Filming descent & landing - a first!

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3 years 7 months ago - 3 years 7 months ago #965 by marekv
marekv created the topic: Filming descent & landing - a first!
We have never seen a probe land on another celestial body - well, duh: how would the camera get there first, without impossible expense?
But I believe we may be able to get this done, with the advances in miniaturization that have already happened. Consider the following design:
  • A "camera ball" consists of a transparent dodecahedron shell; a "ball" made out of regular pentagons.
  • Behind each pentagon we place one ultralight, small camera - such as the front camera of a mobile phone. The camera has a fixed universal focus, and a field of view such that it overlaps with neighbouring pentagons
  • In addition to the twenty cameras, the ball contains a small battery, a simple controller, (optionally) storage, and a short-range communications module - preferably Bluetooth or WiFi to leverage existing components. The balls only transmit to the main spacecraft, not to Earth
  • The interior of the ball is filled with a very lightweight potting compound/foam to fix all components in place
  • One or more such balls are placed on the exterior of the probe, each behind a small spring, held by a latch
  • Towards the end of the decent, at (for instance) 30 metres, when the remaining speed is moderate, the balls are activated and unlatched. The springs push them away from the probe, and they will fall to the surface. Since the probe is in powered descent at this point, they will land first

We now have a set of camera balls sitting on the moon's surface, with the probe some seconds away. Whichever way they have landed and rolled, at least one set of cameras on each ball will have a view of the probe as it comes in to land. The image stream can either be transmitted live, if communications/processing capacity allows; or it can be stored onboard in a simple flash memory and transmitted later.
The main point is that I believe it is possible to make such a camera ball with relatively little expense - it is not meant to function for an extended period, so we should be able to use commercial components. This in turn makes it possible to eliminate the need for moving parts, descent control etc., - with a full spherical field of view, we just unlatch it and let it hard-land.
With multiple balls we can accept some chance of failure. If they all work, then we can photogrammetrically reconstruct the landing in full 3D, gaining knowledge about the surface composition from how it reacts to the descent engine exhaust, as well as seeing how the probe behaves the final few metres.
Imagine the PR value of being able to live-broadcast the landing, from the surface of the Moon. And - if the landing goes wrong, we'll be able to see the final moments. No-one has been able to do that, though NASA came close when they filmed Curiosity's entry from above. We can do it from below.
Ok, lots of details... rad-hardening, thermals, how to activate (battery life in Earth-Moon transit?), light/shadow contrasts, ... but I think the principle is sound.
Last Edit: 3 years 7 months ago by marekv.
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3 years 7 months ago #971 by Stefan
Stefan replied the topic: Filming descent & landing - a first!
A fantastic idea. I'll be disappointed if this doesn't happen now!

I don't know much about the final approach velocity and direction of landers, but could they not drift substantially from a height of 30m? Would falling balls cause an issue for the landing process itself? Could they kick up dust and block out any visuals?

I guess if this (or something similar) doesn't go ahead, then it's a payload problem.
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3 years 7 months ago - 3 years 7 months ago #978 by Paul Conway
Paul Conway replied the topic: Filming descent & landing - a first!
Marekv this is truly inspired thinking but as Stefan (I'm loving reading many of your posts sir) commented, the drawback could be these camera balls have an effect on the landing (unless calulations can prove that they will be a safe distance away from this landing which may well be the case after calculations and if released at the right level of descent)

I have mentioned filming the launch, trip and ascent to the Moon by using camera's on the LM1 which could later be used to take selfies on the moon looking back at Earth (it is my hope this will happen) but I like this idea a lot, it's inventive and fun (trouble might be that it just takes up too much of the 50% payload remaining)

Inspired, clever thinking, hope LM look into this great idea.
Last Edit: 3 years 7 months ago by Paul Conway.
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3 years 7 months ago #986 by marekv
marekv replied the topic: Filming descent & landing - a first!
Thank you both Stefan and Paul,

Yes, I have thought a bit about the various problems the balls might cause. The release should be at a point where lateral drift is close to zero, then it's a matter of spring tension to inject enough lateral velocity to the balls to keep them safely away.
However, if they are small enough, then their actual impact position relative to the lander doesn't matter to the safety of the landing: they are just another small rock, should the landing pads hit them. Bad for the camera, but that would still be a great video, right? As for dust, yes that one worries me the most. From the Apollo experience the lunar dust is fairly sticky, so there is a risk of clouding the optics. But since there is no air, any dust kicked up will go straight down like an anvil... and I hope this means very little will contaminate the upper faces.
This is at the core of this whole idea: do not jeopardize the mission, do not demand lots of power/weight/development, etc. For final testing we should drop them into a sandbox in a thermal/vacuum chamber, but there are no sophisticated operations to run through.



Perhaps we will meet tomorrow? I'm travelling from Oslo, Norway to the Mission Control event in Londom tomorrow - no way I'm going to miss out!
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3 years 7 months ago #1001 by BenRLille
BenRLille replied the topic: Filming descent & landing - a first!
Great chatting with you today, this idea is genius. As this may well be the social media moon shot having some way to capture the landing live in colour and possibly from the surface should be pursued!
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3 years 7 months ago #1006 by chris perkins
chris perkins replied the topic: Filming descent & landing - a first!
This looks fantastic Markev :) and just the type of contribution that i guess should be evaluated in the Labs forum where the guys with the experiance of prevous landings can evaluate the idea.
Love the idea!