Construction of the Space probe for NASA's Psyche Mission

[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.