Antisatellite Operations

Jonathan C. McDowell

ASATs (antisatellite weapons) have been used since the beginning of the space age. So far, thankfully, they have only been used against targets belonging to the same nation as the ASAT launch team. However, when used to destroy orbital targets, ASATs generate orbital debris, often large amounts of it. Attempts to reduce the amount of long lived debris by firing against a low orbit target are better than nothing, but in my view still unacceptable.

When a satellite in a circular orbit at height H is destroyed by an explosion or an orbital-velocity impact, energy is imparted to the resulting fragments, which typically orbit in the same orbital plane but in elliptical orbits where either the apogee or perigee is close to H, but the other apsis may be hundreds of kilometers lower or higher.

A traditional way to understand such events is the use of the Gabbard diagram, where each debris object in an orbit of perigee P and apogee A with orbital period T is mapped to a pair of points (T,P) and (T,A) in a period-height plot.

First, I summarize the various antisatellite programs which have resulted in test launches. Note that launches to test a launch vehicle which werenot aimed at a target, launches against imaginary `point in space' targets, and systems using a dummy nuclear warhead (which do not involve physically hitting the target) do not generate orbital debris.

A series of Russian satellites in the `Nivelir' program, including Kosmos-2535/2536, may also be antisatellite tests, but their status is unclear at the moment.

The US insists that the Burnt Frost operation, in which a failed NRO satellite was destroyed by an SM-3 missile just prior to reentry, was carried out for public safety (fears that the hydrazine on the satellite would be a health risk after impact). Nevertheless, it involved the destruction of a satellite and the generation of orbital debris, and in my view was seen by other nations as normalizing the use of antisatellite weapons (in the context of previous US ASAT programs and the continuing rhetoric of US space control and dominance). I therefore count it as an antisatellite weapon and include it within the scope of my condemnation of all such activities.

There are two broad trajectory types used:

There are three basic types of warhead used, which I label:

Antisatellite projects
Agency Program Launch Vehicle Trajectory Warhead Debris? Period Notes
US Air ForceHigh VirgoB-58/High Virgo DA DN? No 1959
US Air ForceBold OrionB-47/Bold Orion DA DN? No 1959
US Army Program 505 Nike Zeus DA DN No 1962-1965
US Air ForceProgram 437Thor DA DN No 1964-1970
OKB-52, SSSRIS Tsiklon-2 CO HEYes1968-1982
US Air ForceASM-135 F-15A/ASAT DA KE Yes 1984-1986
SDIO Vector SumDelta 3920 CO KE Yes 1986
PKO MO RF Kontakt Mig-31D/79M6 DA KE (Yes)1991 Not tested against target
Khrunichev, RFNaryad Rokot CO HE? Yes 1990-1994Not tested against target
PLA, China Chinese ASAT DF-21? DA KE Yes 2005-2014?
US Navy/ABMDABurnt Frost SM-3 DA KE Yes 2008
DRDO, India PDV-II PDV-II DA KE Yes 2019-?
Almaz/MO RF Nudol' Nudol' DA HE or KE Yes 2014-

See also:

The 2021 Russian test

Image: JCM