell France that they have to give up the international standard for the kilogram? Doesn't it make sense that such an important artifact should be turned over to the UN? (Note: the kilogram is the last unit to be based on an artifact).
Would you say that nobody should have the right to control their own zoning laws except Iraq because the first known zoning laws were invented by the Babylonians?
I would certainly say the Iraqi's have the right to control their own zoning laws and that they should not give up that control because the UN finds them useful for other countries.
One question: What happened to OSI?
One of the reasons that TCP/IP triumphed over OSI was that the US government had a much more pragmatic attitude towards networking than the EU. I don't blame the Department of Commerce for not wanting the TCP/IP network goingthe way of OSI.
I remember reading a short note about MS having only three original products:
#1 The original MS BASIC
#2 Multiplan
#3 Version 1 of Wndows [am not sure about this one]
Everything else was something they bought:
Flight Simulator: Sublogic
MS-DOS: Seattle Computer Products
C Compiler: Lattice
and the list goes on.
You obviously haven't seen HP's Visual User Environment (which is the basis for Common Desktop Environment) from ca 1990. One difference is the default action for double clicking on a data file brings up the text editor, unless the file had been associated with an action (look under ~/.dt/types) and that action could either be keyed to the "file" command or to the extension (it could be set up recognize a ".doc" file created by Island Write or a ".doc" files created by MS-Weird and invoke the appropriate application).
And don't get me started on people who think that Motif copied the Win95 theme.
The beauty of NQR is that it is a bulk detector, not a trace detector. As several people have pointed out, it is easy to pick up explosive residues which could trigger trace detectors. You are correct in that NQR can determine explosive composition (e.g. RDX, PETN, etc).
Which would explain why the people working on SMB at MS needed to use the Samba docs to understand what was going on with SMB.
While there are some aspects of MS-Office that are really refined, the UI for Word strikes me as being more broken the perfected. I was much happier with the UI on the old versions of Word for DOS - it was much nicer to use "keyboard only" than Word for Windoze.
Another big irritation with both MS-Word and OOo Writer is their treatment of everything on the document as being some kind of paragraph - where I find thinking in terms of frames (containers) to be much easier (e.g. Island Write - which also could be driven very nicely from the keyboard) for laying out pages. It makes more sense to me to be able to specify the frame size and location before inserting a picture, rather than having to resize and reposition the damn thing after inserting the picture/graphic/object in Word or Writer. (KWord is sort of getting there.)
My preference would the solid pilots with drop couplers used on the Pennsy ca 1930-50.
Second preference would be the snowplow pilots used on the Espee dismals.
PDF is a closed format but has a freely available reader. How is this different than using a freely available MS Reader?
I can think of several reasons why PDF's are better than MS-Word files for posting laws on websites.
#1 PDF's are much harder to edit
#2 Viewers are available for a lot more platforms than MS-Word and there is at least one GPL'd viewer
#3 PDF's are much more backwards compatible than MS-Word files - a PDF created in the early 90's should still be readable a couple of decades from now - can the same be said of an MS-Word document written in the early 90's?
Before the 1960's, the standard frequency for AC railroad electrifications in the US was 25 Hz.
Why the low frequency? Because it's harder to persuade a current to flow in a coil at high frequency {look up inductive reactance}
Not quite, the main incentive was that AC series motors (AKA universal motors) worked better at lower frequencies. A good reference is CERA Bulletin B-118, which is a reprint of Westinghouse articles on electrification.
The good news with Al is that the half-lives are pretty short. I would guess that your long term activation is from Mn-56 (both from activation of Mn-55 and (n,p) with Fe-56).
the levels near target chamber center can reach around ~5-10 mrem/hr
That's pretty hot - most places don't like Rad workers being exposed to more than 2 mrem/hr. The hottest place I've measured was 6-9 mrem/hr - holding the detector head tight against my chest about 3 hours after a stress test with Tc-99m.
Big problem with DD reactions is that the cross section is pretty darn small and they produce neutrons (albeit at lower enrgies than DT). As such, don't think you would even come close to break-even.
I would guesstimate (don't have access to the 14 MeV cross section data for Lithium) the scattering cross section to be on the order of a couple of barns - which would imply a macroscopic cross section on the order of -say- 0.03cm^-1 (i.e. MFP on the order of 30cm). You would still have to have ports for the optics - which are going to get hammered something fierce.
It probably isn't as big as Halfnium or other "conventional" neutron absorbers.
Hafnium is a good absorber of thermal neutrons, not 14-MeV neutrons (for which Hydrogen is about the best you can do).
