Tuesday, November 10, 2009
Small Body Priorities
Last month, I posted a blog entry on a survey of the scientific community on priorities for small body planetary missions (http://futureplanets.blogspot.com/2009/10/decadal-survey-democracy-in-action.html). The results of the poll were recently posted. You can read all the details at http://www.lpi.usra.edu/decadal/sbag/poll_report.pdf, but I'll post a few highlight here copied from the report. Clicking on the images will bring up larger versions.
Monday, November 9, 2009
ESA-NASA Mars Program Formalized
ESA and NASA have formalized their relationship to explore Mars through a series of joint missions in the mid to late coming decade. (See story at BBC http://news.bbc.co.uk/2/hi/science/nature/8348867.stm ).
ESA is expected to provide a billion euros (~$1.4-1.5B depending on currency fluctuations). No mention is made of NASA's contribution, but based on current budget projections, NASA is likely to contribute several billions of dollars.
The planned missions are as described previously in several blog entries:
2016 - ESA provided orbiter with NASA launch to study trace gases. ESA will also provide a lander that will demonstrate landing technology and carry a weather station. No mention of how long the instruments are expected to function.
2018 - ESA and NASA rovers carried to the same location by NASA's skycrane landing system.
2020 - A network mission is under consideration.
Editorial Thoughts: This would seem to lock in the 2016 and 2018 into NASA's plans for the next decade. The Decadal Survey in progress is specifically limited to proposing missions beyond currently committed missions. By the time of the 2012 Decadal proposal a number of missions are likely to be in that category: the 2016 and 2018 joint Mars missions, the Jupiter Europa Orbiter,a to be selected New Frontiers, and a to be selected Discovery mission. (I'm probabably missing a mission or two. I haven't included missions expected to launch by or within a year or so of the report.) The actual budget left for the Decadal Survey to work with may be fairly small. By my rough accounting, the list above could be in the neighborhood of $7B (before cost overruns) out of an expected decadal $12B.
ESA is expected to provide a billion euros (~$1.4-1.5B depending on currency fluctuations). No mention is made of NASA's contribution, but based on current budget projections, NASA is likely to contribute several billions of dollars.
The planned missions are as described previously in several blog entries:
2016 - ESA provided orbiter with NASA launch to study trace gases. ESA will also provide a lander that will demonstrate landing technology and carry a weather station. No mention of how long the instruments are expected to function.
2018 - ESA and NASA rovers carried to the same location by NASA's skycrane landing system.
2020 - A network mission is under consideration.
Editorial Thoughts: This would seem to lock in the 2016 and 2018 into NASA's plans for the next decade. The Decadal Survey in progress is specifically limited to proposing missions beyond currently committed missions. By the time of the 2012 Decadal proposal a number of missions are likely to be in that category: the 2016 and 2018 joint Mars missions, the Jupiter Europa Orbiter,a to be selected New Frontiers, and a to be selected Discovery mission. (I'm probabably missing a mission or two. I haven't included missions expected to launch by or within a year or so of the report.) The actual budget left for the Decadal Survey to work with may be fairly small. By my rough accounting, the list above could be in the neighborhood of $7B (before cost overruns) out of an expected decadal $12B.
Saturday, November 7, 2009
MAVEN Mission
Science@NASA has a nice article on the motivation behind the 2013 MAVEN mission to study Mars' atmosphere. To whet your appetite, here are a couple of quotes:
But that's not how things turned out."
"One way or another, scientists believe, Mars must have lost its most precious asset: its thick atmosphere of carbon dioxide. CO2 in Mars's atmosphere is a greenhouse gas, just as it is in our own atmosphere. A thick blanket of CO2 and other greenhouse gases would have provided the warmer temperatures and greater atmospheric pressure required to keep liquid water from freezing solid or boiling away."
"MAVEN will be the first mission to Mars specifically designed to help scientists understand the ongoing escape of CO2 and other gases into space. The probe will orbit Mars for at least one Earth-year. At the elliptical orbit's low point, MAVEN will be 125 km above the surface; its high point will take it more than 6000 km out into space. This wide range of altitudes will enable MAVEN to sample Mars's atmosphere more thoroughly than ever before."
