The Nova rocket, AKA the other lunar rocket

[tater]

More efficient? You'd likely need to look at all the associated launch costs, and see if multiple launches/rendezvous is actually cheaper than a single launch, including delays, etc. I'm not saying it isn't, I'm saying I am unsure

In the specific case of Apollo, I think EOR would be a poor choice. Any intermediate launch that has a delay (or accident) can really screw things up, and you have several more launches to have to deal with for mission success. NASA would have to have gone all-in for automatic, or remotely controlled docking as well or they'd be dragging up a bunch of CSMs that were not actually going on the trip to bring up the guys to do assembly. 

[sgt_flyer]

26 minutes ago, Bill Phil said:

I'd say EOR is more efficient, especially in the long term.

problem with EOR is that you'll have to either : use storable propellants (less isp, so you'd need much more fuel) in the transfer stage (but you can fly it in advance and check everything out before sending the rest), or if you go with a cryogenic transfer stage, fly up at least the crew just back to back with the transfer stage, to limit boiloff. (or the 'refueling vehicle' if you launched the transfer stage empty), mobilising an enormous amount of manpower to prepare and conduct both launches in the same timeframe. - EOR is really way more complex to pull off

also, keep in mind that computer technology was really minimal at the time  in 1963, more than 60% of the US integrated circuit production were for the apollo guidance computers  (the AGCs) - just for computers of 64kbits of rom and 4kbits of ram running at 1Mhz  - if you used more classic computers of that time for the EOR, it would have noticably increased the dry mass

Edited March 10, 2016 by sgt_flyer

[wumpus]

42 minutes ago, Bill Phil said:

Umm...

Do you know that we still don't have enough nukes to wipe ourselves out? Hundreds of millions would die, but by no means billions.

Let's look at the Tsar Bomba: 50 megatons. We're all still fine. Orion: 800 0.15 kiloton bombs.Not even a single megaton.

Orion is more dangerous to the crew than anyone else, but that can be solved. Not necessarily easily, but certainly doable. 

Eh?  I guess ~2000 deliverable warheads (down from 30,000+) means its no longer "bounce the rubble" time.  But assuming more than a few hundred survive in any one place, the whole will bounce back in a few centuries (citation: what if?).  The big problem is that the technology will *never* return, largely due to resources requiring 21st century (roughly) heroics to get to.

But the whole "death and destruction bit" wasn't that the Earth would be destroyed, but that the Earth would suffer the *all* the fallout from every explosion used to lift the Orion until at least lunar interception (and probably then some, assuming the fallout is heading toward Earth).  The original Orion calculations assumed that most of the fallout would miss Earth and that it would be fairly safe, and those conditions are only true for an anartic (or arctic) launch.

[GoSlash27]

I voted "no".

 Bigger is definitely not better when it comes to rockets. Whatever gets the payload to its destination most cheaply, reliably, and efficiently is my favorite.

Best,
-Slashy

[Spaceception]

16 minutes ago, GoSlash27 said:

I voted "no".

 Bigger is definitely not better when it comes to rockets. Whatever gets the payload to its destination most cheaply, reliably, and efficiently is my favorite.

Best,
-Slashy

Agree, big rockets are still cool though, and they're still useful for putting large payloads to space for use in interplanetary manned missions however

[HebaruSan]

I chose No because the thread title biased the poll again.

[fredinno]

2 hours ago, tater said:

More efficient? You'd likely need to look at all the associated launch costs, and see if multiple launches/rendezvous is actually cheaper than a single launch, including delays, etc. I'm not saying it isn't, I'm saying I am unsure

In the specific case of Apollo, I think EOR would be a poor choice. Any intermediate launch that has a delay (or accident) can really screw things up, and you have several more launches to have to deal with for mission success. NASA would have to have gone all-in for automatic, or remotely controlled docking as well or they'd be dragging up a bunch of CSMs that were not actually going on the trip to bring up the guys to do assembly. 

