last updated 11/29/08
A Russian SL4 rocket reenters over Colorado January 4, 2007.
Space debris might be defined as material orbiting the earth that has outlived its useful lifetime. We use this term to cover a) satellites that have become inactive, b) discarded rocket bodies, c) small pieces of material jettisoned or having flaked off spacecraft, and d) small objects that are the results of collisions or explosions. Some very old satellites have been known to 'shed' small pieces decades after they were launched into space.
Another form of space debris is that which reenters the earth's atmosphere and is recovered on the ground. An example of this is the rocket carrier from the satellite known as the Midcourse Space Experiment (MSX) launched in 1996. MSX rode atop a Delta rocket. Because the MSX satellite used the Space Shuttle as a target for some of its sensors, it was considered a 'payload' to be followed at the NASA Johnson Space Center. I was designated as the project engineer for MSX at the time. On January 22, 1997, the Delta rocket carrier fell to earth near Georgetown and Seguin, Texas.
Most of the structure disintegrated, but two large pieces survived the reentry and were recovered and sent to Houston. The following photos show a titanium sphere and portion of tank structure, respectively. A woman was 'hit' by piece of thermal blanket.
For earth dwellers, being hit by a piece of reentering space debris is a highly unlikely event. But there are more to interest space buffs than just the extraordinary events involved in surviving a reentry. While it is true that thousands of satellites and rockets have reentered the atmosphere and only a relative few have been found intact or in pieces, the effects of space debris can have an impact on ground based astronomical observations. This first came to light around 1985 when a group of astronomers reported flashes in the sky which later became known as the 'Aries Flasher', 'Perseus Flasher', or 'the Ogre'. The flashes were documented in ASTROPHYSICAL JOURNAL Vol. 307, L33-37, 1986 August 1 by Katz et al. in an article titled "Optical Flashes in Perseus". In this paper, the investigators reported eliminating what could not have caused the flashes. One source they discounted was artificial earth satellites. This conclusion was the catalyst that began my investigation into the Aries flasher phenomenon.
After the announcement of the Aries Flasher, numerous search teams tried in vain to locate the source of these mysterious flashes. Some results included:
1. "A Search for Optical Flashes in Perseus" by P.Garnavich and S. Temple University of Washington, Jan. 1987.
2."Search for X Rays from the Region of the Aries-Perseus Flasher" by W.Lewin et al. from MIT, 1987.
3."Status of the Perseus Optical Flasher", by G.Corso et al. Loyola University, 1987.
4."Evidence from Meteor Patrol Photos for a nonastronomical Origin of the Reported Optical Flashes in Perseus." by I.Halliday et al. NRC of Canada.
...and there were many more to come.
After seeing a photo of the Aries flasher published in SKY AND TELESCOPE magazine, it occurred to me that this flash looked remarkably like others I had seen as an undergraduate student in analyzing photographic plates taken of flashes from the GEOS 1 satellite. If this was indeed a flash of reflected sunlight, then perhaps the orbits of all satellites in space could be analyzed to see if a spacecraft or debris passed through the field of view of the photo at the precise time and location of the published photo. Though obtaining the exact location of the observation site of the Aries flasher report(s) was difficult, it was eventually determined with enough certainty to analyze the circumstances that possible satellite passages might have had.
Using special software developed by the space debris office at the Johnson Space Center, I determined that at 0242UT on March 19, 1985, three satellites passed through the area that could have been source of the flash. Two of them, TOPO I and 1961 Omicron 151 were dismissed as unlikely sources due to their size and distance at the time of the flash. I attempted optical observations of both and eliminated them based on what I saw. The third object was Cosmos 1400. I conducted observations of this satellite which showed brief flashes sometimes reaching +2 magnitude. After more study, I concluded that this satellite was the source of the Aries Flasher event on that date. The Aries flasher photograph was considered the prime target for analysis. However, the Katz group also documented other flashes in the general part of the sky which caused the phenomenon to be called the Aries Flasher, then Perseus Flasher due to the lack of certainty in the position of the flash source(s).
After examining some of the other reported flashes, I was able to correlate some of them with other coincident passages of some other satellites. This was the first time that a direct link was found between space debris and suspected new astronomical discoveries. The results were accepted for publication in ASTROPHYSICAL JOURNAL Vol. 317, L39 1987 as "Specular Satellite Reflection and the 1985 March 19 Optical Outburst in Perseus".
