STRATOSPHERIC BALLOON BASES IN THE WORLD

The second permanent launch site of the NASA balloon program is the Scientific Balloon Flight Facility located inside the boundaries of the Fort Sumner Municipal Airport on the northeast side of the town. Ft. Sumner is about 3 hours drive east and a bit south of Albuquerque, in De Baca county, New Mexico .

The airport was established in the 1920's when the Transcontinental Air Transport company built it as part of its coast-to-coast air passenger network. It was abandoned after the company's plan collapsed during the Great Depression being reopened ten years after by the Army Air Corps which used it as training base during the World War II. After the war the airport and facilities were transferred to the town of Fort Sumner under which control still remains today, serving for operations of small private planes. A very large hanger, two runways, and a large apron area were the primary assets of the airport.

In 1985, the NASA balloon program made a flight safety analysis, identifying a significant risk associated with balloon flights launched at Palestine, and traversing to the east. The primary safety issue was a balloon failure occurring during ascent in the area around Palestine, along with a minor hazard in the planned impact zone of the more densely populated areas to the east. As a result, additional safety requirements were imposed on turnaround and easterly flights of heavy payloads (exceeding 1,600 kilograms). At the same time, a survey was performed in 1986 to identify a new semi-permanent western launch location resulting in the selection for the first time of Fort Sumner as an acceptable site for balloon operations. The only setbacks were related to the surrounding landscape. Fort Sumner is at 4,000 feet altitude in a desert environment, and is subject to a lot of low level winds during the night and during the days in the spring time. One of the reasons that NSBF first chose Fort Sumner was because the presence of the large old World War II airplane hanger that could be used for payload assembly and checkout. The first balloon launch was conducted there in March 1986 while UCAR was the manager of the NSBF. A leased crane was used as a payload launch vehicle.

In the late 1980s, NASA spent about $100.000 to construct large insulated walls and air conditioning inside the hanger so payloads could use the place in a controlled environment. Three bays with tall sliding doors that opened into the main hanger area provided a workable area for scientists and their payloads with large steel A-frames used to suspend the payloads. Another flight safety risk analysis performed in 1988 resulted in performing all stratospheric turnaround balloon flights from Ft. Sumner rather than Palestine. The safety risk associated with stratospheric turnaround flights going toward Houston, TX and other populated areas to the south became unacceptable by NASA.

This forced CSBF to adopt a new operational approach within the NASA Balloon Program using Palestine, as the principal center for scientific ballooning, but only for missions traversing to the west. Ft. Sumner, NM became the primary candidate as a permanent alternate launch site to meet easterly and turnaround flight requirements: where payloads could be impacted in moderate to low population density areas but offering a high probability for recovery. These safety conditions ruled out automatically all areas east of the Mississippi River due to high population issues. Thus the only part of the country which fulfilled the safety and operational requirements was the southwestern area of the US.

A detailed survey was conducted over New Mexico, Arizona, and southern Nevada and 30 candidate sites were identified. A comprehensive study was performed on these places giving consideration to various factors including safety, geography, air traffic activity, meteorology, and existing facilities. Art Gilcrease was the person in charge of that study. He did an exhaustive study for alternate sites and in December 1988 the studys concluded that Fort Sumner was the best location. The site not only best met the selection criteria but offered the advantage of being complementary to the Palestine Base, from the standpoint of downrange tracking and staging of recovery forces.

Immediately an extensive effort was made to build permanent facilities there. The large NASA High Bay building was approved for construction by NASA in the early 1990s but the agency first had to purchase the land at the airport from the city of Fort Sumner since the US federal government cannot build facilities on land not owned by the government. It took a couple of years to complete that transaction.

The building is a 12.2 meter high-bay with over 600 square meters of air conditioned floor area that is used to check and integrate up to four scientific payloads at a time and provide work areas for operations and support personnel. Inside the building structure a 4500 kg monorail crane is used to move gondolas and equipment between two 9.1 meter high doors on either ends of the building.

The second phase of construction of the high bay was completed in mid 1994 with the addition of paved areas around the building, and the completion of a second and third floor with enclosed telemetry station, weather station, and a complete flight control center. A roof platform was added to serve as mounting structure for line-of-sight telemetry antennas and in recent years to mount two cameras allowing to follow the balloon launch operations through the internet. Near the main building, a non-magnetic frame (which some people know as the "Pi" frame) is used to calibrate the magnetic sensors on balloon payloads.

Since the completion of the Fort Sumner base, the operational concept for routine support of line-of-sight zero pressure balloon flights in the Continental US has been stratospheric turn-around flights there, and flights traveling west from Palestine in the summer. Pre and Post-turnaround flights from Fort Sumner are supported using Palestine as a downrange station for easterly going flights while a mobile telemetry station is located at the Winzlow airport in Arizona when the balloons are heading due west.

The first launches were performed using a rented crane with outriggers on to keep it from tipping over to the side. Then NSBF owned a 35 ton crane that was used for a long time, but during a balloon launch under heavy wind the front end of the crane was lifted off the ground and turned the crane about 90 degrees. Taking account that these cranes were not very easy to use for balloon launches, the need for a specially made transportable launch vehicle to handle payloads soon become evident. The large NSBF based payload launch vehicle, "Tiny Tim", was not able to be moved outside Palestine due to its extremely wide wheelbase and inability to be easily disassembled. This limitation resulted in the design and construction of the Mobile Launch Vehicle (MLV).

The MLV was designed and fabricated by the engineers and technicians at New Mexico State University in Las Cruces. They tried to award a contract to build the vehicle commercially, but they could not get acceptable bids from the big companies so they decided to build it within their own organization, with NASA approval. As they had a shop in Las Cruces that had been building trailers and vans for instrumentation/telemetry jobs they were confident on the task.

The MLV is basically the motor and drive wheel unit from a Michigan brand large articulated front end loader. The part of the MLV in front of the articulation point used the articulation hardware from the original machine with the specially designed structure and boom with a 24 foot wheelbase and solid foam filled wheels that could be removed for transportation.

The vehicle is transportable however it is used primarily at the Fort Sumner facility where it provides heavy lift payload capabilities. It has two configurations, one for transporting on the highway, the other for launch. Transition from road configuration to launch configuration can be accomplished by four people in four hours, with the reverse taking six hours. In its launch configuration, the vehicle weighs over 50 tons, measures approximately 13 meters in length and 7 meters in width at its widest point, and has a launch boom that can be raised about 12 meters above the ground.

This unique, one-of-a-kind, vehicle was delivered to Fort Sumner in 1991 and was declared operational during the Fall campaign the next year. It is used along with a spool mounted in a large bulldozer type vehicle which holds the semi-inflated balloon at launch time. The dynamic launch capabilities of the MLV are for balloons with a gross inflation of 6727 kilograms while the suspended load is in the order of 3636 kilograms.

After a while, the MLV was renamed as "Big Bill" after the nick name for Bill Harrison, one of the NSBF mechanical technicians who grew up in Palestine and started working at the balloon base when he was young. He was the primary driver of Tiny Tim and also the Mobile Launch Vehicle (MLV) and a very appreciated member of the program staff.

Current two operational balloon launch campaigns are conducted at Ft. Sumner, NM each year. These occur in the May-June and September-October timeframe surrounding the two stratospheric turnaround events. The NASA Ft. Sumner facility has grown in capability over the years and now includes a machine shop and still utilizes the old World War II hanger as a work area, storage area for support vehicles, and a hanger for NSBF aircraft during balloon flight operations.