There's a fairly robust community that builds and launches water rockets. You know, regular rockets in pretty much every way except for the fact that they use pressurized water and air to launch into the sky. One such water rocket from a South African team of students at the University of Cape Town just broke the world altitude record with it's most recent attempt.
The university team managed to grab the record thanks in part to an extremely lightweight frame. The rocket's frame weighs just over three pounds counting the on-board camera, parachute system, flight computer, and carbon fiber skeleton. The team had tried for the record two times before but had been plagued by equipment failure and air leaks. The third time took.
The group launched their rocket, which clocks in at around nine feet in height, two different times on August 26th to get an average between the two. The first made it to 2,740 feet and the second to 2,707 feet for a world record of 2,723 feet, averaged. That handily beat the previous 2,044 foot record, set in 2007 by a U.S. group.
(Score: 1, Informative) by Anonymous Coward on Sunday October 11 2015, @06:40PM
And then DHS descended on them.
(Score: 2) by Runaway1956 on Sunday October 11 2015, @07:03PM
DHS has offices in South Africa? Do you have their local phone number?
Abortion is the number one killed of children in the United States.
(Score: 0) by Anonymous Coward on Sunday October 11 2015, @07:18PM
They have agents everywhere.
(Score: 2) by davester666 on Sunday October 11 2015, @07:53PM
They have jurisdiction EVERYWHERE, punk!
(Score: 2) by Username on Sunday October 11 2015, @08:26PM
I can go anywhere in Colorado/Utah/Wyoming and launch a rocket that will reach a true altitude at least 300 feet higher than 2723.
(Score: 0) by Anonymous Coward on Sunday October 11 2015, @10:51PM
Estes "D" engine? Want more fun? Get a Tripoli license and fly Aerotech Consumer Aerospace motors, much more fun but expensive.
(Score: 2) by Hyperturtle on Monday October 12 2015, @06:09PM
Launching those D engines without the actual rocket to surround them in -- that's fun! And dangerous as all get out (which makes it more fun...)
Also fun is launching water rockets sideways. Maybe not a rocket of that size... but everyone gets wet and those things are really hard to aim and don't hit hard when you're using a $10 toy store model.
(Score: 2) by frojack on Sunday October 11 2015, @08:57PM
I wonder if there is any amount of water too heavy to lift by any amount of pressurized air via water rocket technology given the limitations on the capabilities of available containment materials.
No, you are mistaken. I've always had this sig.
(Score: 2) by mhajicek on Sunday October 11 2015, @09:56PM
I'd say a black hole's worth would definitely qualify.
The spacelike surfaces of time foliations can have a cusp at the surface of discontinuity. - P. Hajicek
(Score: 3, Informative) by khallow on Monday October 12 2015, @01:05AM
(Score: 3, Informative) by hankwang on Monday October 12 2015, @07:27AM
20 m/s delta v for water sounds rather low. The exhaust speed is sqrt(2p/rho) with p the pressure and rho the density. With p in bar, it's Dv=14 [m/s] sqrt(p/[bar]). The pressurized air takes negligible mass and you surely can get more than 2 bar air pressure in a lightweight container.
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(Score: 2) by PartTimeZombie on Monday October 12 2015, @02:23AM
Completely non-technical answer, but I have a water rocket kit I bought for one of my kids. We've had a lot of fun messing about with it, and found that if we fill the bottle almost to the top, it takes off very slowly, and doesn't get much height, which makes for great slow-mo videos.
(Score: 3, Insightful) by BK on Sunday October 11 2015, @09:55PM
I don't think that word means what you think it means...
...but you HAVE heard of me.
(Score: 2) by cnst on Monday October 12 2015, @07:33AM
What's "2,707 feet"? I thought South Africa was a developed nation, do they still measure stuff the ancient way?
(Score: 4, Informative) by cnst on Monday October 12 2015, @07:36AM
Wow, 830m, now that's impressive!