The elliptic rendezvous problem in DROMO formulation

The extension of DROMO formulation to relative motion is evaluated. The orbit of the follower spacecraft can be constructed through differences on the elements defining the orbit of the leader spacecraft. Assuming that the differences are small, the problemis linearized. Typical linearized solutions to relativemotion determine the relative state of the follower spacecraft at a certain time step. Because of the form of DROMO formulation, the performance of a frozen-anomaly transformation is explored. In this case, the relative state is computed for a certain value of the anomaly, equal for leader and follower. Since the time for leader and follower do not coincide, the implicit time delay needs to be corrected to recover the physical sense of the solution. When determining the relative orbit, numerical testing shows significant error reductions compared to previous linearized solutions.

Microtubule self-organization is gravity-dependent

Although weightlessness is known to affect living cells, the manner by which this occurs is unknown. Some reaction-diffusion processes have been theoretically predicted as being gravity-dependent. Microtubules, a major constituent of the cellular cytoskeleton, self-organize in vitro by way of reaction-diffusion processes. To investigate how self-organization depends on gravity, microtubules were assembled under low gravity conditions produced during space flight. Contrary to the samples formed on an in-flight 1 × g centrifuge, the samples prepared in microgravity showed almost no self-organization and were locally disordered.

Issues affecting dealer service decisions /

Mode of access: Internet.

Distribution of phytoplankton in Alabama lakes /

Issued July 1977.

Distribution of phytoplankton in Virginia lakes /

Mode of access: Internet.

Distribution of phytoplankton in Mississippi lakes /

Mode of access: Internet.

Tests of the dual differential radiometer under field conditions /

Issued Aug. 1978.

Surface water quality parameters for monitoring oil shale development /

Mode of access: Internet.

Airborne measurements of power plant plumes in West Virginia : Kammer and Mitchell power plants, 25 August-11 September 1975 /

"June 1979."

Distribution of phytoplankton in Maryland lakes /

Mode of access: Internet.

Distribution of phytoplankton in West Virginia lakes /

Mode of access: Internet.

Pesticides and polychlorinated biphenyls in the Atchafalaya Basin, Louisiana /

"September 1979."

Investigation of springing responses on the Great Lakes ore carrier, M/V Stewart J. Cort : final report /

"Report no. CG-D-17-81."

Technical report ES.

No. 7 issued as Ohio State University. Columbus. Institute of Polar Studies, Report, no. 20.

Guide to Magellan image interpretation /

"JPL publication 93-24."