Aspects of the disclosure relate to techniques for launching high-altitude balloons. In one aspect, a balloon launching system is provided. The balloon has a balloon envelope, a payload attached to the balloon envelope and a launching projection. The launching system includes a releasable restraint attached to the balloon between an apex and bottom of the balloon envelope. The releasable restraint is arranged to temporarily hold the balloon envelope. The launching system also includes a payload positioning assembly. The payload positioning assembly is configured to position the payload during launch of the balloon and includes a member configured to attach to the launching projection. When attached, the member is also configured to maintain the position of the payload relative to the balloon while the releasable restraint is temporarily holding the balloon envelope.