The New Horizons Spacecraft

The New Horizons spacecraft was launched on 19 January 2006. The spacecraft was designed to provide a platform for seven instruments that will collect and return data from Pluto in 2015. The design drew on heritage from previous missions developed at The Johns Hopkins University Applied Physics Laboratory (APL) and other missions such as Ulysses. The trajectory design imposed constraints on mass and structural strength to meet the high launch acceleration needed to reach the Pluto system prior to the year 2020. The spacecraft subsystems were designed to meet tight mass and power allocations, yet provide the necessary control and data handling finesse to support data collection and return when the one-way light time during the Pluto flyby is 4.5 hours. Missions to the outer solar system require a radioisotope thermoelectric generator (RTG) to supply electrical power, and a single RTG is used by New Horizons. To accommodate this constraint, the spacecraft electronics were designed to operate on less than 200 W. The spacecraft system architecture provides sufficient redundancy to provide a probability of mission success of greater than 0.85, even with a mission duration of over 10 years. The spacecraft is now on its way to Pluto, with an arrival date of 14 July 2015. Initial inflight tests have verified that the spacecraft will meet the design requirements.Comment: 33 pages, 13 figures, 4 tables; To appear in a special volume of Space Science Reviews on the New Horizons missio

Multi-trait genome-wide association study identifies new loci associated with optic disc parameters

A new avenue of mining published genome-wide association studies includes the joint analysis of related traits. The power of this approach depends on the genetic correlation of traits, which reflects the number of pleiotropic loci, i.e. genetic loci influencing multiple traits. Here, we applied new meta-analyses of optic nerve head (ONH) related traits implicated in primary open-angle glaucoma (POAG); intraocular pressure and central corneal thickness using Haplotype reference consortium imputations. We performed a multi-trait analysis of ONH parameters cup area, disc area and vertical cup-disc ratio. We uncover new variants; rs11158547 in PPP1R36-PLEKHG3 and rs1028727 near SERPINE3 at genome-wide significance that replicate in independent Asian cohorts imputed to 1000 Genomes. At this point, validation of these variants in POAG cohorts is hampered by the high degree of heterogeneity. Our results show that multi-trait analysis is a valid approach to identify novel pleiotropic variants for ONH