The Space Junk Remediation Project
The following design document was the result of a thought experiment February through April, 2008, on remediation of orbital debris, "space junk".
A. General Methodology for Larger Objects (≥ 10 cm)
ii) Contain (secure for disposal or redeployment)
iii) Re-Deploy (into deep space, solar trajectory, or to earth; de-orbit/re-orbit
iv) Recover/Recycle (if re-deployed to earth
My first attempt at a concept design for space junk removal (based upon the opening sequence in the James Bond film You Only Live Twice):
THE JUNK EATER
Multi-functional Utility Craft for Controlled Elimination of Debris (MUCCED)
A dedicated, single space craft would require great amounts of energy to intercept objects in different orbital planes.
Size limitation: need to redeploy contained objects frequently.
Maneuver Junk Eater to different altitude (taking advantage of differential precession of node lines) then return to altitude of interest (N.L. Johnson).
Nuclear (NERVA engine?) or plasma energy source (on board) or Hydrogen fuel cells (or both); de-obit or re-orbit objects (above LEO ?), thus limited need for containment (if redeployed to Earth for analysis/recycling)
SOME ALTERNATIVE IDEAS:
The "Junk Collie": Drone/robotic device attaches to junk, and, through remote control, shifts junk into deep space/solar trajectory, or earth re-entry (if piece is wanted for analysis or recycling). Also, drone could attach metallic "drag strip", or carbon mesh sail (see OLDA concept design; laser targeting) to junk to accelerate decay. (Note: “current manned space craft cannot reach key orbital regimes above 600km” – N. L. Johnson)
Energy source, propulsion system.
Significant long-term power and altitude control subsystems.
Drone may need space base.
Cost ≤ Military drones.
Ion engine, or, solar-electric propulsion technology.
Lower energy system that “nudges” junk incrementally into desired orbit (longer term) or decay trajectory (reduces speed). Docks at ISS. Engineering challenge.
Orbital Laser Decay Accelerator
Dedicated, space-based, omni-directional laser platform (in HEO; above 2000km) for selective tracking, targeting, and heating of objects (under 10 cm or critical size) to accelerate decay (mimics "cleansing" effect from high solar activity and/or radiation pressure).
Technical feasibility; DOD concept (SBL system); large mass of satellites = large amount of energy needed to deposit on object to effect orbital changes; laser ‘sail’ (C mesh) needed for large junk (?); process may increase debris?
Use for smaller debris (lower energy needed for altitude changes); joint gov./civilian usage; augment beam through amplification "lensing"; use "pulsed capacitors" for super efficient laser pumping; use "junk collie" drone to attach sail; realistic goal: reduce altitude.
Plasma Beam “Junk Blower”/OPRA
Similar function to Laser craft – accelerates decay of debris; also: use as a junk "re-locator", ala "leaf blower", to create temporary launch window (or altitude reduction). Magnetized Plasma Beam (Mag-Beam) concept was conceived as a way of accelerating space flight between distant planets (Winglee, UW); same concept here (without the dual station plan; one plasma beam source for junk targeting).
Technical challenge; initial energy source; "beaming" or re-locating space junk could cause break ups and increased risk of collisions, thus total debris (and risk, etc.)
Highly controlled targeting within debris "fields"; combine solar-electric and H fuel cells; lower energy impact, i.e., nudging into reduced altitude band; possible complete decomposition of object in orbit (size to energy per unit area dependent)
Designer’s Note: if it can be used for spacecraft transportation, it can be used for space junk re-location
For Smaller (10 cm or less) Debris (unknown number, perhaps millions)
Electro-magnetic Debris Accumulator
Requires dedicated space craft; energy source; disposal of debris post accumulation; possibly non-magnetic particles.
Adapted to existing craft (?); tether can be over a kilometer (or more) long, attached to space craft which retrieves accumulator or maneuvers into desired LEO and lowers accumulator, cuts EM current, releasing debris into new altitude (use in conjunction with Junk Eater?) ALTERNATIVE (for not magnetic metal/debris): Tethered sphere is coated with a thick layer of AEROGEL (entire sphere could also be hollow and/or filled with aerogel; sphere shell made of penetrable material to capture small, high velocity debris inside it.
LONG-TERM (BIG PROJECT) STRATEGY:
Orbital Plasma-gasification Station (OPS)
Maneuverable station, like the International Space Station.
Advantages: Debris is gasified in space (less risk of more "catastrophic" collisions)
"Syngas" waste (H and CO) can be converted into hydrogen (for fuel cells), methane, ethanol; gases and "glass slag" can be used on earth
OPS is self-sustaining, generates energy flow after jolting (can be a power station for other spacecraft)
COST! Also: space installation, positioning, operation, maintenance
Long-term, multi-national project; built in space (?); merely an engineering/management problem…
The Challenges of Junk Remediation
Technical Feasibility (includes energy sources)
RESPONSE: Are we not a creative species (tech innovation/ invention)?
Economic Viability (viable=affordable means: given other space programs and priorities)
RESPONSE: If we can spend trillions on warfare, can’t we spend 50 billion to build a dedicated space junk remediation system?
HOW MUCH RISK IS ACCEPTABLE?
"The bottom line is very simple." Liou said. "Although the risk is small, we need to pay attention to this environmental problem."
Risk is “small” now, but will increase over the next century, especially after 2055.
IF WE DO NOTHING - Worst Case Scenario:
THE KESSLER EFFECT: the space around Earth becomes so riddled with junk that launchings are almost impossible. Vehicles that entered space would quickly be destroyed.
More likely Scenario:
ECONOMIC BARRIER: more shielding = more weight = more cost to launch => too expensive to do business in space
Through a government and private sector partnership: Implementation of a forty year plan to build an orbital, maneuverable, space debris control station with multiple energy sources and debris remediation strategies.
What is needed—vis-a-vis Space Junk remediation—to maintain space activity and to insure a relatively safe transition to a space-based culture and economy is…
Public Support (education)
Political Will (Money)and Technical Creativity
STEAM = Science, Technology, Engineering, Art, Mathematics.
Just as a Superfund was created for earth industrial cleanup, so too, we may need a Superfund for space industrial clean up, paid into from a space tourism tax.
It's a job that's never started that takes the longest to finish.
— J.R.R. Tolkien
Michael A. Ricciardi, author/designer, is a naturalist, science scholar, and tech-art designer.