By Jonathan Goff
CEO and President
Altius Space Machines
Part 2 of 2
In the last post, I introduced the two SBIR Select Phase 1 contracts that Altius has commenced work on. This blog post will focus on the other two Asteroid Redirect Mission contracts which mentioned there. These have been selected for contract negotiation, but aren’t active contracts yet, so I will try to be a little more high-level in this blog post.
Asteroid Redirect Mission Background
Before jumping into a discussion of our contract wins, I’d like to provide a short background on NASA’s Asteroid Redirect Mission for those who haven’t been following the mission closely. Starting around 2011, NASA has been studying Near Earth Objects (NEOs) as a potential next destination for human exploration. While there have been some innovative industry ideas for how to do this, such as the “Plymouth Rock” mission conceived by Josh Hopkins’ group at Lockheed Martin, a Keck Institute study from the 2011-2013 timeframe suggested an alternative to visiting a “free-range” NEO—sending a robot out to bring a whole NEO back to lunar orbit for further study. This “asteroid heist” approach has the benefit of both bringing a lot more material back to the Earth-Moon system (almost an ISS-equivalent mass!) on the first mission, and being available for multiple follow-on visits from NASA and/or commercial entities. Depending on how lucky NASA gets with the material content for the asteroid it brings back, this could be really interesting both for getting experience in processing asteroidal materials, and for providing an initial, convenient, easy-to-reach destination for commercial mining operations to start with. It also provides a destination for manned exploration that are actually reachable with the SLS/Orion system that Congress is having NASA invest so much of its human spaceflight resources into.
NASA has been studying two main categories of approaches for this mission: the original Keck study approach of enclosing a whole 6-10m diameter asteroid in a bag for return, and an approach using one or more robotic manipulators to pluck a 3-10m boulder off the surface of a larger asteroid.
Here are animations of the two main approaches:
While the boulder capture approach above shows the use of a space-truss grasper, the group we worked with on the DARPA Phoenix Gecko Gripper project is also looking at approaches using 7DOF robotic manipulators with microspine grippers, and other NASA groups are studying a variety of other hybrid approaches, as outlined in this presentation.
So where does Altius fit into all of this? Starting about a year ago, NASA started reaching out to industry to solicit feedback and additional approaches, and in late March they released a Broad Area Announcement solicitation to fund industry research in some of the areas they had identified from that industry outreach process. One of the topic areas was for asteroid capture mechanisms, including boulder capture mechanisms. Another topic area was for studying the idea of adapting commercial spacecraft buses for use on the ARM mission, instead of NASA developing a custom Solar Electric Propulsion bus for this mission.
Release the Kraken (Asteroid Boulder Retrieval System)!
Of the proposals Altius submitted to the asteroid capture mechanism subtopic, the one that NASA selected for contract negotiation was by far the crazier more creative of the two—our Kraken Asteroid Boulder Retrieval System. We named it Kraken after the mythical sea monster because the proposed boulder grasping mechanism ended up looking and functioning a lot like an octopus or squid’s suckered tentacles. Any relation to silly Liam Neeson-y internet memes or awful 2010 action movies was entirely coincidental at the time.
The proposed Kraken system is a hybrid of several boulder retrieval approaches that builds on some of the previous work Altius has performed over the years on Sticky Boom™ and other non-cooperative graspers and resettable space adhesives. Altius will be priming this contract with support from Empire Robotics, Brad Blair of NewSpace Analytics LLC, and Lockheed Martin Space Systems.
The Kraken system consists of two main components:
- A selectively-compliant, underactuated, space-truss grasper, using space-compatible jamming grippers for local adhesion (think: “space octopus”)
- A 5DOF STEM Arm for situational awareness and electrodynamic dust collection (think: “shop vac that works in vacuum”)
The STEM Arm(s) are used to perform close inspection/mapping of the candidate boulder, electrodynamic removal of regolith from the boulder surface and around the boulder base, and if desired can also collect additional regolith samples from other locations around the asteroid. Once cleaned, three of the six Boulder Grasping Mechanism Arms are wrapped around the boulder, locally adhered to the boulder surface using the Space Compatible Jamming Grippers, and then rigidized for boulder removal, using the other three arms as landing legs. Once clear of the asteroid, the six arms can be adjusted in a way to tighten the grip on the boulder prior to maneuvers back to cis-lunar space.
The Phase 1 contract is focused on maturing two key new technologies—the Electrodynamic Dust Collection System and the Space-Compatible Jamming Grippers—and developing a subscale proof-of-concept prototype for the Boulder Capture Mechanism Arms. While some of these technologies have proprietary elements, I’ll give you a brief overview of what we’re trying to accomplish with these two new technologies.
Electrodynamic Dust Collection System (EDCS)
The EDCS concept uses electrodynamic forces to remove regolith from the asteroid surface and transfer it to a sample collection system. This concept is an extension of some phenomena we saw back when we were working with electrostatic adhesion for our Sticky Boom™ capture system in 2011, and will be leveraging work done by Dr. Hiroyuki Kawamoto of Waseda University (Tokyo) on the use of electrodynamic forces for dust manipulation, and work by Brad Blair of NewSpace Analytics on asteroid material science and mining engineering.
