Recalling the Voyages of the Space Shuttle Endeavour

Space Shuttle Endeavour on launch pad 39A prior to mission STS-127, May 31, 2009.

Space Shuttle Endeavour on launch pad 39A prior to mission STS-127, May 31, 2009.

The quest for a reusable spaceplane extends far back into the 1920s, but it only found realization with the inaugural flights of the Space Shuttle in the early 1980s. NASA initially built four spaceworthy orbiters—Columbia (OV-102), Challenger (OV‑099), Discovery (OV‑103), and Atlantis (OV‑104)—and named them for famous ships of exploration and scientific discovery. After the loss of Challenger on January 28, 1986, NASA built the replacement orbiter Endeavour (OV-105), the namesake of Captain James Cook’s HMS Endeavour of his first voyage between 1768 and 1771. Constructed beginning in 1987, Endeavour flew the first of its 26 space missions in May 1992 (STS-49) and closed its career with its last mission in May 2011 (STS-134).

Two missions stand out in Endeavour’s history. First, this shuttle proved exceptional in the hands of the STS-61 crew that performed the first servicing of the Hubble Space Telescope (HST).  Deployed in orbit by another shuttle in 1990, the HST had a “spherical aberration” that resulted in a hazy ring, or halo, that degraded the imagery. At first many believed that the spherical aberration would cripple the 43-foot-long telescope, and NASA received considerable negative publicity. Because of the difficulties with the mirror of the HST, in December 1993 NASA launched the shuttle Endeavour on a repair mission to insert corrective equipment into the telescope and to ser­vice other instruments.

No flights demonstrate the flexibility of the Space Shuttle more effectively than this servicing mission, the first of five such efforts on behalf of the HST. During a weeklong mission, Endeavour’s astronauts conducted a record five spacewalks and successfully completed all programmed repairs to the spacecraft. The first reports from the newly repaired HST indicated that the images being returned now ­were more than an order of magnitude (10 times) greater than those obtained before.

Because of the servicing mission, the HST dominated space science activities throughout the next several years. The results from Hubble touched on some of the most fundamental astronomical questions of the twentieth century, including the existence of black holes and the age of the uni­ver­se. Highlights of the Hubble Space Telescope results after this first servicing included, as stated in Space Times in 1995:

Compelling evidence for a massive black hole in the center of a giant elliptical galaxy located 50 million light years away. This observation provided very strong support for predictions made 80 years ago in Albert Einstein’s general theory of relativity. Observations of great pancake-shaped disks of dust, raw material for planet formation, swirling around at least half of the stars in the Orion Nebula, the strongest proof yet that the pro­cess which may form planets is common in the universe. Confirmation of a critical prediction of the Big Bang theory, that the chemical element helium should be widespread in the early universe. The detection of this helium by HST may mark the discovery of a tenuous plasma that fills the vast volumes of space between the galaxies, the long-sought intergalactic medium. In October 1994, astronomers announced measurements that showed the uni­verse to be between 8 and 12 billion years old, far younger than previous estimates of up to 20 billion years. These measurements were the first step in a three-year systematic program to mea­sure accurately the scale, size and age of the universe.

These discoveries continued thereafter.

Second, a stunning science experiment occurred with the flight of the Shuttle Radar Topography Mission (SRTM). This flight on Endeavour in 2000 obtained elevation data on a near-global scale to generate the most complete high-resolution digital topographic data ever created. It consisted of a specially modified radar system that flew during an 11-day shuttle mission. Virtually the entire land surface between +/- 60 degrees latitude was mapped by SRTM and it has been an enormously significant data set for land use scientists.

Then there is the building of the International Space Station (ISS). Without the Space Shuttle program the ISS could never have been completed. The Space Shuttle and two types of Russian launch vehicles launched a total of 36 missions to assemble the station. Of those, twelve were flown by Endeavour, the first in late 1998 when Endeavour’s crew rendezvoused with the already orbiting Russian Zarya module and attached it to the American Unity module on December 6, 1998. When the Space Shuttle left, Unity and Zarya were in an orbit 250 miles above Earth monitored continuously by flight controllers in Houston and Moscow. The last ISS assembly mission by Endeavour was its final mission, STS-134 in May 2011, delivering the Alpha Magnetic Spectrometer and the ExPRESS Logistics Carrier (ELC-3) to the space station.

From first flight to the present the Space Shuttle was always an important symbol of the United States’ technological capability, universally recognized as such by both the American people and the larger international community. Endeavour, as well as the other orbiters, was one of the most highly visible symbols of American technological capability worldwide.

Space Shuttle Endeavour over Houston.

Space Shuttle Endeavour over Houston.

Even critics of the program, such as journalist Greg Easterbrook acknowledge this. As he wrote in Time in 2003: it “is a metaphor of national inspiration: majestic, technologically advanced, produced at dear cost and entrusted with precious cargo, rising above the constraints of the earth. The spacecraft carries our secret hope that there is something better out there—a world where we may someday go and leave the sorrows of the past behind. The spacecraft rises toward the heavens exactly as, in our finest moments as a nation, our hearts have risen toward justice and principle.”

The Space Shuttle Endeavour’s last flight took place in September 2012 when NASA delivered it to Los Angeles International Airport (LAX). It then made a slow trip through the streets of the city to its final resting place, the California Science Center in Exposition Park, arriving there on October 14, 2012. It is currently on display, but the California Science Center has bigger plans for it. Eventually it will be stacked with the external tank and the solid rocket boosters as if ready for launch.

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