Orion to the Moon
Lockheed Martin’s design for the Orion represents a kind of back to the future approach to space flight. Instead of being a winged, airplane-like vehicle resembling the space shuttle, the Orion is designed as a capsule, much like the Apollo space craft that carried men to the Moon back in the late 1960s and early 1970s. NASA Administrator has famously called the Orion “Apollo on steroids.”
Of course the resemblance of Orion to Apollo is really superficial. Orion will be no more the same vehicle as Apollo than a modern 777 airliner is the same vehicle as a 1970 version of the Boeing 747 airliner.
Like the Apollo space capsule, the Orion will consist of two parts, the crew module, equivalent to the Apollo command module, and the service module. The Orion crew module will superficially resemble the Apollo command module. The Orion service module, on the other hand, will be shorter and tapered at the end, rather than the cylindrical shaped Apollo service module.
As currently imagined, the Orion crew module will have within it technology that was undreamed of by the designers of the Apollo command module. Apollo flew to the Moon will about the same amount of computer power of a modern digital watch. The avionics of the Orion crew module will incorporate not only “glass cockpit” digital control systems currently used by the space shuttle, but also “smart cockpit” technologies that have been developed for modern aircraft.
Whereas the Apollo command module was designed to land in the ocean, thus requiring a large and expensive recovery fleet, the Orion crew module will have a combination of parachute and airbags that will permit it to land on the ground.
The Orion crew module will be built of friction stirred aluminum-lithium, a composite material lighter and stronger than those with which Apollo was built. The crew module will also be protected from micrometeoroid and space debris damage by blankets of Nextel and Kevlar. A detachable heat shield is currently baselined as a phenolic impregnated carbon ablator. Much of the rest of the crew module will be resusable, though how much is yet to be determined.
The Orion crew module will have a diameter of 16.5 feet and a mass of about 25 tonnes. It will have a total pressurized volume of 691.8 cubic feet, of which 361 cubic feet is habitable. It will carry up to six astronauts, though only four will travel to the Moon on board the Orion.
There is one other vast improvement over Apollo. The Orion will have a modern waste disposal system (i.e. toilet) such as used currently on board the International Space Station and the Russian Soyuz.
The Orion service module will also be constructed of aluminum-lithium. It will carry two deployable, circular shaped solar panels to provide power for the vehicle, thus eliminating the need for hydrogen fuel cells as used in the Apollo space craft. The Orion service module will have a modified space shuttle orbital maneuvering system engine as its main rocket engine. The engine will be capable of 7500 pounds of thrust. The service module will also contain tanks for the hypergolic propellants that the engine will use, oxygen, radiators, and related hardware.
The Orion will be outfitted with a solid rocket powered escape system that will allow it to separate from its launch vehicle during an emergency. The Orion is designed to be launched into orbit by a planned launch vehicle, the Ares 1, also under development.
Officially, the first crewed Orion is scheduled to launch into low Earth orbit in September, 2014. Some observers have pointed out that this would create a “gap” in American capacity to launch people into space, since the last space shuttle mission is scheduled to launch in 2010. On the other hand, NASA recently selected two commercial companies, under the Commercial Orbital Transportation Systems (COTS) program to develop vehicles to send people and cargo to the International Space Station by 2010.
The fact that the initial version of the Orion will also be capable of taking people and supplies to the ISS has caused some controversy. Would it constitute a government financed competition to the commercial vehicles being developed under COTS? Others maintain that NASA needs to Orion as a “backup” vehicle, in case the vehicles under COTS fail to materialize. In any case, Orion missions to low Earth orbit will be needed to test its systems before a voyage to the Moon is attempted.
