article_snippet.sent: This programme includes both ground and flight tests, the exact timing of which will be dictated by safety and readiness rather than deadlines.'
article_snippet.sent: While the fault appears to have been down to human error - and not a mechanical fault - the National Transportation Safety Board is yet to publish the fault appears to have been down to human error - and not a mechanical fault - the National Transportation Safety Board report on the resultant crash.
article_snippet.sent: While the crash of VSS Enterprise (shown) appears to have been down to human error - and not mechanical - the National Transportation Safety Board
article_snippet.sent: (NTSB) is yet to publish (NTSB) .
article_snippet.sent: One issue is that spacecraft are normally required to be capable of handling two errors.
article_snippet.sent: But in this case only one - the pulling of the lever - was enough to cause a catastrophic failure.