There are parts of the F-1 engine that would be difficult to exactly replicate because while the engineering specs are known the exact fabrication processes weren't all documented. An exact workalike could be made for those parts that fit the specification without a problem. That new engine would need to be entirely requalified for use.
The F-1 is big and expensive and rebuilding them has long been outside of NASA's budget. If they were going to rebuild the F-1 it would be the same expense and effort to just design an entirely new engine.
This is why, for instance, the SLS is using the SSME as its first stage engines. It's a known system with a long and successful (the engine itself) flight history. It's been iterated upon and is well understood.
The design philosophy of rockets has also changed from the 60s when the Saturn was designed. Solid fuel boosters were not considered useful for Saturn but have been proven since then and have a long flight history. There's also the SpaceX/Soyuz model of an array of smaller/simpler engines. A small number of monster engines is just not needed like it was for Saturn.
The expense of the F-1 and the lack of real need has kept NASA from using them, not some loss of technology. The guidance systems...are a long long solved technology. Modern guidance systems are better than the Apollo and Saturn systems by orders of magnitude. They're far smaller which allows redundancy and still lower weight than old systems.
Since Saturn NASA has launched successful probes to every planet in the solar system and several dwarf-planets, landed several extremely long lived rovers on Mars, launched hundreds of satellites, over a hundred Shuttle missions, and assembled one of the most complex machines ever in orbit.
What's sad is the mistaken belief that Apollo was some pinnacle of capability and technological prowess for NASA.
"The largest solid rocket motors ever built were Aerojet's three 260 inch monolithic solid motors cast in Florida.[18] Motors 260 SL-1 and SL-2 were 261 inches in diameter, 80 ft 8in long, weighed 1,858,300 pounds and had a maximum thrust of 3.5M pounds. Burn duration was two minutes. The nozzle throat was large enough to walk through standing up. The motor was capable of serving as a 1-to-1 replacement for the 8-engine Saturn 1 liquid-propellant first stage but was never used as such. Motor 260 SL-3 was of similar length and weight but had a maximum 5.4M pounds thrust and a shorter duration."
and
"Between Sept. 25, 1965 and June 17, 1967, three static test firings [of the AJ-260 rocket] were done. SL-1 was fired at night, and the flame was clearly visible from Miami 50 km away, producing over 3 million pounds of thrust. SL-2 was fired with similar success and relatively uneventful. SL-3, the third and what would be the final test rocket, used a partially submerged nozzle and produced 2,670,000 kgf thrust, making it the largest solid-fuel rocket ever."
For more see: https://en.m.wikipedia.org/wiki/Aerojet#Florida_facility_and...
That's not really true [1]. Although the project is dead AFAIK a fair bit of work went into reviving the F-1 engine in the early 2010s.
>And the guidance systems would have to be built back up from scratch.
As with many things, you can't easily replicate complex old artifacts because you don't even have the tools to make the tools to make the tools... No, we couldn't build an Apollo Guidance Computer today. I doubt you could easily get things like rope core memory or just about any of the components. But you wouldn't want to anyway. (The guidance computer would probably be the least of your challenges; this is a pretty well-understood technology and the company that made it is even still around.)
"Any of the components" is an exaggeration. For example, bipolar transistors are still here, here's the schematics [0] of the switched-mode power supply in the AGC - still perfectly understandable, rebuilding it can a fun weekend project. Also, discrete NOR gates are still around, although the underlying technology is different.
> As with many things, you can't easily replicate complex old artifacts because you don't even have the tools to make the tools to make the tools... No, we couldn't build an Apollo Guidance Computer today.
I think there's a difference between a 1:1 faithful replication and a replication based on the same architecture and/or principle of operation. While it's difficult to build a 1:1 faithful replication, rebuilding a new one based on the same architecture in general is much easier.
So when the original commenter said, "no one understands how the engines on the Saturn V work anymore", I think the point to be made is whether the ideas from the Space Age, e.g. whether the Saturn V architecture has survived, it is not necessarily meant that rebuilding it makes sense - it probably does not.
> The guidance computer would probably be the least of your challenges
+1.
[0] https://www.righto.com/2019/08/reliable-after-50-years-apoll...
