generate questions: In February 2007, the fourth and last satellite of the BeiDou-1 system, BeiDou-1D (sometimes called BeiDou-2A, serving as a backup satellite), was sent up into space. It was reported that the satellite had suffered from a control system malfunction but was then fully restored.
When was the fourth satellite for the BeiDou-1 system launched? {sep_token} What is the name of the fourth BeiDou-1 satellite? {sep_token} What is the BeiDou-1D satellite sometimes called? {sep_token} What is the purpose of the BeiDou-1D satellite? {sep_token} What happened to the BeiDou-1D satellite that needed to be repaired?