Space Debris: Obstructions in the Final Frontier

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Space Debris: Obstructions in the Final Frontier

By Erik Buschardt

Webster University

CSSS 5250-OA F2, (2016)

INTRODUCTION

As prominently highlighted in the movie “Gravity” (2013), space debris is a threat to cybersecurity and national interests around the world.  This paper will serve to explore various aspects of space debris, from the sources, to threats posed to manned missions and machines placed in orbit.  As will be demonstrated in this paper, space debris is a clear and present danger, and its removal is both essential and mandatory for the safety and future of the international space program.  Finally, we end with a hopeful resolution that once the threat of space debris is realized, mankind will continue to make efforts to literally and figuratively remove these obstructions to future space as well as extraterrestrial planetary missions.

The opening scene of the Warner Brothers movie “Gravity” (2013), featuring Sandra Bullock as biomedical engineer Dr. Ryan Stone and George Clooney as veteran astronaut Matt Kowalski, shows a spacewalk mission with repairs to the Hubble Space Telescope via the Space Shuttle Explorer.  Soon after these repairs are completed, a Russian space debris cloud from a defunct satellite rapidly approaches from the east (with reference to the earth below) and severely impacts the Hubble Telescope, the Shuttle, and ultimately the entire mission.  

This initial scene is the highlight of the entire movie, and the 17-minute-length of this unedited take is highly unusual within Hollywood blockbuster productions.  The goal of director Alfonso Cuarón’s story is to slowly immerse the viewer into the reality and awesome scope of spaceflight, while exposing the significant dangers that space debris introduces to manned missions. (Lubin, G.)

(For the record, the rest of the 91 minute drama focuses on Dr. Stone’s heroic recovery and journey back home to Earth.  Despite some flaws, misconceptions and some artistic-license exaggerations, it is a must-watch for any space enthusiast.)

As demonstrated in the first module of our class at Webster University, CSSS 5250 OA with Mr. John Sprague, Deputy, Technology & Innovation Division and End User Architect at NASA, such spacewalking missions will prove futile with the increase of debris found orbiting around our planet.  Since this debris is almost entirely manmade, it is up to mankind (all of us) to remove as much debris as we can, either by sending it back down to Earth for destruction by the atmosphere, or by finally removing it from Earth’s gravitational pull altogether.

We now turn to the various sources of debris and how we are continuing to add to the problem with each new space launch.  Typically, space debris will fall under four general classifications: (1) Dead spacecraft, (2) Lost equipment, (3) Launch Boosters, and (4) Space Weapons.  As a reference point,. The Union of Concerned Scientists has classified 902 fully or partially functional satellites within a database of over 19,000 large objects launched. (“UCS Satellite Database”).

In terms of spacecraft that has expired its mission lifecycle, Derelict, Kosmos 1402, and Kosmos 954 stand out as prime examples.  Vanguard I, currently the oldest surviving artificial satellite, was launched in 1958 into a Medium Earth Orbit (MEO), a distance between 2,000 Km (1,243 miles) Mean Sea Level (MSL) and 35,786 Km (22,236 miles) MSL.

Unfortunately, space debris collisions do not cease.  In February of 2015, the United States Air Force DMSP-F13 suffered an explosion while in orbit, creating a debris field of over 150 objects, estimated to remain in orbit for several decades before returning to Earth.  (Gruss, Mike.)

Lost equipment includes anything lost, misplaced, or any object that floated out of the reach of astronauts during a mission.  These objects can include gloves, nuts, bolts, camera equipment, garbage bags (lost by Soviet cosmonauts during manned missions on the Mir Space Station), and everything in between.  Depending on the vector of the initial trajectory when lost, these small objects could either float harmlessly back towards the earth’s atmosphere, or stay in orbit indefinitely.

        In terms of the weaponization of space, much of that study has been shelved because of the unintended consequences of blowing stuff up, thereby creating large debris fields.  As our textbook indicates, “One can only imagine, for example, the different outcome in the New World if-as with orbital space debris-all of the arrows and bullets fired in those wars of conquest had continued to speed around the Earth causing damage for decades after they had been fired.” (Moltz, p. 17)

Cubesats, as introduced to Webster University’s CSSS 5250 OA F2 2016 class in Module 3 (Week 3) are a unique solution to the problem of space debris, but are no means the final word in satellite design and functionality.  They are designed to fall back to Earth after an expected mission end time of usually a few months, but are limited in duration to short-term projects due to their size and limitations of hardware.  That said, they are designed by students, and provide an excellent opportunity for the exploration of space while not significantly adding to the space debris field. (Robertson, G. A. )

The characterization of space debris can be thought of as that of two separate mutually exclusive function parameters: size, and position (altitude).  It is estimated as of July 2013 that there are over 170 million objects with a diameter of less than one (1) centimeter, while there exist approximately 670,000 objects ranging in size from one to ten centimeters.  Anything larger than a decimeter across, currently counted at 29,000 objects, is tracked by the United States Strategic Command (USSTRATCOM) as well as the Union of Concerned Scientists (Union of Concerned Scientists).

In terms of location, two particular orbit standardizations remain paramount and critical to the nature of the utility of the satellite, and thus to the threat of data security.  Upon a casual glance of the debris cloud image provided on the cover of this thesis, two orbital regions seem to stand out among all other orbital possibilities as primary and dominant.  These are Low Earth Orbit (LEO) and Geosynchronous Earth Orbit (GEO), so named for its synchronization to certain locations on Earth’s surface.  The GEO is also referred to as the Clarke Belt, after Arthur C. Clarke, a British author of science fiction, who hypothesized in 1945 that such a belt would maximize the potential for worldwide radio broadcasts. Thus, the GEO or Clarke Belt is located in the plane of the earth’s equator, at an altitude of 35,786 km or 22,236 miles (calculated to be over 4,000 times the height of Mount Everest from MSL), and is about 265,000 km (165,000 miles) in circumference.  (Basics of Space Flight, Section 1 Part 5).

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