The Space Shuttle program, a cornerstone of NASA’s human spaceflight efforts for three decades, captivated the world with its daring missions and technological prowess. One of the most frequently asked questions about this iconic spacecraft is: how fast does the space shuttle travel? Let’s delve into the details of the orbiter’s speed and explore the factors that influenced its velocity.
Understanding the Orbiter: The Heart of the Space Transportation System
The Orbiter was a marvel of engineering, serving as both the brains and heart of the Space Transportation System. Comparable in size and weight to a DC-9 aircraft, it housed the pressurized crew compartment (accommodating up to seven astronauts), the expansive cargo bay, and the three main engines at its rear.
Orbiter Dimensions:
- Height (on runway): 57 feet
- Length: 122 feet
- Wingspan: 78 feet
The forward fuselage contained the cockpit, living quarters, and experiment operator’s station. The mid-fuselage held the payload bay, while the aft fuselage housed the main engines and maneuvering thrusters.
The Ascent: A Symphony of Speed and Power
The Space Shuttle’s ascent was a carefully orchestrated dance of power and precision. The three Space Shuttle Main Engines (SSMEs), in conjunction with the Solid Rocket Boosters (SRBs), provided the initial thrust to lift the Orbiter off the ground. The SSMEs continued firing for approximately 8.5 minutes after launch, powering the Shuttle’s journey into orbit.
STS-36 Atlantis glides above Runway 23 at Edwards Air Force Base
Alt text: Space Shuttle Atlantis, designated OV-104, approaches landing at Edwards Air Force Base, with landing gear deployed.
After the SRBs were jettisoned, the main engines accelerated the Shuttle from 4,828 kilometers per hour (3,000 mph) to over 27,358 kilometers per hour (17,000 mph) in just six minutes. This incredible acceleration was crucial for achieving orbital velocity. Together, the engines generated a maximum thrust exceeding 1.2 million pounds.
Main Engine Power: Fueling the Journey to Orbit
The SSMEs were high-performance engines that burned liquid hydrogen and liquid oxygen, consuming half a million gallons of propellant from the external fuel tank during ascent.
Space Shuttle Main Engines inside the Engine Shop at Kennedy Space Center
Alt text: Six Space Shuttle Main Engines (SSMEs) from Endeavour and Atlantis missions are prepared for shipment to Stennis Space Center.
These engines operated at a liquid oxygen/liquid hydrogen mixture ratio of 6 to 1, producing a sea-level thrust of 179,097 kilograms (375,000 pounds) and a vacuum thrust of 213,188 kilograms (470,000 pounds). The engines could be throttled from 65% to 109% to manage acceleration during the ascent phase.
Solid Rocket Boosters: Providing the Initial Push
The Solid Rocket Boosters (SRBs) worked in tandem with the main engines during the first two minutes of flight, supplying the additional thrust required to overcome Earth’s gravity.
Solid Rocket Booster being transported to California Science Center for display
Alt text: A Space Shuttle Solid Rocket Booster (SRB) is transported by truck to the California Science Center in Los Angeles.
SRB Facts:
- Thrust at lift-off: 2,650,000 pounds per booster (total of 5,300,000 pounds)
- Weight (Gross): 1,300,000 pounds
At an altitude of roughly 45 kilometers (24 nautical miles), the SRBs separated from the orbiter and external tank, descending via parachute into the Atlantic Ocean for recovery and reuse.
Reaching Orbital Velocity: The Key to Staying in Space
So, how fast does a space shuttle need to travel to stay in orbit? To maintain a stable orbit around Earth, the Space Shuttle needed to reach a velocity of approximately 28,000 kilometers per hour (17,500 miles per hour). This speed balanced the force of gravity with the centrifugal force of the orbiter’s motion, allowing it to continuously “fall” around the Earth without crashing into it.
The External Tank: Fueling the Journey
The External Tank (ET) was the Orbiter’s “gas tank,” containing the liquid hydrogen and liquid oxygen propellants used by the SSMEs.
Workers inspect External Tank 118 in the Vehicle Assembly Building
Alt text: Workers in the Vehicle Assembly Building inspect External Tank 118 before transfer to NASA’s Michoud Assembly Facility.
External Tank Stats:
- Weight Empty: 78,100 pounds
- Weight Propellant: 1,585,379 pounds
The ET also served as the structural backbone of the Shuttle during launch, providing attachment points for the SRBs and the Orbiter. Approximately 8.5 minutes into the flight, the ET was jettisoned and disintegrated in the atmosphere.
Conclusion: The Space Shuttle’s Incredible Speed
The Space Shuttle’s speed was not just a number, but a testament to human ingenuity and engineering excellence. The ability to accelerate from standstill to over 17,000 mph in a matter of minutes was a critical component of the Space Shuttle Program. How fast does the space shuttle travel? It traveled fast enough to overcome Earth’s gravity and open new frontiers in space exploration. The Orbiter’s legacy lives on, inspiring future generations of scientists, engineers, and explorers.
