Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Date | Time ( GMT ) | Serial | Apogee | Outcome |
| --- | --- | --- | --- | --- |
| 1957-06-11 | 19:37 | 4A | kilometres (mi) | Failure |
| 1957-09-25 | 19:57 | 6A | kilometres (mi) | Failure |
| 1957-12-17 | 17:39 | 12A | kilometres (mi) | Success |
| 1958-01-10 | 15:48 | 10A | kilometres (mi) | Success |
| 1958-02-07 | 19:37 | 13A | kilometres (mi) | Failure[ citation needed ] |
| 1958-02-20 | 17:46 | 11A | kilometres (mi) | Failure |
| 1958-04-05 | 17:01 | 15A | kilometres (mi) | Failure |
| 1958-06-03 | 21:28 | 16A | kilometres (mi) | Success |
Question:
What is the time (GMT) for the 12A Serial?
Answer:
17:39