Ariane 5 has a much larger they-diameter, tank capacity and greater thrust power than Ariane 4. The reliability of Ariane 5 also must be improved.

阿里安5和当前正在使用的阿里安4相比，直径和贮箱容积以及推力都有了极大增加，还提高了可靠性要求。

youdao

The old Ariane 4 only has two remaining flights scheduled, one of which is due to take place next week.

BBC: Ariane 5: A short history

Also aboard the Ariane-4 rocket will be the GE-5 satellite that will provide television services to North America.

CNN: Ariane to launch radio satellite for Africa

Wednesday's mission was the ninth Ariane rocket launch this year and the 40th consecutive successful launch of an Ariane-4 rocket.

CNN: Ariane rocket orbits U.S. communications satellites