Supersonic Human?

[SASless]

The French are at it again....this time parachute jumping from 132,000 feet MSL (25 miles).

That would break the record held by USAF Maj. Joe Kittinger, who did a 24 mile high jump from a balloon.

http://www.dailymail.co.uk/pages/live/articles/news/worldnews.html?in_article_id=474879&in_page_id=1811


You reckon they will have a helicopter filming the jump? Say....the one that made the landing on top of Everest?

[Hover Bovver]

Am I correct in thinking that 760 mph will not be the speed of sound at that altitude?

[majmun]

Correct. ~760 mph is the speed of sound at standard atmospheric temp (21C). Slower for colder and faster for warmer.

[Graviman]

HB, speed is proportional to SQRT(temp) in Kelvin, ie no need to consider pressure or density. Just look at speed at sea level then assume -6deg per 1000ft until at -60`C or 213K. Clouds change it to -3deg per 1000ft, but i'm guessing the risk is already high enough!

Good luck! Just reading about it gives me vertigo...

[arismount]

The jump will be made at 132,000 ft. From the jump website, he reckons he'll go past M 1.0 in about 37 seconds...this should be around 110,000 feet.

At 110,000 ft altitude, ISA temp would be 233 K (-40 C). M in Knots = approx. (39 x sqrt K), therefore M 1.0 at that altitude would be about 595 Kts.

Helpful website:

http://www.desktopaero.com/appliedaero/appendices/stdatm.html