This is the third of a three-part series that looks back at the 30-year history of the U.S. space shuttle program.

Before the 1986 Challenger disaster made safety paramount and new constraints had been established, the shuttle could carry fueled upper-stage rockets to launch space probes, which embarked for planetary destinations.

From low orbit to deep space

The delivery into orbit of the Hubble Space Telescope, considered one of NASA's greatest science achievements, stands out. Not as well known, but very important to solar system astronomy, were the highly successful Magellan, Galileo and Ulysses probes, sent on to orbit Venus, Jupiter and the sun, respectively, from shuttles' cargo bays. Besides Hubble, these trucks also hauled into orbit two other important orbiting telescopes: the still operating Chandra X-Ray and the deorbited Compton Gamma-Ray observatories.


BY JOVE: The Jupiter-bound Galileo spacecraft attached to the Inertial Upper Stage booster is ejected from space shuttle Atlantis’s payload bay. Credit: NASA

Of course, besides safety concerns, there were other drawbacks. Space probes had to be configured and sized to fit into the shuttle bay. For example, Galileo was designed with a foldable high-gain antenna, to be opened like an umbrella after embarkation. Unfortunately, it added complexity to what would have been designed as a rigid dish, and once Galileo was Jupiter-bound the antenna did not completely unfurl—a problem that almost ended the mission. Fortunately, innovative flight engineers were able to program the craft to use a low-gain antenna for sending back the torrents of data, albeit much more slowly. Patience, new trajectories and compression programs saved the mission.

Wrangle, repair and release

Although the refurbishment and repair of the Hubble Telescope is well known, spacewalking shuttle astronauts have also captured, repaired and released errant communication and military satellites, including the dramatic rescue in 1992 of the Intelsat 6 by three astronauts, who pulled the wobbling, five-meter-tall sat into Endeavour's cargo bay with their hands after specially designed tools had failed and installed a booster rocket to place it into a useful orbit. Shuttles have carried dozens of communications and military sats into orbit.

THE HUMAN TOUCH: Three astronauts hold onto the 4.5-ton Intelsat 6 after a six-handed "capture" was made minutes earlier. Left to right: mission specialists Richard J. Hieb, Thomas D. Akers and Pierre J. Thuot. Behind the three spacewalkers is the rocket motor that boosted the satellite into its proper orbit. Credit: NASA

Although the final mission set for launch later this week will be mostly to bring more than 3,500 kilograms of groceries, staples, spare parts and other supplies to the ISS crews to get them through the first year without shuttle service, there will be one experiment that will prepare NASA for the post-shuttle era. The final mission will deploy a package demonstrating a satellite-refueling system that it is hoped will spur U.S. private sector investment into the satellite-resurrection business.

Science at 28,000 kilometers per hour

Shuttles have been used to carry laboratories into orbit. Both SPACEHAB and Spacelab allowed mission specialists to run astronomy, microgravity life science, atmospheric and other experiments from inhabitable modules in the school bus–size cargo bay or to operate from inside the cabin pallets laden with telescopes or experiments exposed to the space environment.

Also notable, a very fruitful science mission took place on Endeavour in February 2000. The Shuttle Radar Topography mission returned with more than 300 high-density tapes containing nine terabytes of raw data that have been made into one of the highest-resolution digital topographic maps of Earth. Not as successful were two attempts to fly a tethered satellite developed by the Italian Space Agency. On the first flight the tether jammed; on the second, as it unfurled out to 20 kilometers, it snapped. Valuable data on ionospheric charge (3,500 volts were generated) and ionized shock waves were garnered nonetheless.

Pink slips and the final countdown

All good (and otherwise) things must come to an end. But it is not going to be smooth sailing into the next space transportation system for many shuttle employees. The United Space Alliance, the consortium that services the shuttle, laid off 1,000 employees as of October 2010. Unfortunately, that will be only the beginning of the downscaling. All told, it is expected that thousands of jobs will be lost, with the biggest blow to Florida workers, after Atlantis touches down.

And so, warts and all, three decades of U.S. space history reaches its culmination with the upcoming flight of Atlantis. Looking back, the old space trucks that cost an estimated $195 billionmore than the AIG bailout, but less than the Iraq and Afghanistan wars—may have been a government bean-counter's nightmare, and there no doubt will be more efficient and safer ways to get crews and cargo into orbit. But for better or worse, the shuttle program has been an integral part of the Space Age, and those who were part of it should feel proud as the old, dinged-up and dirty space truck settles into its hard-earned and distinguished role in the history of human accomplishment.