Human Operations in Space During the Space Shuttle Era

Abstract

Abstract When the Space Shuttle Columbia was launched on its maiden flight 20 years and more than 100 flights ago, it carried a crew of two, an instrumentation pallet as its only payload, and the key mission objectives were to see if launch and landing could be performed safely. That launch also carried the promise of a new era of space operations, including research in space, launching and retrieving of satellites, in‐orbit maintenance of spacecraft, and ultimately the building and use of a space station. Slowly and deliberately during these 20 years, the flight team on the ground and in orbit has developed the maturity of operations in space and the goal of achieving complex operations with humans from the Space Shuttle. This article looks back at the last 20 years of Space Shuttle operations to review what has been accomplished in attaining these objectives. The goal of this review is not to serve as a chronology of all 100 flights, but rather to highlight some of the key milestones in developing the sophisticated level of human operations in space that is possible today. On NASA promotional material published before STS‐1 highlights one of the claims made for the Space Shuttle before its first mission: “Shuttle crews will be able to retrieve satellites from Earth orbit and repair and redeploy them or bring them back to Earth for refurbishment and reuse. The Shuttle can be used to carry out missions in which scientists and technicians conduct experiments in Earth orbit or service automated satellites already orbiting.” The key design characteristics of the Space Shuttle that made these claims possible 20 years ago included a heavy lift launch capability, a large payload bay, a robotic arm, the ability to carry a sizable crew, development of routine extravehicular activity (EVA) capability, and reusability of most key system components. Methodically, step‐by‐step during the last two decades, the ability of humans to work in space was expanded, increasingly more complex tasks were undertaken, and more and more of the resources of the crew and Shuttle were devoted to accomplishing the mission objectives. Neither large flight rate nor vehicle autonomy has been achieved. In fact, the greatest number of flights flown in one calendar year was eight and, although mission control has been streamlined since STS‐1, particularly by using modern software applications and workstations, the issue of the appropriate division of labor between the ground and the flight crew is still debated today. Nevertheless, the vision of the Shuttle as a versatile platform for humans, hardware, and associated space operations was realized very much as advertised 20 years ago. This article concludes with a discussion of the assembly of the International Space Station and what type of vehicle should replace the shuttle.