Space Shuttle System: The History and Engineering of NASA's STS

From 1981 to 2011, the Space Transportation System (STS), commonly known as the Space Shuttle, served as the backbone of American human spaceflight. This partially reusable spacecraft system was designed to provide crewed orbital launch and reentry capabilities, enabling NASA to conduct unprecedented scientific research, deploy vital satellites, and construct the International Space Station (ISS).

The system was a complex integration of three primary components: the orbiter (the winged spacecraft that carried the crew and cargo), the Solid Rocket Boosters (SRBs), and the massive External Tank (ET). Together, these elements formed a heavy-lift vehicle capable of transporting massive payloads into Low Earth Orbit (LEO).

The five Space Shuttle orbiters launching — Shuttle launch profiles. From left: Columbia, Challenger, Discovery, Atlantis, and Endeavour

Key Facts

Enterprise being release from the Shuttle Carrier Aircraft for the Approach and Landing Tests — Enterprise during the Approach and Landing Tests

Program Duration: 1981 to 2011
Total Missions: 135 launches
Success Rate: 133 successful missions; 2 failures
Orbiter Fleet: Columbia, Challenger, Discovery, Atlantis, and Endeavour
Primary Launch Site: Kennedy Space Center, Florida
Total Program Cost: Approximately US$211 billion (2012 value)

Technical Specifications and Capabilities

The Space Shuttle Columbia launching on the first Space Shuttle mission — Columbia launching on STS-1[b]

The Space Shuttle was a marvel of engineering, designed to meet the heavy-lift requirements of both NASA and the U.S. Air Force. The system's scale was immense, with a stacked vehicle height reaching 56 meters (184 feet).

The Orbiter and Payload Bay

The orbiter functioned as the crew's home and the primary cargo carrier. Its payload bay, measuring 18 meters (60 ft) long and 4.6 meters (15 ft) wide, was essential for carrying large satellites, scientific modules like Spacelab, and components for the ISS. To manage the extreme heat of reentry, the orbiter utilized a sophisticated thermal protection system, including ceramic tiles.

The Space Shuttle Columbia under construction — Columbia undergoing installation of its ceramic tiles

The payload bay doors also served a critical thermal function; once in orbit, they were opened to act as radiators, rejecting excess heat from the vehicle.

Atlantis in orbit in 2010. Image shows the payload bay and the extended Canadarm.

Spacelab in the payload bay while in orbit — Spacelab in orbit on STS-9

Propulsion: Engines and Boosters

To reach orbit, the shuttle relied on a combination of liquid and solid propulsion. The orbiter was powered by three RS-25 engines, which used liquid hydrogen (LH2) and liquid oxygen (LOX) stored in the External Tank. These engines provided high efficiency with a specific impulse of 455 seconds.

The two engine systems at the aft-section of the orbiter — RS-25 engines with the two Orbital Maneuvering System (OMS) pods during STS-133

Providing the initial massive thrust required for liftoff were two Solid Rocket Boosters (SRBs). These boosters burned for approximately 124 seconds, contributing a combined 27 MN of thrust. The propellant used in the SRBs was a mixture of PBAN and APCP.

Two Solid Rocket Boosters that are not attached to an external tank or orbiter — Two SRBs on the mobile launcher platform prior to mating with the ET and orbiter for STS-134

Early ignition and lift-off view of main-engines and SRB (ground-camera view)

The External Tank (ET)

The External Tank was the central structural link between the orbiter and the SRBs. It held the liquid oxygen and liquid hydrogen necessary for the RS-25 engines. The tank was coated in orange spray-on foam to protect it from the intense heat of ascent.

The ET from STS-115 after separation from the orbiter. The scorch mark near the front end of the tank is from the SRB separation motors.

On-board camera-view of external-tank separation

Mission Profiles and Operations

The view from the Atlantis cockpit while in orbit — Atlantis was the first Shuttle to fly with a glass cockpit, on STS-101.

A typical shuttle mission involved a highly choreographed sequence of events. During ascent, the RS-25 engines were throttled to manage aerodynamic stress at Max Q (the point of maximum dynamic pressure). Once in orbit, the crew could utilize the Remote Manipulator System (a robotic arm) to deploy satellites or service telescopes like the Hubble Space Telescope.

An astronaut conducting an EVA while the Hubble Space Telescope is in the payload bay — Story Musgrave attached to the RMS servicing the Hubble Space Telescope during STS-61

Following mission objectives, the orbiter would perform a high-speed reentry, utilizing its thermal protection system to survive the atmospheric friction before gliding to a landing at a designated site, such as the Kennedy Space Center.

Discovery deployed a parachute to slow itself after landing — Discovery deploying its brake parachute after landing on STS-124

The Space Shuttle Discovery on the runway as ground crews work to get the crew out of the orbiter — Discovery being prepared after landing for crew disembarkment following STS-114

Summary of Shuttle System Data

The two general-purpose computers used in the orbiter — General Purpose Computers: AP-101S (left) and AP-101B CPU with I/O Processor (right)

Space Shuttle System Overview
Feature	Specification
Stacked Height	56 m (184 ft)
External Tank Diameter	8.7 m (29 ft)
Total Launch Mass	2,030,000 kg (4,480,000 lb)
Payload to LEO (Altitude 204 km)	27,500 kg (60,600 lb)
Payload to ISS (Altitude 407 km)	16,050 kg (35,380 lb)
SRB Burn Time	124 seconds
RS-25 Burn Time	480 seconds

Frequently Asked Questions

A recovery boat with a recovered Solid Rocket Booster — MV Freedom Star towing a spent SRB (STS-133) to Cape Canaveral Air Force Station

The Space Shuttle moving to the launch complex on a crawler-transporter — The crawler-transporter with Atlantis on the ramp to LC-39A for STS-117

Shuttle lift-off via on-board camera view.

The Space Shuttle Endeavour docked with the International Space Station — Endeavour docked at ISS during the STS-134 mission

A view of the commander and pilot during reentry on STS-42 — Flight deck view of Discovery during STS-42 re-entry

STS-51-L Challenger loss, shortly after launch - January 28, 1986.

STS-107 Columbia disintegrates during atmospheric re-entry - February 1, 2003.

Atlantis being towed back with some workers in the front after its final landing — Atlantis after its final landing, marking the end of the Space Shuttle Program

What were the main components of the Space Shuttle?

The system consisted of the winged orbiter, two Solid Rocket Boosters (SRBs), and a large External Tank (ET) that provided fuel to the orbiter's main engines.

How many orbiters were in the shuttle fleet?

Five complete orbiter vehicles were built and flown: Columbia, Challenger, Discovery, Atlantis, and Endeavour.

What caused the two major shuttle disasters?

The program suffered two tragic losses: the Challenger (STS-51-L) during launch in 1986, and the Columbia (STS-107) during atmospheric reentry in 2003.

What was the primary purpose of the Space Shuttle?

The shuttle was designed for crewed orbital launch and reentry, allowing NASA to deploy satellites, conduct scientific research, and build the International Space Station.

When did the Space Shuttle program end?

The program officially concluded with its final flight, STS-135, on July 21, 2011.