Friday, September 16, 2005

DIY satellites reinvent the space race

The satellites are tiny--they weigh a kilogram and generally measure about 10 centimeters on each side--but they cost far less than conventional commercial satellites. A CubeSat unit costs roughly $40,000 to build and only $40,000 to launch. As part of the program, Cal Poly takes care of the bureaucratic and logistical hurdles.

(Via Future Feeder.)

Now I'm itching for an excuse to have my very own satellite. How about the world's first Smiths/Morrissey-only satellite radio station?


razorsmile said...

sf idea occurs - you're in orbit over the planet. Perhaps it's covered in forerunner ruins, perhaps it's even populated by intelligent life.

So you seed the upper atmosphere with a few dozen of these. Few hours later, they've established orbital surveillance supremacy and you know everything you can know before you land ...

weevee: cxevh (sexy vehicle, Maserati perhaps?)

Ken said...

One nice thing about such small units is that they can be launched very cheaply indeed. I'm thinking about guns. Shoot the little buggers into orbit. There have been several designs over the years just for this scenario. Explosives can be conventional, various gases, steam, even coal dust!

An excellent and well illustrated article on the concept can be found at .

..."Hunter is also devoting considerable attention to the design of specially hardened satellite packages and has recruited experienced satellite designers for his team of engineers. They will use the prototype systems to ensure satellite stability as it leaves the launch tube, as well as to address g-force hardening. The largest commercial guns will subject the satellites to 1000 g's for approximately 1 second. Although this is easily met by circuit designs, it may require hardening of components like solar cells or deployable antenna structures. Based on SHARP experience, Hunter's engineers predict that the guns can easily be fired once per working day. Given a rate of 300 launches per year and a payload of 10,000 pounds per launch, the system has the potential of placing approximately 1500 tons a year into LEO. Moreover, at a target launch cost per pound of about one-twentieth of a modern rocket launch, the company estimates a breakeven point between the first 50 and 100 launches."...

Also, from

..."Gram and Smith envisioned digging a 3,050 meter long gun barrel 6.4 meters in diameter straight down into the top of a tall mountain. A hot-hydrogen chamber 25.9 meters in diameter and 427 meters long was dug below the bottom of the barrel, with the two connected by 70 fast-opening valves, each 1.2 meters in diameter. A spherical steam chamber 95 meters in diameter was dug below the hot-hydrogen chamber in turn, with the two also connected by 70 similar valves.

A network of tunnels and chambers was dug into the mountain to take in natural gas and water and produce hot hydrogen and steam. When the steam reached maximum pressure of about 510 atmospheres at a temperature of 540 degrees Celsius, it was vented into the hydrogen chamber through the valves.

There would be little mixing between the light hydrogen and heavy steam as the hydrogen was compressed, and so no piston was required. When the hydrogen reached maximum pressure of about 320 atmospheres at a temperature of 1,730 degrees Celsius, it was released into the barrel through the valves, blasting a rocket sitting on a sabot baseplate up the barrel and out the top of the mountain.

Foam plastic sabot segments kept the rocket upright in the barrel. The barrel was sealed at the top with a diaphragm, and partially evacuated by filling it with steam that then condensed. The rocket simply punched through the diaphragm on the way out, followed by a blazing pillar of hydrogen and then a huge mushroom cloud of steam.

Gram and Smith estimated cost for their space gun as $270 million USD in contemporary dollars. NASA didn't bite on the proposal and it never happened, either, but it certainly looked spectacular on paper. "...

For a beginning, try these. Plenty of more info around, if you wish to look. Search "space gun" for a start.