Pre-Determined Debris Avoidance Maneuvers (PDAMs) of ISS as Functionability Action

NASA's long-standing guidelines require the ISS to maneuver if any satellite comes within a "pizza box"-shaped area of space surrounding the orbit of the station. The box is roughly 4 by 50 by 50 km with the ISS at the centre, according to agency officials. Tractable pieces in that orbital plane are roughly 5 cm in diameter, but even paint flecks can cause issues given the high velocities involved with objects in orbit.

When predictions indicate that any tracked object will pass close enough for concern and the quality of the tracking data is deemed sufficiently accurate, Mission Control centers in Houston and Moscow work together to develop a prudent functionability action for its avoidance. The collision risk is calculated many hours in advance of a potential collision based on the orbital elements of the debris object and potential target.

Successfully operated and finished pre-determined ISS debris avoidance maneuver PDAM and passing of orbital debris on the safe distance, will mark the moment in time when the ISS negative functionability action is finished, and ISS starting the positive functionability action to return to positive functionability state – normal operation mode.

ISS negative functionability actions between 1999 – 2003

During this period of operation the ISS performed 7 PDAMs, all of which are noted below:

27th October 1999: ISS performed collision avoidance action to prevent conjunction with Pegasus Rocket Body (COSPAR ID: 1998-046K, NORAD ID: 25422). [1]

30th September 2000: ISS collision avoidance action to escape conjunction with Vostok Rocket Body (COSPAR ID: 1971-031B, NORAD ID 5143). [1]

10th February 2001: ISS/Space Shuttle collision avoidance action to prevent the conjunction with Electron 1 Debris (COSPAR ID: 1964-006, NORAD ID 87618). [1]

14th March 2001: ISS/Space Shuttle collision avoidance action avoiding conjunction with ISS/Shuttle Debris (COSPAR ID: 2001-010B, NORAD ID 26723) and Cosmos Rocket Body (COSPAR ID: 1990-078B, NORAD ID 20775). [1]

15th December 2001: ISS executed collision avoidance action to avoid conjunction with Cosmos Rocket Body (COSPAR ID: 1971-119B, NORAD ID 5730). Space Shuttle conducted action prior to undocking and conjunction. [1]

16th May 2002: ISS collision avoidance action avoiding conjunction with Cosmos Rocket Body (COSPAR ID: 1994-061B, NORAD ID 23279). [1]

30th May 2003: ISS collision avoidance action avoiding conjunction with MegSat (COSPAR ID: 1999-022B, NORAD ID 25722). [1]

ISS negative functionability actions between 2008 – 2015

There were no pre-determined debris avoidance maneuvers between 2004-2008. However, there were 18 PDAMs between 2008-2015. Those known to the authors are presented below:

27th August 2008: The ISS collision avoidance action occurred when a fragment from the Cosmos 2421 spacecraft was projected to pose a collision risk of 1 in 72. ESA’s Automated Transfer Vehicle, the Jules Verne, performed the collision avoidance maneuver. [2]

October, 2010: The ISS was forced to action to avoid a potential collision with a piece of debris which had come off a 19-year-old NASA scientific spacecraft only one month earlier. The collision avoidance action was successfully performed by the Progress M-07M logistics vehicle that docked at the aft port of the ISS Zvezda module on 12 September. [3]

2nd April 2011: The ISS performed collision avoidance action regarding a fragment from Cosmos 2251. A small evasive maneuver action was done by the European Automated Transfer Vehicle 2 (ATV-2), which was docked at the aft end of the ISS complex on 24 February. The burn, which lasted 3 minutes and 18 seconds, was executed early 2 April (GMT), imparting a change in velocity to ISS of only 0.5 meters per second. [4]

29th September 2011: International Space Station dodging of orbital debris from the Russian Tsyklon rocket body. [17]

13th January 2012: International Space Station dodging of orbital debris. Avoiding conjunction with fragmentation debris from Iridium 33. [17]

28th January 2012: To avoid a possible conjunction with fragmentation debris from Fengyun-1C the ISS performed a required maneuver. [17]

12th November 2014: The ISS avoided satellite debris by activating engines of “Georges Lemaitre” Automated Transfer Vehicle for 3 minutes, 25 seconds. This pre-determined debris avoidance maneuver (PDAM) was done to move well away from a small piece of debris from a spent Chinese satellite (Yaogan 12) launched in November 2011. It was coordinated with Russian and European flight controllers, and raised the station’s altitude by 9/10 of a mile at apogee and 2/10 of a mile at perigee and left the station in an orbit of 262.3 x 252.0 statute miles. [5]

ISS negative functionability actions between 2020 – 2023

During this period 13 pre-determined debris avoidance maneuvers have been performed by ISS to protect it from identified orbital debris. Majority of them are listed below:

22nd September 2020: The ISS conducted PDAM by Progress 75 thrusters, with a 150-second reboost to avoid a possible conjunction with an unknown piece of space debris. Due to the late notification of the possible conjunction, the three Expedition 63 crew members were directed to move to the Russian segment of the station to be closer to their Soyuz MS-16 spacecraft as part of the safe haven procedure out of an abundance of caution. This functionability action raised the station’s orbit out of the predicted path of the debris at the estimated distance of 1.39 km. [6]