Additional work done by Brad Schaefer, myself and others was published later that contradicted many other flash events that appeared in the original Aries Flasher paper. See "The Perseus Flasher and Satellite Glints", ASTROPHYSICAL JOURNAL Vol. 320, pp.398-404, 1987 Sept. 1. For additional references to this topic:
1) SKY AND TELESCOPE, July 1985, p.54.
2) SKY AND TELESCOPE, June 1987, p.694.
A second high profile flash event was reported in ICARUS Vol. 76, pp. 525-532 in 1988 by Kolovos et al. titled "Photographic Evidence of a Short Duration Flash from the Surface of the Moon". In this story, a photo was taken of a low phase moon in which a bright flash is seen superimposed over the dark side of the lunar disk. The investigators claimed that the origin of the flash was a lunar transient phenomenon with an origin below the moon's surface. The appearance of this flash is very similar to that of the Aries flasher and I attempted to determine if this, too, might be associated with satellite glints. I found an even more convincing candidate for this flash, the satellite called DMSP F3. Its passage correlated almost exactly over the moon at the precise time. What was even more remarkable, after beginning a campaign to study the optical nature of this satellite, I observed distinct specular short-lived flashes that reached magnitude -4. I was able to photograph one of them. Its appearance was uniquely similar to that on the ICARUS photo. The results were published as "Space Debris and A Flash on the Moon", ICARUS, vol. 90, pp.326-327, 1991. For more references on this topic:
1) SKY AND TELESCOPE, May 1989, p.468.
2) SKY AND TELESCOPE, June 1990, p.590.
Both the Aries Flasher and Moon Flash were apparently caused by sunlight reflecting off a metallic surface of an inactive satellite. Because there is no effective removal process of dead spacecraft from orbit, they continue to swirl about the earth until the natural forces of orbital decay bring them to a fiery end in the earth's atmosphere.
As a result of these two events, I received a host of inquiries trying to link other flashes in the sky seen over the prior decades with satellite flashes. Most could not be correlated either due to incomplete information or lack of coincident satellite orbits. It should not be concluded that all flashes seen in the night sky come from space debris. But it is important to recognize that satellites can be the sources of some false astronomical discoveries. The papers increased awareness as did some follow-on popular published articles which helped to mitigate the spread of subsequent reports.
The term "reentry" is a misnomer. It implies that an object has entered the atmosphere, survived and is now entering again. Almost every satellite that encounters the atmosphere (unless it is designed to resist the heating of reentry) will either be partly or completely destroyed and will certainly not reenter. An exception is the Space Shuttle. Another is a capsule that is engineered to land via parachute or other system that returns samples, for example. Forces and heating during the process are such that man-made objects will have a hard time surviving the length of time, peak heating temperatures, and pressures involved in the high velocity encounter. When part of a satellite does survive it can take many unexpected forms, the most classic must be that of the Space Shuttle COLUMBIA which broke up about 40 miles above the earth's surface in February 2003. All kinds of mechanical, electrical, pieces of paper, clothes and even some human body parts were recovered; many were in 'recognizable condition'.
AUTOMATED TRANSFER VEHICLE-1
On September 29, 2008, the European Space Agency's ATV-1 reentered the atmosphere at the end of its mission to resupply the ISS. An airborne observing campaign was organized to monitor the reentry from two aircraft (P.I.: Peter Jenniskens, SETI Institute). I had proposed to the ATV Project in 2002 that the reentry of the first flight of this new, unflown vehicle should be considered for monitoring and reentry documentation. In late 2007, Jason Hatton of ESA/ESTEC and Peter Jenniskens proposed a way to do this with help of NASA Ames and NASA Dryden aircraft. ESA funded the flight of two airplanes loaded with instrumentation to intercept the entry path.
The first ATV vehicle to fly in space as it moves away from the International Space Station.
Two experiments I proposed were flown onboard a Gulfstream aircraft and used by Ed Barker to obtain more than 3 minutes of video. An image sequence is shown below. These photos were extracted from an 8mm video shot with a 75mm objective lens and image-intensified. The imagery was obtained when the Gulfstream was about 13,000m altitude and were provided courtesy of the NASA Orbital Debris Office.
Two portable video imagers set in the 17-inch window of the Gulfstream were used to capture the data.
First image. Note time stamp below each photo in hours, minutes, seconds, milliseconds. The three objects to the lower left of the fireball are internal lens reflections and are not debris.
This image shows a view behind the main fireball as debris star to trail backwards.
