50 Years Ago Today the last human walked on the Moon

[tdracer]

Yep, it was 50 years ago today that Gene Cernan and Harrison 'Jack' Schmitt were the last of 12 American astronauts to walk on the moon.
I wonder how many people thought that 50 years later, they would still be the last humans to walk on the moon - with little likelihood that someone will change that in the near future. Worse, that we no longer even possess the technology to perform that feat.

[Lookleft]

Worse, that we no longer even possess the technology to perform that feat.

Well NASA have just had the splash down of what looks like the pointy end of a CM that had crash test dummies as crew. Exciting news for those with short memories.

[Hokulea]

Yep, it was 50 years ago today that Gene Cernan and Harrison 'Jack' Schmitt were the last of 12 American astronauts to walk on the moon.
I wonder how many people thought that 50 years later, they would still be the last humans to walk on the moon - with little likelihood that someone will change that in the near future. Worse, that we no longer even possess the technology to perform that feat.

We have the technology, we just don't have the money or political will. However, hopefully, that will change in the next decade.

[tdracer]

We have the technology, we just don't have the money or political will. However, hopefully, that will change in the next decade.
OK, bad choice of words - the technology is probably there, but not the ability. If someone wrote the blank check it would take to go back to the moon, it would still take years to develop the needed hardware and software to go. NASA did demonstrate the ability to duplicate Apollo 8 (sort of - Artemis isn't yet capable of the near moon orbit that Apollo 8 did), but we are nowhere near being able to even send the payload to the moon necessary for a moon landing - never mind a craft capable of actually landing on the moon with a human payload and returning.

[HOVIS]

You need to keep up with current affairs at SpaceX.

[Asturias56]

of course we have the technology - we could just recreate the Apollo kit - but its the cash thats' needed. NSAA have a plan to land in 2027,

https://www.nature.com/articles/d41586-022-01253-6
https://www.space.com/nasa-artemis-4-second-moon-landing

SPACEX has a plan and I'll bet the Chinese have one as well

[Gordomac]

Now don't ask Uncle Buzz if he actually went to the moon !

[India Four Two]

I was lucky enough to meet Gene Cernan in the early 80s. A very interesting experience, but since I'm a geologist, I would have preferred to meet Harrison Schmitt, the only geologist to go to the moon.

[B Fraser]

Artemis isn't yet capable of the near moon orbit that Apollo 8 did.

Can you explain that one please. NASA did set the record for the greatest distance for a man rated spacecraft. OK, the piece of paper has yet to be signed on formally accrediting the craft but it is arguably fit for purpose.

[Jhieminga]

I suspect that Artemis still lacks the ability to accurately monitor and correct a near-moon orbit. The only close approaches were on entering and leaving lunar orbit. The moon has several mass concentrations that influence any close orbit and because of this, a lot of checking and correcting was needed during the various trips around the moon that Apollos 8 and beyond carried out. Basically, the gravitational field around the moon is far from uniform. Or perhaps Artemis has that capability, but they decided to play it safe for a first outing.

[tdracer]

Can you explain that one please. NASA did set the record for the greatest distance for a man rated spacecraft. OK, the piece of paper has yet to be signed on formally accrediting the craft but it is arguably fit for purpose.
Artemis went into a highly elliptical orbit - not the nearly circular orbit that Apollo did. Reportedly, it can't currently carry enough propellant for the burns needed to get into and out off a 'low moon' orbit. For all the buzz about the heavy lift capabilities of the SLS, it could barely perform that moon orbital mission (remember, Artemis is quite a bit bigger and heavier than Apollo) - forget adding a moon lander to the payload.

[tdracer]

of course we have the technology - we could just recreate the Apollo kit - but its the cash thats' needed. NSAA have a plan to land in 2027,

https://www.nature.com/articles/d41586-022-01253-6
https://www.space.com/nasa-artemis-4-second-moon-landing

SPACEX has a plan and I'll bet the Chinese have one as well
At one time, NASA said 2023 for a moon landing - at the rate they are going they'll be lucky to make it by 2032. At $4 Billion a pop, they can't afford to launch SLS more than once every 2 or 3 years - and even if they had a moon lander, they'd need to test fly it in earth orbit before taking it to the moon.
Plans are a start - little more. No one currently has the ability - and that's not going to change anytime soon.

