Construction of the Space probe for NASA's Psyche Mission

[roma847]

Hello everybody,

first of all, I still wish everyone a Happy Easter.

During my trip to Florida, I witnessed the launch of a Falcon 9 Heavy for NASA's Psyche mission from Launch Pad 39A live from the Viewing point of the Apollo Saturn V Center on October 13, 2023, which was an unforgettable experience that I reported on in my German Travel report.

This Official NASA Trailer gives a very good overview of the Psyche spacecraft and its mission.


Source: NASA, JPL-Caltech, ASU

As I mentioned at the end of the post, one could take along a simple paper kit of the Psyche spacecraft in the KSC Visitor Complex, which even contains short illustrated instructions, so putting it together shouldn't be rocket science.

But when I took a closer look at the kit and the instructions,



I immediately had some concerns about the 15 cm long Solar arrays and their point-like attachment to the space probe.



To do this, a folded and glued carrier strip (5 mm x 200 mm) should be glued in the middle of a folded panel and pushed through side slits through the space probe body, onto which then at the other side  the other panel should be glued.



As you can see, the space probe only consists of six parts, which I first cut out of the slightly thicker cardboard. Then one can clearly see that for the intended assembly of the panels with the help of the carrier strip, the inner areas of the filigree struts must not be cut out in order to provide the whole thing with sufficient support,



which of course doesn't correspond to the original and would be totally resist me, as one can see in the Trailer (2:00).



That's why I came up with a different, even though adventurous solution, that should come closer to the original. The only problem is the virtually point-like, stable attachment of the widely overhanging panels to the space probe walls.

Of course, it would be ideal if I made the struts out of thin wire, which is why I first cut out the spaces, but what was quite tricky.



To bend the struts, I first had to make a sketch, which I then used to bend brass wire (Ø 0,5 mm) into a double Z shape. I could then first glue these struts on one side of each of the separate panels and push them through the side slots through the probe cube. Separate panels because the relatively stiff cardboard would probably be difficult to glue with inserted struts.



Then I've still thought about a Balsa support that is glued to the interior of the space probe, onto the top of which the middle parts of the struts are glued to ensure that they are held in place adequately.





Now I just have to think of a clever sequence of assembly steps, whereby I can thread the struts of the panels glued on one side individually and one after the other and only then can glue them to the panel parts on the other side, before I can finally glue the space probe cube.



If the whole bizarre structure had sufficient stability and rigidity, I could perhaps even leave out the paper strips of the rod systems that are actually too wide, which would then be even closer to the original.

As one can see, a lot of things are still formulated in the subjunctive, therefore Trial & Error, let's see what can be done.

[mike robel]

AS usual Manfred, your attention to detail and creativity holds no bounds.

[roma847]

Thanks Mike for looking in on my little Psyche Space probe.

When I heard the audible notification from NSF forum on my smartphone, I immediately knew that it could only be my friend Mike, which I was right about. I'm just a clairvoyant.

You know my crazy love for detail, and white surfaces in a paper kit like this hurt my eyes because that's simply a no-go.
Let's see if my solution will work and what it will look like in the end.

[roma847]

Hello everybody,
and now to the assembly order, which I thought carefully about.

Since my two Z-shaped brass struts are supposed to go through the probe cube, it quickly became clear that I wasn't allowed to glue the cube together on all sides yet otherwise it would not be possible to thread the struts through.

That's why in the following picture I tried to mark the individual steps in order with arrows, which may not be understandable straight away, which is why I would like to briefly explain the steps.



In order to still have enough freedom of movement when threading the struts, I can in the 1st Step first just only glue the two rear side walls to the floor and the Balsa support.



In the 2nd step I only glued the end of the brass strut onto the back of the upper panel with UHU CA,  because I might want to leave out the white paper triangle.



In order to be able to handle these bizarre structures when threading through the struts, I cut two Styrofoam blocks to the required height to support the panels.



In the 3rd Step then followed the careful threading of the glued strut first through the front side wall and then by turning the rear support so that the strut could also be threaded into the rear side wall and then could carefully pulled through,



which actually worked.



The other panel is only temporarily placed in these images.





With this panel and the Steps 4 to 8 it will continue tomorrow.

[roma847]

Hello everybody,

let's continue with the Solar panel on the other side, whereby I changed the assembly sequence a little bit.

First I glued the longer leg of the brass strut up to the bend onto the underside of the panel.





And then it went to the Styrofoam platform, in order to thread the strut, hoping that everything would work.



