WASHINGTON Arianespace is entering an ambitious launch campaign aimed at sending up a commercial booster every three weeks to catch up its 1999 delays, company sources tell space.com. The European company will next launch V-120 on September 1, followed by another Ariane 4 vehicle every three weeks until December.

At year's end, the company will attempt to launch V-119, the delayed commercial debut of the Ariane 5. Announcement of the final set of payloads for that launch and the specific payloads of the Ariane 4 launchers will be made Monday, company sources say.

The company is also expected to announce six additional Ariane 5 launches planned for 2000. Along with the Ariane 4 launch plans, the addition of the six commercial Ariane 5 missions would make the year 2000 the most ambitious commercial manifest yet attempted by the French-led space launch provider.

Ariane V-118, launched Thursday night, is the fourth launch by the company this year. Launches had been delayed and payloads backlogged by manifest problems in getting multiple spacecraft ready for their flights.