Communists in heavy attack on U.S. infantry divisionSAIGON (UPI) — The Communists’ winter-spring offensive blazed into its 32nd day today with a devastating attack on a U.S. 9th Infantry Division ammunition dump in the Mekong Delta and a mortar and ground assault on a 1st Air Cavalry Division post northwest of Saigon.The assault, already the longest sustained Communist offensive of the war, was proving costly to them. Tin* first three weeks cost them more than 15,000 dead and the figure probably was close to the 20,000 mark by now. At least 275 were killed in fighting Tuesday and today.But the offensive showed no sign ofslackening and North Vietnamese andSatellite set to track elkA $10 million Nimbus spacecraft will be launched from here by NASA April 10 to gather data on weather conditions and to track the movements of an elk in Yellowstone National lark.Hie Nimbus DB is the sister spaceship to one which crashed into the I*a-cific near San Miguel Island after being launched from here last May 18.The destructed satellite carried expensive nuclear generators. A search sponsored by NASA and the Atomic Kn-ergy Commission located the nuclear generators on the ocean floor near San Miguel Island. The generators were taken ashore in October.The Nimbus launched last year cost $50 million and was billed as the most sophisticated weather satellite ever launched. The upcoming shot is made up of back-up components already funded and officials say the cost is about $10 million for the launch.The Nimbus is a weather watching satellite which carries high resolution cameras to track Earth’s cloud cover night and 'lay. It will also carry seven experiments including equipment to track an elk which will be roving Yellowstone National Park with a transponder en-bedded in its body.Officials say the experiment will aid in developing techniques for tracking the migration of animals, protecting species of animals that are becoming extinct, and collecting data on navigation techniques used by certain animals. The latter may help scientists improve navigation methods used by humans.Another accidentViet Cong gunners slammed shells into 30 cities, towns and allied bases during the night. The most costly was the attack on the 9th Infantry Division’s base in the Delta which fared evacuation of half of the sprawling complex.The Delta attack killed three Americans and cost the Communists an unknown number of dead.The attack against the 1st Air Cavalry Division |»ost 50 miles northwest of Saigon cost the Americans eight dead and 17 wounded. The Communists carried out a ground assault under cover of a heavy rocket barrage but were stopped at the barbed wire defenses. Two enemy dMd were found on the tarbed wire.U.S. military sources said barrages from the biggest mortar in the guerrillas’ Vietnam arsenal also damaged or destroyed six helicopters, the cop-ter fad, a mess hali and several other of the wooden buildings on the U.S. Army-Navy base.According to these sources, three American fils died awl 65 suffered wounds in the post-midnight attack. The U.S. command said casualties and damage were light to moderate.”Karely do Communist shellings, however heavy, cause more than light damage to big U.S. liases. This time, the sources said, hundreds of men fled the Navy portion of the complex to escape more explosions in fuel stores.”The base at Dong Tam, 42 miles southwest of Saigon, is headquarters for the U.S. 9th Division and lias an adjacent naval facility where ships of the division’s Mobile Kiverine 1-orce are repaired.Firelalls erupting from the exploding ammunition dump were visible for miles across the delta ricebowl. The U.S. command refused to confirm precise details of the attack reported by mill-tary sources.It was one of approximately 30 overnight Communist barrages into South Vietnamese cities or allied military camps as the guerrillas' nationwide offensive entered its 32nd 'lay with no end in sight. No major fighting was reported under way today.American headquarters issued this announcement on the iJong Tam shelling and refused further comment:The U.S. naval support activity at Dong Tarn received more tl»an 15 rounds of 120mm mortar fire resulting in light U.S. casualties and moderate to heavy materiel damage.The base camp headquarters of the U.S. 9th Infantry Division at Dong Tam received an unknown number of rounds of unknown caliber mortar fire resulting in light casualties. Damage to materiel is light to moderate.”