Red kangaroo has the ability to freeze the development of an embryo until the previous joey is able to leave the pouch. This is known as diapause, and will occur in times of drought and in areas with poor food sources. The composition of the milk produced by the mother varies according to the needs of the joey. In addition, red kangaroo mothers may "have up to three generations of offspring simultaneously; a young-at-foot suckling from an elongated teat, a young in the pouch attached to a second teat and a blastula in arrested development in the uterus". The kangaroo has also
PWN-9 Kangaroo initial design of what was then called Kangaroo-Dart was developed by the Aeromachnics Branch of the U.S. Navy's Pacific Missile Range. Detailed design was performed by Aerojet; however when bids for developing the prototype, given the designation XPWN-9A, were requested, United Technologies Corporation submitted the winning bid and was given a contract for construction of prototypes in November 1969. Flight trials of the Kangaroo booster were undertaken at the Pacific Missile Range at Point Mugu; they proved unsuccessful, and production of the rocket was not undertaken. PWN-9 Kangaroo The XPWN-9A Kangaroo was a project to develop a sounding rocket intended