Emily Lakdawalla • Jul 20, 2005
Deep Impact Sets a New Course as Tempel 1 Returns to Normal
I just posted a new story on Deep Impact [appended to the blog entry below], covering the really surprising press release issued today by NASA Headquarters. The Deep Impact mission has been really quiet for more than a week. Various stories were leaking out to the media about a possible trajectory correction maneuver to be performed today, which would put Deep Impact on course for an encounter with another comet, Boethin, in 2008. I sent off an inquiry to Lucy McFadden to see if she wanted to comment on this for me; when she replied she said that she'd sent an inquiry upstairs, basically asking why there was news circulating that wasn't on the Deep Impact website. The response was that a press release would be issued later today covering the trajectory correction maneuver, so Lucy told me I should wait for that.
Lucy was right, there was a press release about the maneuver, but the release avoided any mention of Boethin. What's worse, the release doesn't guarantee an extended mission for Deep Impact. In fact, the release states that in order for an extended mission to happen, anyone interested in such a mission will have to re-apply to the Discovery Program for more funding, through a mechanism called Missions of Opportunity. (For more detail on this and the release, read the news story I just posted.) I had never heard of any extended mission being worked in this way, so I had to call one of my bosses, Bruce Betts, and ask him about it. (Bruce used to be a Headquarters wonk.) He confirmed that no extended mission has ever been funded through this kind of re-application process, though when he checked the last Mission of Opportunity announcement it did contain language allowing such applications.
It makes a weird kind of sense, if you're a bureaucrat, to force Deep Impact to reapply for funding if they want to extend their mission. It creates a peer-review process for the additional funding. That's all well and good, I suppose. But I can't help but consider: what if the team's application is rejected, as lots of worthy applications are? A couple of things come to mind: the failure of NASA to fund American co-investigators who'd already been working for years on ESA's Venus Express mission, not to mention the recent, completely inexplicable proposal to cancel Voyager. It's so hard to get assets into space -- as we here at The Planetary Society know all too well, from our recent failure to launch Cosmos 1. In my humble opinion, it's false economy not to capitalize on existing space assets and thereby save a few million bucks. Keep Deep Impact going, and keep Voyager going, as long as there is nothing out there that can do any better.
Speaking of Voyager -- we're running a political advocacy campaign now to save Voyager, with a petition you can sign; or you can make a donation to us for the campaign, if you can spare some change!
Deep Impact Sets a New Course as Tempel 1 Returns to Normal
With its mission at Tempel 1 over, the Deep Impact spacecraft has altered its course in order to allow a future mission at another comet. This morning's trajectory correction maneuver has placed Deep Impact on a course that will result in an Earth flyby in December of 2007. A statement from NASA Headquarters says that "The maneuver allows NASA to preserve options for future use of the spacecraft." The statement does not mention the likely target, comet Boethin, in an encounter that would take place in 2008.
The reason that a target is not mentioned is because NASA has not yet allotted funding for an extended mission for Deep Impact. In fact, funding for such a mission is not guaranteed, said Andy Dantzler, Director of the Science Mission Directorate of the NASA's Solar System Division. "All proposals for use of the Deep Impact spacecraft will be evaluated for science merit and feasibility along with all submitted proposals for [Discovery Program] Missions of Opportunity," he said. "The spacecraft is being offered as is. Proposers must include mission management and spacecraft operations in the total proposed funding."
Following is the language of the 2004 NASA Discovery Program "Mission of Opportunity" Announcement of Opportunity (AO) regarding the use of Discovery Program funds for extended missions. Deep Impact scientists will have to propose their extended mission to the next Discovery Program AO.
5.12 Specific Requirements and Constraints for Mission of Opportunity Investigations
By supporting U.S. participation in MO investigations, NASA seeks to allow the U.S. scientific community to conduct a science investigation of interest to OSS [Office of Space Science] as part of missions sponsored by non-OSS organizations and/or using existing flight hardware for missions that have completed their prime science missions. Such "parent" non-OSS missions may be sponsored by non-U.S. governments, other U.S. agencies, NASA organizations other than OSS, the U.S. military (only if the satellite is not planned for weapons testing), or private sector organizations, and all are equally qualified. Mission extensions and proposals for new science missions that utilize existing in-flight OSS spacecraft are also allowed in this opportunity. The total cost to NASA for a Discovery MO investigation, including all costs for Deep Space Mission System (DSMS) support and/or Navigation and Ancillary Information Facility (NAIF) services, through this AO is limited to $35M (FY 2004 dollars).
5.12.3 Extended Science Missions
Approved NASA SSE [Solar System Exploration] missions nearing the end of their Prime or Extended Missions may propose a mission extension through this AO. The extended science mission being proposed must commence no later than December 31, 2005. A proposal for an extended science mission must include all costs to NASA for the extension of the mission including mission operations, DSMS costs, any proposed data analysis, and adequate resources for archiving new results.
Such a move is unusual to say the least. "I don't think there's any precedent for it," said Planetary Society Director of Projects Bruce Betts, who was Program Scientist for various NASA missions. "Discovery Program Missions of Opportunity usually are used for people to propose for funding for an instrument to fly on a foreign spacecraft. Never before has it actually been used to fly a spacecraft. This time, it really is a 'mission' of opportunity."
Betts added that, in fact, only two Missions of Opportunity have ever been funded, ASPERA on ESA's Mars Express, currently in orbit, and the Moon Mineralogy Mapper on the Indian Space Research Organization's lunar orbiter Chandraayan-1, scheduled for launch in 2007. In addition, an experiment to place wind sensors and seismometers on the French-led NetLander was funded, but discontinued with the cancellation of that mission.
It took a large and complex team of scientists and engineers from the University of Maryland, the Jet Propulsion Laboratory, and elsewhere to guide Deep Impact past Tempel 1. If they want to fly the spacecraft by another comet, they will have to re-propose to the Discovery program, competing against all other proposals for the limited pot of money up for grabs in the 2005 Missions of Opportunity.
Meanwhile, Comet Tempel 1 has quickly returned to a normal state, only a few weeks after Deep Impact smashed it with a 370-pound ball. Astronomers around the world have continued to monitor the comet and have seen its behavior grow quiet.
At the European Southern Observatory in Chile, astronomer Hermann Boehnhardt headed a campaign to use all seven of the ESO telescopes to watch Tempel 1, at every wavelength of light that was not blocked by the Earth's atmosphere. "For a number of days after the impact you have this ejecta cloud going to the southwest, and this disappeared after three or four days in the coma again, because the dust was blown off," he said.
Based upon the observations performed at ESO, Boehnhardt believes that Deep Impact had no lasting effect on Tempel 1. "The comet never went away from its normal state -- its [formerly] active regions were still active during the impact of course, and you can see the active regions shining through the ejecta cloud. It looks like the ejecta cloud was on top of something that was there all the time, before and after."
These conclusions represent just the beginning of the scientific results of the Tempel 1 observation campaign. The first peer-reviewed papers to present new results from Deep Impact's encounter with Tempel 1 are now being written and submitted to Science magazine. Members of the Deep Impact science team and the international observers hope to see those first results in print by the time of the annual meeting of the Division of Planetary Sciences of the American Astronomical Society to be held in Cambridge, England, in September. The Planetary Society will be there for the latest news on this and other developing stories in planetary science.
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