3rd December 2021: The ISS orbit adjusted to dodge debris from old U.S. Pegasus rocket (object 39915) rocket. Russian Progress 79, attached to the space station, fired its thrusters for 2 minutes and 41 seconds to lower the station’s orbit. This action generated a safe margin of separation from a fragment tracked by ballistics specialists. The Expedition 66 crew aboard the station was not in any additional danger. [7]

16th June 2022: The ISS conducted a collision avoidance action to escape a large fragment (COSPAR ID: 1982-92BYX, NORAD ID: 52590). This was the first time the risk of a collision exceeded the requirements for an avoidance maneuver. [8]

24th October 2022: The ISS conducted a second collision avoidance action for the year to avoid a potential high-risk collision with a large debris fragment (COSPAR ID: 1982-092BMN, NORAD ID: 51561). [9]

21st December 2022: The tracking data showed a close approach of a fragment of Russian Fregat-SB upper stage debris to the ISS. The consequential functionability action was the Roscosmos Progress 81 thrusters firing for 10 minutes and 21 seconds to avoid the estimated passing of the debris as closed as less than a half of kilometre from the station. This functionability action resulted in a postponement of the planned spacewalk by two NASA astronauts. [10]

6th March 2023: The ISS fired thrusters to avoid collision with an Earth observation satellite. The power came from the docked ISS re-supply ship Progress 83 and lasted just over six minutes slightly raising the station’s orbit to avoid the approaching satellite. The new orbital trajectory did not impact the upcoming departure of the Crew-5 mission. [11]

14th March 2023: To provide extra distance from a fragment of Russian Cosmos 1408 satellite debris the ISS Progress 83 thrusters fired for a 2-minute and 35-seconds. NASA and Russian flight controllers worked together to conduct the maneuver to prevent the fragment potentially passing within 200 metres from the station. [12]

6th August 2023: The ISS taken PDAM to mitigate a projected high-risk conjunction with Cosmos 1408 debris (COSPAR ID: 1982-092BZV, NORAD ID: 52808). The 83P Progress vehicle thrusters were used to raise perigee altitudes by 0.73 km and 0.40 km, respectively. [13]

24th August 2023: Using the Zvezda Service Module’s main engines as thrusters the ISS completed a PDAM to avoid a high-risk conjunction with Fengyun-1C (FY-1C) debris (COSPAR ID: 1999-025DPV, NORAD ID: 35213). This action lowered the ISS apogee and perigee altitudes by 0.18 km and 1.34 km, respectively. Both the timing of the action and its retrograde direction were chosen to minimise the impact of the PDAM upon Progress 85P, the SpaceX Crew-7 vehicle, and the Soyuz 69S departure and 70S launch operations. [13]

10th November 2023: The International Space Station (ISS) performed a Predetermined Debris Avoidance Maneuver (PDAM) at 15:07 GMT to mitigate a projected high risk conjunction with SL-16 debris (COSPAR ID: 1992-093KT, NORAD ID: 39841). This fragment was created during one of four known breakup events; the first event occurred on 26 December 1992, within 26 hours of the 25 December launch, and the last event occurring on 30 December 1992. The breakup parent was the Cosmos 2227 rocket body, a Zenit-2/SL-16 second stage. [14]

ISS negative functionability actions between 2024 – onward

19th November, 2024. The Pre-determined Debris Avoidance Maneuver (PDAM) took place at 3:24 GMT on 19 November 2024. The avoided object (International Designator 1995-015FU, U.S. Satellite Catalog Number 40680) was a fragment generated from the accidental explosion of a Defense Meteorological Satellite Program (DMSP) 5D-2 F13 spacecraft in 2015. It was estimated that without this adjustment, the debris could have passed within approximately 2.5 miles of the International Space Station. [19]

25th November, 2024. At 3:30 GMT on 25 November 2024, the ISS conducted another Pre-determined Debris Avoidance Maneuver (PDAM). The target this time was a different fragment (International Designator 1999-025AEN, U.S. Satellite Catalog Number 30423), which was generated from the Fengyun-1C (FY-1C) anti-satellite test conducted by China in 2007. [19]

30th April, 2025. The International Space Station (ISS) conducted its first Predetermined Avoidance Maneuver (PDAM) of 2025 to mitigate repeated high-risk conjunctions with a debris object (International Designator 2005-024L, U.S. Satellite Catalog Number 35272). The PDAM took place at 22:10 GMT on 30 April 2025 and raised the altitude of the ISS by approximately 0.53 km. The avoided object appears to be associated with the CZ-2D upper stage (International Designator 2005-024B, U.S. Satellite Catalog Number 28738) that deployed China’s SJ-7 spacecraft in 2005. This PDAM increased the total number of collision avoidance maneuvers conducted by the ISS to avoid potential collisions with objects tracked by the U.S. Space Surveillance Network (SSN) to a total of 41 since 1999. [20] [21]