When EOR was revived for project Constellation, there was a ~55 day storage requirement for the Ares V transfer stage, which made the mission requirements much more ambitious. The problem is that any lunar return needs EOR, SLS Block I/IB is too small to put 4 people on the moon, and Block II would likely give a lander without enough capability.

We need to figure out how to make EOR work, and solve the problems of boil-off, whether we like it or not. Thankfully, EUS uses RL-10s, and can thus integrate IVF, making the problem more about hardening the stage and engines to last a few months in orbit (we only have 1 pad to do this from), and carrying enough insulation as to not make the boil-off too high.

2 hours ago, sgt_flyer said:

problem with EOR is that you'll have to either : use storable propellants (less isp, so you'd need much more fuel) in the transfer stage (but you can fly it in advance and check everything out before sending the rest), or if you go with a cryogenic transfer stage, fly up at least the crew just back to back with the transfer stage, to limit boiloff. (or the 'refueling vehicle' if you launched the transfer stage empty), mobilising an enormous amount of manpower to prepare and conduct both launches in the same timeframe. - EOR is really way more complex to pull off

also, keep in mind that computer technology was really minimal at the time  in 1963, more than 60% of the US integrated circuit production were for the apollo guidance computers  (the AGCs) - just for computers of 64kbits of rom and 4kbits of ram running at 1Mhz  - if you used more classic computers of that time for the EOR, it would have noticably increased the dry mass

Indeed, people bascially decided LOR was easier.

2 hours ago, wumpus said:

Eh?  I guess ~2000 deliverable warheads (down from 30,000+) means its no longer "bounce the rubble" time.  But assuming more than a few hundred survive in any one place, the whole will bounce back in a few centuries (citation: what if?).  The big problem is that the technology will *never* return, largely due to resources requiring 21st century (roughly) heroics to get to.

But the whole "death and destruction bit" wasn't that the Earth would be destroyed, but that the Earth would suffer the *all* the fallout from every explosion used to lift the Orion until at least lunar interception (and probably then some, assuming the fallout is heading toward Earth).  The original Orion calculations assumed that most of the fallout would miss Earth and that it would be fairly safe, and those conditions are only true for an anartic (or arctic) launch.

Yes, that raises the question that if you can reduce fallout by launching from the poles, why wouldn't you? You need new facilities for this anyways...

[HoloYolo]

I said yes as improved tech is better than present tech.

[fredinno]

10 hours ago, Bill Phil said:

No, it's no fantasy. If it was developed instead of the Apollo program, we could have easily sent men to Mars. The Saturn V had a similar mass and much less capability. Chemical rockets have limits. Orion is truly the only way to get past a few thousand seconds of Isp. The only thing that could do it that isn't Orion is medusa, which is even more insane (throwing the bomb in front) and can only be built in space.

Yes there were engineering hurdles that would've needed to be overcome. But the Saturn V had plenty, as well. F-1 instability, for example. That took years to solve. But that's only the major hurdle I can think of off the top of my head... 

It's not fantastically dangerous. Nuclear bombs tend not to have a chain reaction between bombs. It just can't work like that. A bomb going off in the stack would be very problematic, but it wouldn't completely destroy the ship, if proper shielding were in place. Graphite would probably be a good material for the shield. Not only that but these are small yield bombs, a thousand launches wouldn't put a dent in the total fallout from nuclear testing.

Then you have the danger of misfire. That's probably more dangerous, and in truth I can't tell you how it would be counteracted. But that's the reason that it needed development. Probably less than the Saturn V, in fact.

So, if Orion is a fantasy, so was the Saturn V. Until they built it.

The damage for an Orion disaster would, at most, kill all the crew. But, it's pretty easy to prevent. The next worst case is stranding the crew in outer space. But we should have the capably to get them back, especially if we use multiple ships per mission.

Orion was too ambitious to enable a 1969 lunar landing.

