The flying Orion Module.
Orion is the first spacecraft designed to transport astronauts as far as Mars. NASA plans to launch the first Orion test flight later this year. Longer distance space flight poses a number of design challenges.
“In deep space the challenges are zero gravity and a radiation environment. So bone loss, muscle loss and the radiation as you don’t have the atmosphere of the Earth to protect you,” said Laurence Price Deputy Program Manager at Lockheed Martin.
Price is talking about the Van Allen Belt, a tightly packed field of radiation around the earth that acts as a layer that protects earth from charged ions. NASA has to study this area of radiation before they can send a manned spaceflight through it, and possibly on to Mars sometime after 2020.
The test flight will allow NASA to, among other things, experiment with different approaches to shielding radiation. “At Langley we have an analysis tool that we use that understands the shielding and the ability of different materials to shield different types of radiation,” said Mark Geyer Manager of the Orion Program at NASA. Price added, “So these are things we have to solve in the future before we can have long duration exploration with humans following machines.”
A Student Competition
Team ARES (Green) and the remaining 4 finalist teams in front of an inflatable Orion Module.
To come up with a radiation shield, Lockheed Martin, NASA and the National Institute of Aerospace (NIA) created the Orion spacecraft Exploration Design Challenge for high school students. “So the idea behind the challenge is to get the students interested in something that is very necessary and we need to make a lot of progress in it… the students put a proposal together and build an experiment to measure the different approaches to radiation shielding,” said Price.
Student teams from around the country participated in the competition. Five finalists were selected to create models of their designs of a shield to house a radiation dosimeter. Geyer said, “We took the designs these guys (the five finalist teams) came up with and then ran them through a model to see how effective they would be.”
The Winners
While at the USA Science and Engineering Festival last week, the winning design was announced by Team ARES from the Governor’s School for Science and Technology in Hampton, VA.
The American Radiation Eradication in Space (ARES) team created a 7” cubic shield called the Tesseract. It will house and protect a dosimeter from radiation while in flight. The final incarnation will be made of Tantalum, Tin, Zirconium, Aluminum, and Polyethylene. The heavy metals will block gamma rays while ions and neutrons are captured by the hydrocarbons of the polyethylene. The students selected their materials based on cost, malleability, machinability, weight, and abundance. Thanks to CAD models, the design was made to have flanges and bolts which allow the Tesseract to be strong, easily produced, and opened.
"This is a great day for Team ARES– you have done a remarkable job… I really want to congratulate all five of our finalists. You are outstanding examples of the power of American innovation. Your passion for discovery and the creative ideas you have brought forward have made us think and have helped us take a fresh look at a very challenging problem on our path to Mars," said Charles Bolden, NASA Administrator.
Now ARES will work with Lockheed Martin and NASA to have their final prototype built, integrated, and approved for test flight.
The Orion Module
Mock-up of the Orion Module.
Geyer said, “Orion is the capsule system that will allow crews to go into deep space. The crew module at the top capsule part is where the crew actually lives and work. It’s where their suits would be, seats would be, it is also where heat shield is when they get back to Earth. The bottom part is the service module that has the solar arrays. It has the propulsion system, the large orbital maneuvering engine and these RCS (Reaction Control System) thrusters for attitude control and the heat rejection…”
Price mentions that the Orion Module looks a lot like the old Apollo capsules because they already have a lot of the aerodynamics data on this shape. The ship can even fly a bit as it experiences some lift. It is also a much cheaper approach to a shuttle.
Geyer expands by saying that, “coming back from the moon, you’re coming back a lot faster (than from orbit), so thermal protection with the capsule you can make it a lot simpler if you don’t have wings… Material called an ablator burns off which keeps the capsule cool, as it heats up it ablates and provides a layer of cooling between itself and the capsule. Something like the tiles on the shuttle would not be strong enough.”
By the time Orion takes off to Mars, some of these students might be manning Mission Control.
Reference Lockheed Martin.
Image from Wikipedia.