To ensure the panel had a sure laying, I had to put another block of Styrofoam underneath. I then carefully threaded the front end of the brass strut with tweezers a few millimeters into the tiny opening on the side wall,



then slowly pulled across the Balsa support to the other side wall and carefully pushed through the opening there until it could be seen on the other side. So far so good!



After that, however, it became increasingly difficult as the bend in the brass support had to go through the wall and I had to be extremely careful not to bend everything,



especially since the front end behind the other wall had also to be pulled at the same time, which was quite tricky.



But finally I have succeed in doing it,



and was able to take a little breather.



Then I still glued the wires to the Balsa support on both sides with UHU CA.

I then still glued a Channel profile (1,5 mm x 3 mm) onto it to make sure that the glued wires would not get loose if I would have to bent the finally glued panels a little for position correction. 



Tomorrow the steps 6 and 7 can also follow now, whereby the last side wall and the ceiling will be glued.

And then I'm already excited to see what everything will look like when I turn the space probe over to glue the struts onto the undersides of the panels too.

[roma847]

Hello everybody,

sorry, but my original second post with my tricky assembly order somehow wasn't saved, which is why I've added it again.

So please read again.

[roma847]

Hello everybody,

today was the day, and when I've turned the probe around full of curiosity I was pleasantly surprised that both Solar panels remained almost horizontal, especially since both were only glued on one brass strut, wherewith my idea actually proved to be a viable solution.



In Step 6 the side wall could now be glued,



and then also the top finish (Step 7).

However, I don't like the blue X-Band High Gain Antenna yet,



and since it is covered with foil in the original probe anyway, I tried that too and cut the part out of thin aluminum foil.



I then stuck the foil with CA onto the cone, which looks better to my taste. However, I will not glue the X-Band Antenna firmly onto the probe until later, as I would like to add a few details that have so far only been hinted at in the paper kit.



I've then turned the probe over again and glued the remaining brass struts onto the undersides of both panels.





Now that both panels were sufficiently stabilized, I turned everything over and took a closer look at all again.





Afterwards I decided to remove the paper covers of the struts because this look corresponds more to the original and will only glue the downscaled front covers,



which I've scaled from the video shown at the beginning. 


Source: Official NASA Trailer (2:00)

Now the crossbars are still missing on both panels, which I have therefore already removed from the kit and will also replace with brass wire, as well as some details such as the Rod systems in the two corners, as well as Thruster and Spectrometer, which I could possibly hint at.

[roma847]

Hello everybody,

today I dared to the cross struts (brass wire Ø 0,5 mm), but gluing them in turned out to be extremely difficult, which required a lot of sensitivity.

The top priority when gluing was a secure bearing and locking of the probe and panels so that nothing could slip.



Since the gluing had to be done with UHU CA, the strut could initially only be glued on the rear side. So that after the strut moistened with CA had been positioned accurately, it could be carefully placed on the front side after a short time to set, I glued a tape strip there as a shelf, what has also proven successful.





After carefully removing the tape strip, the strut could also be glued at this point by dabbing it with CA using an acupuncture needle.

The small triangular strut on the probe wall was then glued onto the struts, wherewith this side was completed.



The crossbar on the other side was glued in the same way.



Maybe you probably haven't noticed yet, I've colored the white edging of the middle panel area blue, which I like better that way.

[roma847]

Hello friends,

the longer I look at the greatly simplified Solar probe body from the Paper Kit and compare it with NASA photos and videos, the more things I notice that I don't like yet, which is why I decided to scratch several details that were only printed and thereby refine the probe's outfit a little.

The X-Band High Gain Antenna shown in the kit as a flat cone actually has, like all space probe antennas, an inwardly curved, concave shape and is covered by a foil, whereby it because  of the three struts underneath just appears as a flat cone, which I have already covered by gluing on aluminium foil.

That's why I first stuck over the blue outline of the antenna on the top of the probe, which is simply wrong there and is just irritating.



But I could have saved myself that, because as you can see on NASA videos, the sides of the probe body are partially covered with reflective silver and black foil, which is why I came up with a new idea.







And since I like to use different materials, I looked for suitable stuff in my stocks and found some too,



such as:

1 Aluminum household foil, smooth, shiny front

2 Aluminum household foil, heavily creased, matt shiny back

3 Aluminum household foil, slightly wrinkled, matt shiny back

4 Plastic film (robidog.com), , is certainly familiar for German dog owners.

5 Construction paper, black, smooth

6 Construction paper, black, slightly creased

Now I just have to decide, although I'm leaning towards aluminum foil and paper because it's easier to glue.