>whether the Saturn V architecture has survived
We understand very well the basic approach that was taken to land on the moon and the hardware we used to do so. We'd have to re-engineer a lot of things that aren't just off-the-shelf to do it again. But we could do so pretty quickly if there were any compelling reason to do so.
As I understand it, current technologies that could include moon landing are being worked on in the broader context of going to Mars.
Yes. I think this is the perspective that people trend to overlook - every engineering project is unique, in the sense that it's optimized to do the job under very specific constraints - costs, production capabilities, available materials, etc. When the circumstance changes, sometimes you simply can't just pull the same blueprint out of the archive to make another one - redesigning it is sometimes unavoidable, even if the older design is nothing wrong from a technical point-of-view. I think the same applies to software development.
The scientific case for the moon was always weak, and most anything they could come up with has been done. Just look at the useless lets-grow-salad-in-space-oh-look-its-just-salad timesinks the ISS has been busying themselves with.
So, in a way we've become much smarter. And SpaceX, a commercial outfit with both solid financials, a good track record on safety, and rather unlimited ambition is probably the most exciting thing happening since the first moon landing.
This is called basic research. It's geared towards building greater knowledge of a study area without specific concerns towards application. That's how science works. We don't just fund the stuff that's immediately profitable (though things are shifting that way).
More than doubling the number of visible man made objects (~200 till the start of the SpaceX Starlink project).
And with fcc approval for another 12,000 and plans for a further 30,000.
It excites me alright, but certainly not in a good way...
Ditto guidance systems. Why try to replicate something designed around the constraints of hardware that seems ancient by today's standards? No reason to think we couldn't build something new with equivalent or better features on modern hardware.
In fact if you take various “high tech” designs from middle of the 20th century you will see a pattern of things that cannot work if built as designed, but work because of random effects that are certainly outside of what the original designers thought of (I have seen large amount of instrumentation electronics where voltage sag on supply voltage is part of feedback loop and it will not work without it. I highly doubt that the original engineers consciously designed that.)
The budget plan for the James Webb Space Telescope was $500m with completion in 2007. We're now at $9.6b with completion predicted in 2021. Some of the cost overruns and delays were caused by the unexpected complexity of fabricating the mirrors and assembling them in space, but that underscores my point. The Apollo mission was orders of magnitude more ambitious at the time.
I'm not pointing any fingers because the causes are complex. NASA is underfunded and relies on unreliable funding from Congress, which itself is a source of inefficiency. Defense/aerospace contractors are greedy, sure, but there's a much bigger pie to be had if past successes encouraged even larger-scale projects like moon colonization they could bid for.
I don't know what's gone wrong, but we are failing on these big projects as a species for some reason.
On the same tech we did 50 years ago.
There are things to do on the Moon, right now. Basic science ought to be enough; but applied things like material extraction and tourism would add to that. However, we consider those things lesser priority than some others - and we're getting a lot of short-term bang for our bucks, just not so much of foundation for future developments.
So, today we don't see the reason to apply efforts to get there. Those few who could justify going "in small", are to few and far between to mount a concerted effort. So we're slowly developing such things as cheap LEO launchers and lunar landers - the precursors to return to the Moon. We'll get back there - in the future, not in present. In present we still can't.
Other than all the advances that will give you much better performance at a lower cost enumerated in other comments, there is another problem.
When you dive a bit deeper into the history and design of the Saturn V (the NASA history website is a good source) you kinda get the feeling it was hacked together in many places to meet a deadline. Many of its systems were very complicated, labor intensive or hard to upgrade or extend jus so that they could meet the deadline and beat the Soviet Union to the lunar surface. The unlimitted money pass they got for this for a while definitelly did not help matters.
This also in my opinion is why Saturn V ended production so quickly - it did meet the deadline, but was just too expensove and inflexible due to all the hacks for a regular budget conscious "production" use.
Interestingly, China germinated plants on the moon this year, but that news seems to have been buried in the UK. So getting a payload to the moon, guidance systems and such, isn't the problem.
We've actually lost the ability to go. No one understands how the engines on the Saturn V work anymore. It would take years to tear them apart and analyze them, and most of the original engineers are dead.
And the guidance systems would have to be built back up from scratch.
Kind of sad if you think about it.