February 21, 2008: Satellite Explodes over Pacific Ocean
"More than 100 metric tons of man-made objects reenter in an uncontrolled fashion each year. Of satellites that reenter, approximately 10-40% of the mass of the object is likely to reach the surface of the Earth.[17] On average, about one catalogued object reenters per day. Approximately a quarter of all objects are of U.S. origin.
Due to the Earth's surface being primarily water, most objects that survive reentry land in one of the world's oceans. The estimated chances that a person will get hit and injured is around 1 in a trillion." Source: Wikipedia - Atomospheric Re-entry
"WASHINGTON (Reuters) - The Pentagon declared on Monday that its mission to blast apart a defunct spy satellite with a missile fired from a Navy warship had been a success.
The strike took place 247 km (153.5 miles) above the Pacific Ocean last Wednesday as the satellite sped through space at more than 17,000 mph (27,000 kph), according to U.S. officials.
"By all accounts this was a successful mission," Marine Gen. James Cartwright, vice chairman of the U.S. military's Joint Chiefs of Staff, said in a statement.
Cartwright said analysis of debris supported the initial conclusion that the missile had most probably destroyed the satellite's tank of hazardous hydrazine fuel as intended.
"From the debris analysis, we have a high degree of confidence the satellite's fuel tank was destroyed and the hydrazine has been dissipated," he said.
Experts were tracking less than 3,000 pieces of debris, all smaller than a football. "The vast majority of debris has already reentered or will shortly reenter the Earth's atmosphere in the coming days and weeks," Cartwright said."
"The Kessler Syndrome is a scenario, proposed by NASA consultant Donald J. Kessler, in which the volume of space debris in Low Earth Orbit is so high that objects in orbit are frequently struck by debris, creating even more debris and a greater risk of further impacts. The implication of this scenario is that the escalating amount of debris in orbit could eventually render space exploration, and even the use of satellites, too prone to loss to be feasible for many generations.The Kessler Syndrome is especially insidious because of the "domino effect and Feedback runaway." Any impact between two objects of sizable mass will create additional shrapnel debris from the force of collision. Each piece of shrapnel now has the potential to cause further damage, creating even more space debris. With a large enough collision (such as one between a space station and a defunct satellite), the amount of cascading debris could be enough to render Low Earth Orbit essentially impassable."
Labels: Space debris
Comment Posted By 
warnpc1, at
4:56 PM
IMHO, we should start looking at ways to clean up space.
A couple of thoughts come to mind. 1. attach small rockets to the larger pieces and slow them down or change their trajectory to reenter earth and burn up or send them into the sun. We already have the ground control, robotics, telemetry, and computers to handle the job.
2. for the small stuff, 18,000 KPH isn't very fast if if you come up from behind at a speed of 18,001 KPH. You could scoop them up with a large funnel shaped device and when the "bin" is full, off it goes to the sun.
Comment Posted By warnpc1, at
4:57 PM
IMHO, we should start looking at ways to clean up space.
A couple of thoughts come to mind. 1. attach small rockets to the larger pieces and slow them down or change their trajectory to reenter earth and burn up or send them into the sun. We already have the ground control, robotics, telemetry, and computers to handle the job.
2. for the small stuff, 18,000 KPH isn't very fast if if you come up from behind at a speed of 18,001 KPH. You could scoop them up with a large funnel shaped device and when the "bin" is full, off it goes to the sun.
You may know James Oberg as NBC News' space analyst using his 22 years experience in NASA mission control to add context to technical issues. In another of his frequent contributions to the IEEE Spectrum blog he puts some perspective on China's anti-satellite technology.
The missile used to destroy the satellite was a 'kinetic kill' device - it had no explosives. The satellite was destroyed by the force of the collision.
Oberg points out that the head-on collision between the missile and its target sums the velocity of the two objects. The satellite's LEO orbit speed is around 28 000 km/hr, adding the missile's speed "creates a hypersonic shock wave that propagates from the inside of the target outward and, at the outer edge, shreds the target into metallic confetti that moves away at up to hundreds of meters per second."
He goes on to say the satellite was an easy target whose position, orbit and velocity were known in advance.