Then I looked closer at the rod constructions at the two corners, which are also covered, but I still have to take a closer look at them. At the top of the wider construction there is a Gamma-ray spectrometer for analyzing Gamma-ray spectra.



In order to be able to scratch these constructions, I first have to determine their dimensions, which is known to be a stressful business of measuring and scaling based on a reference dimension, At least I've already started with the wider construction. The one on the opposite side is narrower, for whatever reason.


Source: Arizona PBS
This will be another stressful torture for my eyes again, but don't panic, they always survived it so far.

[roma847]

Hello everybody,

and since I've just gotten my head around my approved scaling procedure again, I want to continue straight away and have done the same on the opposite side with the narrower rod system, which is also covered with foil.

It is always important to define a reference dimension for scaling all other dimensions, in this case the height of my model probe body.



In addition to the dimensions of the rod systems, I also have the dimensions of the Deep Space Optical Communications (DSOC) System and the two probe engines (Hall-effect Thrusters) determined.

The DSOC dimensions can be determined a little more precisely in this image, which is why a plausibility analysis is still advisable between similar images to select the final dimensions.



At this point I would like to point out to anyone interested this video image (1:36:22), where based on this model the individual parts of the Psyche probe, are explained clearly, which was very helpful for me in terms of overall understanding.



If you want to watch the whole video from the beginning, you can click at the next linked image in order to see the video after (1:30) without the meaningless opening credits.



On the back of the probe there is this covered transverse rod system, which connects the two side rod systems.



With these dimensions I can now create assembly sketches for all three the rod systems and for the blankets.

And then we'll see.

[roma847]

Hello everybody,

I still found a better material for the dark covering of the probe sides and rod systems.

I had an appetite for After Eight once again, and when I unpacked it I had the little wrappers between my fingers and immediately thought Eureka - I have it!



The outside of the cases is matt black and the inside is glossy. And after I've crumpled up and then unfolded it again I think that this variant is the best solution.
Then I thought about how best to scratch the foot of the X-Band High Gain Antenna, but so far I haven't been able to find a useful photo that would show it in more detail.

Since you can hardly see the base anyway, I first cut a small cylinder out of a discarded ballpoint pen and stuck it under my existing antenna, what I also wanted to cover with aluminum foil.

Then in this image it almost looked to me as if there was a cone-shaped cover beneath the antenna,



which is why I've enlarged it again, which seems to confirm my suspicion.



That's why I covered this paper lampshade with foil,




 
and glued from below over the base against the bottom of the antenna.



Here the antenna, covered in this way, is only temporarily placed on the probe, but that still doesn't convince me.



As one can clearly see on this model, the entire lower part of the antenna is loosely covered with dark foil.



That's why I'm going to rethink the entire cladding of the space probe including the rod systems and use both shiny aluminum foil and the After Eight paper.

[roma847]

Hello everybody,

Brevity is the soul of wit!

By using the laboriously determined dimensions of the covered rod systems I've created this drawing on a scale of 1:1,



with the help of which I can now first cut the blankets of the rod systems. For the rods themselves I will use steel wire (Ø 1 mm).
That's it for today, I have to go to bed sooner again.

[roma847]

Hello everybody,

today it was time to implement the sketched parts of the rod systems and their blankets, whereby I changed my plans again a bit and because of the easier gluing of the Foil blanket will not use steel wire but plastic round rods.



First, as a test, I inserted a rod Evergreen Styrene Rods (Ø 1 mm) of the rear rod system into the pre-drilled holes in the probe top, down to the ground,



and then cut both rods to the required length (40 mm).





Then I thought about the fact that for the stability of the entire frame it would be useful to glue a connecting plate made of cardboard (0,9 mm) between the two rods on which I could then stick the black After Eight paper on both sides as a cladding, which would probably be the easiest solution.



Said and done!



Meanwhile I also decided to make the entire cladding from three parts, which are then glued one after the other, starting at the back. 

To do this, I first transferred the back onto the black paper and cut it out,





and after crumpling it was glued to the back of the rod system.



Finally, I also tried adding the white markings or labels that can be seen on all sides of the blankets.


Source: wikimedia.org

For this I used a white permanent marker (Montana Acrylic), which I tried out first.



And since the dashes on the smooth paper are also smudge-proof, I then marked both sides of the rear rod system, which is not that easy as the marker sometimes fails and has to be shaken again.



And this is what the result looks like from both sides, which I can live with.





Now I can make the side blankets in the same way and then glue.

