Sir - You are wrong to say that NASA's STS70 Shuttle mission is the 100th US manned space flight (Flight International, 7 - 13 June, P29). There were 31 US space flights, before the Shuttle flew for the first time in April 1981, and, to date, there have been 67 space flights with this re-useable vehicle.
STS70 would make the 99th US space flight - of which only 97 have been orbital flights, since the first two, in 1961, were ballistic flights. The brief and disastrous flight of the Challenger in January 1986 did not leave the atmosphere and therefore was not a space flight.
If launches count, we should include the Challenger and the aborted flight of Stafford and Cernan in 1966 when their Gemini-Titan launch vehicle rose 50mm off the pad before shutting down and settling back.
With these launches included, that would make the STS70 the 101st flight. Yet the F,d,ration Aeronautique Internationale credits all flights above 80km as space flights, so 12 rocket-powered X-15 flights must be counted, and that makes the STS70 the 111th US space mission.
Clearly taken from a NASA press release, your report should have given the space agency's acronym (Never a Straight Answer) as a warning.
This nit-pick aside, congratulations on superb space coverage.
DAVID BAKER
Cambridge, UK
Source: Flight International
