There’s new information about the difficulties encountered in U.S. planning for shooting down one of its dead NRO satellites, unexpected results and how quickly an ASAT capability could be reconstituted for some new space threat.
“We didn’t predict an explosion,” says RADM Brad Hicks, U.S. Navy manager of the Aegis air and space defense program. “But the hyzdrazine tank did burn for tens of seconds. [The impact] also created smaller pieces than we had predicted. What’s still up there [is so small that] it is not showing up in the debris field.”
There are a few hundred tiny pieces, say aerospace contractors involved in the ASAT effort. Most will fall this month and the rest will follow by the end of June. While U.S. officials say it was a one-time event, they also say they learned a lot that might not have to be repeated for a second ASAT mission.
“I wouldn’t tell you that [we couldn’t go after a new space target in less than six weeks],” Hicks says. How quickly an ASAT capability can be reconstituted, “depends on the object, how we characterize the orbit and what we understand about the object [and whether we’re] killing the satellite or killing something inside the satellite.”
Planning the ASAT mission was more complicated than expected.
“[The dead satellite] was not stable,” Hicks says. “It was rolling and tumbling and [its gyration] wasn’t always the same from one orbit to another which added to the technical challenge. We tried for six weeks to see what was predictable about what it was doing each orbit, and we just couldn’t do it.”
As a result, gathering radar and infrared information on the satellite was crucial and the results are considered a huge lesson in integrating sensors.
“We needed everything to come together to give us the knowledge we needed. It was a totally dead satellite [so there was no maneuvering],” says Hicks. “There were early warning radars. There also were sensors in space. The problem is to not integrate too much. It can rapidly become unaffordable. We’re looking at the after action reports StratCom is to pull together [recommendations on future radar integration]." Other radars in the effort included those designed for THAAD, Alaska’s SBX and the targeting and test radars at Barking Sands, Hawaii.
The ASAT success apparently hasn’t generated a line of customers, at least so far. Just before the U.S. ASAT operation, Japan’s Kongo air defense ship completed the first international Aegis intercept of a ballistic missile. Japanese officials also were briefed on the satellite intercept.
“They congratulated us on our success,” Hicks says. “[But,] There is no interest by the government of Japan, to the best of my knowledge, to acquire [ASAT] capability. [Moreover,] Nobody has given us a mission to build an ASAT.”
Firstly, this means that important details of the physical chemistry of hydrazine were missing from the NASA/NRO/DoD models, and that raises questions whether we ought to believe that the re-entry modeling that predicted that the hydrazine would not have exploded/deflagrated if US-193 re-entered is really believable. Most likely, the hydrazine fuel would have auto-ignited and since the decomposition reactions are highly exothermic this would have propagated throughout the mixed-phase hydrazine in the tank and consumed all the hydrazine in a thermal runaway or deflagration.
Secondly, that the tank burned for "tens of seconds" raises a big question-mark over the assertion that the SM-3 kill vehicle really hit the "bulls-eye" of the fuel tank. If it really did that, then the frozen hydrazine ice ball would quickly be dispersed (while also being possibly ignited), but a tens of seconds "burning" [really decomposition] would not be expected.
Thus, all the public information to date on the interception would appear to indicate that the Raytheon KV did not hit the bulls-eye, and further that the hydrazine would have in any case burnt up if US-193 had been allowed to re-enter os its own accord.