[roma847]

Hello everybody,

for a change, today I dealt with the covered the X-Band High Gain Antenna again and initially replaced its surface with a more shiny silver aluminum foil.



Then I've thought about how I could scratch the continuous all-round covering of the antenna below the cone, by using dark paper (After Eight), which on this image could be seen more clearly than I had previously recognized.



Due to the slight inclination of the antenna, I needed the unrolling of this fairing, which I've fiddled with for a while.

To do this, I first cut a strip of paper the length of the circumference of the antenna (Ø 30 mm), which had to be 100 mm. I then rolled it up and placed it around the antenna so that I could mark the height contour of the antenna against the lamplight,





which wasn't that easy.



I could use this small plastic can (Ø 30 mm) as a support for the wrinkled lower foil blanket, which does not have sufficient inherent stability, when I mark the determined contour line on it and remove the remaining excess.



This is the unrolling of the blanket, which I can now transfer to the After Eight paper and cut out after wrinkling and apply it below the antenna,



which I hope will succeed.

[roma847]

Hello friends,

due to a discussion in the KitMaker Forum regarding my 'markings', where it was said that NASA used white duck tape, I was even more interested in these markings on the solar probe's blankets.

Even if the arrangement of these strips of different lengths may seem completely arbitrary and irregular at first glance, these markings must have had a purpose, especially since in the zoom it looks as if they were labels with legends, for  whatever ...


Source: NASA


Source: NASA

In this image, just for fun, I determined the dimensions of these markings for my model probe, according to which the tiny lines (approx. 0,5 mm x 1 mm) should be.


Source: NASA

Here I have drawn a corresponding approx. 0,5 mm wide strip on label paper, and marked then 1 mm long sections for the mini labels,



which then were cut off.



In a crazy action comparable to mouse milking, as it is called in Germany, I’ve then patiently tried to use tweezers and a cutter to form a row that would now be roughly true to scale, while these 'dashed lines' are not so evenly arranged in reality.



That's why one can see that my lines are too long, but with the permanent marker (Montana Acrylic) you can't draw such tiny dashes, at best you can only hint at them.

Then, during my research, I came across some NASA original photos that I had not previously seen. Upon closer inspection, I became aware of further details that plays havoc with my previous view of these rod systems and their foil blanket, which is why I have to rethink and modify my previous solution approach.

As one can see in this image (zoom!), the area between the rod systems behind the X-Band High Gain Antenna is not open, but is also covered by dark foil with such strips, which means that the bottom part of the antenna is literally enveloped from behind,


Source: NASA

which can also be seen from this image (zoom!).


Source: NASA

The bottom part of the antenna is also covered in dark foil all around, which I had already noticed and still needs to be taken into account.

That's why there are crossbars on the rear rod system that run diagonally downwards for attaching the film, which one can just about see in this image,



which appear under the blanket in this image too.



I now have to try to put these new insights into practice.

There's nothing like good NASA original photos, you just have to know how and where to find them.

[roma847]

Hello everybody,

speaking of covered crossbars, anyone who knows me knows that as a retired researcher I can't stop thinking about it and I want to know what it looks like underneath.

So I continued searching and actually found what I was looking for.

In this photo from an early phase of the construction of the solar probe (2021-03-29) you can also see the uncovered rod system, which consists of more struts than previously assumed.
   

Source: NASA

Now I don't want to recreate that exactly, but the insight alone helps me with my scratch build, as I can at least modify the back of the rod system a little, so that the rear Foil blanket should then resemble the shape of the images shown in the last post and look better.

In this way one can get the model closer and closer to the original until you are satisfied with the result.

[Jim]

Hello friends,

due to a discussion in the KitMaker Forum regarding my 'markings', where it was said that NASA used white duck tape, I was even more interested in these markings on the solar probe's cladding.

]

It isn't "white duct" tape on the MLI/blankets but rather another type of tape.

[ccdengr]

Even if the arrangement of these strips of different lengths may seem completely arbitrary and irregular at first glance, these markings must have had a purpose...

They're pieces of fiberglass tape that reinforce the thermal blanket tie-downs.  Apparently the Psyche spacecraft vendor liked to use that method, which I hadn't seen previously on spacecraft from other vendors.

[roma847]

Hello friends,

due to a discussion in the KitMaker Forum regarding my 'markings', where it was said that NASA used white duck tape, I was even more interested in these markings on the solar probe's cladding.

]

It isn't "white duct" tape on the MLI/blankets but rather another type of tape.

Thanks Jim for looking in on me,

finally someone from the NSF experts speaks out.

What kind of 'another type of tape' do you think about? Do you know what these tapes are good for?

