Attached to the sides are two P241 (P238 for Ariane 5 G and G+) solid rocket boosters (SRBs or EAPs from the French Étages d’Accélération à Poudre), each weighing about 277 tonnes full and delivering a thrust of about 7,080 kilonewtons (1,590,000 pounds-force). They are fueled by a mix of ammonium perchlorate (68%) and aluminum fuel (18%) and HTPB (14%). They each burn for 130 seconds before being dropped into the ocean. The SRBs are usually allowed to sink to the bottom of the ocean, but, like the Space Shuttle Solid Rocket Boosters, they can be recovered with parachutes, and this has occasionally been done for post-flight analysis. (Unlike Space Shuttle SRBs, Ariane 5 boosters are not reused. ) The most recent attempt was for the first Ariane 5 ECA mission. One of the two boosters was successfully recovered and returned to the Guiana Space Center for analysis. Prior to that mission, the last such recovery and testing was done in 2003.