433 Eros Landing – Development of NEAR Shoemaker’s Controlled Descent Sequence

On February 12th, 2001, the NEAR Shoemaker spacecraft made its historic descent to the surface of the asteroid 433 Eros, becoming the first spacecraft to soft land on a small celestial body. Development of the final descent activity offered the NEAR team a difficult technical challenge as the spacecraft had been designed solely as a free flyer, not as a lander. The NEAR Shoemaker spacecraft rendezvoused with 433 Eros on February 14th, 2000. Following an intensive year of orbital operations collecting science data at decreasingly lower altitudes, the spacecraft was prepared to conduct its final activity, descending from its current 36 km orbit in a series of five propulsive maneuvers to land on the surface of 433 Eros. As a free flyer, the spacecraft’s orbital operations were extremely successful, collecting an order of magnitude more images of the asteroid’s surface than originally planned. However, since the spacecraft was not designed to be a lander, landing presented a whole new challenge to the Navigation, Mission Design, Guidance and Control, and Mission Operations Teams. This paper discusses the development of the controlled descent sequence from an operations perspective, focusing on the inherent difficulties of performing an activity for which the spacecraft was not originally designed, and the way in which these challenges were overcome by the NEAR team

Unattended network operations technology assessment study. Technical support for defining advanced satellite systems concepts

The results are summarized of an unattended network operations technology assessment study for the Space Exploration Initiative (SEI). The scope of the work included: (1) identified possible enhancements due to the proposed Mars communications network; (2) identified network operations on Mars; (3) performed a technology assessment of possible supporting technologies based on current and future approaches to network operations; and (4) developed a plan for the testing and development of these technologies. The most important results obtained are as follows: (1) addition of a third Mars Relay Satellite (MRS) and MRS cross link capabilities will enhance the network's fault tolerance capabilities through improved connectivity; (2) network functions can be divided into the six basic ISO network functional groups; (3) distributed artificial intelligence technologies will augment more traditional network management technologies to form the technological infrastructure of a virtually unattended network; and (4) a great effort is required to bring the current network technology levels for manned space communications up to the level needed for an automated fault tolerance Mars communications network

Solanezumab in- depth outcomes

BackgroundSolanezumab is a monoclonal antibody targeting soluble forms of β- amyloid protein important in the pathogenesis of Alzheimer- s disease (AD). Three previous 18- month double- blind placebo- controlled trials of low- dose solanezumab in late- onset sporadic AD found inconsistent benefits on cognitive and functional assessments. Dominantly- inherited mutation- associated AD subjects both before and after onset of symptoms form an ideal population to study potential benefits of solanezumab therapy.MethodMutation- carrying asymptomatic (CDR 0, N=41) or mildly symptomatic (CDR 0.5 - 1, N=28) patients were treated for a minimum of 4 years and up to 7 years in a double- blind 3 to 1 active versus placebo randomized clinical trial that measured disease progression by clinical, neuropsychological and biomarker evaluations. The trial was initiated with a dose of 400 mg every 4 weeks and escalated to 1600 mg when low dose trials in sporadic AD did not meet their primary endpoints. The primary cognitive outcome measure was DIAN- MCE, composed of Delayed Recall Score of the International Shopping List Test, the Delayed Recall score of the Logical Memory IIa subtest from the Wechsler Memory Scale- Revised, the Digit Symbol Substitution Test total score from the WAIS- R and the MMSE total score. Secondary outcomes included a battery of other cognitive and functional measures. The study was powered to detect delay of cognitive disease progression in the DIAN- MCE. Biomarkers include imaging modalities (volumetric MRI, FDG, amyloid and Tau PET). CSF markers included β- amyloid, Tau and PhosphoTau species. NfL was measured in both CSF and plasma. The study used a pre- specified Bayesian multivariate disease progression model, which included dynamic borrowing of control subjects from the DIAN Observational study.ResultThe topline efficacy, safety and biomarker results will be reported.ConclusionThis study provides the first test of targeting soluble abeta forms in DIAD. It addresses the efficacy of early initiation of higher doses of solanezumab targeting soluble forms of amyloid as a disease modifying therapy. While these results are specific to DIAD, they have the potential to inform the application of anti- amyloid therapy in sporadic AD.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163859/1/alz038028.pd