KENNEDY SPACE CENTER, Florida-- The future of human space transportation, not only into Earth orbit, butalso back to the Moon and onto Mars, kick-started this week as NASA receivedcontractor proposals for the Crew Exploration Vehicle (CEV).
A glimpse into one concept -- provided by Lockheed MartinSpace Systems near Denver, Colorado - shows a lifting body craft thatcan be outfitted for lunar as well as Mars operations.
"Basically what we came down on was the side of safety forthe crew in making our decision to go with a lifting body," said Patrick McKenzie, CEV BusinessDevelopment Manager at Lockheed Martin Space Systems Company.
Additionally, the design of the basic vehicle would allow itto be utilized to support near-term human expeditions to the Moon, as well asMars in the future, McKenzietold SPACE.com in a phone interview.
McKenziesaid the lifting body design was preferred over a capsule for several reasons.
For one, that approach allows more cross-rangemaneuverability, thus the craft can touchdown on land versus water. Secondly, alifting body can lessen the g-loads on returning crews from long-duration spacestints, McKenzie said.
Whether they are lengthy stays in Earth orbit, a prolonged missionon the Moon, or the round-trip trauma on the human body from a Mars mission -the lifting body approach helps to minimize the g-forces on crew members, McKenzie noted.
As part of a flight test program, McKenzie said that an unpiloted,full-scale version of the front-end of the company's CEV design -- a rescuemodule -- would be flown to verify the safety elements of getting a crew backunder a wide-range of circumstances. That would take place in 2008.
One feature of the company's CEV design -- along with thefirm's teammates -- is use of a titanium shell, along with two layers ofthermal protection materials.
"Even in the highly unlikely circumstance that you mighthave a burn through of the outer thermal protection system, the crewcompartment inside would maintain its integrity and that burn through would notend up being a fatal situation for the crew," McKenzie said.
McKenzieemphasized that the first mission for a CEV is returning to low Earth orbit."But it makes sense to make sure that the vehicle that you'redeveloping this first go-round is going to be lunar capable," he added, withthe firm's engineers also looking into how the concept could be made Marsready.
"We're attempting to the best extent possible to build inmodularity into our systems and maintainability and ease of operations...so asnew technologies and new capabilities are developed over the next 10 to 15 to20 years, we'll be able to take advantage of those without having to totallyredesign a new vehicle," McKenziesaid.
McKenziesaid that Lockheed Martin stands ready to work with NASA to help realize astated objective of incoming NASA chief, Michael Griffin - to try and close thegap between shutdown of the shuttle in 2010 and operating a piloted CEV in2014.
Furthermore,use of the CEV to support the International Space Station is on the table.
"Our CEV will certainly be capable of servicing station," McKenzie stated,but the company's proposal did not address that use as a key top requirement.This prospect would receive a thorough look early in the execution of a CEVprogram if the firm is selected, he said.
NASA has announced in the past the plan to award two teamsCEV work this September.