Details of the balloon and launch operations

Launch site: Scientific Flight Balloon Facility, New Mexico, US  
  Launch team: National Scientific Balloon Facility (NSBF)
Balloon: Open balloon (zero pressure) Raven - 39.570.000 cu ft - 0.8 Mil. - SF3-39.57-.8/.8/.8-NA
Serial number: W39.57-2-23
Flight identification number: 497N
Campaign: - 
Payload weight: -
Gondola weight: -
Overall weight: -

The balloon was launched by dynamic method assisted by launch vehicle on May 23, 2001.

The balloon flight spent 17 hr at a float altitude of 39 km during the day and 37 km at night.

Description of the payload or experiment

HERO (High Energy Replicated Optics)

Responsable institution:  NASA Marshall Space Flight Center
Principal Investigator:  Dr. Brian Ramsey

The instrument, is the first one aimed to obtain focused images of astronomical X-ray sources at hard X-ray energies (20-45 keV).

The key component (the hard X-ray optics) are full-shell electroformed-nickel-replicated (ENR) mirrors coated with iridium to enhance high-energy reflectivity. As the critical grazing angle for reflection varies approximately inversely with energy, these mirrors employ smaller angles than their low-energy counterparts and consequently have smaller diameters and collecting areas per shell. The mirrors have a 6 meter focal length.

To exploit the full potential of the HERO optics necessitates a balloon gondola that can provide commensurate pointing accuracy, stability, and pointing knowledge. The HERO gondola utilizes a coarse aspect system for slewing based on a differential global positioning system (GPS) and a fine inertial-mode pointing system that uses a novel day/night aspect camera system to update onboard gyroscopes.

Performance in flight and data obtained

During this flight -a test one-, the hard X-ray telescopes were pointed at the Crab Nebula, Cyg X-1, and GRS 1915+105, where they captured the First high-energy focused images of cosmic sources. This test flight confirmed the stability of the optical bench and the ability of the attitude control system to hold X-ray targets with suficient stability for extended periods of time.

External references and bibliographical sources