of the next generation launch vehicle Ariane 6 called for a lower-cost and smaller launch vehicle capable of launching a single satellite of up to to GTO. However, after several permutations the finalized design was nearly identical in performance to the Ariane 5, focusing instead on lowering fabrication costs and launch prices. , Ariane 6 was projected to be launched for about €70 million per flight, about half of the Ariane 5 price. Initially development of Ariane 6 was projected to cost €3.6 billion. In 2017, the ESA set 16 July 2020 as the deadline for the first flight. As of June 2022, Arianespace expects the maiden flight to occur in 2023. Notable launches Ariane 5's first test flight (Ariane 5 Flight 501) on 4 June 1996 failed, with the rocket self-destructing 37 seconds after launch because of a malfunction in the control software. A data conversion from 64-bit floating-point value to 16-bit signed integer value to be stored in a variable representing horizontal bias caused a processor trap (operand error) because the floating-point value was too large to be represented by a 16-bit signed integer. The software had been written for the Ariane 4 where efficiency considerations (the computer running the software had an 80% maximum workload requirement) led to four variables being protected with a handler while three others, including the horizontal bias variable, were left unprotected because it was thought that they were "physically limited or that there was a large margin of safety". The software, written in Ada, was included in the Ariane 5 through the reuse of an entire Ariane 4 subsystem despite the fact that the particular software containing the bug, which was just a part of the subsystem, was not required by the Ariane 5 because it has a different preparation sequence than the Ariane 4. The second test flight (L502, on 30 October 1997) was a partial failure. The Vulcain nozzle caused a roll problem, leading to premature shutdown of the core stage. The upper stage operated successfully, but it could not reach the intended orbit. A subsequent test flight (L503, on 21 October 1998) proved successful and the first commercial launch (L504) occurred on 10 December 1999 with the launch of the XMM-Newton X-ray observatory satellite. Another partial failure occurred on 12 July 2001, with the delivery of two satellites into an incorrect orbit, at only half the height of the