Editorial Thoughts: A lot of science doesn't involve flashy exploration or engaging images. MAVEN and the Lunar GRAIL missions are solid examples of the planetary missions that collect data that tell important stories only after careful analysis. As the easy missions to many destinations are completed, these are the yeomen missions that will fill in important gaps in our understanding of processes. [Note: A previous version of this entry mentioned a lunar GRACE mission when I meant to say GRAIL mission. They are similar missions, but the former studies the gravity field of the Earth and the latter will do the same for the moon.]
Resources:
Science@NASA article: http://science.nasa.gov/headlines/y2009/06nov_maven.htm
MAVEN website: http://lasp.colorado.edu/maven/
Tuesday, November 3, 2009
Proposed Discovery Venus Radar Mission
A few posts ago (http://futureplanets.blogspot.com/2009/10/venus-new-frontiers-radar-mapping.html), I wrote about proposed radar missions to remap Venus at higher resolution. At that time, the idea of doing this within a New Frontiers budget (~$650M) was an eye opener for me. I listened into part of the most recent VEXAG meeting, and learned of a Discovery mission (~$425M) that could remap Venus.
The principle investigator, Dr. Sharpton, sent me the following synopsis of the mission: "RAVEN, utilizes the latest in the RADARSAT lineage, extending back to 1996 (RADARSAT 1 launched in Nov. '95). We can accomplish reconnaissance level mapping of Venus at 30-m/px and map about 25% of Venus each cycle (a venusian day). Alternatively, we could map about 3% of the planet at 3-m resolution each cycle. Obviously, we would want to have a combination of resolution modes and have overlap so that we can extract topography. Topographic resolutions would be on the order of 20m vertical resolution and either 300-m postings (if using 30-m images) or 30-m postings (with 3-m images). If InSAR turns out to be feasible (we believe it will), the vertical resolutions would drop to a meter or less."
Dr. Sharpton pointed me to an AGU abstract about the mission. Since there is no easy way to link to AGU abstracts, I'm posting parts of it below. You can search for it and other planetary abstracts athttp://agu-fm09.abstractcentral.com/planner
RAVEN – High-resolution Mapping of Venus within a Discovery Mission Budget
V. L. Sharpton1; R. R. Herrick1; F. Rogers2; S. Waterman3
1. University of Alaska Fairbanks, Fairbanks, AK, USA.
2. The Boeing Company, Huntington Beach, CA, USA.
3. Alliance Spacesystems, Boulder, CO, USA.
It has been more than 15 years since the Magellan mission mapped Venus with S-band synthetic aperture radar (SAR) images at ~100-m resolution. Advances in radar technology are such that current Earth-orbiting SAR instruments are capable of providing images at meter-scale resolution. RAVEN (RAdar at VENus) is a mission concept that utilizes the instrument developed for the RADARSAT Constellation Mission (RCM) to map Venus in an economical, highly capable, and reliable way. RCM relies on a C-band SAR that can be tuned to generate images at a wide variety of resolutions and swath widths, ranging from ScanSAR mode (broad swaths at 30-m resolution) to strip-map mode (resolutions as fine as 3 m), as well as a spotlight mode that can image patches at 1-m resolution. In particular, the high-resolution modes allow the landing sites of previous missions to be pinpointed and characterized... Our current estimates indicate that within an imaging cycle of one Venus day we can image 20-30 percent of the planet at 20–30-m resolution and several percent at 3-5 m resolution. These figures compare favorably to the coverage provided by recent imaging systems orbiting Mars. Our strategy calls for the first cycle of coverage to be devoted to imaging large geographic areas (e.g., Thetis Regio) at 20–30-m resolution with interleaved observation of pre-selected targets at high resolution. The second cycle will include additional imaging, but the focus will be repeat-pass coverage to obtain topography for a significant fraction of the first-cycle targets... All components of the spacecraft are expected to remain operational well beyond the nominal mission time, so global mapping at 10 m or better resolution during an extended mission is conceivable."
The principle investigator, Dr. Sharpton, sent me the following synopsis of the mission: "RAVEN, utilizes the latest in the RADARSAT lineage, extending back to 1996 (RADARSAT 1 launched in Nov. '95). We can accomplish reconnaissance level mapping of Venus at 30-m/px and map about 25% of Venus each cycle (a venusian day). Alternatively, we could map about 3% of the planet at 3-m resolution each cycle. Obviously, we would want to have a combination of resolution modes and have overlap so that we can extract topography. Topographic resolutions would be on the order of 20m vertical resolution and either 300-m postings (if using 30-m images) or 30-m postings (with 3-m images). If InSAR turns out to be feasible (we believe it will), the vertical resolutions would drop to a meter or less."
