Sputnik II--or "Muttnik" for dog lovers--is up and away. Not only has it and its canine passenger been up since 11:38 EST Saturday night, but by 8:30 this morning they will have circled the earth 19 times.

But Cambridge scientists seemed a little blase about the whole thing last night. Fred L. Whipple was more than usually restrained as he commented at the Garden St. headquarters of the Smithsonian Astrophysical Observatory that the second Russian launching probably required no greater effort than the first. Whipple speculated, as have most other American scientists, that the 1,120-pound object speeding around the earth is the third-stage of the rocket rather than a spherical satellite.

Whipple, basing his calculations on figures released by Radio Moscow, computed the lowest point in the rocket's orbit as 104 miles. Although this height is some 81 miles lower than the height of Sputnik I's rocket, the apogee--or highest point--of Sputnik II is 1,056 miles, compared to 560 miles for the first satellite.

The speed, too, is different. "II" moves at 17,840 m.p.h. compared to 18,000 m.p.h. for the original. Muttnik, which has a longer orbit, consequently takes 103.7 minutes to circle the globe, compared to 96.2 minutes for its predecessor. The most impressive difference, though, is in weight: 184 pounds to 1,120.

Scientists at the Smithsonian, however, remained markedly calm in the face of the latest Russian achievement. Admitting that Muttnik is "definitely an improvement over the first one," John S. Rinehart, an associate director of the observatory, maintained that the actual force needed to lift the rocket into orbit was not much greater than that used a month ago.

The difference in weight, he explained, was probably due to the shape and size of the rocket, compared to a sphere with a 23-inch diameter. He added that the weight of the instruments and the dog in the forward section of the cylinder might also total more than the mass of the first satellite.

Whipple, again basing his predictions on announcements from Radio Moscow and from the Associated Press, indicated that the object's orbit might be turned in such a way that it would be visible at twilight this evening. Whipple said that it would be at least a few more days before it would be "a morning object." Moscow has announced that the satellite is broadcasting, as did the first one, on 20 and 40 megacycles alternately.

Whipple added that the second rocket, although in a more elliptic orbit than the first, would probably take "a comparable period of time" to be affected by the atmosphere drag which is slowly destroying Sputnik I's rocket. Meanwhile, he said, "Curly," the first dog in space, is comparatively safe.

Dr. J. Allen Hynek, also an associate director at the observatory, commented that it "seems feasible" not only to keep the dog alive and as happy as dogs normally are, but also to retrieve it safely. He pointed out that the United States had successfully regained high-speed objects jettisoned at great altitudes. The dog is believed to be hermetically sealed into a capsule, similar to the containers used for instruments in U.S. test rockets.

Observatory officials were non-committal on the stage of alertness of Moonwatch teams around the country. Leon Campbell, Jr., director of the observation program, commented only that "Moonwatch teams are on the alert all the time, naturally." Another scientist revealed that the one operative satellite-tracking camera had been disassembled in Pasadena Friday and would arrive in New Mexico today.

The calm attitude of Cambridge officials was paralleled in scientific circles in Washington, where Dr. John P. Hagen said "It (the weight of the satellite) doesn't surprise me, since they must have done the same thing with their first satellite." Hagen continued, according to the Associated Press, that the Russians "seem to be using any old hardware they have on hand" for satellite launchers. Hagen's statement implies that he believes the Russians have a stockpile of rockets powerful enough for intercontinental ballistic missiles.

A less calm American reaction came from the SPCA, which deplored the experiment, and requested that its sentiments be conveyed to Moscow.