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:
| Pilot | Organization | Total Flights | USAF space flights | FAI space flights | Max Mach | Max speed (mph) | Max altitude (miles) |
| --- | --- | --- | --- | --- | --- | --- | --- |
| Michael J. Adams † | U.S. Air Force | 7.0 | 1.0 | 0.0 | 5.59 | 3822.0 | 50.3 |
| Neil Armstrong | NASA | 7.0 | 0.0 | 0.0 | 5.74 | 3989.0 | 39.2 |
| Scott Crossfield | North American Aviation | 14.0 | 0.0 | 0.0 | 2.97 | 1959.0 | 15.3 |
| William H. Dana | NASA | 16.0 | 2.0 | 0.0 | 5.53 | 3897.0 | 58.1 |
| Joseph H. Engle | U.S. Air Force | 16.0 | 3.0 | 0.0 | 5.71 | 3887.0 | 53.1 |
| William J. "Pete" Knight | U.S. Air Force | 16.0 | 1.0 | 0.0 | 6.70 | 4519.0 | 53.1 |
| John B. McKay | NASA | 29.0 | 1.0 | 0.0 | 5.65 | 3863.0 | 55.9 |
| Forrest S. Petersen | U.S. Navy | 5.0 | 0.0 | 0.0 | 5.3 | 3600.0 | 19.2 |
| Robert A. Rushworth | U.S. Air Force | 34.0 | 1.0 | 0.0 | 6.06 | 4017.0 | 53.9 |
| Milton O. Thompson | NASA | 14.0 | 0.0 | 0.0 | 5.48 | 3723.0 | 40.5 |
| Joseph A. Walker | NASA | 25.0 | 3.0 | 2.0 | 5.92 | 4104.0 | 67.0 |
Question:
Who was the pilot of max altitude of 55.9 miles?
Answer:
John B. McKay