I still think that they are some kind of tags of local positions of special equipment or sensors of the probe, especially since on some of them at high magnification one can see inscriptions that I have circled.


Source: NASA

Although I am only a retired materials researcher and not a space probe designer, in addition to my model building, I am still interested in these technical details and their special tasks especially in the view of technology assessment I was also working.

[roma847]

Even if the arrangement of these strips of different lengths may seem completely arbitrary and irregular at first glance, these markings must have had a purpose...

They're pieces of fiberglass tape that reinforce the thermal blanket tie-downs.  Apparently the Psyche spacecraft vendor liked to use that method, which I hadn't seen previously on spacecraft from other vendors.

Thanks,

that sounds very interesting, do you know what material the thermal blankets are made of?

So far I was only thinking of a type of foil and wanted to ask the manufacturer, Maxar Technologies in Westminster (Colorado), already.

[ccdengr]

AFAIK, black blankets are most likely black kapton ( https://sheldahl.com/wp-content/uploads/2023/07/RedBook.pdf page 35) or equivalent.  The silver is maybe aluminum on FEP (page 25) except for the antenna radome, which typically can't be conductive (germanium, perhaps.)

It does look like some of the white patches are labels.

[roma847]

Thanks for your information of the wide field of Multilayer Insulation (MLI) Blanket Materials for heat and/or cold protection for space probes as well as the interesting Red Book PDF.

First of all, it's enough for me to know that it's not just one film but a multilayer insulation blanket.

[Jim]

I still think that they are some kind of tags of local positions of special equipment or sensors of the probe, especially since on some of them at high magnification one can see inscriptions that I have circled.

Part tags

[roma847]

Whatever that means ...

[roma847]

Hello everybody,

this contact (ccdengr) and the interesting Red Book lead me to the Sheldahl Corporation, the global specialists for Heat management materials, who have provided corresponding solutions for every major US Space Program since the 1950s, as are particularly needed for Lunar modules, Space probes, Space telescopes, etc. so that their electronics can work.


Source: Sheldahl Corporation

"Since it was first published, the Red Book has been recognized as one of the industry’s leading sources for information on aerospace technologies."

Accordingly, the probe claddings are Multilayer Insulation (MLI) Blankets, which are fitted with MLI ceiling fastening tapes (MLI Blanket closure tapes), which are intended to prevent gaps in the insulating layer. 

"Depending on the specific needs of your mission, the number of layers and thickness of our MLI blanket materials can be adjusted to provide the optimal level of insulation. And because our MLI blanket materials are lightweight, they can help reduce the overall spacecraft weight, allowing for a larger payload on board." Source: Sheldahl (Red Book)

So much for this problem of Thermal protection, which has now become a lot clearer to me thanks to the support from your NSF Forum, which is why I will adapt my space probe blankets a little more.

[roma847]

Hello everybody,

the more closely I look at the original photos, the more some details of my previous solution still seem to need improvement.

As a first detail, I took another look at the upper blanket of the X-Band High Gain Antenna and discarded my previous solution because its silver foil isn't wrinkled as much and only the struts in the form of the Mercedes star become apparent underneath.

That's why I thought of a film can (Ø 31 mm) from from yesteryear to support the enveloping black blanket, on which I taped the slant with a narrow strip of tape,



and then have carefully cut it off with the fine saw.



Then I discarded the previous somewhat battered blue cap from the Paper Kit,



and replaced it with a new one made of cardboard, onto which I've glued the three struts made of brass wire so that they would hopefully become apparent out a little under the smooth silver foil,



which worked out quite well. 





Then I still glued the slightly folded black AE paper around the bottom part,
 


wherewith I'll leave it at that for now. 



I then glued the Top Deck of the probe with my AE black paper.





As next detail I still will have to modify the rod systems a little bit, as I don't like the previous version with the black AE paper glued to cardboard, because the blankets just seem too flat,





and should look a little more 'airy'.

[Jim]

use blanketing/blankets vs "cladding"

[roma847]

Thanks Jim for the right technical term blanket instead of cladding.

I hope I replaced all of them.

[roma847]

Hello everybody,

that's why I rebuilt the rod systems new again, for which I used Evergreen Styrene Rods (Ø 0,88 mm), which I taped on my template fixed and then glued together.

First I've cut the struts for the two side rod systems and glued them together.



So that the individual rods cannot slip, my tried and tested pin-pin technique on a balsa plate was used again.







Then the struts for the rear rod system were glued together.