"The Chinese targeted a low-orbiting, obsolete, weather satellite, where the kinetic kill energy was very great. However, the really strategic satellites fly much higher—the navigation network is 20 000 km up, and the communications constellations are in a geosynchronous arc at 40 000 km. At geosynchronous altitudes, the orbital velocities are so much lower that the impact energy would be only about a tenth as high as in last week's test.
Distance introduces a second burden: terminal navigation. When a target satellite is close to the Earth, ground radars can track it and relay final course corrections, both to the rocket during its ascent and to the kill vehicle, once it has been deployed on its hoped-for collision course. Radar operates at an inverse fourth power law, which means that for the Chinese system to aim many times farther than low Earth orbit—as it would have to do to track objects geosyncronously—the demands on a ground-based radar would be simply impossible."Labels: China Satellite, Space debris, Space Militarisation
Washington, DC -- On January 11, 2007 China destroyed one of its old weather satellites by launching a kinetic energy device from a ballistic missile fired from the ground leaving hundreds of pieces of debris orbiting the earth in the path of existing satellites and, potentially, the space elevator (SE).
The Space Elevator Journal was conceived to cover not only the technical aspects of the SE but the issues that affect it and near-Earth real estate. Watching how the various governments and agencies react gives us an idea of how they will work for/against each other in the future. An area that is sure to heat up as space becomes more valuable in the years to come.
In this excerpt of a January 19, 2007 US State Department daily press briefing Deputy Spokesman Tom Casey outlines the US governments policies on the issue and response to date in response to questions from various reporters.
"U.S. policy is that all countries should have a right to peaceful access to space ... simply because so much of the world we live in today is dependant on space-based technology, communications in particular. We certainly are concerned by any effort, by any nation, that would be geared towards developing weapons or other military activities in space. That's absolutely contrary [to our policies]. So we have raised our concerns with the Chinese Government ... both here in Washington and in Beijing. I think you've seen comments from the Japanese Government as well as from Australian Prime Minister Downer and I think several other governments as well raising these same issues.
We don't want to see a situation where there is any militarization of space. We certainly don't want to see a situation in which even tests of this kind that produce extensive amounts of space debris have the potential for disturbing or accidentally disrupting communications satellites or other kinds of space vehicles that are out there. So certainly this is an issue that I think is of general concern not only to us but to the broader international community and we'll be looking to get some more information from the Chinese about it.
"We've been on record previously I think as saying that there are concerns about the level of transparency in China's military and [the satellite kill ] fits in with this pattern. We would like to see and understand and know more about what they're really trying to accomplish here.
The US conducted similar tests in the 1980's and Casey was questioned as to why the US can do it and the Chinese can't. His response portends the potential for conflict caused by the growing importance of space.
"I think there's two factors you might want to take a look at. The first is the fact that 22 years ago, there was a Cold War ... between the United States and the Soviet Union ... [which] dictated. I think, quite a different policy on the part of the U.S. that exists now.
"More importantly, though, I think you need to look at the development of space in those past 22 years. The extent to which countries not only the United States, but countries throughout the world are dependent on space-based technologies, weather satellites, communications satellites and other devices to conduct modern life as we know it. And so the consequences of any kind of activity like this are significantly greater now than they were at that time.
Reporter: "Since you don't think anybody should be engaged in such kind of activities, will the United States foreswear or say it won't do this, or do you wish to reserve the right to do so?"
MR. CASEY: "Arshad, my understanding is there are no plans or intentions on the part of the United States to engage in such activities." ... there's always concern whenever there's debris in space, regardless of the cause, for the potential impact it might have on commercial satellites on manned space missions like the space shuttle, on the international space station, on anything that's potentially up there. You've certainly seen, given the history of some of the events of manned space flight, that small things can cause very big problems."
It'll be interesting to watch this unfold. As space activities increase and their relative importance to those back on Earth grows, will we simply extend territorial thinking into space? I'm hoping the SE is too big and important a project to be left to any one country or vested interest and we set aside our terrestrial differences and humanity climbs up the gravity together.
View Video
Labels: China Satellite, Space debris, Space Militarisation
Space debris already causes major problems in space elevator design and space operations and the situation just got worse.
Aviation Week & Space Technology reporter Craig Covault says the January 22 issue will carry an article detailing reports of a "a major new Chinese military capability" in the form of an Anti-Satellite (ASAT) weapon.
