Columbia Scientific Balloon Facility

The Columbia Scientific Balloon Facility (CSBF) (established in 1961, formerly known as the National Scientific Balloon Facility (NSBF)) is a NASA facility responsible for providing launch, tracking and control, airspace coordination, telemetry and command systems, and recovery services for unmanned high-altitude balloons. Customers of the CSBF include NASA centers, universities, and scientific groups from all over the world.

Mission
CSBF has a threefold mission:
 * Provide maintenance, operations and logistics support for NASA's scientific balloon program and facilities.
 * Provide sophisticated ground and flight systems for launch, control, data retrieval, commanding, and recovery of NASA's balloon missions.
 * Perform research and development to advance the capabilities of NASA's suborbital programs.

History
The Balloon Facility was established by Vincent E. Lally at NCAR in Boulder, Colorado in 1961 under the auspices of the National Science Foundation. It was moved to Palestine, Texas in 1963 and designated as the National Scientific Balloon Facility (NSBF) in January 1973.

In 1982, sponsorship of the NSBF was transferred from the National Science Foundation to the National Aeronautics and Space Administration (NASA) and the NSBF became a separate entity under the University Corporation for Atmospheric Research (UCAR).

Since October 1987, the NSBF has been operated by the Physical Science Laboratory under the auspices of New Mexico State University located in Las Cruces, New Mexico. It is administered by Goddard Space Flight Center's Wallops Flight Facility Balloon Program Office.

Its Texas location put the NSBF in the middle of the area where the debris from the Space Shuttle Columbia dropped to Earth on February 1, 2003. In February 2006, the NSBF was renamed the Columbia Scientific Balloon Facility in honor of the Crew of STS-107.

Balloon
CSBF conventional and long duration (LDB) balloons are made of 20 micrometer thick polyethylene film, and at float have a diameter of up to 140 meters (460 ft) and a volume of up to 1.12 million cubic meters (39.57 million cubic ft). The balloons are filled with helium gas, can carry payloads up to 3600 kilograms (7,936 lb), fly at altitudes of up to 42 kilometers (26 mi), and can remain at float in excess of 40 days.

The balloons are zero pressure difference balloons, and are vented at the bottom. They are only partially inflated when launched, and as they rise up, the lower atmospheric pressure causes them to fully inflate.

The bottom of the balloon is attached to a parachute, which is then attached by steel suspension cables to the payload. A flight is terminated by firing an explosive squib which separates the parachute from the balloon. A rip line simultaneously tears open the top of the balloon. The balloon quickly deflates and falls to the ground, to be recovered and disposed of (balloons are single use). The payload descends, suspended by the parachute, and is recovered by the ground crew.

Conventional payloads typically have a float duration at altitude of 72+ hours. Long Duration Ballooning payloads float at durations of 42+ days. Ultra long duration balloons (ULDB) are being developed which can operate at float for +100 days. The limiting factor is the diurnal cycle of the sun, rising and setting. Heat during the day causes the balloon to expand and gain altitude, thereby losing helium. Heat loss at night causes the balloon to sink and contract. Ballast is carried to overcome the effect. Flying in a polar region during full sunlight allows more negligible altitude variations. ULDB balloons are sealed to prevent helium loss, but further engineering is required to create a balloon system that can survive the greater pressures involved.

Preparation, Launch, and Flight
A balloon flight involves both the CSBF and a scientific team(s). The CSBF determines the launch site based on scientific goals, and provides local preparation facilities, a balloon(s), launch and recovery vehicles, and personnel to support the logistical aspects of pre flight, flight, and post flight activities. Scientific teams ship a payload to the launch site, and set up a small field station to assemble their equipment, make last-minute preparations, and manage the experiment during flight. The payload is typically a large instrument or cluster of instruments, plus onboard computers, radio telemetry equipment, and ballast.

Launching a balloon requires the conjunction of light low-level winds (to comply with the limitations of the CSBF dynamic launch technique) and suitable upper-level winds (so the balloon remains within telemetry range of a ground station, and within the permitted flight region). The payload may be rolled out to the launch area several times before surface and upper atmosphere conditions are acceptable for launch.

During the flight, data is transmitted to the ground for quick-look analysis, and is usually recorded on board as well. Scientists on the ground usually actively control the payload. An astronomical telescope, for example, can be real time directed toward a variety of sources for observations, or left in an autonomous mode of operation.

Launch Sites
CSBF launches balloons from several sites in the world, depending on the needs of the experiment they carry. Sites include:
 * Palestine, Texas
 * Fort Sumner, New Mexico
 * McMurdo, Antarctica
 * Australia
 * Esrange, Sweden
 * Fairbanks, Alaska
 * Lynn Lake, Manitoba