Historical clue formulations

• Balloon-carried probe — 2016-02-05
• Atmospheric probe — 2014-10-12
• Meteorological probe — 2013-09-21
• Meteorological probe — 2012-10-06
• Meteorological probe — 2004-12-11
• High-altitude probe — 1997-07-11
• Atmospheric probe — 1996-10-06
• Balloon probe — 1995-08-11