Covault's report explains as-yet unconfirmed intelligence agency reports indicate China performed a successful ASAT weapons test at more than 500 mi. altitude destroying an aging Chinese weather satellite target with a kinetic kill vehicle launched on board a ballistic missile.the attack is believed to have occurred at about 5:28 p.m. EST Jan. 11.
"Details emerging from space sources indicate that the Chinese Feng Yun 1C (FY-1C) polar orbit weather satellite launched in 1999 was attacked by an ASAT system launched from or near the Xichang Space Center ...as the weather satellite flew at 530 mi. altitude 4 deg. west of Xichang located in Sichuan province ... a major Chinese space launch center.
The test, if it occurred as envisioned by intelligence source, could also have left considerable space debris in an orbit used by many different satellites."
Labels: Space debris, Space elevator
[Author's Note: This posts documents three cases of nuclear power supplies on spacecraft whose orbit decayed. At this time I don't have any hard information about the size of the nuclear power supplies, radioactivity levels or expert opinion on any environmental damage. --PB--]
Sometimes nuclear power is the only source of long-term power stable enough to drive spacecraft and/or their onboard experiments. That may seem to be funny thing to put at the top of a post about nuclear mishaps but the point I'm trying to make is that nuclear power supplies will likely be a growing reality in space. Space debris isn't an issue only spacers need to worry about. It has and can continue to have an impact down here on the surface.
On December 12, 1959, quickly following the 1957 launch of Sputnik, the United Nations (UN) General Assembly adopted Resolution 1472 (XVI) - International Co-operation in the Peaceful Uses of Outer Space beginning with the following laudable sentiments;
"The General Assembly,
Recognizing the common interest of mankind as a whole in furthering the peaceful use of outer space,
Believing that the exploration and use of outer space should be only for the betterment of mankind and to the benefit of States irrespective of the stage of their economic or scientific development,
Desiring to avoid the extension of present national rivalries into this new field,
Recognizing the great importance of international cooperation in the exploration and exploitation of outer space for peaceful purposes,
Noting the continuing programmes of scientific cooperation in the exploration of outer space being undertaken by the international scientific community,
Believing also that the United Nations should promote international co-operation in the peaceful uses of outer space,"
This resolution calls for reports from the Committee for Peaceful Uses of Outer Space which is overseen by the United Nations Office for Outer Space Affairs (UNOOSA) which, along with other programs, maintains the Register of Objects Launched into Outer Space.The register has a searchable index. Setting the search form to 'Uses Nuclear Power Source: Yes' and clicking the search button shows a list of the 62 objects shot into space with nuclear power sources aboard.
Adding 'Presently in Space: No' reduces the results to 11 objects, two of which are on Mars and six are listed as recovered . The remaining three suffered orbital decay, one of which burned up completely in Earth's atmosphere another burned partially spewing 'fragments' into the Pacific Ocean and a third sprayed radioactive debris across thousands of square miles of Canada.
The registration report dated May 23, 1997, describes, in dry, technocratic tones, the demise of Mars-96. The spacecraft, launched November 16, 1996 from the Baikonur launch site by a Proton carrier rocket on a mission to do a global study of the surface of the planet Mars and its internal structure and surrounding plasma, carried a Pu-238 RTG power supply.
"Transfer of the unmanned interplanetary station Mars-96 from artificial Earth satellite orbit to flight path to the planet Mars did not take place The Mars-96 station entered the dense layers of the atmosphere and broke up, with individual fragments falling into the water areas of the Pacific Ocean" [emphasis added]
"Potential radiation impacts from launch of the Ulysses solar exploration experiment were evaluated using eight postulated accident scenarios. Lifetime individual dose estimates rarely exceeded 1 mrem. Most of the potential health effects would come from inhalation exposures immediately after an accident, rather than from ingestion of contaminated food or water, or from inhalation of resuspended plutonium from contaminated ground. For local Florida accidents (that is, during the first minute after launch), an average source term accident was estimated to cause a total added cancer risk of up to 0.2 deaths. For accidents at later times after launch, a worldwide cancer risk of up to three cases was calculated (with a four in a million probability). Upper bound estimates were calculated to be about 10 times higher."
