By Dr. Gary L. Deel, Ph.D., J.D.
Faculty Director, School of Business, American Military University
This is the second article in a three-part series on the earliest satellites launched by the Soviet Union and the United States
Sputnik II was launched less than a month after Sputnik I on November 3, 1957. It carried the first spacefaring life, a dog named Laika, Russian for “bark.”
Sputnik II was launched on an R-7 ICBM rocket, the same vehicle used for Sputnik I. However, some modifications were made for the Sputnik II launch, including a change in launch trajectory to utilize fuel more efficiently and the removal of some flight control equipment to save weight. A braking nozzle was added to the core booster stage to prevent it tumbling in orbit.
First Mission Component: Test and Refine Launching and Orbiting Capability
The primary mission of Sputnik II had several components. The first was to continue to test and refine spacecraft launching and orbiting capability, based on lessons learned and improvements made from Sputnik I. The second component was to gather more data that would help understand conditions in low-Earth orbit. For example, Sputnik II was equipped with two photometers to measure solar radiation in the ultraviolet and x-ray spectrums.
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Finally, the most notable purpose of Sputnik II was to demonstrate that animals could survive launch and orbit in a space capsule, which Laika famously accomplished, if only briefly. Her flight was obviously a necessary precursor to the launch of humans into space.
Unlike Sputnik I’s beach ball shape, Sputnik II consisted of a cone-shaped capsule about 13 feet high with a diameter at the base of about 6.5 feet. From the outside shell, the cone appeared to be one solid piece, but three notable features on the interior included:
- Radio equipment and telemetry instruments
- Temperature management hardware
- A sealed compartment for Laika
Sputnik II never actually separated from the upper stage booster. So, although the space capsule weighed about 1,100 lbs., the total weight of the orbiting mass was almost eight tons.
Because Sputnik II had no attitude control system, once it achieved orbit it was helpless to change any dynamics of its flight.
The communications system consisted of two radio transmitters operating at the same two frequencies as Sputnik I, telemetry instruments for relaying flight data, and reflective panels for radar tracking. For power, Sputnik II used batteries similar to those on the Sputnik I mission. Metal loops fastened to the outside slope of the cone fuselage served as antennas for the capsule.
The payload of Sputnik II consisted of radio equipment, temperature control hardware, science and telemetry instruments, and, most famously, Laika.
Sputnik II Lacked Any Means of Flight Adjustment, So There Was No Ground Control
Like its predecessor, Sputnik II lacked any means of flight adjustment, so there was no control from the ground. The only signal that ground control gave to the spacecraft was to shut off the second stage booster engine immediately after fuel depletion.
The thermal control system of Sputnik II was fairly successful. It consisted of equipment for absorbing carbon dioxide, generating and regulating oxygen, and cooling the cabin of the space capsule. It managed to competently maintain reasonable conditions for several days in orbit.
However, eventually cabin humidity and temperature climbed dramatically. Laika reportedly succumbed to these conditions, although historians disagree on the exact time of death due to numerous conflicting reports. With one meal and only a seven-day oxygen supply, Laika died a short way into the mission. (In 2002, Russian scientist Dimitri Malashenkov revealed that Laika had actually survived only about five to seven hours after liftoff before dying of overheating and panic.) Nevertheless, it was a major step for only the second successful satellite in history.
The active mission was expected to last about seven days based on the projected life of the batteries, but they lasted six days. The spacecraft itself stayed in orbit for a total of 162 days, burning up on re-entry on April 14, 1958. The main limiting factor to Sputnik II’s active mission duration was the same as that of the first Sputnik mission: battery life expectancy. Once Sputnik II’s batteries died, the spacecraft became little more than space debris.
Sputnik II was put into an elliptical orbit that was approximately 132 miles in altitude at perigee and 1,030 at apogee. The orbital period was about 104 minutes, just a few moments longer than its predecessor. The inclination of the Sputnik II orbit was the same as Sputnik I, 65 degrees.
Sputnik II was just as much of a success as its predecessor. The launch and orbit were successful, the spacecraft communicated reliably with ground monitors; it gathered all sought-after data, and the mission component of delivering Laika successfully into orbit and monitoring her vital signs was accomplished. There was never a plan to recover her.
In the third and final part of this article, we’ll examine Explorer I, the first American satellite in space.
About the Author
Dr. Gary Deel is a Faculty Director with the School of Business at American Military University. He holds a J.D. in Law and a Ph.D. in Hospitality/Business Management. Gary teaches human resources and employment law classes for American Military University, the University of Central Florida, Colorado State University and others.