Columbia’s STS-87 crew had a very busy mission plan that began in mid-November, 1997. Among the many items was the deployment of SPARTAN-201-4.

The Shuttle Pointed Autonomous Research Tool for Astronomy (say that three times fast) was not a permanent satellite but a collection of experiments in several package types, activated and then left to fly free for several dozen orbits to study aspects of the sun and the solar wind and more. SPARTAN is later collected by the Orbiter crew for return to Earth.

SPARTANs have been around since 1985, starting with a prototype carried on STS-51G in 1985 to make some x-ray astronomy measurements. The simple, elongated rectangular box concept was successful enough that the next two concept flights were cancelled and a new design was commissioned.

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SPARTAN Halley. (NASA)

SPARTAN Halley was to make ultraviolet studies of Comet Halley during its return to the inner solar system in 1986.

Unfortunately that sub-satellite was destroyed, along with a TDRS satellite and the crew intending to deploy them, aboard Challenger on the ill-fated STS-51L launch.

Aboard Columbia in 1997 was SPARTAN model 201, which flew three times before on STS missions 56, 64 and 69.

SPARTAN 201-4 was an important element in calibrating instruments on the Solar and Heliospheric Observatory (SOHO) satellite, in orbit for a couple of years prior. SOHO needed a day to come online again before SPARTAN could be deployed to begin.

The crew ran through their deployment procedures, picked up SPARTAN with the remote manipulator arm, and set it free.

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SPARTAN 201 deployment during STS-64. (NASA)

About 3 minutes after deployment, SPARTAN was pre-programmed to activate jets to perform a pirouette–a slow spin for taking measurements. But the experiment simply stayed put.

Crewmember Kalpana Chawla, enjoying her first mission, tried to grab SPARTAN to return it to the payload bay, but the arm’s end-effector failed to get a solid grasp.

On removing the arm after the failed retrieval, SPARTAN was accidentally given a small roll, making further attempts to use the Orbiter’s arm very problematic. After expending a bit too much reaction-control system fuel to chase the sub-satellite, the flight director nixed further work to retrieve the satellite until they could think out a better plan.

Since the mission included a spacewalk that would test out procedures that would later be used in the assembly of the International Space Station (to begin about a year later), Mission Control hashed out an idea based on an older trick used in the early days of the program on a couple of wayward satellites.

During their EVA three days later, Columbia moved to close range of SPARTAN. After verifying how it was moving and adjusting Columbia as needed, the two astronauts simply reached out to grab SPARTAN to berth it in the payload bay.

The glitch occurred when the Orbiter payload computer used to activate SPARTAN had sent a command, but the experiment didn’t receive the command. Both the crew and Mission Control were oblivious to the issue as the process lacked verification or telemetry procedures to check the signal.

SPARTAN would not fly free any further on that mission, but would get a final shot at work as SPARTAN-201-5 aboard STS-95 (the mission which also carried John Glenn once more to orbit). It completed 201-4’s mission to calibrate SOHO, as well as conducting a ton of medical experiments (many revolving around Glenn and aging) as well as deploying PANSAT, an experimental marine communications satellite.

Designed for a lifetime of only three years, SOHO is still in operation today, over 21 years later.

You can enjoy a summary of STS-87’s mission, including coverage on SPARTAN-201-4’s deployment and recovery, in this 18 minute video, narrated by the some of the crew.

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