Each piece of debris can be seen, some are still 'on fire'; others have a stellar appearance. It is also possible to discern separate streams of particles moving within the reentry pathway.
At 13:36:20 an explosion occurred. The resultant cloud is shown above.
The main fireball is visible here and one can see how overbright it is such that you cannot make out any definition within its close proximity.
A galaxy is faintly seen below the bright star (Alpha Centauri) on the right side of the above frame.
The fireball begins to lose its cohesiveness as more and more debris is shed.
A glow can be seen from the last major portion of the fireball as it moves toward the horizon.
ATV-1 is almost eclipsed by the aircraft structure.
The last image of the fireball and its trailing pieces.
SHUTTLE COLUMBIA DEBRIS
Although I have a separate page for STS-107 reentry debris, the following are some representative examples of pieces that survived reentry.
Fuel Cell
Tank
Connectors
Debris can land anywhere, for example on top of a roof.
...in the street.
...at a gasoline station.
If the debris stream is detected on radar, it can show up in spectacular form as the red track shows from the National Weather Service Radar at Shreveport, Texas.
Tank
STARDUST
A capsule carrying intersetellar dust reentered the earth's atmosphere at 12km/second and was protected by an ablative material which resulted in the successful recovery of its contents. The landing was on January 15, 2006 after a six year trip.
GENESIS
Another capsule landed and was recovered but not in good shape since the spacecraft parachute failed to deploy properly. Landing occurred September 2004.
ROCKET MOTOR CASINGS
The above images are of a large fragment that survived reentry on January 12, 2001 after falling in Saudi Arabia. It is from a Delta rocket third stage motor casing. There were no sonic booms or flashes in the night sky signalling its arrival. It was simply discovered lying in the sand, weighing some 70kg. This is a titanium case and located inside a PAM-D (payload assist module). This particular module gives the satellite payload its final thrust and allows for some positioning maneuvers in orbit to release the spacecraft properly. The PAM-D completes its task and becomes space junk, eventually decaying from orbit. The following images shows the intact PAM-D in the factory.
This casing (above) was found by A. Taylor while flying over an area in Australia in 2008 surveying cattle. From markings it was determined to be part of a Delta 2 rocket that launched INSAT 1B in 1990. Depending on the remoteness of the area it is not uncommon for objects never to be discovered or discovered decades after they have entered the atmosphere.
A titanium rocket casing fell near the town of San Roque, Argentina January 20, 2004. It was measured to be 3.m around, 1.6m long, 1.4m wide weighing about 45kg. Boeing serial numbers A41-8106037501-S or 1060370-501F (information is not clear) were identified:
The recovered debris is believed from a Delta launch October 26, 1993 to place the NAVSTAR-34 GPS into orbit. Note the similarity in the physical appearance of the picture on the lower left in this sequence and the first image in this section which landed in Saudi Arabia.
Accounts indicate that the object leaked a yellow liquid. No injuries were reported from the impact which occurred in the afternoon in a field belonging to the Bolo family 15km from the city of San Roque.
Thanks to Luis Augusto Reggiardo for the above information.
Here is an image of a PAM-D casing that fell in Thailand. Date is uncertain.
CHINESE FSW IMAGERY SATELLITES
A Chinese satellite capable of imaging from space and returning those images in a recoverable capsule is another example of a reentry. However, this one is non-destructive in nature. The photo above shows an example of a normal recovery of this capsule. This one was launched November 3, 2003 and landed some 18 days later in Sichuan Province, China.
Sometimes the capsule does not land nominally. FSW 3-3 was a recoverable, photo-imaging spacecraft that was launched on 27 September 2004. Its purpose was advertised to be used in scientific research, geological surveying, and mapping. After its 18 day mission the capsule returned to Earth on October 15, suspended on its parachute, crashed through the roof of a house in the village of Penglai, Sichuan province.
CHINESE SPACE CAPSULE
The Shenzhou spacecraft carries Chinese astronauts to and from space. The photo below is the reentry capsule after landing. Technically it is space debris once it hits the ground.
MISCELLANEOUS SPACE JUNK
I received these photos of space junk that had been stored at NORAD at one point in time (Space Control Center). Unfortunately, I do not know their heritage.
The bolt and threads above survived intact even though the sphere itself is very scorched and the other side has a large hole in it.
