National Scientific Balloon Facility (NSBF) Newsletter, lists balloon flights for April 1977, flights scheduled for the next three months, upcoming events, and a special note about problems with fires in gondolas during recovery operations. Flight schedule includes the names of the scientists and... Show moreNational Scientific Balloon Facility (NSBF) Newsletter, lists balloon flights for April 1977, flights scheduled for the next three months, upcoming events, and a special note about problems with fires in gondolas during recovery operations. Flight schedule includes the names of the scientists and their institutions. Show less