![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |
. | ![]() |
. |
![]()
Cameron Park - March 7, 2001 After several Russian landers and a detailed radar mapping mission in the 1980s, planetary scientists are starting to turn their gaze back to the Venus which many scientists believe holds valuable answers to our own planet and the danger of runaway greenhouses. In light of this growing interest, NASA's Solar System Exporation Subcommittee will set up a committee to evaluate plans for further exploration of Venus. Although probes to study Venus' atmosphere and weather aren't that hard, and in fact several such probes (orbiters and atmospheric entry probes) have been finalists in the competitions to select low-cost Discovery missions, but so far none have yet been selected. But the study of Venus' geology - requiring long-lived seismometers, detailed surface composition analysis, or the actual return of surface samples to Earth - is tremendously hard, thanks to its savage lead-melting 480-degree C. surface temperature. Again, no acceptable strategy that is affordable has yet been devised, and this subcommittee will try to come as close as possible to doing so. Both subcommittees will issue their findings at the next SSES meeting in mid-July. Meanwhile, the latest SSES meeting did reach one very firm conclusion on another subject -- namely, the issue of extended missions, in which spacecraft survive beyond the end of the mission for which they were officially designed. Most spacecraft do in fact do so - but the inadequacy of the funds that NASA puts into planning such extended missions, and operating the spacecraft during them, has long been a scandal, given the fact that such extended spacecraft operations represent an excellent cost-effective opportunity to get more science at a tiny fraction of the total cost of the original mission. The most recent example was the NEAR spacecraft's survival of its landing on Eros. While unlikely, this had always been quite possible -- but NASA still ended up in a frantic impromptu effort to try to squeeze as much post-landing science as possible out of it. The SSES will announce that the time has come for NASA to incorporate such extended missions into its Solar System exploration budget planning, by dealing properly with three different issues. The first is the continued stubborn survival of the Galileo spacecraft - whose primary "orbital tour" to study Jupiter and its moons lasted only two years, but which is still ticking away three years and two more extended missions later despite Jupiter's high radiation levels, suffering only some limited damage to its scientific instruments. During Galileo's most recent close pass at Jupiter, its camera began suffering occasional electronic malfunctions causing it to produce blank pictures - but so far it has been easy to reset it by Earth command, and once it even spontaneously fixed itself. Obviously abandoning it at this point would be a foolish waste of taxpayer funds; but another one million dollars still needs to be added to its operating budget for another extended mission - during which it would make a flyby of Callisto and three more close flybys of Jupiter's volcanic moon Io this year (including two passes over the poles to look for any innate Ionian magnetic field), and the first close flyby of the tiny inner moon Amalthea in 2002, before it finally plunges into Jupiter's atmosphere and burns up in late 2003. This money, of course, is a tiny fraction of the mission's billion-dollar total cost up to now. Second, a detailed planning effort needs to start immediately on possible extended missions for the Cassini spacecraft after its initial complex four-year orbital tour of Saturn and its moons and rings has been completed. Since Cassini won't be subject to the same level of destructive radiation as Galileo, it could survive for decades. Moreover, Cassini's orbits around Saturn are much shorter in period than Galileo's, but the craft also has a larger number of additional scientific targets to look at. Additionally, with its high-gain antenna (unlike Galileo's) operational, it will be able to transmit far more highly detailed observations back to Earth. All of this means that its operating schedule will be at a frenetic pace, and as much planning for various alternative extended missions as possible should be done in advance. Finally, NASA needs to make a general change in its funding philosophy for all future planetary missions, with a certain amount of money for mission operations and data analysis during an extended mission being included from the start in the initial funding request for each mission - thus reducing NASA's need to rattle the proverbial begging bowl and reallocate money from other projects on an impromptu basis whenever an extended mission becomes possible. So, as the result of its latest meeting, the SSES will thus make some initial firm recommendations for the Solar System program, while also initiating some new studies that will probably lead to a radical revision of NASA's current "roadmap" for planetary exploration. It will be interesting indeed to see what those recommendations - due in July - turn out to be, and how NASA and the Bush Administration react to them. Related Links SpaceDaily Search SpaceDaily Subscribe To SpaceDaily Express
![]() ![]() |
![]() |
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2006 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA PortalReports are copyright European Space Agency. All NASA sourced material is public domain. Additionalcopyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement |