Sputnik in a biscuit tin challenge

The BBC is challenging readers to build their own "Sputnik in a biscuit tin," using today's marvellous household objects to recapitulate the birth of the space program:

In simple terms, the Sputnik satellite was a metal sphere almost 2ft (61cm) in diameter, containing a radio transmitter. It also had a battery; equipment to measure temperature; barometric and temperature activated switches; and a fan to stop it getting too hot.

It sent its famous "beep beep" radio signals to earth, altering the transmission to indicate changes in temperature or a sudden drop in pressure caused by a puncture in the satellite's case. And that's about it.

You could probably find most of these components lying around your home. There are transmitters in mobile or cordless phones, wireless internet routers and baby monitors, and you may well have a thermometer in the medicine cabinet.

Link (Thanks, Bonnie!)

[#1 posted by Stefan Jones , October 22, 2007 11:44 AM]

Bah! What we really need is a contest to design a rocket capable of reaching orbit that fits in a biscuit tin.

[#2 posted by bricology , October 22, 2007 12:49 PM]

"...and a fan to stop it getting too hot."

Huh? At 560 miles above the earth, there's cooling air to be blown around?!

[#3 posted by C. Elvis Maximus , October 22, 2007 12:56 PM]

A fan to keep it from overheating? How did that help given that its operating environment was a vacuum, or near vacuum? I'm not trying to be a wiseass; I presume there was a logic behind it, I am just curious as to what it was.

[#4 posted by Mark Gritter , October 22, 2007 1:03 PM]

It sounds like Sputnik was pressurized. The fan was to keep air circulating inside. From later in the article:

"The fan will help get heat out of the middle of the satellite to its surfaces, so it can radiate away. But you also need to think about the colour of your space craft, because dark surfaces will heat up if they are facing the sun or a planet."

[#5 posted by edgore , October 22, 2007 1:04 PM]

Bah! A biscuit tin indeed. Either fit it into an Altoids tin, or don't bother. If someone can do it in a Smint case, THAT would be impressive.

I wonder if I can fit a dog into an Altoids tin by November to commemorate the Sputnik 2 launch?

...crap, now I am sad. Laika was a good brave dog.

[#6 posted by sinclair , October 22, 2007 6:20 PM]

Many Soviet/Russian spacecraft, from Sputnik to present day, are pressurized. It means that they can use fan cooling, and not worry too much about component outgassing or tin whiskers. The bulkhead also provides thick radiation shielding, which is handy as their spacecraft have often occupied high dose orbits such as the Molniya.

I'm not sure if the article made it clear, but the pressure sensor on Sputnik was intended to detect hull puncture.

The disadvantage of a solid hull, besides the large mass, is the need to run all of your electrical connections to the outside world through hermetic feed-throughs.

[#7 posted by SteveKiwi , October 22, 2007 10:25 PM]

Don't forget to carry your Sputnik IED through the airport! If they ask, just tell them the BBC sent you.