TELSTAR 402
An oxidizer tank was found near Belem (Para), Brazil in August 2006 related to the reentry of Telstar 402 which occurred November 14, 2004. It measured about 80 cm in diameter and was 1m in height. The owner of a farm found this tank 2 years after the actual reentry. The tank probably belonged to the Ariane 3rd stage rocket.
Note the marking from GE Astrospace.
An end view shows significant damage from the inside out.
APOLLO MANNED CAPSULE
Earlier examples of reentry include Apollo capsules
In addition, we observed several Apollo missions on the way to the moon. In this view Apollo 12 Command Module is seen as a small dot illuminated by sunlight on November 14, 1969 at 02hUT from a slant range of 50,000 miles. It is at the apex of the arrow labeled A12. There are 3 other pieces also visible which are so-called SLA (Spacecraft Lunar Module Adapter) panels. They were 28 feet high with a diameter ranging from 12 ft. 10in to 21 ft 8in. Sunlight reflected quite well off these panesl which stayed in close proximity to the Command Module for some time. Two SLA panels are seen as dots directly below the second arrow and the third below and to the right of the right-most of those two objects. These are Polaroid images taken off a video monitor. The telescope used was a 16-inch telescope and an intensified video camera was employed. The 3 objects qualify as space debris since they were jettisoned as part of the mission scenario yet followed along in roughly parallel trajectories to the Apollo.
In this view, a water dump is occurring from the Apollo 13 Command Module on April 13, 1970 at 2:14 UT. It is the slightly out of focus object at the apex of the arrow. The water dump itself is an example of space debris. Light is reflecting off the frozen ice crystals.
COSMOS 2267
Near Cosala Mexico a piece of Cosmos 2267 that decayed from orbit in December 1994 was found and displayed; it is 2.4 x 2.4 m with a 20kg mass.
SPUTNIK IV
"On May 15, 1960 Russian scientists launched a 5 ton spaceship known in the western world as Sputnik IV (the official Russian name is Korabl-Sputnik 1). It was the first satellite designed for the purpose of human spaceflight. This top secret satellite contained a pressurized cabin and life support equipment. Reports were widespread that the satellite also carried a life-sized "mannequin cosmonaut”. If such reports were correct, the mannequin must have been an ancestor to cosmonaut “Ivan Ivanovich”, a dummy that flew on subsequent Sputnik missions. Photo: Ivan Ivanovich, the dummy cosmonaut that flew on Sputnik 9 and 10. "MAKET", Russian for "dummy", was displayed inside Ivanovich's helmet to prevent public panic after his return to earth.
Unfortunately, the flight of Sputnik IV was doomed. Five days after launch, the rocket re-entry system was activated to bring Sputnik IV back to earth. A major malfunction caused the capsule to become incorrectly oriented...it drifted into space. Sputnik IV remained trapped in its unwanted orbit until September 5, 1962." Source: http://www.meteoriteswanted.com/sputnik_iv.htm
One of the earliest recorded man-made space debris falls occurred in Manitowoc, Wisconsin on May 15, 1960. A piece of Sputnik IV fell in on North 8th street and was recovered there. It was 0.15m in size and 9.5 kg in mass. And even though the original piece was ultimately returned to the Russians, there is an intensely realistic piece of it protected in a glass case inside the Rahr-West Museum. There is also a small brass ring in the middle of the street that commemorates the fall.
Pictured here are the squad car officers who first saw the remnant of Sputnik, which had apparently just fallen on this spot at the end of North Eighth and Park Street in front of the Rahr West Art Museum. (then known as Rahr Civic Center) Officers Ronald Rusboldt and Marvin Bauch are pictured at the site of the landing. They were particularly astute at associating the news of the disintegrating of Russian Sputnik IV over Wisconsin with their recovery of this sizable piece of hot metal.
The figure above marks the spot where the Manitowoc fragment hit the street.
The above map shows the track of the reentry and locations of recovered fragments around the church all of which appear to line up with the ground track and main fragment that fell into the street. Source: http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1962SAOSR.109...15M&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf
In June 1969 pieces of another Soviet spacecraft fell on the deck of a Japanese freighter sailing off the former USSR.