Key elements of the EDCS can be built into the STEM composite laminate, and the whole thing can be wrapped into a multi-purpose robot arm that also provides situational awareness cameras/illumination for the mission. The DARPA Phoenix STEM Arm project retired a lot of the technical risk for the rest of the STEM Arm system, so the Phase 1 research will focus just on the EDCS hardware aspects.
Space-Compatible Jamming Grippers
Local adhesion for the Boulder Grasping Mechanism Arms will be provided by Space-Compatible Jamming Grippers, which will be developed by our teaming partner, Empire Robotics of Boston, MA. Empire Robotics has developed the VERSABALL® vacuum jamming gripper, which can conform to and grasp a wide variety of terrestrial objects using the jamming phase transition of granular materials. Basically, as shown below, you have a membrane surrounding granular materials. You provide a little air to stretch the membrane a little and loosen the particles. You can now conform to an almost unlimited number of shapes. Once conformed, you pull a slight vacuum, and the differential air-pressure jams the particles together, locking them in place, and creating a grip around the object via local envelopment/pinch grasping, friction grips like palming a basketball, and induced vacuum pocket.
If you think about this for a few seconds, it’s obvious that this approach won’t work in a vacuum environment, but Altius and Empire Robotics have come up with a few alternative approaches to inducing the jamming phase transition that don’t require external atmospheric pressure, and thus should work properly in a vacuum environment. In Phase 1 we’ll experiment with a few of those approaches, with the goal of developing a prototype we can test on simulated asteroid boulder surfaces in the same thermal-vac chamber that we used for Sticky Boom™ electroadhesive gripper testing in 2011.
Underactuated Boulder Grasping Mechanism Arms
The last technology piece for our system is the selectively-compliant, underactuated space-truss arms that the Space Compatible Jamming Grippers are mounted to. For those of you unfamiliar with the term, an underactuated mechanism is one that has more joints/degrees-of-freedom than it has actuators, with joint angles controlled by a combination of mechanism compliance and the actuation system (often a tendon). Selectively-compliant in this case means that each of the joints in the grasper arms can be locked or unlocked using some form of joint locking mechanism. Our earliest Sticky Boom™ capture head incorporated selective compliance and a crude form of underactuation. This type of actuation scheme enables conforming to a very complex shaped object, and rigidizing once locked in.
A few examples of such hands should illustrate the point:
For more reading on this class of grippers, I’ll refer you to the research groups at Stanford (Dr Cutkosky’s Biomimetics and Dextrous Manipulation Laboratory), Yale (Dr Aaron Dollar’s Grab Lab), and RightHand Robotics, though there are several other groups active in this field.
Multipurpose SEP Module for ARM and Beyond
As mentioned in the previous blog post, in this contract Altius will be part of a large industry team led by ExoTerra Resources that is looking at ways to develop a commercial Solar Electric Propulsion satellite bus that could be used for ARM and other missions. Altius will primarily be consulting on options for asteroid capture systems (such as Kraken) and how to integrate them into the SEP bus. More details on this effort, and the industry team involved, can be found on the ExoTerra blog post about the contract announcement: ExoTerra to Help Prove Humans are Smarter than Dinosaurs.
Those of you who have been following the NASA political scene know that the Asteroid Redirect Mission is not very popular with a few members of Congress. These members of Congress recently inserted language into some of the NASA-relevant authorization and appropriation bills to limit NASA’s ability to fund research on Asteroid Redirect Mission technologies that aren’t also relevant to other non-NEO destinations. Fortunately for us—we didn’t find out about this legislative verbiage till a month after we had submitted the applications—the technologies we’re developing for our Kraken system have a wide range of non-asteroid applications, which should hopefully help make NASA’s job easier if our Phase 1 research is successful and they desire to fund any Phase 2 follow-on efforts.
Specifically, the EDCS technology is relevant for sample acquisition and in-situ resource utilization/mining on most interesting inner solar-system bodies, including Mercury, Venus, the Moon, NEOs, Phobos/Deimos, and Mars. The Space-Compatible Jamming Grippers are potentially useful for spacecraft capture, satellite servicing, and active orbital debris removal. Lastly, the underactuated Boulder Grasping Mechanism is also potentially useful for orbital debris removal, and on a smaller scale, the underlying technology is related to grasping technology we’d like to use for satellite servicing, space facility micro-deliveries, propellant depots, and orbital debris removal.
While these other potential applications don’t guarantee that the technologies will work out as expected in Phase 1, and they definitely don’t guarantee they’ll be selected by NASA for further research even if they are successful, they at least make NASA’s life easier if they do want to select them for follow-on Phase 2 funding.
How You Can Be Involved
If any of these technologies sound interesting to you, and especially if your company has potential applications for them (space or terrestrial applications), please contact us. Also, while this Phase 1 effort is going to be a bit of a whirlwind, we will try to post occasional updates to our blog, so feel free to follow the adventure. Lastly, if the Phase 1 research is successful, there may be partnership opportunities for Phase 2, and Altius is always open to discussing opportunities for partnerships.