Trajectory correction maneuver design based on B-plane targeting for low-thruster
For the interplanetary mission, the spacecraft must require the trajectory correction maneuver (TCM) to reduce the trajectory error due to the influence of unexpected external perturbation forces. There are many kinds of researches focused on these TCM techniques for the impulsive thrust. Among them, the B-plane targeting method is mainly applied to the interplanetary mission as TCM method. However, there are brilliant developments in the propulsion systems; especially the electrical propulsion system is adopted in some spacecraft. Thus, it is necessary to design the TCM algorithm for such low-thruster for future interplanetary missions. Therefore, in this paper, the TCM algorithm for the low thrust such like electrical propulsion system is suggested to correct the target B-vector and target time to closest approach (TCA). To design the low thrust guidance scheme, the Lyapunov feedback control is used in this paper.
Interplanetary mission design handbook. Volume 1, part 3: Earth to Jupiter ballistic mission opportunities, 1985-2005
Graphical data necessary for the preliminary design of ballistic missions to Saturn are provided. Contours of launch energy requirements as well as many other launch and Saturn arrival parameters, are presented in launch date/arrival date space for all launch opportunities from 1985 through 2005. In addition, an extensive text is included which explains mission design methods, from launch window development to Saturn probe and orbiter arrival design, utilizing the graphical data in this volume as well as numerous equations elating various parameters. This is the first of a planned series of mission design documents which will apply to all planets and some other bodies in the solar system.
Single-incision laparoscopic cholecystectomy: lessons learned for success
Since its introduction approximately 20 years ago, laparoscopic cholecystectomy has rapidly become the treatment of choice for symptomatic cholelithiasis [1–3]. Conventional laparoscopic cholecystectomy generally is performed through four small incisions in the abdominal wall [4]. In recent years, a less invasive method has been sought in an effort to reduce postoperative pain and morbidities such as wound infection and trocar-site hernias while further enhancing the cosmetic results. Initial attempts to perform the procedure through three and then two ports or with reduced-diameter trocars (needlescopic surgery) [5–9] have since been superseded by even less invasive and more innovative techniques, namely, single-incision laparoscopic surgery (SILS) and natural orifice transluminal endoscopic surgery (NOTES) [10–13]. 
 
Single-incision laparoscopic surgery is an attractive technique for cholecystectomy due to its superior cosmetic results and potential to reduce the rate of wound complications such as infection, hematoma, and hernia. This technique, however, is not straightforward. The technical complexity of SILS naturally results in a steep learning curve and increased operating room time and requires specialized equipment. 
 
 
The primary technical obstacles of SILS currently include 
 
 
Collision of instruments both within and outside the abdomen as a result of their common entry point (“sword fighting”) 
 
 
Inadequate triangulation 
 
 
Compromised field of view due to obstruction by instruments entering the common port 
 
 
Inadequate exposure and retraction. 
 
 
 
 
Several techniques have since evolved to overcome these potential pitfalls [14–16]. By incorporating a number of these techniques, we have created a simplified technique that has proved successful with both animal and human subjects. We describe both our experience and what we have learned, which have allowed simplification of a technical complex procedure.