Ionson defends SDI programFirst in a series on the Oct. 21 Strategic Defense Initiative forum.
Dr. James Ionson, director of science and technology for the Strategic Defense Initiative (SDI) Office, predicted last Monday that there will be an 85 percent chance SDI systems can stop all but one Soviet missile from reaching the United States.
Ionson spoke at a forum sponsored by the MIT Technology and Culture Seminar, the MIT Disarmament Study Group and the Boston chapter of Computer Professionals for Social Responsibility.
A panel of respondents from the MIT community also appeared: Professor Vera Kistiakowsky of the Department of Physics; Professor Shaoul Ezekiel '68 of the Departments of Aeronautics and Astronautics and Electrical Engineering and Computer Science; and Scott Saleska '86 of MIT Student Pugwash.
Ionson said he began travelling around the country to clear up "SDI misunderstandings," addressing "audiences from liberal to radical."
He said he would not try to change the minds of listeners, but rather to provide information. "I will not even attempt to convey an illusion of objectivity," Ionson explained.
Ionson initiated his 45-minute presentation with a defense for the foundation of SDI.
"We all believe in peace through law and negotiation," he said. He asserted that offensive deterrence is currently necessary to back up the negotiation process. Reducing arms can at best reduce the costs of the reliance, he said.
"Defensive deterrence could be a more moral alternative, and it should be investigated," said Ionson. "Defensive deterrence, remember, is non-nuclear and incapable of destruction." He stated the intent of SDI was to make nuclear weapons uneconomical and obsolete.
Ionson emphasized that "nothing is in the deployment scenario. We are only doing research ... The US is engaging in open research of political, economic and technical issues."
To demonstrate his confidence in the feasibility of SDI, Ionson explained that the effectiveness will lie in the layering of defense shields along missiles' trajectories:
O+ The first layer covers the five-minute boost phase in which the rocket's flame is on and easy to detect. Ionson claimed this layer is 90 percent effective; only 140 of 1400 missiles would get through the first layer.
O+ The second layer, the five-minute bussing phase of the missile, can be covered with 80 percent efficiency. The 140 rockets escaping the first phase, Ionson explained, would mean that 1400 warheads would escape that layer. Only 280 warheads would escape the bussing phase, he said.
O+ In the midcourse phase of 30 minutes, Ionson claimed that SDI's 70 percent effectiveness would allow only 84 warheads to escape.
O+ The three minute exoatmospheric phase in which the missile reenters the atmosphere could be covered with 80 percent efficiency, Ionson claimed, allowing only 17 warheads to survive.
O+ In the endoatmospheric phase, Ionson estimated a 95 percent effectiveness rate. The end result is an 85 percent chance that only one of the 17 remaining warheads would ultimately escape the defenses.
Ionson cautioned that the effectiveness depends on the number of missiles in the attack.
Kistiakowsky was the first to respond following Ionson's presentation. She opened by arguing that Ionson's numbers on SDI effectiveness were purely hypothetical. "Their charming presentation does not make them real," she said.
SDI is technically infeasible, Kistiakowsky continued; it encompasses "no new ideas by and large." SDI is instead "based on stretching existing things to technological limits." She cited a study which stated that at least 42 warheads could escape SDI defenses, killing 25 to 30 percent of the US population.
Kistiakowsky also addressed the fact that a retaliatory posture would still have to be maintained. Relying on SDI would be analogous to relying on a large fortress.
She also said the satellites are highly vulnerable relative to launch and reentry vehicles.
Kistiakowsky also quoted SDI Director General James A. Abrahamson '55, who stated, "A perfect astrodome defense is not a realizable thing."
Responding to Kistiakowsky, Ezekiel stated, "Research should be done even though on paper things look impossible."
Saleska concluded by stating "if you believe in SDI, then go ahead ... If you do not believe in SDI or you believe it will lead to the annihilation of the planet, then don't take the money ... Educate yourselves."