Mars Curiosity Rover: Lessons Learned on Wheel Design

Public domain image courtesy NASA/JPL-Caltech/MSSS.

"The anomalous wheel wear suggests that loads and terrains representative of actual operational conditions were not adequately simulated during life testing"

 

The tyres are made from aluminium. According to this recommendation by JPL, metal fatigue and single event punctures caused by wind-eroded, immobile pyramidal shaped rocks was responsible for the damage.

The Curiosity rover has travelled over 20 miles on the surface of Mars since it landed on the red planet in 2011 as part of the Mars Science Laboratory mission. The robot is about the size of a small car and weighs around 900 kg.

5 Live Science Podcast — Jocelyn Bell Burnell and Pulsars

Image produced using Bing Image Creator.

In this 5 Live Science podcast, Northern Ireland native Jocelyn Bell Burnell talks with Dr Chris Smith about radio astronomy and her discovery of pulsars. These are rotating neutron stars that emit beams of electromagnetic radiation from their magnetic poles, the radiation sweeping the Universe like a lighthouse beam. Neutron stars are extremely dense. Atoms are mostly empty space, a simplistic model resembling our Solar System with electrons existing in outer orbitals and a nucleus at the centre. However just like the Solar System, there is lots of space between the electrons and nucleus. In a neutron star, gravity squeezes everything together so tightly that nuclei in adjacent atoms pack up against each other. The result is super-extreme density and according to Scientific American, a ping-pong ball sized piece of a neutron star would weigh over a billion tonnes.

https://www.bbc.co.uk/sounds/play/p0kds1xg

Linked content, courtesy the BBC. The BBC in no way endorses content on this blog.

Video From Photos Using AI — Turning Your School Photos into Videos

Image created by Bing Image Creator

Many of us over a certain age don't have any "home movies" of ourselves from when we were young and just handfuls of photos, not like the hundreds or thousands that parents take of their kids today. Imagine if you could turn your photos into home movies?

I've been playing with this AI, video generating online application called Hailuo AI that can turn photos into videos. You might remember Pic Me, the animated TV series for pre-school kids where a child's face was cut out and pasted onto an animated body that got up to all sorts of activities. However this AI technology is light years ahead. Once an image is uploaded, just like with Dall-E, Bing Image Creator or other AI image generating application, a text description of what the video should look like is provided is provided by the user. The application then effectively "skins" the person in the image and wraps their outsides around wire frames it can animate.

The results are somewhat mind boggling. Try it on your old school photos.

Pump Post Mortem

Checking the capacitance of the run capacitor. © Eugene Brennan

 

I've been doing a post mortem on my central heating pump. The shaft is spinning freely, there's very little rust internally and just as predicted, the run capacitor for the motor had failed, a part that would have cost about €5 to €8. I thought the leads for the capacitor might have been held by spring clamps, just like the power cable, but the pump was facing inwards when in situ, so I couldn't get at them to check. It turned out they were crimped onto the connector plug terminals. So the replacement capacitor's leads would have had to be joined to the existing leads, soldered and heat shrinked. According to the plumber, the pump would have swivelled out for access and the threads aren't sealed with Plumber's Mait, washers are used for sealing. So I'll be fitting a new one myself the next time, or probably this one with a replacement capacitor. (I've fitted two pumps before in the workshop).

 

WARNING! If you're ever checking mains capacitors, make sure they're discharged first, because they can potentially be charged to almost 400 V DC and lethal.

 

Circulating pump. © Eugene Brennan

Not much sludge accumulated in the pump. © Eugene Brennan

Motor run capacitor. © Eugene Brennan

Pump details. © Eugene Brennan

 

Sailing By

Image generated by Bing Image Creator

You may have heard Joe Duffy's segment the other day on Liveline about the BBC Shipping Forecast, broadcast at 00:48 on BBC Radio 4, before the station closes down at 1 am. On LW, the frequency then carries the BBC World Service. For some, the forecast is like a soothing mantra, the repetitive structure and intonation or melody of the words easing them off to sleep. In this documentary, local man Al Ryan who is a BBC presenter, amongst others, speak about the forecast which celebrates its centenary this January.
https://www.bbc.co.uk/sounds/play/m002699p

46,000 Year Old Frozen Worms

Nematodes. Image courtesy CSIRO, CC BY-SA 3.0 via Wikimedia Commons.

Your freezer doesn't kill germs like high temperatures in an oven does, it only slows down their metabolism so the reproduce more slowly. One of the the reasons germs are a hazard is because they manufacture toxins as waste products. Therefore, even cooking food at normal temperatures that has "gone off", while killing the germs, doesn't necessarily render those toxins harmless. If you've ever put tomatoes or other watery food in a freezer, you'll know that they become mushy when thawed. That's because all living things are built from cells, just like Lego. The cells are like capsules of water which burst when water expands on freezing, causing a loss of structural integrity and limpness in a fruit such as a tomato (Is it a fruit or veg? That's another argument!). Half-hardy flowers such as petunias are damaged by frost for the same reason, but hardy flowers have "anti-freeze" in their cells. This prevents the cellular fluid from freezing at low temperatures, so the plants can withstand severe frosts. Possibly this is the mechanism by which this worm survived 46,000 years in permafrost, having evolved and achieved this survival technique.

Drag Acts

Image: Heavens-Above

 

The atmosphere doesn't end at a certain altitude, it just gets thinner and thinner. According to NASA however, the Karman line at an altitude of 62 miles is generally recognised as a boundary, and 99.99997 percent of Earth's atmosphere lies beneath this level. It's also speculated that a cloud of hydrogen atoms around the Earth, called the geocorona, may extend to over twice the distance between the Earth and the Moon.

The International Space Station (ISS) orbits at an altitude of 370–460 km.

Curtain Pole Polishing and Silicone Emulsions

So my curtains have been sticking for weeks on the poles and I got around to cleaning them today. It's amazing the amount of crap that builds up. I presume everyone knows that furniture polish is great for making the rings slide easily? Also good for the rails on mitre saws.

Mr Sheen contains silicone emulsion and PEG-40 hydrogenated castor oil which I presume are what do the polishing.

An emulsion is a non-soluble solid suspended in a liquid (e.g. emulsion paint or milk). More info on silicone emulsion here.
https://www.elkem.com/products/silicones/emulsion/

This is what accumulates on curtain poles. © Eugene Brennan

 

You Can't Have Too Many G-Clamps

Boots without soles. © Eugene Brennan

I'm glueing back on the soles that came off my boots after the tree planting at the Field of Dreams a couple of weeks ago. The boots are probably nearly 30 years old, but not worn much because they don't have any sole or toe protection, and I've worn out a few other pairs of safety shoes and boots in the meantime. According to CAT Footwear, the adhesive degrades (and also the soles. A new pair of safety shoes I had in storage for 9 years only lasted three weeks after I started wearing them).

Clamps for holding the glued soles onto the boots. © Eugene Brennan