OA-6 Reentry Campaign
REBR-W Provides No Data on OA-6 Reentry, but Observation Campaign a Success
A new version of Aerospace’s Reentry Breakup Recorder known as REBR-Wireless would record data inside Orbital ATK’s OA-6 space station supply vehicle when it reentered on June 22, 2016. Scientists aboard an aircraft flying high over the South Pacific Ocean would watch from below and record visual and spectral data during the reentry and breakup. REBR had successfully returned data three of its four previous flights, so expectations were high for the OA-6 reentry. The data from REBR-W and the observation campaign would provide the greatest insight into the nature of reentry breakup of any experiment to date. But it was not to be.
REBR is designed to collect data during the reentry and breakup of space vehicles and to “phone home” that data after it is released during breakup. REBR has a 3-axis accelerometer, a rate gyro and other internal sensors, and the new version on OA-6, REBR-Wireless or REBR-W, had the added capability to record data from several sensors external to the device. Astronauts installed these external sensors at specific locations inside the OA-6 vehicle prior to reentry and activated REBR-W by pulling three wires. The activation lights came on. All looked fine.
During the planning for the OA-6 reentry, the SETI Institute contacted Aerospace about the possibility of placing an aircraft loaded with instruments in the area where reentry was expected. The FAA and Aerospace each provide half of the funding required for the flight and the subsequent data reduction; SETI handled details of the flight and arranged for a suite of instruments to be looking out the aircraft’s windows as the OA-6 vehicle flew by many kilometers away. An Aerospace employee, Janna Feeley, was on the observation aircraft and recorded a video of the late portion of the reentry.
Unfortunately, REBR-W was silent and no data was returned. Post-flight information from Iridium indicates that REBR-W made several attempts to communicate while floating in the South Pacific well after reentry, but none was successful.
The reentry environment to which REBR-W was exposed is not well understood. We know there are factors that can prevent REBR from transmitting, including metallic residue on REBR’s aft dome and REBR tumbling in flight if its heat shield is damaged while emerging from the breakup debris. We’re constructing a fishbone of the event to be sure that there are no software or other controllable factors that might have prevented REBR-W from communicating. We will document our findings.
The observation campaign, on the other hand, was a great success. The aircraft was in the right spot to view the critical part of the trajectory, and all sensors worked as designed. Data from the observation campaign is now being evaluated. Since the campaign focused on the early part of the entry, hopes are that events such as failure of the solar panels and early breakup will be visible. If so, we hope to correlate these early events with data REBR recorded on previous reentries.
Opportunities such as that provided by the OA-6 reentry are rare, but we have the makings of another REBR-W in storage. We’ll be looking for another ride.
Approved for public release. OTR 2017-00313