And this is what the finished three rod systems look like:





for which I will now prepare the blankets from the black AE paper. 

[ccdengr]

The biggest mistake that modelers make with blanketed surfaces is making them too wrinkly.  A thermal blanket is made of layers roughly the thickness of a thick mylar party balloon, and the layers are spaced apart with layers of polymer mesh called scrim.  The blankets don't work correctly if the layers contact each other, but they are puffy and won't lie perfectly flat, so the appearance is more that of a loosely-wrapped package, certainly nothing "crinkly".

I've got a 1/48th scale Monogram LM sitting in a box because I just don't think I can do the blankets justice.  Even if I used actual blanket material, it wouldn't work at that scale.

[roma847]

It is exactly this too much crinkly appearance of the blankets that I want to change by modification of the rod systems blankets, as you can see at the new X-Band High Gain Antenna.

Let's see if such a puffy and seemingly loosely-wrapped surface look of the blankets is possible by scratch building.

Attaching the MLI Blanket closure tapes and these labels is much more difficult. But for that I'll probably base myself on the model in the Official NASA Trailer.

Unless you have a smart idea for doing that?

[roma847]

Hello everybody,

before that, I wanted to try on the three rod systems on the space probe, but I didn't want to glue them together, but only have connected them movable with Masking tape (1,5 mm) so that I could spread them out again to attach the black MLI Blankets to make this tricky work a little easier.



And so far I really like the arrangement. After blanketing with the blankets made of AE paper, one can no longer see any of the rod systems anyway.



And the new X-Band High Gain Antenna also fits the picture well,



so that I can now confidently tackle the tricky blankets.

[roma847]

Hello everybody,

all well and good, but in the meantime I've thought that it would be better if I would not scratch individually the the black MLI Blankets to cover the three rod systems, but to scratch as a cohesive unit.

As for the line-like markings, labels, blanket closure tapes, or whatever on the blankets, I wanted to base myself on the following Psyche mission video for the sake of simplicity and make do with that.

That's why I've first created the following Screenshots of the corresponding three views of the blanketed rod systems,


 
and then combined them in MS Word in a photo montage at the scale of my model solar probe.

And after a tricky adjustment of the size of the individual graphics, I finally managed to create this coherent unit,



on which the connected rod systems also fits quite well. 



So far so good.

Then there was the well-intentioned critical but helpful note by expert ccdengr regarding the biggest mistake that modelers make with blanketed surfaces is making them too (wrinkly), which made me sit up and take notice, especially since his lucid explanation made me understand the technical sense of these blankets, so the appearance of the blanketed parts is more that of a loosely-wrapped package, but certainly nothing "crinkly".

And that's exactly what the blankets look like in this well-known picture, like a kind of airy wrappings, I would say.


Source: NASA

That's why I went back to the dark Robidog foil, which I initially wanted to cut it out using this rods system template, but I quickly rejected it because attaching it to the rod systems would have been too tricky.



That's why I left plenty of overhang that was intended for blanketing of the inside.





But then there is also still the problem of applying the markings/labels/blanket closure tapes, which would have to be done beforehand, whereby my previous painting with the Permanent marker (Montana Acrylic) still was not convincing me.

And after some thought, I came up with the following idea.
A long time ago I completed my collection of masking tapes of different widths with black tape (0,5 mm), which I now remembered, because that is exactly the needed width.





And then I experimented a bit with it and made short lines with the marker,



and glued strips marked in this way onto the dark foil, which looks quite acceptable. Above that is my first too flat panel glued to cardboard for comparison, where marking by hand was more or less a matter of luck and also quite time-consuming.



The new technique can definitely still be improved by preparing strips with dash spacing according to the template, which can then be glued before applying the blankets.
 




I believe that I have found with it a more suitable solution for marking of the blankets and blanketing of the rod systems.

But before I continue with the rod systems, I will probably blanket the remaining sides of the solar probe first.

[roma847]

Hello everybody,

after my German travel report Florida and Visit to the KSC 2023 is finished, the construction of the Psyche Space probe can and should continue.

To get back in, I've started to stick parts of my prepared tape strip with the markings of the insulation blankets around the lower part of the X-Band High Gain Antenna, which actually turned out pretty well.



As one can see in this picture, the stripes appear to be placed completely haphazardly, sometimes horizontally, sometimes vertically, so the exact directions and distances are not so important anyway, which is why I wouldn't have to mark the stripes so regularly.


Source: NASA

So much for a casual Warm up, so I can definitely continue with this stripe solution for the blankets.

