TransFormers for Lunar Extreme Environments
This summer of 2016 I will be joining the TransFormers for Lunar Extreme Environments Project at NASA’s Jet Propulsion Laboratory. The aim of the project is design large deployable solar reflectors that can transform the ~90k (~ -300°F) eternally dark interior of Shackleton Crater to an environment that could support robotic, and eventually human, exploration.
Trans-Formers for Lunar Extreme Environments: Ensuring Long-Term Operations in Regions of Darkness and Low Temperatures. NASA Innovative Advanced Concepts Presentation.
Presentation begins at 26:27
Ends at 52:50
Total presentation time: 26 minutes 23 seconds
Shackleton Crater. The rim of the crater surrounds the moon’s south pole at a height 4.2km (13,800ft) above the crater floor. The crater floor is thought to bear water ice and mineral hydrates in its regolith. The crater floor is 6.6km (4.1 miles) in diameter.
The colonial appeal of Shackleton Crater stems from its unique location at the lunar south pole where darkness and extremely low temperatures have allowed icy comet debris to accumulate for billions of years. This icy debris, composed of water ice and mineral hydrates, could be processed into liquid hydrogen and oxygen, then prepared for use as rocket fuel. There may be enough icy ore to fuel a shuttle launch from the moon every day for 2,000yrs, and require less energy than on Earth to do so, where the force of gravity is much stronger. A dramatic reduction in fuel costs and energy use would catalyze Mars colonization. A limited, but recyclable reservoir of water on the Moon would also catalyze lunar colonization. Each endeavor, a forward thrust into planetary exploration. Due to eternal darkness and low temperatures however, robots without heavy and expensive radioisotope thermoelectric generators would be unable to operate. Reflecting solar energy from the nearly eternally lit crater rim offers an alternative.
Origami Solar Reflectors
In direct contrast to Shackleton Crater’s cold dark interior, its rim receives sunlight nearly all year round, lunar eclipses permitting. A single solar reflector with 1,000m2 of reflecting surface area would be able reflect 300W/m2 at a distant of 10km (6.2 miles) to the crater floor, and be capable of powering hundreds of MSL-class rovers at once. Several of these reflectors would further increase the illumination area and effectively transform the environment, at select sites around the crater floor, to one that sustain robotic exploration and lunar colonization. A reflector of this size, approximately 41m by 30m, would have to be stowed to a size small enough, ~1m3, to be transported to the moon, and deploy after placement on the crater rim. Where tightly packing and deploying a large surface reliably offers a challenge, origami offers a solution.
It would also be advantageous if the solar reflector could transform their shape (to focus sunlight), generate power (for powering reflector movements), and also function as an antennae with circuits running through the reflector membrane (in order to provide telecommunications with the robots and Earth)
President Bush Calls for an Extended Human Presence on the Moon
January 14th, 2004
Returning to the moon is an important step for our space program. Establishing an extended human presence on the moon could vastly reduce the cost of further space exploration, making possible ever more ambitious missions.
Lifting heavy spacecraft and fuel out of the Earth’s gravity is expensive.
Spacecraft assembled and provisioned on the moon could escape its far-lower gravity using far less energy and thus far less cost.
Also the moon is home to abundant resources. Its soil contains raw materials that might be harvested and processed into rocket fuel or breathable air.
We can use our time on the moon to develop and test new approaches and technologies and systems that will allow us to function in other, more challenging, environments. The moon is a logical step toward further progress and achievement.
With the experience and knowledge gained on the moon, we will then be ready to take the next steps of space exploration: human missions to Mars and to worlds beyond.
In Favor of an Extended Human Presence on the Moon
In response to President Bush’s call and as part of the California Cadet Corps state Individual Major Awards Competition, I gave a speech at the capitol building in Sacramento in favor of establishing a base on the Moon where permanently shaded regions could be accessed for harvesting water-ice. In response to my speech and my activities in the California Cadet Corps I was recognized by the California Senate and Legislature with a certificate.
Joining the TransFormers for Lunar Extreme Environments Project
June 16th, 2016
I joined the TransFormers for Lunar Extreme Environments to help meet the challenge of designing large deployable solar reflectors for illuminating permanently shaded regions on the Moon.
The original solar reflector design consists of 1,000 hinged and interlocking reflective panels, less than 1mm thick, that deploy from a cube 1 cubic meter in volume. The packing efficiency is nearly 100%, but to achieve the required flatness high precision interlocking mechanisms and actuators are required. The mass of the rigid panels, actuators, and interlocking mechanisms could be reduced by deploying a taught membrane instead. The procession of origami crease patterns were designed to deploy that membrane and determine its material composite through finite element analysis.
A Tale of Two designs
July 7th, 2016
Spiral Type crease patterns have the advantage of being more compact and having more free volume in the center of the stow envelope than their concentric counter part. The Concentric Type crease patterns can be made from an order of magnitude less panels than the spiral type, if the reflector is divided into rigid interlocking panels instead of a flexible membrane.
Spiral Type Deployment Sequence
Concentric Type Deployment
Deploying the Massive Membrane
August 5th, 2016
Inspired by the design of L’Garde’s inflatable rigidizable antennae, we decided to take a similar approach of using an inflatable rigidizable torus to inflate our reflectors.
Below is L’Garde’s demonstration of their antennae deployment in low Earth orbit
A New Degree of Freedom: Crease Pattern Developments
August 9th, 2016
By subdividing the gores and increasing the thickness accommodation values in the equations, a new degree of freedom is earned, where one can control stow height independently of the number of gores. New algorithms will need to be developed in order to include these folds into future designs while maintaining maximum compaction.
2m Solar Reflector with Inflatable Deployable Torus Complete
August 18th, 2016
This reflector doesn’t include an origami pattern, but the next reflector due for completion at the end of 2016 will.
A Reflector Inspired by Racing Sails
August 24th, 2016
It may be that the world’s best racing sails are well suited for our applications, especially tape driven sails. Tape driven sails are made of very light weight, high Young’s modulus, and UV resistant UHMWPE fabric with carbon fiber fabric tape running along the load bearing paths to prevent permanent “creep” of the fabric. Alternatively, a die cut carbon fiber polymer sheet with a sheet of aluminized biaxially-oriented polyethylene terephthalate on top may be used.
2m Deployable Solar Reflector in Process
December 16th, 2016
Preparing to fold a 2m prototype from aluminized biaxially-oriented polyethylene terephthalate.
2m Deployable Solar Reflector
January 25th, 2017
Paper Inflatable Torus Attachment Test
March 6th, 2017
Newly Attached Inflatable Torus
March 20th, 2017