That's some serious neutron production - I'm assuming that's with a DT reaction (if it was a DD reaction, I'd be really impressed). You haven't said anything about activation - which is going to be significant with that many neutrons per pulse - especially with the 14 MeV neutrons produced by the DT reaction. At least the N-16 byproduct from the (n,p) reaction with O-16 has a short half-life, but there enough other reactions that you will need to let the system cool down after a pulse.
I was in a materials course (a "few" years ago) where Prof. Kulcinski of UofWisc came in to talk about the issues with fusion reactors. The one statistic that stood in my mind was that each atom in the first wall was expected to be knocked out of its lattice position an average of 10 times during the life of the first wall. That's why he is hot about the idea of using the D-He3 reaction - although his idea of mining the moon for He3 is far-fetched.
The percentage of freight traffic moving by rail in the US compares quite favorably to Europe. Each of the big boys of US railroading (UP, BNSF, CSX, NS) carries as many ton-miles of freight as all of Western Europe combined.
FWIW, the ISO cargo container's dimensions are defined in feet/inches due to the container being invented in north America.
The US was investing heavily in public transportation systems prior to WW1. Investment stopped after WW1 because most state and municipal regulators were holding fares to pre-WW1 levels even though operting costs had doubled. This was also the same time that cars were becoming rapidly more affordable.
Also have a K&E slipstick in the garage.
That's about what I remember from the spec sheet for the Soekris. Bear in mind that is the DC power input to the board and not the draw on the AC mains (which will be higher due to losses in the power supply). The Mac Mini idles around 10 to 11 watts from the AC mains, which would be about the same for the Soekris (assuming the Soekris is running off an effiecient supply).
This is not intended to belittle the Soekris. A dream set-up for firewall/mail server for me is a Soekris running off float charged batteries which would also supply power to the DSL modem and ethernet switch. Just don't see the point of converting AC to DC to charge batteries, then converting back to AC just so it can be converted back to DC. A DC-DC converter is smaller and a lot more efficient.
Since you are already familiar with the Mac OS, the mini sounds like the most logical choice to me. I strongly doubt that a mini-itx will have as low of a draw as the Mini.
This is an interesting application of magneto-immunoassay - using the change in magnetic properties to determine if there has been a reaction.
Yes, and for good reason. The reliability aspects of TCP would really mess up the packet timing necessary for proper functioning of NTP.
Reminds me of a conversation I had with our company IT guy about opening up the firewall to allow IPSEC traffic through. The first thing he wanted to know was "what port to open" - meaningless because IPSEC uses a different IP protocol than TCP (much the same way that UDP is separate from TCP). Should note that he is normally a fairly sharp and clueful guy.
The central theme of "Longitude" is knowing what time it is at a reference longitude (e.g. the time in Greenwich). For a ship, the only practical method prior to radio was having a very accurate and stable clock. (On land you use a telescope to measure the motions of the moons of Jupiter to determine the time in Paris - from the late 1700's on).
A few decades later, the railroads needed an accurate source of time for dispatching trains by time-table. Fortunately, the electric telegraph came into being not long after the railroads to allow signaling of time and then dispatching (prodding of Charles Minot of the Erie RR in 1851). By the late 1870's, the northeast US had an electric time service (the ball dropped on Times Square on New Year's Eve probably descends from the time balls used to indicate 12 noon).
With the advent of clocks being set by telegraphic signals, there came a need for a means of keeping all of the clocks in synch - and lots of patent applications were filed for means of assuring or improving synchronization. There is speculation that seeing all these patent applications caused one Swiss patent examiner to muse on the nature of time. The examiner being a young Albert Einstein.
One of the first topics covered in books on astrodynamics or planetary motion (e.g. "Astronomical Algorithms" by Meeus) is - time. In this case talking about the difference between UTC, TDT (TAI) and GPS time.
I remember that show with great fondness.
Along those lines, Disney's "Tomorrowland" DVD has some wonderful productions from the 1950's - including one about getting to Mars and back, which I remember first seeing in 1962.
If you think about it - we're still traveling about the same speed that we were in the late 1950's - no passenger plane significantly faster than the 707 (air travel now is generally slower than it was in the early 1970's), max speed on the freeways about the same (though average speed up in non-congested areas), trains generally slower in the US (although faster in many other parts of the world). The fastest production plane first flew in 1962.
And for space... What ever became of the follow-ons to the Saturn V? (examples would include an uprate S-V and the Nova).