8 hours ago, StrandedonEarth said:

Because staging (leaving unnecessary parts behind) is the only way to defeat the tyranny of the rocket equation. Bringing everything down to the lunar surface and back up again requires a LOT more fuel, and lifting that fuel takes more fuel, then you need even more fuel to lift THAT fuel, and so on. They save a lot of mass by leaving the stuff they need to get home (Fuel for the Moon -->Earth burn, heat shield, parachutes, etc) in lunar orbit instead of bringing it down and back up again.

Well, Gemini could do a direct ascent from a Saturn V https://en.wikipedia.org/wiki/Advanced_Gemini#Lunar_landing

The Apollo-LEM offered more capability, along with the ability for its use in LEO, but considering that we ended up only having 6 lunar landings (and one failed one), this mattered much less than the development costs justifed. But hindsight is key.

3 hours ago, _Augustus_ said:

Nova would have been harder to mothball, but it was hard to justify in the first place.

The Saturn V could have had a higher payload capacity than Nova by stretching the stages, using a NERVA in place of the S-IVB, replacing the F-1 with F-1A, J-2 with J-2S or HG-3, and by adding SRMs.

Umm, no, you couldn't stretch the stages. 10m is the max diameter for stages built at the MAF, and the Saturn V height was the max height for a rocket using the VAB to process the rocket.

[wumpus]

14 hours ago, fredinno said:

Yes, that raises the question that if you can reduce fallout by launching from the poles, why wouldn't you? You need new facilities for this anyways...

My point was that you could build the facilities and assemble the rocket on Cape Canaveral without too much danger (I doubt that such things are all that safe, but presumably the workers would simply find similar work with similar dangers).

Building the facilities and assembling the rocket in an extreme environment such as Antarctica would presumably add more danger than simply "driving a car".  Having your dexterity limited by parka, getting concrete to set in extreme cold, and the difficulty of inspecting welds (can only be done when you can safely remove face cover and googles, presumably "winter"*)?

I really don't know what the dangers are for polar launch.  It seems that not enough people take an Orion launch seriously to bother looking into it.

*winter for the northern hemisphere

[NuclearNut]

3 hours ago, wumpus said:

My point was that you could build the facilities and assemble the rocket on Cape Canaveral without too much danger (I doubt that such things are all that safe, but presumably the workers would simply find similar work with similar dangers).

Building the facilities and assembling the rocket in an extreme environment such as Antarctica would presumably add more danger than simply "driving a car".  Having your dexterity limited by parka, getting concrete to set in extreme cold, and the difficulty of inspecting welds (can only be done when you can safely remove face cover and googles, presumably "winter"*)?

I really don't know what the dangers are for polar launch.  It seems that not enough people take an Orion launch seriously to bother looking into it.

*winter for the northern hemisphere

Actually the pulse units wouldn't pose a risk of pre detonation before launch due to their requirements of an implosion and the environment needed to detonate the plastic explosive lenses.

[wumpus]

1 minute ago, NuclearNut said:

Actually the pulse units wouldn't pose a risk of pre detonation before launch due to their requirements of an implosion and the environment needed to detonate the plastic explosive lenses.

The problem isn't unplanned explosions.  The planned explosions are bad enough (and need to be in the anarctic for minimal damage).

"Plastic explosive lens": sounds like tech needed to make an Orion work properly (or at least without a ton* of plutonium) that didn't pan out at the National Ignition Facility.  Obviously "we" (for values of humans with DOE/DOD assistance, or Russian equivalent) could build an Orion with plutonium detonators, but I'm wondering what these "plastic explosive lenses" are and if they have been shown to work.

* might even be literal.  Consider just how much plutonium is needed per [H]bomb and how many an Orion will need.  This should definitely keep Orion on the ground purely on nuclear proliferation grounds (unless you can set of an H-bomb with lasers or similar).

[Tyrred]

The Saturn V actually got men to the moon, remember?  Several times.  Nova was an evolving launcher for a mission profile that had to be abandoned because it was not practical.

Orion, on the other hand...  It was actually more practical if executed properly, meaning MUCH more payload to orbit... and beyond.  The pulse units were actually nuclear shaped charges, not bombs in the traditional sense, and the entire workings were being carefully crafted for the rigors of spaceflight.  It actually made more sense to scale it up than to scale it down. 

