REENTRY BREAKUP RECORDER (REBR)
Research Area: Space Structures
Expedition(s): 27-ongoing
Principal Investigator(s): ● William Ailor, PhD, The Aerospace Corporation, El Segundo,
California
RESEARCH OBJECTIVES
The Re-Entry Breakup Recorder
(REBR) tests a cost-effective
system that rides a re-entering
space vehicle, records data during
the re-entry and breakup of the
vehicle, and returns the data for
analysis. Understanding how
vehicles behave during
atmospheric re-entry gives future
spacecraft developers unique
information that can enhance
design efficiencies and safety.
EARTH BENEFITS
Data regarding how a spacecraft breaks up during deorbit can be applied to the design of future
spacecraft to minimize hazards to people and property in the event the re-entering spacecraft
becomes uncontrollable.
SPACE BENEFITS
REBR increases the understanding of vehicle breakup during re-entry, potentially resulting in
removing the need for deorbit propulsion capability, thereby decreasing cost and complexity
and increasing mission life and payload mass budget.
RESULTS
REBR units were installed and activated in the H-II Transfer Vehicle 2 (HTV2) and Automated
Transfer Vehicle-2 (ATV-2) 1 day prior to vehicle undock from ISS. The REBR in HTV2 was soft-
mounted while the REBR in ATV-2 was hard-mounted. HTV2 undocked from the International
Space Station (ISS) on March 28 and re-entered the atmosphere on March 29, 2011. ATV-2
undocked June 20 and re-entered on June 21, 2011 (Wada 2011).
According to REBR data, interaction with the atmosphere gradually slowed HTV2, put it into an
unstable tumble, and heated its structure until breakup and release of REBR at an altitude of
66.5 km and speed of Mach 23. During re-entry, HTV2 experienced increasing rotation rates
because of aerodynamic moments, which built to highly erratic behavior during HTV2 breakup
and REBR release. Two hundred seconds after re-entry began, the rotation rates took on a
damped oscillatory character, which was consistent with REBR stabilizing with its conical nose
View of the REBR installed in the ATV-2.