Space Shuttle Columbia Flown HRSI Tile Fragment
This specimen is a fragment of the black, reaction cured glass coating of the HRSI Space Shuttle Tile which appears in the Fourth Edition of the Mini Museum.
NASA disposition paperwork accompanying the tile indicates it was removed after the Space Shuttle Columbia’s 7th mission, STS-61-C, which flew on January 12, 1986.
As pictured, the item is roughly the size of a standard Mini Museum specimen (4-5mm). The glass coating is very thin, so for protection this item will be enclosed in an acrylic specimen jar. The jar is housed in a glass-topped riker display box measuring 4x3x1 (inches). A small information card will accompany the specimen.
About the Space Shuttle Columbia
"The powered flight took a total of about eight and a half minutes. It seemed to me it had gone by in a lash. We had gone from sitting still on the launch pad at the Kennedy Space Center to traveling at 17,500 miles an hour in that eight and a half minutes. It is still mind-boggling to me. I recall making some statement on the air-to-ground radio for the benefit of my fellow astronauts, who had also been in the program a long time, that it was well worth the wait." ~ Bob Crippen, STS-1 astronaut, regarding first flight of the Space Shuttle, April, 12 1981
On April 12, 1981, the Space Shuttle Columbia roared to life on the pad at the Kennedy Space Center’s historic Launch Complex 39A. Solid rocket boosters and Columbia’s own engines delivered more than 6,600,000 pounds of thrust, lifting the crew of two and 4,500,000 pounds (2,000,000 kg) of dreams into orbit at more than 17,500 miles per hour (28,163 kmh).
The successful launch and return of Columbia heralded a new age in space exploration. Envisioned in the 1950’s as a fleet of reusable spacecraft, Columbia was joined by Challenger, Discovery, Endeavor, and Atlantis. Over the course of 135 missions, the fleet delivered hundreds of astronauts and thousands of tons of materials into orbit. They also deployed satellites and served as a platform for the advancement of science while traveling more than half a billion miles during three decades of operation.
Despite a tremendous record of success, two tragedies also struck the program. On January 28, 1986, the Space Shuttle Challenger exploded 73 seconds into flight as the result of a failed O-ring seal on the right solid rocket booster. Seventeen years later, the Space Shuttle Columbia was lost when the craft disintegrated due to an undetected puncture in the wing which occurred during liftoff but did not present a problem until re-entering the atmosphere on February 1, 2003. Both tragedies claimed the lives of their respective crews, fourteen brave women and men in total, a powerful reminder of the dangers humanity faces as they move boldly toward the stars.
This specimen is a fragment of a mission flown High-Temperature Reusable Surface Insulation Tile (HRSI) that was once attached to the space shuttle Columbia (OV-102). HRSI tiles are made of low-density silica, but 90% of the volume is actually air. This design allowed the tiles to protect parts of the orbiter exposed to re-entry temperatures exceeding 2,300 °F (1,260 °C). NASA disposition paperwork accompanying the tile indicates it was removed after Columbia’s 7th mission, STS-61-C, which flew on January 12, 1986.
Please Note: This item includes the black, reaction cured glass coating, which sets it apart from the specimen in the Acrylic Fourth Edition Mini Museum. The material is very limited in quantity.
A Material's Engineering Triumph: The Space Shuttle's Thermal Protection System
While the Space Shuttle orbiter's structural skin consisted of a graphite epoxy over aluminum, the spacecraft would require a Thermal Protection System (TPS) capable of withstanding peak temperatures between 752 °F to 2300 °F during reentry into the Earth's atmosphere. The insulation system used to cover the metal orbiter frame consisted of different layers of protection, each specifically designed to meet the aerodynamics, weight, and temperature requirements at each location on the orbiter's shell. The three main layers of passive thermal protection systems include:
- RCC - Reinforced Carbon-carbon panels on critical surfaces such as the wing-leading edges.
- LRSI - white Low-Temperature Reusable Surface Insulation tiles protecting against extremely low temperatures in outer space.
- HRSI - 20,000 black High-Temperature Reusable Surface Insulation Tiles protecting 90% of the spacecraft surface from high temperature extremes.
RCC panels were placed on surfaces that required protection against temperatures exceeding 2,300 °F upon reentry. The lower surface of the nose cap, the wing-leading edges, and areas where the orbiter's external tanks were attached, required 22 reinforced carbon-carbon panels with T-seals. They provided thermal protection upon atmospheric entry along with improved aerodynamic performance. The LRSI tiles to protect the craft from the freezing temperatures of a sun-less environment were of the same silica-based material, except they were much thinner - a uniform 8" by 8" square with a 10 mils thick coating to resist moisture. Other thermal barriers were engineered for specific locations, such as the payload bay doors, the main landing gear, and the external tanks.
The HRSI tiles were a new generation ceramic composed of rigid, fibrous silica - protecting at temperatures below 2,300. This high-performing, engineered material is known for its robust material properties, thermal stability, and uniform molecular shape. Each tile was different from the next, as each of the over 20,000 tiles were specifically designed to meet the exact shape, weight, and possible temperature resistance required at its specific location.
These high temperature tiles were actually ninety percent air, and weighed only nine pounds per cubic foot. Depending on how much heat the specific surface area needed to withstand, the tile would vary in thickness, between 1 to 5 inches. Thicker tiles protected the front of the spacecraft, and they became thinner as they progressed towards the rear of the orbiter. The tiles were a feat of materials engineering - able to withstand thermal shock without cracking or breaking, during repeated cycles of heating and cooling in outer space and during atmospheric reentry.
As always, when the Space Shuttle crosses through the Earth's atmosphere, it is literally burning up, and several tiles in different locations are always lost. Additionally, these tiles did not possess exceptional mechanical properties. They had to be isolated from the shuttle's frame to prevent stress failures from acoustic excitation and deflection (or movement) of the orbiter's structural frame.