Project Highwater was an experiment carried out as part of two of the test flights of NASA

NASA

The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

's Saturn I

Saturn I

The Saturn I was the United States' first heavy-lift dedicated space launcher, a rocket designed specifically to launch large payloads into low Earth orbit. Most of the rocket's power came from a clustered lower stage consisting of tanks taken from older rocket designs and strapped together to make...

 launch vehicle

Launch vehicle

In spaceflight, a launch vehicle or carrier rocket is a rocket used to carry a payload from the Earth's surface into outer space. A launch system includes the launch vehicle, the launch pad and other infrastructure....

 (using battleship

Battleship (rocketry)

In rocketry, a battleship is a non-functional rocket or rocket stage which is used to test configuration and integration of a launch vehicle.The term should not be confused with the term boilerplate, which refers to a non-functional spacecraft....

 upper stages), successfully launched into a sub-orbital

Sub-orbital spaceflight

A sub-orbital space flight is a spaceflight in which the spacecraft reaches space, but its trajectory intersects the atmosphere or surface of the gravitating body from which it was launched, so that it does not complete one orbital revolution....

 trajectory from Cape Canaveral, Florida

Cape Canaveral, Florida

Cape Canaveral is a city in Brevard County, Florida, United States. The population was 8,829 at the 2000 census. As of 2008, the estimated population according to the U.S. Census Bureau was 10,147...

. The Highwater experiment sought to determine the effect of a large volume of water suddenly released into the ionosphere

Ionosphere

The ionosphere is a part of the upper atmosphere, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere...

. The project answered questions about the effect of the diffusion of propellants in the event that a rocket was destroyed at high altitude.

The first flight, SA-2

SA-2 (Apollo)

SA-2 was the second flight of the Saturn I launch vehicle, the first flight of Project Highwater, and was part of the American Apollo program. The rocket was launched on April 25, 1962 from Cape Canaveral, Florida.-Objectives:...

, took place on April 25, 1962. After the flight test of the rocket was complete and first stage shutdown occurred, explosive charges on the dummy upper stages destroyed the rocket and released 23000 gallons (87,064.5 l) of ballast water weighing 95 short tons (85 LT) into the upper atmosphere at an altitude of 65 miles (105 km), eventually reaching an apex of 90 miles (145 km).

The second flight, SA-3

SA-3 (Apollo)

SA-3 was the third flight Saturn I launch vehicle, the second flight of Project Highwater and was part of the Apollo Program.-Objectives:...

, launched on November 16, 1962, and involved the same payload. The ballast water was explosively released at the flight's peak altitude of 104 miles (167 km). For both of these experiments, the resulting ice clouds expanded to several miles in diameter and lightning-like radio disturbances were recorded.