[roma847]

Hello friends,

next we go with the insulating blankets made of crumpled aluminum foil for the front and back of the space probe,



with the recesses for the two engines (Hall-effect thrusters), which I want to at least indicate in a simplified form.





Then came the cutting of the parts for the bottom side from crumpled AE paper, as well as from aluminum foil for the inner coupling adapter,





which I then glued under the black blanket.



Then I created a true to scale template from the 2nd video image for applying the blankets markings.



with which I made corresponding tape strips (0.5 mm), which I then glued to the underside blanket, which was a bit laborious, stressful and time-consuming.

Since the adapter is set a little deeper into the bottom, I tried to indicate this with a silver wire ring (Ø 0,4 mm),





which I carefully glued piece by piece with UHU CA after trying it on.



On the bottom and on the back there are further X-Band Low Gain Antennas as additional details,



which I have scaled in this image.



And on the back there are these two Multispectral Imagers that I would like to point out already.



So all in all there is still some tricky detail work waiting for me on this small space probe, but everything in its own time, strength lies in calmness.

[ccdengr]

Be warned that the animation may not be very accurate in terms of the external blankets.  For example, the imagers don't poke out nearly that much and are enclosed in a "doghouse" on the nadir panel.  See https://www.flickr.com/photos/nasakennedy/53213102534/in/album-72177720298576586/ but there is a remove-before-flight cover over the apertures.

[roma847]

Thanks for looking in on me again and for your kind warning, but as you have hopefully seen, building the simple 1:72 scale NASA paper model kit has been a lot of fun for me so far and for God's sake it doesn't want to compete with the real thing.
And the animations only help me to call the details by their proper names, nothing more.

To scratch-build them somewhat to scale, I scale them using original photos like the ones one can see in your NASA link, which I know all, or using screenshots e.g. of the faithful model in the Official NASA Broadcast Video.

Therefore stay tuned, the building of the Multispectral Imagers will follow later, although they are relatively simple.

[roma847]

Be warned that the animation may not be very accurate in terms of the external blankets.  For example, the imagers don't poke out nearly that much and are enclosed in a "doghouse" on the nadir panel.  See https://www.flickr.com/photos/nasakennedy/53213102534/in/album-72177720298576586/ but there is a remove-before-flight cover over the apertures.

Hello brother,

you know your stuff, do you know what this device on the back side is called and what it's good for?



Unfortunately I couldn't find its name so far.

[ccdengr]

Those are SPT-140 ion thrusters, there are two sets on two sides: see https://psyche.asu.edu/2020/03/02/why-does-the-psyche-spacecraft-look-like-that/

[roma847]

Thanks for your information.

Is this part of the Hall-effect thruster or a separate device?

I mean this linkage next to the Hall-effect thruster.



Or was that a side mount for the thruster when folded in, which was only folded out during operation?

In this NASA photo it looks like the thrusters are folded to the right onto the mount.


Source: NASA/Kim Shiflett

Perhaps this is a special question for the Lead Systems Engineer David Oh, whom I should ask.

[ccdengr]

I mean this linkage next to the Hall-effect thruster.

The thrusters are on gimbals.  See https://theory.pppl.gov/news/Psyche%20talk%20Goebel_June2023.pdf slide 36.

[roma847]

Thanks for this interesting JPL PDF.

Okay, this means that the Hall thruster is mounted on gimbals. But that's not the lateral mount next to the thruster which I mean, or are these the gimbals?

In its working position the thruster is aligned vertically, as one can see in the video, which however differs from the laterally folded position in the photo.

[roma847]

Hello everybody,

in this Official NASA Broadcast video one can see the moment the Psyche space probe is separated from the Falcon 9 rocket. One can clearly see that the thrusters on both sides are not yet in operation and are therefore locked onto the lateral linkage.



This position is only left when the thrusters are to be put into operation and are swung out by the gimbals. I can't imagine any other explanation.

Maybe I'll still try to contact and ask Lead Systems Engineer David Oh.

[roma847]

Hello everybody,

it is probably just a question of the limited space in the Falcon 9's Payload fairing – the cone at the top of the rocket,


Source: flickr.com

which is why the thrusters have to be folded in, as one can also see in the following image, and are only unfolded after separation. Maybe I'll still figure out if this linkage is only a mounting, which is what I suspect.


Source: Jet Propulsion Laboratory (David Oh)

Regardless of this, the blanketing of the probe with the insulating blankets continues, where today it was the turn of the back, on which there are not as many details as was already seen in the last post.



