Launch News Arianespace Flight VA214 - ALPHASAT & INSAT-3D: 25/7/2013

[boogabooga]

Interesting that the fairing sep is < 120km of alt. At 107.5, there's still a small amount of atmo drag. At least when I think of the dynamic pressure coming alive on re-entry, it would be going through 120km.

Crossing 100 km going up, the velocity of a whole stage (or two) is yet to be added. Things tend to be much slower going up than when they cross that altitude coming down. Hence, much less dynamic pressure.

 

[Urwumpe]

Interesting that the fairing sep is < 120km of alt. At 107.5, there's still a small amount of atmo drag. At least when I think of the dynamic pressure coming alive on re-entry, it would be going through 120km.

Important is the aerodynamic heatflux (product of dynamic pressure and velocity) for that, not just dynamic pressure or drag. The fairing for all satellite launchers is jettisoned once there is no risk to exceed 1800 W/m². This limit is a standard design criteria for all satellites.

 

[N_Molson]

At least when I think of the dynamic pressure coming alive on re-entry, it would be going through 120km.

Also, consider that during the re-entry, the spacecraft is blazing at 7.7 km/s at least. If I remember the figures displayed, Ariane 5 is "only" at 2.5 km/s when the fairing is jettisoned. Which means much less energy resulting from the collision of the rare air particles.

 

[ADSWNJ]

Very cool guys! Interesting to look at the set of answers and they all make total sense now!

 

[Cosmic Penguin]

[ame="http://www.youtube.com/watch?v=2383GD-9Q7Y"]Vol Ariane 214 - Décollage le 25 juillet 2013 [/ame]

 

[Notebook]

BBC article on AlphaSat:

http://www.bbc.co.uk/news/science-environment-23714597

N.

 

[Evil_Onyx]

Brazilian fisherman finds satellite launch debris in Amazon

A fisherman in Brazil's Amazon region has found a large piece of debris from a European space launch.

The man said he found the metal object floating on a remote river in the municipality of Salinopolis.

The debris has been confirmed as coming from a satellite launched from the Kourou base, in neighbouring French Guiana, last July.

The piece bears the logo of the UK Space Agency and Arianespace - the European satellite company.

A spokeswoman for the UK Space Agency, Julia Short, confirmed that the debris was from the launch of Europe's largest telecommunications satellite last year.

"It is the launch vehicle payload shroud from the Alphasat launch last year. It probably landed in the Atlantic and then floated inland,"