Lambda is the name of a series of Japanese carrier rockets.^[1][2] It consisted of the types Lambda 2,^[3][2] LSC-3,^[4] Lambda 3,^[5][2] Lambda 3H,^[2][6] Lambda 4S,^[2][7][8] Lambda 4SC,^[2][9] and Lambda 4T^[2][10] developed jointly by Institute of Industrial Science of the University of Tokyo, Institute of Space and Astronautical Science of the University of Tokyo, and Prince Motor Company, which merged with Nissan in 1966.^[11]

Lambda series rockets did not have guidance systems, as they had the potential to be converted for offensive military use, thus interpreted as a violation of Article 9 of the Japanese Constitution. However, future Japanese launch vehicles, such as the H-II, were allowed to have guidance systems.^[12]

Lambda types differ regarding the upper stages used. The following table shows the actual configurations:^[2]

Lambda rockets were launched by ISAS, from Kagoshima pad L.^[1][2]

On February 11, 1970, the first Japanese satellite Ohsumi was launched using a Lambda 4S rocket.

The Lambda 4S was launched nine times, though five were failures.^[13][8] The first launch of the Lambda 4S rocket took place on September 26, 1966, from Kagoshima.^[14] A fourth-stage attitude control failed resulting in loss of the vehicle and payload.