NASA Lunar Orbiting Deep Space Gateway in the planning stage

[ThomasP]

For anyone interested in the ongoing space program:

"Lockheed's Prototype Habitat Plans for NASA's Lunar Orbiting Deep Space Gateway - AmericaSpace"

There are also a bunch of interesting articles related to the space program linked at the bottom of the page.

 

[33k in the air]

It's all interesting, but I expect the timeline for development and implementation is optimistic.

 

[ThomasP]

Probably, but meeting the timeline is not as important as actually doing it eventually. At some point, preventing control of space by other entities will become a critical matter - for military and/or economic reasons.

 

[ThomasP]

One of the possible future space endeavors it asteroid mining. To accomplish this we will need bases in space - ie the Moon and Mars, and maybe others. I wrote and article on the subject back in 2020.

The subject in the excerpt below concerns just one asteroid - ie 16 Psyche - and some of the mineral wealth contained in the asteroid. The mission I refer to is NASA's Psyche Mission. The numbers in the excerpt are from 2019 data. More recent data has changed the metal content from 80% to 60%, so if you multiply the following numbers times .75 you will get estimates of the tonnage and wealth involved based on the newer data.

The Psyche Mission is currently scheduled to launch in early October 2023.

<
The asteroid I was talking about is called 16 Psyche. The mission is set to launch in August of this year. They only know a little bit about its composition from low temperature reflected-spectrum analysis, and the mass of the asteroid is estimated at about 4.1x10^16 tons. They figure even if it is only about 80% metal and the metals are of the lowest dollar value (ie iron at $0.05/lb) then it would be worth about $3,500,000,000,000,000,000. But since almost all elements go into solution in molten iron there should be plenty of other valuable elements in the mix. So less iron, more other useful stuff.

If the normal level of Germanium is present in 16 Psyche, the quantity there would be about 4.8x10^10 tons.

Total amount of Metallic Germanium processed here on Earth for 2020 was ~130 tons.

The price of Metallic Germanium (99.9% pure) is about $450/lb today, so the value of the Germanium in 16 Psyche alone would be ~$2.1x10^13.
<

A couple of links to the NASA Psyche Mission:

"In Depth | 16 Psyche – NASA Solar System Exploration."

"https://beta.science.nasa.gov/mission/psyche/"

 

[33k in the air]

It should have been continued fifty years ago, building on the technology and success of the Apollo program.

The road not taken . . .

 

[GrauGeist]

When I was a kid (back in the 60's), there was optimism that not only would there be a moonbase by the end of the century, but a colony on Mars and a permament space station in orbit.

And there is also the issue of flying cars...

 

[SaparotRob]

They promised us flying cars.

 

[eljefe]

When I was a kid (back in the 60's), there was optimism that not only would there be a moonbase by the end of the century, but a colony on Mars and a permament space station in orbit.

And there is also the issue of flying cars...

When I was a new engineer fresh out of college in 1985, I testified before a commission on America's future in space. I emphasized that the Shuttle was great, but it had no place to "go to". I urged that we build a Space Station, and testified at length how its best use was as a transportation node in space, allowing flights to depart from near earth orbit for any place in the Solar System (and eventually the galaxy).

At the time, that was the vision for the space station: research, repair of spacecraft on-orbit, fuel depot...all the things.

The space station went through many iterations, losing capability each time it was revised. We got to the "dual keel" iteration, and an astronaut raised the valid concern that dual-keel would take too many spacewalks to assemble.

The "solution" was yet another iteration that deleted the last vestige of operational logistics from the design...a sort of "hangar" in which spacecraft could be stored pending refurbishment. Aside from reducing overall complexity, I don't know what that had to do with reducing spacewalks needed for assembly.

Every version of ISS after that was a pure research facility...a laboratory in space, and nothing more. So it is to this day and for the foreseeable future. Full disclosure: I was an ISS flight controller (PLUTO position) from about 2003 to 2010. At one time in my career before that, I designed ISS assembly missions.

About the time the announcement was made that Shuttle would be retired in a few years, an agency "vision" for ISS in a world without Shuttle was released. Specifically, in one sentence, it was to support the research needed for human exploration of the solar system.

Now, what can you think of that is the most limiting factor, the one frailty of the human body that keeps us from hopping in a craft bound for Mars tomorrow? Wouldn't it be the propensity for the human body to deteriorate in the absence of gravity over time? The longest stay in space in history was 14.5 months on Mir in 1994. Nobody has stayed on ISS a full year (although some have come close). With current technology, a Mars mission would take about 18 months.

The solution to this was well known in the 1950s, before any human had ever ventured into space: artificial gravity through the use of centripetal acceleration. Chelsey Bonestall was drawing covers for Collier's Magazine in 1952 showing a spinning Station. 1968's 2001: A Space Odyssey had rotating structures. Since that announcement was made, do you think there have been any plans for a centrifuge aboard ISS, even a little one for small animals?

Nope.