In addition to the X-Band Low Gain Antenna and the two Multispectral Imagers, which should be comparatively easier to scratch-build, the two complex Hall-effect Thrusters (SPT-140) are far more difficult details, as can easily be seen in this true-scaled NASA model.



In contrast, this is a highly simplified model representation that could serve as inspiration for the later Scratch-build construction.


Source: psyche.asu.edu

But first, the insulating blanket for the back, which I have already prepared from crumpled aluminum foil, into whose small recess on the underside the finished Thruster will later be glued. To mark the other parts, I again created several 1:1 templates of the back in MS Word in the tried and tested way.



To ensure that nothing can slip when marking the attachment points of the parts, the aluminum foil was first fixed,



then the template was placed exactly on top of it and also fixed in place. Then I used pins to mark the points on which the X-Band Low Gain Antenna and the two Multispectral Imagers should sit.



After removing the template, the piercing points are clearly visible in the foil.



The bottom three points belong to this leverage next to the Thruster, which has been discussed so far, but which I did not want to simply leave out.





For better visibility, I inserted short round rods into the piercing points.



I've still  postponed gluing the blanket to the back of the probe for a while, because I had considered not leaving the previously 'bare' backs of the solar panels as they were so far, but also refining them with a solar panel structure.



The paper kit only provided gray panels for this, but which does not correspond to the original and I therefore do not like it.



More on the solution to the problem in the next post.

[ccdengr]

I'm 98% certain that the structures you are asking about support the Hall thruster gimbals during launch vibration.  See https://www.flickr.com/photos/nasakennedy/53213102534/in/album-72177720298576586/ and https://www.flickr.com/photos/nasakennedy/53213229385/in/album-72177720298576586/ though the view is partially blocked by the red remove-before-flight covers on the thrusters.

The gimbals aren't to save space but to correctly point the thrusters through the center of mass of the spacecraft, see https://electricrocket.org/2019/192.pdf

[roma847]

Thanks for your reply.

I have now looked into the subject a little more closely and was able to clarify some terms and abbreviations for my better understanding.

Abbreviations are all well and good if you know what they mean, so that we don't compare apples with oranges.

So now I know that SPT means Stationary Plasma Thrusters.

And these SPT are on a Dual Axis Positioning Mechanism (DAPM), and together they make a DSM, or DAPM-Actuated SPT Module.

This is what I've learned from this great NASA photo NASA's Psyche DAPM Deployment and Stow for Launch,


Source: NASA (Kim Shiflett, 2023-08-04)

Because I was, as usual, very interested in such technical details, I continued searching and came across this interesting NASA Video, that goes with this photo, which shows very clearly and slowly how this DAPM-Actuated SPT Module can be moved,

what I've marked in this image by red arrows.



The movement starts at 4:25 and ends after 4:51, whereby in this image one can see, in my opinion, the two location points of the holding device for locking the SPT Module in the folded state.



BTW, I've read the linked article but found no references to your information regarding "... to correctly point the thrusters through the center of mass of the spacecraft, ..." But maybe I've missed the part.

Finally, a nice comparison.

During my further research I came across another great Psyche Video, in which Professor Linda Elkins-Tanton (ASU) has compared the white Thruster DAPM with a white arm:



"The arm has an elbow and a shoulder, so you can move the thrusters in any way that you want relative to the spacecraft." 

[ccdengr]

BTW, I've read the linked article but found no references to your information regarding "... to correctly point the thrusters through the center of mass of the spacecraft, ..." But maybe I've missed the part.

Unlike Deep Space 1 and Dawn, which used the EP gimbals for direct attitude control of two axes while the EP
thruster is operating, the Psyche GN&C uses RWAs for full 3-axis control even while thrusting.  GN&C performs
nominal RWA unloading and momentum control using torques generated by the EP system. The approach is similar
to that used for Maxar's GEO communications satellites. The RWAs provide 3-axis control of the spacecraft attitude
while a low-bandwidth momentum control algorithm positions the EP gimbal to direct the thrust vector near the
vehicle center of mass. Small offsets to the EP thrust vector produce torques that allow near continuous unloading of
two transverse axes of RWA momentum.

I think I ran across a variety of other more detailed references about the Psyche Hall thrusters, but I'll leave you to track those down if you care.

[roma847]

It seems we are talking past each other.

That's why it's enough for me to now know how the main components of the Thrusters are constructed and how they can be moved by the DAPM during being unfolded. And only this unfolded state of the SPTs is what I'll try to scratch-build, after all, they are not supposed to work.

And these special mountings next to it only serves to securely lock the SPTs in the folded position, as one can see in the photos and videos.