* Posts by Mark_S

5 posts • joined 9 Apr 2015

Mars rover Opportunity shuns dodgy flash chips, relies on RAM


Re: Three months....

"0.5% likelihood of subsystem failure in the first three months. 10% failure chance of the whole in the first three months???

You wouldn't accept that in a commercial product let alone something being sent into space.


Space hardware does not have the option of the development cycle of a commercial product. You usually only get to make 1 or 2 units, and even then have your testing on earth in simulated environments. Your development costs are amortized over 1 unit, and every fractional increase in computed reliability costs ever more. So you make a design tradeoff for reasonable reliability and non-infinite budget.

Behold the mighty Swiss SPACE JUNK NOSHER PODULE


It's a start

It is not intended to be a final design that solves everything. It is intended to show that you can make a small garbage collector for space junk.

If they can catch the cubesat, it is a win. We can then build more advanced systems based on the knowledge gained.

Swisscube was not launched just to be junk. It had it's own mission.

Hubble hits 25th anniversary IN SPAAACE – time for telescope to come home


It has not gone unnoticed that if you can boost it down, you can boost it up. The question is how much of the telescope is still working when you decide to do it. For example, the NICMOS infrared instrument is not currently working because of a problem with the cooling loop. The other instruments are all working well, so the telescope may have quite a long life span ahead it it, even without repairs.

The cost of continued operation is small -- on the order of a few 10's of millions of dollars a year, so after all the initial investment, you might as well get as much as you can out of it.

If SpaceX finds a way to refurbish Hubble inexpensively some day, that is all the better.

Soil and sand harden as SPEEDING MISSILES and METEORS SLAM into GROUND – boffins


Re: Research

"When it comes to Learning about how best to detonate nuclear weapons in enclosed spaces filled with people, then yeah, i'd prefer people not to understand. There are better things they could use their IQs studying"

What is the purpose of an army?

Recognizing that many bad guys have armies, should your country have one too, at least for self defense?

If no, please abolish your army so that I can bring mine to your country and appoint myslef emporer.

If yes, what exactly is the problem with armies trying to develop ways to perform their function more effectively?

Stop climate change by drinking Coca-Cola says Oz government



Every ton of co2 recovered from emissions and used in a fizzy drink is a ton that is not explicitly manufactured for use in fizzy drinks. It is just one of many possible dispositions of the captured co2. An important question is whether it is pure enough to use in food products.

I once read a write up of a plan to draw co2 out of the atmosphere and electrolysize it into carbon and oxygen. You need a non carbon energy source do do it. The author suggested nuclear. It can all work using exisxting technology - no inventions, just do it.

He wanted to reduce atmospheric co2, but If you capture the co2 from a plant that runs day and night, you could also use solar to break down the co2 during the day - effectively storing your solar energy by converting it into coal. You could even make a closed loop out of it. The only thing we need is a way to capture the co2 as fast as it is created.


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