So I view this all like the happy early days of ISS, when we would have a transportation node in low earth orbit that would allow us to repair, refuel, ride up on a Shuttle and then transfer to an interplanetary explorer, etc. What is proposed now is nothing less than the exact same thing in lunar orbit. They use pretty words that will be used to pry pretty dollars from the hands of taxpayers.

I will be very pleasantly surprised if any of the proposed logistics capabilities materialize. I'm not holding my breath.

 

[ThomasP]

One of the major problems (in my opinion the major problem) with the large space station (say something like a single-ring version of the 2001: A Space Odyssey type) is the logistics for the construction and continuing support of the personnel and mission requirements.

Living in a small station and using centrifuge wheels to simulate G fro 30-60 minutes a day does not work in the long run, although it would slow down the bone loss and muscle atrophying effects. You need to live in a 1G environment for most of the day.

In order to have a living and working 1G single-ring space station, capable of supporting 100 or more people, I was told you would have to use over 100,000 long tons of material in the construction of the living and work spaces. Then you have to add the supply requirements for the personnel and whatever scientific, manufacturing, support platform logistics, etc, needed to accomplish the mission and it adds upto a lot of lift and cost.

The space shuttle had a payload of ~29 long tons (nothing to laugh at) so using the space shuttle to accomplish the lift needed for a near-earth single-ring space station would require over 3400 heavy lift missions. If you used a heavy lift rocket similar to the Saturn V (40 long ton payload) it would take about 2500 heavy lift missions to build a similar single-ring station near the Moon.

To give you a comparison, the ISS (International Space Station) is expected to weigh in at about 450 long tons when complete. This is equal to 15.5 space shuttle or 11.25 Saturn V heavy lift missions. To date it has taken 37 shuttle missions and 5 Proton/Soyuz heavy lift missions to get the major part (95%+) of the ISS into orbit.

 

[PFVA63]

...

If the normal level of Germanium is present in 16 Psyche, the quantity there would be about 4.8x10^10 tons.

Total amount of Metallic Germanium processed here on Earth for 2020 was ~130 tons.

The price of Metallic Germanium (99.9% pure) is about $450/lb today, so the value of the Germanium in 16 Psyche alone would be ~$2.1x10^13.
...

Wouldn't the value of Germanium per pound drop dramatically if a massive source of it sudenly became available once you start mining the asteroid

 

[ThomasP]

I do not know. Obviously, if that much Germanium suddenly appeared on the face of the earth the price would drop an extreme amount. But what would the costs be of everything needed to mine an asteroid? Would said costs increase or decrease the end cost of the Germanium?

IC chips are relatively small and light, so presumably a system could be worked out where complete chips would be manufactured in space and shuttled (or otherwise dropped) to Earth surface. What would it cost to create an entire ore processing and chip manufacturing installation in space?

Alternately, what if the ore was rough mined in space and then dropped to Earth surface in 'small' meteor(ite) form and recovered from the sea bottom? How much would such a method cost vs the cost of space based ore processing and chip manufacturing? What would the potential environmental impact be of thousands/tens of thousands/hundreds of thousands of such drops be?

Or maybe some method in between? Or something not yet announced/thought of?

In general there would be 3(?) steps needed to accomplish the mining of an asteroid

1. Get to the asteroid
2. Either mine the asteroid in place and move the ore to Earth/Moon orbit, or move the entire asteroid to Earth/Moon orbit and then mine it
4. Deliver the ore or finished product to Earth surface

Even if the cost ended up higher than Earth based production of Germanium, it may end up being worth it to have access to such strategic material(s).

I find it all very interesting. It is the Sci-fi of my youth coming to life.

 

[eljefe]

One of the major problems (in my opinion the major problem) with the large space station (say something like a single-ring version of the 2001: A Space Odyssey type) is the logistics for the construction and continuing support of the personnel and mission requirements.

Living in a small station and using centrifuge wheels to simulate G fro 30-60 minutes a day does not work in the long run, although it would slow down the bone loss and muscle atrophying effects. You need to live in a 1G environment for most of the day.

In order to have a living and working 1G single-ring space station, capable of supporting 100 or more people, I was told you would have to use over 100,000 long tons of material in the construction of the living and work spaces. Then you have to add the supply requirements for the personnel and whatever scientific, manufacturing, support platform logistics, etc, needed to accomplish the mission and it adds upto a lot of lift and cost.

The space shuttle had a payload of ~29 long tons (nothing to laugh at) so using the space shuttle to accomplish the lift needed for a near-earth single-ring space station would require over 3400 heavy lift missions. If you used a heavy lift rocket similar to the Saturn V (40 long ton payload) it would take about 2500 heavy lift missions to build a similar single-ring station near the Moon.

To give you a comparison, the ISS (International Space Station) is expected to weigh in at about 450 long tons when complete. This is equal to 15.5 space shuttle or 11.25 Saturn V heavy lift missions. To date it has taken 37 shuttle missions and 5 Proton/Soyuz heavy lift missions to get the major part (95%+) of the ISS into orbit.

