— Ch. 1 · Origins And Evolution —
Orion (spacecraft).
~7 min read · Ch. 1 of 6
The idea for a Crew Exploration Vehicle arrived on the 14th of January 2004. It emerged as part of the Vision for Space Exploration following the Space Shuttle Columbia accident. A design competition followed, and Lockheed Martin won with their proposal. The agency later named it Orion after the stellar constellation and mythical hunter. This version became part of the Constellation program under NASA administrator Sean O'Keefe. The original plan intended to land on solid ground using airbags before switching to ocean splashdown. The service module was originally planned to use liquid methane fuel but switched to hypergolic propellants due to technology limitations. The goal was to launch by 2012. On the 7th of May 2009, the Obama administration enlisted the Augustine Commission to review the ongoing space exploration program. The commission found the Constellation Program woefully under-budgeted and behind schedule by four years or more. As a consequence, the commission recommended significant re-allocation of goals and resources. On the 11th of October 2010, the Constellation program was canceled, ending development of the Altair, Ares I, and Ares V rockets. The Orion Crew Exploration Vehicle survived the cancellation and transferred to be launched on the Space Launch System. The development program restructured from three different versions into the Multi-Purpose Crew Vehicle as a single version capable of performing multiple tasks.
Engineering Architecture
The Orion crew module is a reusable transportation capsule that provides habitat for the crew. It contains storage for consumables and research instruments plus a docking port for crew transfers. This module is the only part of the spacecraft returning to Earth after each mission. Its shape measures 57.5 degrees frustum with a blunt spherical aft end. The diameter spans roughly five meters while length reaches about seven meters. Mass totals approximately nine tons. Lockheed Martin Corporation manufactures it at Michoud Assembly Facility in New Orleans, Louisiana. The module holds fifty percent more volume than the Apollo capsule and carries four astronauts. NASA selected the Avcoat ablator system to provide heat protection during reentry. This material consists of silica fibers with resin inside fiberglass honeycomb cells. The CM uses Glass cockpit digital control systems derived from Boeing 787 aircraft. An autodock feature allows flight crews to take over operations in emergencies. Waste management facilities include a miniature camping-style toilet and unisex relief tube used on the Space Shuttle. A nitrogen-oxygen mixed atmosphere maintains either sea level or reduced pressure conditions. Construction utilizes aluminium-lithium alloy for durability. Recovery parachutes use Nomex cloth based on designs from both Apollo and Space Shuttle Solid Rocket Boosters. Water landing remains the exclusive means of recovery for the Orion Crew Module. The European Service Module propels and powers the spacecraft while storing oxygen and water for astronauts. Solar energy replaces fuel cells allowing longer missions. The Launch Abort System separates the crew module from the launch vehicle using three solid rocket motors.