[B Fraser]

I suspect that Artemis still lacks the ability to accurately monitor and correct a near-moon orbit. The only close approaches were on entering and leaving lunar orbit. The moon has several mass concentrations that influence any close orbit and because of this, a lot of checking and correcting was needed during the various trips around the moon that Apollos 8 and beyond carried out. Basically, the gravitational field around the moon is far from uniform. Or perhaps Artemis has that capability, but they decided to play it safe for a first outing.

I beg to differ (warning - Apollo geek). The ability to navigate in space is vastly different between today and around 1970, For example, the 4th planned return transit correction for Artemis required a delta V of a mere 0.164 meters / second. The 1st correction was even smaller at 0.146m/s

The Mascons of the moon are very well mapped and are common to all rocky planets including the earth. Our own Mascons are so well understood that their effect on the GPS in your phone is allowed for. When Apollo 8 entered a 60 mile orbit, it was not known if the far side had any 60 mile mountains.

If the current ESM cannot place a capsule in a near recto-linear halo orbit then the objective is well and truly screwed w.r.t. a capsule and lander. The real reason for the eccentric orbit is greater inherent stability as the sun, moon, earth system is the famous 3 body gravity calculation. In the event of a systems failure, Artemis will neither collide with the moon nor be flung out into space. In other words, it's a stable holding pattern that gives plenty of time to solve any problem should one arise.

Scott Manley does his usual excellent job of explaining it here...... What Is Distant Retrograde Orbit, And Why Is Artemis 1 Using It? - YouTube (https://www.youtube.com/watch?v=XFIvKSVRtZ0)

[wiggy]

NASA did set the record for the greatest distance for a man rated spacecraft. OK, the piece of paper has yet to be signed on formally accrediting the craft but it is arguably fit for purpose.

It's become the custom amongst older space geeks to cough and mutter " but what about LM4" when that claim phrased in that manner gets mentioned....

Agree with you entirely on the subject of mascons, modern knowledge of the Moon's potential and the reason for the orbit used by Artemis....all to do with long term stability for testing, not navigation accuracy.

[B Fraser]

Yup, the record may well be held by a piece of Apollo hardware but there's no hard evidence.

As an add-on, there is a slim possibility that the Apollo 11 LM ascent stage is still in lunar orbit. Furthermore, a 3rd stage from one of the Apollo missions is now in a deep space helio-centric orbit and is thought to have swung by the Earth a few years back.

If anyone is a hard-core Apollo geek, my darling wife bought me Apollo Remastered by Andy Saunders. It's excellent.

:8

[wiggy]

Yup, the record may well be held by a piece of Apollo hardware but there's no hard evidence.


Well...the ascent stage for 10 certainly left Lunar orbit and was tracked for several hours after the (to depletion) burn ended, so I'd say the Physics means we know where it went, but you are right to say that there's no definitive proof...yet.

https://skyandtelescope.org/astronomy-news/astronomers-might-have-found-apollo-10-snoopy-module/#:~:text=Snoopy's%20trajectory%20was%20unique%20among,an%20o rbit%20around%20the%20Sun.

Of course unlike Orion there was never any intent to return it to earth, so Orion does hold that subset of the record.

Second the recommendation re the book.

[Jhieminga]

And thirded... I just bought it yesterday. For a couple of weeks I was trying to reason with myself that "it's just another Apollo photobook, there are plenty of those around already". It most certainly is not! (if you're still in doubt... have a look here (https://amzn.to/3PXtdKF). There are some nice Gemini photos in the online sample version. But you have to see the level of detail in the photos in real life to really appreciate the work that Andy Saunders put into this.)

And thanks for setting me straight on my Artemis assumptions B Fraser!