wrote:
On Fri, 14 Dec 2018 17:19:14 -0000 (UTC), Bill
wrote:

Its Me wrote:
On Thursday, December 13, 2018 at 3:17:29 PM UTC-5, Tim wrote:
You know civilian space travel is coming...

https://www.cnbc.com/amp/2018/12/13/...-of-space.html

It's not the same thing, but back in the 90's I was into high power
rocketry. During that time frame there were 3 guys that got together and
built an amateur rocket that flew to the edge of space. It was a boosted
dart, which means the bottom part was a big, fat rocket motor and the top
was a skinny but heavy small rocket with no motor. When the lower stage
burns out the upper stage drag separates and keeps going (from inertia)
until gravity does its thing.

They launched it in the Black Rock Desert in Nevada. It had a downward
looking camera with a RF downlink for video and telemetry. It hit mach
3.something, and the dart traveled to a bit over 50 miles. I can't find
it now, but there used to be a video showing the flight. You saw the
earth fall away, and when it hit apogee (arced over), you saw the
curvature of the earth and then tons of stars. Unfortunately, it came in
ballistic and impacted a few miles downrange. Even with a backhoe, they
only recovered a few bits.

The story was it took them over a year to build it, and it cost one of
the guys his marriage.


I always loved rockets. We built a bunch of aluminum tube rockets powered
by zinc- sulfur. We used to fire them at the Albany, CA police range when
no one was around. Probably go to jail these days for doing that.

I played with zinc sulfur rockets too. We started with Crossman
cylinders in Bering Cigar tubes. You could really send one for a ride.
Then we started using longer tubes. A Crossman cylinder is a pretty
good fit an 3/4" copper pipe. Solder alone won't hold but if you shoot
a few screws in there and use the solder for a seal it works ok. The
trick is how far up you cut the "nozzle". Just make sure it is
perfectly square or you will just make a pinwheel.
We also played with fins but shooting them out of a long pipe gets
them fairly well stabilized.
The best solution is still a long stick out the back. ;-).

The real trick is finding someone to sell you zinc powder.
We got it from a plating shop until they would not sell it anymore.


Easier to get 60 years ago. We used aluminum tube from a TV antenna for a
lot of them. Had a pair of pliers that had a great shape for necking down
the tube up from the end.