Coming Together

Hey everyone, Kevin here. Today is Sunday the 21st of March. Tomorrow we have a pretty substantial report due for our design class. At this point it is our responsibility to have the design nearly finalized and I think we are panicing a little! Most of our group was here at engineering hall last night (morning) until past 6am working on this design and we anticipate being up late again tonight! Fortunately some of us were able to break away for a while to watch the badgers get slaughtered by cornell.
All in all, even though we feel behind, I am optimistic about how mcuh we have really gotten done. The life support systems are almost all modeled in Solidworks, the fuel tanks and engine have been spec'ed, the structural frame has undergone some vibrational analysis and the crew cabin is starting to take serious shape. While I'm running on minimal amounts of sleep at the moment, I feel confident that we can hammer this out by the end of the semester. I'm looking forward to finishing up the design!

Damping Update

Update on the damping system. We decided to go with dry damping (Couloumb Friction) to damp the landing. Essentially, the system will work like car brakes, using plates to rub against each other to create friction. We have done some preliminary calculations to see the response of LEVITATE when it touches down. Here is a graph showing the response, or the motion the crew will feel when they land.

Damping the Frame

Hey Everybody,

Tim here with some news on the structure. When the spacecraft lands on the surface, there will be a lot of loads on the structure. Tyler and I are worried about the "dynamic" loads, or the ones caused by motion. Specifically, we want the structure to be strong enough to touch down, but also stop the motion. In structures on Earth, we use shock absorbers, which are a type of damper. Most shock absorbers on Earth use fluids such as oil to create a resistance to motion (actually a resistance to velocity!) Because the temperatures on the moon are so extreme (-300F to +300F) we cannot use fluids. Here are soem alternatives that Tyler and I are investigating:

• Memory Shape Alloys
• Magnetic Damping
• Gaseous Damping
• Heated Fluid Shock Absorbers

Memory shape allows would deform as the craft lands, but with a current or temperature change, return to their original form. Magentic damping has to do with eddy currents cause by magnetic flux. Gaseous damping would implement a gas whose viscosity does not depend on temperature greatly, but similar to shock absorbers. Lastly, the heated fluid shock absorbers would be similar to those used on Earth, but maintained at a constant working temperature.

These are just some preliminary ideas. Let us know if you have any questions or comments!

Tim

Life Support

Kevin here, providing a quick update on life support. As of now, the life support systems will consist of 5 subsystems to provide LEVITATE's crew with a habitable environment.

The Trace Contaminate Removal System (TCRS) will provide a means to scrub the air of basic contaminates produced from electronic offgassing and metabolic processes. These things might include ammonia, carbon monoxide, methane, etc... It will use an activated charcoal bed to trap the contaminates and a catalytic oxidizer to combust the low molecular weight components like CO and CH4.

The Carbon Dioxide Removal System (CDRS) will remove CO2 from the cabin. It will use molecular seive media to trap the CO2. This media can be regenerated under heat and vacuum. Therefore, multiple beds will be used on LEVITATE to provide a regenerative system. This will provide a long-life minimum maintenance system for the crew.

The Temperature and Humidity Control (THC) sub-system will provide a means to control the temperature and humidity. It will use two heat exchanger asssemblies which utalize hydrophilic fins to control condensate and temperature levels.

The condensate and other waste water from the cabin will be processed in the Waste Water and Condensate Processing (WWCP) assembly. This system utalizes a distillation assembly to purge the contaminated water of brine and other micro-organisms so the crew can have refreshed water stores throught their mission.

Finally, the Nitrogen and Oxygen Control (NOC) system will provide the cabin pressurization as well as the breathable oxygen that we require to survive. Since the mission duration of LEVITATE is specified to be no more than 14 days, onboard oxygen will not be required.

These life support systems will be stored in standard ISS lockers, which can be house in standard ISS EXPRESS Racks. Each locker is approximately 20" x 10" x 15". Each rack is about 6' tall, 40" wide and 2' deep. Each rack can hold ~ 8-10 Lockers.

I'm looking forward to more posts in the future!

-Kevin and the UW LEVITATE Team

Presentation #1

We are presenting for the second time this semester (still presentation #1 though).

We will be presenting on:

• Preliminary Structural Considerations
• STK Simulation of Orbital Trajectory
• Propulsion Decisions
• Life Support Systems
• Preliminary Cost Analysis

Also, you can follow us on twitter now at: http://twitter.com/uw_levitate

Welcome to Our Blog!

We are keeping this blog as a way to keep people informed of our progress on our design project LEVITATE.

LEVITATE stands for Lunar Exploration Vehicle for Intra-planetary Transport And Terrestrial Expansion. It is a concept vehicle that will allow two astronauts at a permanent lunar base to fly anywhere on the lunar surface they want, conduct research for up to 14 Earth days, then return to the base with cargo to analyze.

This project is the objective of our capstone course EMA 569 and also a finalist in the 2010 RASC-AL competition. We are very excited about our design and will keep you updated as we continue in the process.

- Team LEVITATE