Soviet President Kostantin Chernenko appeared on Soviet television tonight at a medal-awarding ceremony at the Kremlin, dampening speculation about the state of his health.

His appearance after an absence from public view of more than seven weeks put to rest questions about his whereabouts by portraying him in one of the traditional ceremonial roles of the Soviet leader.

Chernenko, who turns 73 on Sept. 24, looked tan and somewhat thinner as he presented awards to three Soviet cosmonauts and read a three-minute speech from a prepared text.

While not appearing to be in worse health than before, Chernenko again exhibited the shortness of breath and slowness of movement that have led to speculation that he suffers from emphysema.

After reading his speech, Chernenko stood stiffly during the rest of the ceremony. Instead of pinning the medals on the cosmonauts, he handed them over in their cases, smiling woodenly as he shook hands with the recipients.

The ceremony, shown as the lead item on the Soviet nightly news program, took place today, according to the official Soviet news agency Tass. The medals were awarded to three crew members who took part in a mission to the space station Salyut-7 last July.

In his speech, Chernenko reiterated the Soviet view that there is a need to prevent a "military rivalry" in space and he challenged the United States to "display political foresight and appraise the Soviet Union's constructive approach at its true worth."

"An accord on this problem would be vitally important to all mankind," he said. "Besides, it could in a measure infuse Soviet-American relations with elements of mutual trust they need so badly."

Chernenko last appeared on Soviet television July 13 during a meeting with U.N. Secretary General Javier Perez de Cuellar. Shortly afterwards, it was announced that he had left Moscow for a vacation in the Crimea that was expected to last until September.

Speculation about his health began when only one announcement in his name appeared in a five-week period -- a gap considered unusual even while a leader is on vacation. It culminated in reports from informed Soviet sources that Chernenko had returned to Moscow Aug. 7 and was placed under medical supervision for heart trouble. His status was unknown until his appearance today.

After the report about Chernenko's ailment was published in the western press late last month, the Soviet press issued a series of items under his name, including an "interview" with him that appeared in Sunday's edition of the Communist Party daily Pravda.

The sudden spate of news items issued in Chernenko's name only heightened the speculation, since they resembled similar pronouncements -- including a Pravda "interview" -- issued last January in the name of then-president Yuri Andropov, who died in February.

Chernenko's health has been closely watched since he succeeded Andropov in February. He has needed help walking on several occasions and his speech has been halting, marked by the same shortness of breath and tendency to swallow words heard tonight.

The first indication that Chernenko would make an appearance at the previously unannounced ceremony for the cosmonauts was reported yesterday by Soviet journalist Victor Louis in accounts published in Britain and West Germany.

Chernenko's return to work had not been announced here. Asked about the leader's whereabouts at a press conference Monday, a spokesman for the Foreign Ministry said only that he was "carrying out his duties as general secretary of the Central Committee and chairman of the Presidium of the Supreme Soviet" -- his formal titles as party leader and president. The answer did not address the question of whether Chernenko was in Moscow, which only a public appearance could satisfy.

During the uncertainty about Chernenko's absence, western analysts here desperately dissected the Soviet press for possible hints of his condition.

One report, for example, seized on an article in Sovetskaya Rossiya Saturday that recounted how V.I. Lenin, founder of the Soviet state, learned of his mother's illness.

"Suddenly reading between the lines, it was clear: mother had fallen ill. Of course at that age -- 73 -- any ailment can take you by surprise," the newspaper article said.

The report speculated on whether the reference to the age could be taken as a veiled hint about Chernenko.