COSMOS 954
A stir was created in January 1978 when pieces of the Soviet Cosmos 954 rained down on Canada. Beryllium rods and cylinders were recovered from the Northwest Territories and were found to be radioactive. "A large piece of the satellite known as the ’antlers’ was discovered quite inadvertently by two young explorers who were part of a team of six adventurers making a voyage in the Thelon River Game Sanctuary, some 400 miles to the east of the eastern tip of Great Slave Lake. They were travelling by dog-sled with two teams of dogs, following the route that had been taken by the English Naturalist John Hornby in the 1920’s." Source: http://gsc.nrcan.gc.ca/gamma/ml_e.php
EXPRESS CAPSULE
A capsule dubbed "Express" never obtained its full orbital altitude and fell back to earth in 1994. It was recovered in Ghana.
ATLAS ROCKETS
On April 27, 2003 at 1535UT several pieces of an Atlas rocket stage launched in 1998 fell on a farm in Mataquesquintla, Jalapa, Guatemala.
The principal object shown above is 1.2 m in diameter and is spherical and was immediately transported to police headquarters in Guatemala City. It was seen hitting a hill and rolling down to the point where it was found and reported. You can see the trend that hardened spherical objects are more prone to survive reentry intact. The sphere bears keen resemblance to the Shuttle fuel cell shown at the top of this page.
Does this look familiar? Another similar object fell in Rio Goias, Brazil around March 24, 2008.
Then there are these images from James Stirten who found this object 54 cm wide and weighing 20kg in 2007 at a location about 800km west of Brisbane, Australia.
DELTA ROCKETS
One such as this one fell in South Africa (courtesy W.Koorts) and these parts were located in a museum outside of Capetown in April 2000. What was found was a steel propellant tank (1.7 x 2.7 m, mass 270 kg), a titanium pressure sphere (diameter 0.58 m, mass 32 kg), and a composite combustion chamber (0.76 m long, average width 0.25 m). The small titanium sphere and larger tank are two parts that 'typically' survive reentry. This is at least the 3rd such instance where both parts were recovered. (See the top two photos on this page)
MIR Space Station
Here is an example of a reentry of the famous Russian station Mir in March 2001 that should not have been seen from a populated area; but it is not always possible to plan and control a reentering, massive spacecraft. This photo was taken in daylight from Fiji. Note how the ground track came very close to a large island in Fiji resulting in the successive image.(courtesy R.Matson)
VOSTOK
Many Russian spacecraft were designed to return humans back to earth. This Vostok capsule is an example of one which survived reentry and is now housed in a space museum in Moscow.
FOTON
A small pressure sphere from the Foton 1 satellite was launched into space in April 14, 1988 from Russia. It reentered tw weeks later and was found by Graham Ducas, an employee of the Western Australia State Water Company while prospecting in the desert. The sphere was 6.5 gallons in capacity and is made of titanium; it has a 0.37m diameter. Source: http://www.space.com/peopleinterviews/satellite_auction_000214.html
While we cannot be sure of the identity of this fragment, it looks very much like the Foton debris above and was found in Brazil (courtesy Jose Ildefonso) and derived from a web page by Flavio Tobler. This first object was found in Piaui, Brazil in 2002.
This second object was also found in Brazil in 2001.
SKYLAB
One of my earlier jobs was as a spaceflight controller at the Johnson Space Center and on the Skylab reentry control team. Although we did everything we could to ensure a safe, controlled reentry, some pieces of the spacecraft survived reentry in 1979 and were recovered in Australia.
Here is a large piece preserved in Australia.
RECOVERY FROM THE OCEAN FLOOR
Mercury 4 was launched July 21, 1961. Gus Grissom, the 3rd astronaut to return from space, rode the spacecraft for 15 minutes before landing in the ocean. Liberty Bell 7 sank after a hatch blew open and it dropped to a depth of 5 km into the water. After a 14 year search an expedition in 1999 uncovered the spacecraft and raised it to the surface where this piece of space debris is now stored in a museum.
LAUNCH DEBRIS
Russian rocket launches out of Kazahkstan have resulted in a lot of debris being scattered about. The following are a collection of images that are representative of some of that debris. While none of this is technically 'space debris' it is considered launch debris.
Reminiscent of the cow that was supposedly killed in 1960 by space debris, these cows were apparently victims of toxic fuel.
CHALLENGER SPACE SHUTTLE
A large piece of debris from the Space Shuttle orbiter Challenger washed up at Cocoa Beach, Florida almost 11 years after Challenger exploded in 1986. The piece, about 5m x 2m, is believed to be part of an elevon or rudder.
ADVERTISING SPACE DEBRIS
The internet has created a market for advertising all sorts of products including recovered pieces of space debris.