Cosmos 1402, another nuclear accident in the sky carrying a BOUK, described by the State Research Center of Russian Federation Institute of Physics and Power Engineering (IPPE) as "a small fast neutron reactor and remote thermoelectric generator based on semiconductors", launched Aug. 30, 1982. While the IPPE site says "more than 30 BOUK units were in operation on the board of the Cosmos spacecraft for a number of years" and there's nothing pointing to the reactor as the source of failure, Cosmos 1402 only lasted little more than 5 months.
Cosmos 954, launched Sept. 18, 1977 and also carrying a BOUK, crashed to the ground on Jan. 24, 1978 in northern Canada spreading radioactive debris over a wide swath of remote territory south and east of Great Slave Lake in Canada's Northwest Territories (Google map of approximate location).
In his report of December 22, 1978, the Permanent Representative of Canada notified UNOOSA that the search for the scattered remains of Cosmos 954 had ended. The details of the recovery of a number of parts emitting "man-made radiation" included;
- 6 beryllium cylinders approximately 10 cm. diameter x 25 cm. long
- 41 beryllium rods approximately 10 cm. long x 2.5 cm. [diameter]
- 1 piece of "sheath-like material"
- 18 small flakes, slivers and chunks
- 1 metallic cylinder approximately 51 cm. max length x 36 cm. diameter with a 2.5 mm. thick wall
Labels: space commercialisation, Space debris, Space Law
While the space elevator faces a number of significant engineering challenges that need to be overcome before it gets built, the Space Elevator Journal has focussed on challenges that will occur once it's up and running. The issue of space debris, natural and man-made, will be a constant of life in space. Unfortunately, most of the man-made junk is in Low-Earth Orbit (LEO).
Millions of people have lived on Earth for thousands of years but, considering the few humans that have been in space, there may be more garbage per person in space than on Earth.
The link in the title of this post points to a flash animation from the European Space Agency (ESA) that is as compelling as it is disturbing. It shows the accumulation of space debris from the Sputnik launch in 1957 until the year 2000. Earth disappears from view in the mid-1970's.
The ESA's European Space Operations Centre (ESOC) runs a space debris program that explains since October 4th, 1957, more than 4,200 launches have lifted some 5,500 satellites into orbit but only approximately 700 are still operational. This unconscionable waste may be the best single reason for getting a space elevator built and ending Earth-based rocket launches forever.
On 21 January 2001, this 70 kg titanium motor casing from a PAM-D (Payload Assist Module - Delta), reentered the atmosphere over the Middle East landing about 240 km from the Saudi Arabia capital of Riyadh.
Source: NASA Orbital Debris Photo GalleryAccording to SOCRATES, the free daily service that predicts the probability of orbital close encounters between satellites and the thousands pieces of debris orbiting Earth, today (/2007/01/02) at 15:32:01.539 UTC Cosmos 489, an old Russian satellite launched in 1972 and SL-8 R/B, a Tsyklon Stage 2 rocket body (launched in 1979) will pass within 0.054 kilometers (177.2 feet) of each other at a relative velocity of 14.225 km/sec (31,820 mph !!!). Allowing for reasonable margins of error means there's a distinct chance these two pieces of space junk will collide (and possibly explode if there's residual fuels, batteries or other volatile materials involved) scattering chunks all over LEO endangering operational satellites and the humans that depend on them.
Orbital debris in LEO*
- 95% junk -
Source: NASA Orbital Debris Program Office
Ironically, both objects are from the Tsiklon program, the first prototype Soviet navigation satellite system but that is only one potential collision among Several large pieces of space debris re-enter the atmosphere every month according to the Aerospace Corporation, a US space R&D centre.
Did it ever occur to you to wonder how many of the satellites have nuclear power sources on board and if any of them have ever decayed back into the atmosphere and/or crashed to Earth? Stay tuned to the Space Elevator Journal.
--PB--
* LEO - Low Earth Orbit: the region of space within 2,000 km of the Earth's surface. It is the most concentrated area for orbital debris.
Source: NASA Orbital Debris Photo Gallery
Orbital debris in LEO*
- 95% junk -
Labels: Space debris, Space elevator, space environment
Latest Space Elevator Headlines by Google News™