That 100,000 tons seems a bit much to me. There are naval platforms that host a comparable crew indefinitely that weigh much less than that.

And ISS can support about 6 people for a long duration. 100/6*450 = 7500 tons. The real answer is somewhere between 7500 and 100,000.

Anything of any size will be built by Starship ($100 million per launch...really, probably closer to $200 million) than by SLS ($2 billion per launch). Yes, SLS has had a successful launch and Starship has not. That will change.

 

[ThomasP]

While there are rotating ring designs from the early days of Scifi and the real space age that are relatively small in diameter (~100 ft max for the military orbital surveillance stations), they were for a compact living environment (10-20 people max) with compact work spaces utilizing electronic and electro-optical equipment. This was for relatively short term occupation of 1 or 2 months at a time (basically the length of a nuclear war ) and the crews were considered expendable (if necessary). The effects of long term living in space were not really taken into account as they really had no idea of what they were.

I think a large part of the 100,000 tons is due to the need for a large part of the structure to rotate and produce a 1G living/working environment. The stresses involved in something like that are rather large. The size of the rotating ring is important as a rotating ring that is too small in diameter will produce motion sickness in nearly everyone - just going from a standing position to a crouch (or vice versa) will cause most people to lose their balance. I have read estimates that the minimum ring size for a long term living environment would be in the region of 400 ft diameter - maybe more (they have no real data as of yet). What kind of safety factors would be involved I do not know, but just being able to slow or stop the ring quickly(ish) would be problematic without sufficient structure.

Then there are the large work facilities that will be required. Imagine what you would need for construction, maintenance, and docking facilities for a base that supported long-range transport and/or mining spacecraft and their crews. Long range transport and mining ships would not be small, and even if they did not dock directly with the station there would be the need for short range movement of the various support and supply/replenishment 'vehicles'.

Then add on things like the radiation shielding and armour vs particle impacts, storage tanks for fuel, etc, and the weights add up fast.

Interesting fact - the current ISS occupants that are going to live on the station for any significant length of time work out ~2 hours a day in order to reduce loss of muscle mass and bone density. This amount of exercise does not solve the problem of long term effects in terms of sustained living in space.

 

[ThomasP]

A few examples of the difference the ring diameter has on tangental velocity and rpm, all for 1G at the diameter specified.

Ø100' ring gives 40.1 ft/sec and 7.66 rpm
Ø200' ring gives 56.7 ft/sec and 5.41 rpm
Ø300' ring gives 69.5 ft/sec and 4.42 rpm
Ø400' ring gives 80.2 ft/sec and 3.83 rpm
...
Ø1466' ring gives 153.6 ft/sec and 2.00 rpm
Ø5868' ring gives 307.2 ft/sec and 1.00 rpm (That's right, to get the rpms down to 1 the ring would have to be over a statute mile in diameter.)

As I mentioned in my last post, the people working on the problem really have no idea yet what the eventual requirements will be in order to allow effective long-term functioning of inhabitants re the rotational speeds (ie tangental velocity and rpm). The gravity gradient/change in acceleration along the communication arms would require all entrances to be located on/near the polar axis where the G force would be near 0. A long non-rotating tube structure extending along the polar axis would allow this, and the structure and equipment that do not need to be at 1G could be located along the tube, as could the docking positions if needed.

The image below is actually from the movie "The Martian" and represents a longhaul spaceship built along the same lines as a space station. The ring with the 4x pods rotates while the central tube remains stationary (for the most part). The ring is, however, much smaller in diameter than would be needed for long-term semi-permanent habitation.

 

[PFVA63]

Hi,
I thi k I read once that 1G wasn'y necessarily needed to preserve muscle mass and such for a human body and that something like 0.8G (or something) might be acceptable.

Pat

 

[GrauGeist]

The biggest issue, is gravity in relation to bone mass/density.
The stronger the gravity, the stronger the bone structure.

Without at least a 1G environment, bone density suffers and can lead to weakening of the skeleton and complications.

 

[PFVA63]

The biggest issue, is gravity in relation to bone mass/density.
The stronger the gravity, the stronger the bone structure.

Without at least a 1G environment, bone density suffers and can lead to weakening of the skeleton and complications.

Hi,

I'll have to look through some old books I have, but I thought that I read once that you could potentially make do with a little less. Here is an excerpt from a file that I found on the internet titled "ARTIFICIAL GRAVITY RESEARCH TO ENABLEHUMAN SPACE EXPLORATION" by the International Academy of Astronautics from 2009 that notes;

The minimum gravitational level, normally measured at the rim of a centrifuge, is the key parameter in the design space. The limited animal tests in orbit confirm that continuous rotation to yield 1 G at the feet of a small rodent is sufficient to maintain normal growth (Gurovsky et al. 1980). However, it remains to be determined whether a lesser G-level will suffice. Based on centrifuge studies of long duration, Russian scientists suggest that the minimum level of effective artificial gravity is about 0.3 G and recommend a level of 0.5 G to increase a feeling of well-being and normal performance (Shipov et al. 1981).

Regards

Pat