PEOPLE WHO HAVE BEEN HIT BY SPACE DEBRIS AND LIVED TO TELL ABOUT IT
Lottie Williams was grazed by a lightweight fragment of charred woven material (10 x 13 cm)material that was later identified from the reentry of the MSX Delta rocket that reentered the atmosphere in 1997. She was walking in a park at 330am in Tulsa, Oklahoma on January 22 at the time.
While it is not clear that anyone has been killed by space debris, it was reported that a cow died in Cuba after having been hit by a falling object in 1960. An unknown number of rocket motor and propellant tank pieces were reported to have fallen in Cuba in November 1960 and these are thought to be sub-orbital debris from failure of a Thor booster used to launch the Transit-IIIA satellite on November 30, 1960 (satellite 1960-F16).This was the second launch attempt of the Galactic Radiation and Background (GRAB) satellite declassified in 1998. Neither the cow nor its owners were available for interviews. The principal source of the cow story is from a speech delivered by CIA director G.J.Tenet Sept 27, 2000 in which he stated "One of (the) more spectacular failures rained debris down on Cuba. Havana charged that a cow was killed in a deliberate US action. The Cubans soon paraded another cow through the streets with a placard reading 'Eisenhower, you murdered one of my sisters'. It was the first and last time that a satellite has been used in the production of ground beef. The episode has gone down in history as the herd shot round the world."
Another report indicated Nov. 7, 2002 that a boy was hit by space debris in China. "Debris from a space satellite that fell from its orbit struck a six-year-old boy in Shaanxi Province last week, according to a report in the Beijing Youth Daily.
Wu Fusheng, the father of the boy named Wu Jie, remembers hearing a "thundering" sound and saw a piece of metal plummet from the sky, finally hitting a persimmon tree under which his son was playing with other children. The boy was taken to hospital where doctors found he had suffered a fractured toe and a swelling on his forehead.
The satellite debris was a block of aluminum, 80 centimetres by 50 centimetres and weighing 10 kilograms. The freak accident also hit the Wu family's finances. They had to borrow 400 yuan (US$48) from a neighbour to pay for the medical treatment. After the remains of the satellite had crashed to earth, the village head noticed that the air had a smoky, gunpowdery smell and thought a plane had crashed nearby. He requested that the village be evacuated.
Later, after a total of 19 metal fragments had been recovered, it was found that the debris was the outermost shell of the Resource Second Satellite which had broken up after falling from orbit. Local police and authorities have made a list of all the debris and are waiting for more expert investigation.
The satellite was supposed to have crashed into an uninhabited mountain area in Shanyang County but had landed instead in nearby Yanghe village. The mishap was blamed on unexpected weather conditions. The government will pick up the cost of Wu Jie's medical treatment and also pay some compensation to his family." (Star News)
Space debris comes in many forms. One of the most exciting is when a satellite or rocket explodes unexpectedly. We have watched the aftermath of some of these events. An early sighting of mine was of Cosmos 1823. On December 29, 1987 at 1113 UT, we watched six fragments pass through the field of our binoculars one after the other separated by 53, 7, 5, 83, and 18 seconds, respectively. While the intact satellite had been observed at magnitude +5, the pieces that we observed from an explosion that had occurred earlier varied in brightness from +9 and +10.5 magnitude.
Usually, the sizes of the resultant post-explosion fragments are quite small--less than 0.1 square meters. If the satellite is in low earth orbit (perhaps at altitudes less than 500km , it is possible that some fragments can be viewed in amateur telescopes. If the exploding object is located in an eccentric orbit (one with a low perigee and high apogee), unless you are really lucky, it is not likely you will be able to spot these fragments.
Why should we try to view the end products of explosions? A simple answer might be the following: if the cause of an explosion is not known (usually the case), one may be able to gather information on the rotation and brightness of resultant fragments and correlate the brightness with radar cross section. In certain instances, the exploding object may not be destroyed. This is not an altogether unusual situation. Some objects suffer minor explosions and their radar cross section is largely unaffected. Optical observation bears this out.
An explosion in space is not a desirable outcome since the new fragments become possible sources of impact to working satellites. Even a small fragment moving at orbital velocity is enough to seriously damage or destroy a large spacecraft. Many fragments created as a result of explosions tend to have small cross sectional area and may decay from orbit quickly. During periods of high solar activity when atmospheric decay is accelerated, a temporal 'cleansing' of small pieces of space debris will occur.
LINKS
A historical record of space debris falls is kept by the Aerospace Corporation on their site. Space Debris Fall List