"No, Orion does not make tons of deadly radioactive fallout. If you launch from an armor plated pad covered in graphite there will be zero fallout. And No, it would not create the apocalyptic horror of EMP making the world's cell phones explode and wiping out the Internet. That's only a problem with one megaton nukes, the Orion's charges are only a few kilotons. Just launch from near the North Pole (at least 276 kilometers from anything electronic) and you'll be fine." - RocketCat from projectrho (Atomic Rockets) http://www.projectrho.com/public_html/rocket/realdesigns2.php

When the Air Force presented Kennedy plans for their Orion-derived space battleship to fight the Soviets, he balked.  Wonder why.  The program never recovered. 

More than 50 years since the Cuban Missile Crisis, yet nuclear pulsed spacecraft STILL cannot be trusted to earthlings.  Such a shame.

 

[RCgothic]

I think it's worth mentioning that there were reasons for the different launch profiles under consideration.

Direct Ascent was the least complex, although it required the largest rocket and the most fuel. Remember that in the initial stages of mission planning, nobody had ever attempted a docking in space. They didn't even know how to rendezvous! As most KSP'ers know, it's pretty counter-intuitive and even by Gemini 4 they hadn't worked out the orbital mechanics. Buzz Aldrin had to write a doctoral thesis on the subject. Direct Ascent is the profile for people who don't know how to rendezvous and dock rockets.

Earth Orbit Rendezvous was the cheapest option on the table, because it used the smallest rockets. But as previously mentioned in this thread, the logistics are complicated. You either need to have all the rockets ready to launch near-simultaneously, requiring duplication of assembly facilities, launch pads, mission control rooms etc, or you need to plan for a long in-orbit dwell time which is also non-trivial due to loss of ISP for hypergolics or fuel boil-off for cryogenic stages. And do all those missions have to be sent up manned? At the time automation wasn't great, so probably. Manned systems are a load of payload you wouldn't otherwise have to send up. Also, nobody had ever assembled anything in orbit, which was another complication. And complications add risk, development time, and dilute the budget savings.

Lunar Orbit Rendezvous is a nice compromise if you can master the docking. It requires a medium-sized rocket (in moon rocket terms, obviously the Saturn V turned out to be the largest ever built), and only one docking rendezvous and docking in lunar orbit. That's ultimately why it was chosen.

Dual Orbit Rendezvous is a hybrid of Earth Orbit Rendezvous and Lunar Orbit Rendezvous with both use of in-orbit assembly and a separate lunar lander, and is the theoretically best approach should all the challenges be mastered. 

[PB666]

1 hour ago, RCgothic said:

I think it's worth mentioning that there were reasons for the different launch profiles under consideration.

Direct Ascent was the least complex, although it required the largest rocket and the most fuel. Remember that in the initial stages of mission planning, nobody had ever attempted a docking in space. They didn't even know how to rendezvous! As most KSP'ers know, it's pretty counter-intuitive and even by Gemini 4 they hadn't worked out the orbital mechanics. Buzz Aldrin had to write a doctoral thesis on the subject. Direct Ascent is the profile for people who don't know how to rendezvous and dock rockets.

Earth Orbit Rendezvous was the cheapest option on the table, because it used the smallest rockets. But as previously mentioned in this thread, the logistics are complicated. You either need to have all the rockets ready to launch near-simultaneously, requiring duplication of assembly facilities, launch pads, mission control rooms etc, or you need to plan for a long in-orbit dwell time which is also non-trivial due to loss of ISP for hypergolics or fuel boil-off for cryogenic stages. And do all those missions have to be sent up manned? At the time automation wasn't great, so probably. Manned systems are a load of payload you wouldn't otherwise have to send up. Also, nobody had ever assembled anything in orbit, which was another complication. And complications add risk, development time, and dilute the budget savings.

