Topical Discussion Meeting - Nuclear hardening to protect satellites against high-altitude-nuclear-explosions (HANE)

Johan Ideström (OHB System AG) ; TBD
Thursday 8/11, 14:00-15:15
MTC 00.03

Satellites in space face many threats: natural threats like space weather (Carrington event), meteoroids, atomic oxygen, natural radiation from the sun and the radiation belts; and man-made threats like space debris, jamming, cyber hacking, artificial radiation and electromagnetic pulse (EMP) from High-Altitude-Nuclear-Explosions (HANE).

The most famous example of HANE, is the 1962 Starfish Prime nuclear explosion (1.4Mt TNT equivalent) in the pacific at 400 km altitude. This caused the biggest known EMP, much bigger than expected, even in Hawaii (1445km from the explosion) were artificial polar lights observed and 300 street lights malfunctioned. The HANE damaged as well 8 satellites, of which 7 failed completely just in months after the explosion. In 1962 were only a total of 32 satellites orbiting the earth and with 8 damaged satellites by Starfish Prime, it corresponds to a knock-out quota of 25%. Nowadays are over 1000 satellites orbiting earth in LEO, therefore could a similar event to Starfish Prime result in over 250 damaged satellites.

The protection of satellites against the effect of a HANE is called nuclear hardening. During the cold war was HANE a serious concern which resulted in the nuclear hardening of military satellites, the most famous example being the GPS satellites. After the cold war the threat scenario changed and with it the need for nuclear hardening declined. But due to most recent geo-political developments in North-Korea, a new threat-scenario is surfacing, and nuclear hardening is considered again.

Until today only few nations build military satellites with nuclear hardening in mind. Commercial customers are not considering it, and even new GNSS systems like Galileo are not taking it in account. All satellite manufactures are currently going through a design change by replacing their chemical propulsion with electrical propulsion. They are facing new challenges with Electrical-Propulsion-Orbit-Raising (EPOR) periods of up to 387 days, therefore spending more time in radiation belts and accumulating up to 50% more total-dose then previous missions. This added radiation dose of EPOR requires anyway an update of the satellites radiation shielding design, and then it makes sense include hardening against extreme space weather (Carrington) and HANE as well, since synergies in hardening against EPOR/Carrington/HANE are to be expected.

This Topical Discussion Meeting provides an overview of the history of HANE, list direct and indirect emissions and effects (e.g. radiation belt pumping), and finally present (very general) strategies to harden satellites against those effects.

Other discussion points:
- is it possible to simulates HANE effects in SPENVIS or OMERE?
- could the simulation of solar proton event (SPE) in SPENVIS or OMERE emulate the effects of HANE?
- are GEO satellites already indirectly hardened? (since the radiation belt pumping effects due to HANE in GEO orbit would decay within weeks)
- are synergies in hardening against EPOR/Carrington/HANE to be expected?
- can lessons of Jupiter missions applied to nuclear hardening?
- how to raise awareness about HANE and radiation belt pumping?

This meeting is unclassified and open to everyone. All information is based on open access unclassified reports. The information will be more of general nature, don't expect specific information like: "weapon X generates particles of Y energy and Z total dose", those details are not mentioned in open access unclassified reports. A list of the open access unclassified reports will be provided.

The scope of this Topical Discussion Meeting is to start an open discussion and an exchange of idea, feedback from other participants is welcome.