At the beginning of March we reported to the Solar Physics community on the difficulties that Hinode was experiencing with the data downlink. As a result we announced that requests for HOPs or Hinode Operation Plans, from the external community would be suspended. We expressed hope that this situation would last for a relatively short period. We have now developed sufficient confidence in operating the spacecraft and the three instruments in this new mode that we are ready once again to accept HOPs.
Hinode data are now transmitted through a back-up transmitter that has a considerably lower transmission rate. To compensate for the lower rate we have, over the last four months, increased the level of data compression without significantly affecting the quality of the data and improved our operational efficiency. JAXA has also provided additional funding to increase the number of ground stations and downlinks. Unfortunately there are technical, scheduling and diplomatic issues that have to be resolved before a new ground station can be brought on line. Our Japanese and international colleagues are working hard to resolve these problems and, as they do, the amount of data returned form Hinode will continue to increase from the current level of order 35% to perhaps 60% or more of the original capability by the start of 2009.
Because the planning process that achieves the increases in operational efficiency is more complicated than before, it is necessary to impose new restrictions on HOPs. First the HOP proposal must reflect the reduced data allocation and the recognition that planning is governed by the total data collected in an observation rather than by the rate at which data is acquired. Plans should state clearly which instruments are required and which are optional. Achieving the scientific objectives should not depend on continuous observations over a period of several days. In the future we expect to accept only focused science programs of relatively short duration separated by gaps for data downloading. Currently it is not possible to run high cadence observations continuously for 24 hours per day as was done for the SUMER coordinated campaigns of 2007. Because of these restrictions it is essential that a proposer works closely with an SSC (Science Schedule Coordinator) to develop an observing plan that will fit within the current telemetry limitations.
We look forward to the renewed participation of the international scientific community in the Hinode program and ask for your cooperation and understanding as we continue to recover the original performance of Hinode.
A more detailed set of instructions for preparing HOPs can be found on the - Hinode Monthly Events - link of the Hinode operation page under the banner - Guidance for Hinode Operations at http://www.isas.jaxa.jp/home/solar/hinode_op