Lunar Orbit Rendezvous is a nice compromise if you can master the docking. It requires a medium-sized rocket (in moon rocket terms, obviously the Saturn V turned out to be the largest ever built), and only one docking rendezvous and docking in lunar orbit. That's ultimately why it was chosen.

Dual Orbit Rendezvous is a hybrid of Earth Orbit Rendezvous and Lunar Orbit Rendezvous with both use of in-orbit assembly and a separate lunar lander, and is the theoretically best approach should all the challenges be mastered. 

Docking was not so hard once i realized  the docking tools in Ksp were useless. I remember the first night i played, trying to get whats his face (at that time i didn't know his name Jeb) back into his space craft without a reflex knowledge of the jetpack hotkeys and sitting their watching the space capsule orbit me with each orbit of  kerbin. 

Once i realized you had to approach fast and kill speed then approach more slowly to intercept . . . . . . . .

If you think the US had problems, the soviets had major problems, eventually they had a rule that only an experienced pilot who went on a previous docking mission could be on the next docking mission. 

I like the idea of assembly in space, it allows the standardization of lauch vehicles and ultimately lowerss the cost cause you ca recycle the launch vehicle. Docking is a problem but if you are not to picky it can be done, quickly. Secondarily NASA need not lauch in rapid succession, they could have launch durable vehicles first. 

[Emperor of the Titan Squid]

I think that overall EOR is better, but in a space race, its not. the Orion plan didnt entail launch of Orion directly from earth did it? 

[PB666]

1 hour ago, Emperor of the Titan Squid said:

I think that overall EOR is better, but in a space race, its not. the Orion plan didnt entail launch of Orion directly from earth did it? 

No le hace. No one would ever propose launching it from Earth. Orion is a pipe dream of people who think a space program can ignire national and world .........

[Emperor of the Titan Squid]

1 hour ago, PB666 said:

No le hace. No one would ever propose launching it from Earth. Orion is a pipe dream of people who think a space program can ignire national and world .........

What? Orion is awesome! it would allow exploration of the solar system to become almost easy!

 

[PB666]

9 minutes ago, Emperor of the Titan Squid said:

What? Orion is awesome! it would allow exploration of the solar system to become almost easy!

 

Awesomely unlaunchable from earth, LEO, MEO. 

[Bill Phil]

10 minutes ago, PB666 said:

Awesomely unlaunchable from earth, LEO, MEO. 

Nope. If you launch from a graphite pad, in a very secluded area, there's no fallout.

People like to forget that the propellant, which would be most of the fallout, is going faster than escape velocity and in the up direction. Most of it will never touch the ground.

[PB666]

1 hour ago, Bill Phil said:

Nope. If you launch from a graphite pad, in a very secluded area, there's no fallout.

People like to forget that the propellant, which would be most of the fallout, is going faster than escape velocity and in the up direction. Most of it will never touch the ground.

Still, no one would allow you to do it.....so its not ever going to happen..... so why do we still discuss. 

In fact why do we bring tech here over and over agian that no serious space venture has designs in development to use.......if for no other sake is to argue about them. 

[Nibb31]

Orion is one of those ideas that looks good on paper (like space elevators or Skylon...) but would be an engineering nightmare. The logistics alone of building a supply chain for mass producing nuclear charges, with all the security and safety requirements, would be daunting. The construction facilities to build your Orion in the middle of a no-man's-land covered with graphite would have to be rebuilt from scratch for each new ship.

So yeah, it might work, but the cost in resources, real-estate, manpower, and general effort would be massive.

[tater]

While I'm certainly not sanguine about Orion, making the charges would be substantially easier than it was when it was first proposed (computerized mills, etc). The security is not really an issue, been there, done that (Sandia and LANL have pretty tight security at tech areas, and for X-div).

Edited May 15, 2016 by tater

[Spaceception]

Guys, go to an Orion thread for this, you're going off topic

[cfds]

What is a "graphite pad" supposed to be? I don't see how a slab of a very brittle variant of pure carbon can withstand even a moderate explosion. And I have no idea how it will catch the fission products of a nuclear explosion.