Engineering topics

Richardson, Georgia A.

Publications and source records attributed to Richardson, Georgia A..

3 records

NASA NTRS2010

Using the Two-Burn Escape Maneuver for Fast Transfers in the Solar System and Beyond

The two-burn maneuver to escape the gravitational pull of a central body is described. The maneuver, originally suggested by Hermann Oberth, improves efficiency considerably for a wide range of missions of interest in space exploration and scientific investigation. A clear delineation of when the maneuver is more effective is given, as are methods to extract the most advantage when using the maneuver. Some examples are given of how this maneuver can enable exploration of the outer solar system, near interstellar space, and crewed missions to Mars and beyond. The maneuver has the potential to halve the required infrastructure associated with a crewed mission to Mars and achieve increased solar escape velocities with existing spacecraft technologies.

Adams, Robert B.↗

NASA NTRS1998

GRB 980326 and GRB 980329

M. S. Briggs, G. Richardson, R. M. Kippen, and p. M. woods, University of Alabama in Huntsville, report on behalf of the BATSE team: GRB 980326 (IAUC 6851) was observed with BATSE on Mar. 26.88811 UT as trigger 6660. The event lasted about 5 s and exhibited three narrow pulses. Its peak flux (integrated over 0.5 s) and fluence (50-300 keV) are 8 x l0(exp -7) erg /sq cm sE-1 and 1 x 10(exp -6) erg/sq cm, respectively. GRB 980329 (IAUC 6853) was observed with BATSE on Mar. 29.15600 as trigger 6665; the event was very intense and lasted about 55 s, exhibiting a 10-s-long, highly structured peak. Its peak flux (integrated over 0.5 s) and fluence (50-300 keV) are 8 x 10(exp -6) erg/ sq cm sE-1 and 5 x l0(exp -5) erg/ sq cm, respectively. The BATSE locations are consistent with the locations of the reported optical transient for GRB 980326 (IAUC 6852) and the SAX/NFI x-ray counterpart for GRB 980329 (IAUC 6854). Location maps can be found at http://www.batse.msfc.nasa.gov/-kippen/batsebr.

Briggs, Michael S.↗

NASA NTRS1998

SGR 1627-41

BATSE has detected repeated soft gamma-ray bursts consistent with the same (previously unknown) location. We recorded three bursts on June 15.109, 15.296, 15.411 UT (BATSE triggers 6825, 6826, 6827, respectively) with an average duration of about 200 milliseconds. Preliminary spectral analysis of the data indicates that the events are very soft, with power law spectral indices varying between -3.0 and -7.0. BATSE triggered 5 more times, on June 17.873,17.901, 18.004, 18.035, and 18.071 UT (BATSE trigger numbers 6833, 6834, 6835, 6836 and 6837, respectively). The last trigger had a peak count rate of over 300000 counts/sec above background (integrated over 4 detectors between 20-1000 keV, in 1 second interval) and a duration of about 3 seconds. Due to Rs very high peak intensity, deadtime effects prevent us from using it for localization, until we receive more data types. The weighted location of the 7 remaining triggers is centered on R.A. = 16h27ml2.0s and dec = -41 d06.0' with an error radius of about 2 degrees. This location does not correspond to any previously known SGR source; we conclude that we have discovered a new source, SGR1627-41. We have initiated an RXTE ToO and we strongly encourage wide field observations at other wavelengths.

Kouveliotou, Chryssa↗