The U.S. Defense Department’s Space Surveillance Network (SSN) is the most elaborate ground- and space-based system for tracking what’s going on in orbit. U.S. Strategic Command says the Space Situational Awareness Sharing Program now distributes SSN-derived data on around 1,500 functioning satellites to 285 different organizations. Only 40 of these are U.S. government-owned. Credit: U.S. Strategic Command
PARIS — The seven large geostationary-orbit satellites that were incorrectly disposed of in 2015 include two satellites whose failures forced their owners to abandon them on the geostationary highway, according to documents based on U.S., Russian and European observation data.
The two satellites, Israel-based Spacecom’s Amos-5 and Eutelsat’s Eutelsat 33B, both suffered on-board problems.
Spacecom’s Amos-5 shut down suddenly and no longer responded to ground commands in 2015 despite its relative youth. Built by Russia’s ISS Reshetnev, Amos-5 was just four years old.
Paris-based Eutelsat’s Eutelsat 33B, which had several names over the years — including W5, 70A, 25C — was launched in November 2002 and had already outlived its contracted 12-year service life.
Eutelsat said in October 2015 that the satellite had suffered a solar array failure and would be retired. But apparently some other anomaly prevented its being placed, as per international guidelines, in a retirement orbit at several hundred kilometers above the geostationary arc. Eutelsat said that 33B lost functionality in its second solar panel as well.
Like Amos-5, Eutelsat 33B will now remain in geostationary orbit for centuries or more, drifting from liberation point to libration point.
In a Feb. 6 statement, Eutelsat conceded that something went wrong in the post-retirement maneuver of 33B and tarnished what the company said was an otherwise perfect record in respecting international satellite-disposal best practices.
“The satellite’s batteries were discharged and RF transmissions switched off,” Eutelsat said. “It is being actively tracked with warnings of close approach generated by the U.S. Joint Space Operations Center (JSpOC) on Eutelsat’s behalf.
“Nineteen of the 20 satellite disposal/re-orbit operations we have performed have been fully compliant with rules and recommendations. Measures were taken after the incident with Eutelsat 33B to ensure there won’t be a repeat incident, including for satellites in orbit.”
The documents summarizing 2015 activity confirmed that Eutelsat’s Eutelsat 8 West D — also known as Eutelsat 3A, Chinasat 5C and Zhongxing 5C — had been raised to the accepted altitude at the end of 2014.
Leasat-5, Intelsat-6 F3, ABS-1A, Garuda-1, Raduga-1: insufficient disposal
The five other geostationary-orbit satellites whose disposals fell short of the guidelines were the Leasat-5, operated by Australia’s defense forces; the Intelsat 6 F-3; the ABS-1A, formerly called Mugungwha-2 or Koreasat-2; Indonesia’s Garuda-1; and the Russian Raduga-1.
Intelsat: We respected FCC rules
The appearance of Intelsat on the list of non-conforming disposals was surprising inasmuch as Intelsat, like Eutelsat, prides itself on its orbital good-citizenship.
In a Feb. 7 statement, Intelsat said its disposal of Intelsat 6 F-3 was done in full conformance with U.S. Federal Communications Commission rules.
“As a founder of the Space Data Association, and a company that relies upon a safe space environment to be able to deliver high-performance services to our customers, we advocate strongly for complete adherence to established protocols for de-orbiting of retiring spacecraft,” Intelsat said.
“In the history of Intelsat we have de-orbited over 80 satellites. Intelsat 6 F-3 was deorbited in January 2015 according to the FCC rules established for that class of satellite. Intelsat 6 (like other early-generation satellites) was grandfathered by the FCC to de-orbit at 150 km and not 300 km altitude. Our de-orbit of Intelsat 6 F-33 complied fully with the applicable regulations.”
The problem is not just satellites. Rocket upper stages should be able to perform deorbit maneuvers after dropping off their payloads to assure they do not spend centuries crossing through or near the geostationary arc, which remains the principal operating venue for commercial telecommunications satellites.
Once disposed of, rocket stages need to be passivated — their fuel tanks emptied and stored-energy sources such as batteries drained — to reduce the chances of explosion on contact with a micrometeorite or a piece of space debris.
The less-extensive Russian KIAM network tracks geostationary-orbit satellites and has recently upgraded its network with six new telescopes, one in the North Caucasus and the other placed at an existing facility in Monterey, Mexico. Credit: KIAM
Russian DM-3, Fregat-SB, Breeze-M upper stages left too close to GEO
In 2015, three Russian upper stages — a Russian Proton-M/DM-3, a Zenit-3SLBF Fregat-SB and a Proton-M/Breeze-M — were left in orbits near to the geostationary arc or actually crossing it. NASA reported in early 2016 that the Breeze-M stage had fragmented.
The guidelines on debris mitigation were established by the Inter-Agency Space Debris Coordination Committee (IADC), whose 13 member agencies include all the major space powers.
The IADC relies on inputs from individual nations, with the most sophisticated orbit-watching done by the United States Air Force’s Space Surveillance Network and Russia’s Keldysh Institute for Applied Mathematics (KIAM).
In presentations the week of Feb. 1 in Vienna, Austria, to the United Nations COPUOS, or Committee on the Peaceful Uses of Outer Space, the U.S. and Russia gave updates on their networks. China, the European Space Agency, the Japanese space agency JAXA and the French space agency, CNES, outlined their space debris efforts as well.