Dr. Sharpton pointed me to an AGU abstract about the mission. Since there is no easy way to link to AGU abstracts, I'm posting parts of it below. You can search for it and other planetary abstracts athttp://agu-fm09.abstractcentral.com/planner
RAVEN – High-resolution Mapping of Venus within a Discovery Mission Budget
V. L. Sharpton1; R. R. Herrick1; F. Rogers2; S. Waterman3
1. University of Alaska Fairbanks, Fairbanks, AK, USA.
2. The Boeing Company, Huntington Beach, CA, USA.
3. Alliance Spacesystems, Boulder, CO, USA.
It has been more than 15 years since the Magellan mission mapped Venus with S-band synthetic aperture radar (SAR) images at ~100-m resolution. Advances in radar technology are such that current Earth-orbiting SAR instruments are capable of providing images at meter-scale resolution. RAVEN (RAdar at VENus) is a mission concept that utilizes the instrument developed for the RADARSAT Constellation Mission (RCM) to map Venus in an economical, highly capable, and reliable way. RCM relies on a C-band SAR that can be tuned to generate images at a wide variety of resolutions and swath widths, ranging from ScanSAR mode (broad swaths at 30-m resolution) to strip-map mode (resolutions as fine as 3 m), as well as a spotlight mode that can image patches at 1-m resolution. In particular, the high-resolution modes allow the landing sites of previous missions to be pinpointed and characterized... Our current estimates indicate that within an imaging cycle of one Venus day we can image 20-30 percent of the planet at 20–30-m resolution and several percent at 3-5 m resolution. These figures compare favorably to the coverage provided by recent imaging systems orbiting Mars. Our strategy calls for the first cycle of coverage to be devoted to imaging large geographic areas (e.g., Thetis Regio) at 20–30-m resolution with interleaved observation of pre-selected targets at high resolution. The second cycle will include additional imaging, but the focus will be repeat-pass coverage to obtain topography for a significant fraction of the first-cycle targets... All components of the spacecraft are expected to remain operational well beyond the nominal mission time, so global mapping at 10 m or better resolution during an extended mission is conceivable."
Sunday, November 1, 2009
First Decadal Mission Assessments
A major criticism of both the last astronomy and the last planetary Decadal Surveys was that they prioritized ill-defined mission concepts whose true cost was severely under estimated. As a result, both fields have had embarrassingly large cost overruns on key projects -- the James Webb Space Telescope and the Mars Science Laboratory -- that prevented other high priority missions from being started such as an Europa orbiter.
This time, the planetary Decadal Survey has a major focus on defining and costing missions. The approach is to do "Rapid Mission Architecture" studies on a large number of missions to get an idea of the engineering requirements and technical readiness. Then a smaller set of missions judged to be high priority will get full mission studies that are intended to flesh out the details of implementation. Then a small number of missions will receive detailed cost estimates. As I understand the process, to be proposed as a priority mission, a mission has to make it through all three stages, and not all missions that get through the costing stage will make the shorter list of recommended missions. Only a minority of proposed missions will make the cut at each level of assessment and progress to the next stage.
Three organizations -- NASA Goddard, John Hopkin's APL, and NASA's JPL -- will perform the rapid architectures and full mission studies. Then an outside firm will prepare the cost estimates.
The majority of missions that will enter the process will be proposed by the community itself through the hundreds of White Papers and many panel meetings. To kick start the process, however, the panels and steering committee selected several missions prior to the delivery of the White Papers. Early assessment doesn't mean anything in terms of priority. The goal was to even out the work flow for the organizations involved by getting a head start.
Steve Squyres, chair of the process, listed the first wave of missions in a letter to the community. You can read the full letter at http://www.lpi.usra.edu/decadal/vexag/newsletters/100309.pdf. The rest of this blog entry quotes the sections that list the first wave of missions to assessed. As an editorial note, I'll point out how wide ranging the types of missions are. A wide net appears to be being cast to find the intersection of the best science return and the best mission readiness and cost effectiveness.
"Prior to receiving the white papers, each panel met to identify a first set of candidate missions for study. Mission candidate studies were then reviewed and approved by the steering group, and an organization (APL, Goddard, or JPL) was chosen to conduct each study. These studies are just getting underway. IT IS IMPORTANT TO NOTE THAT THESE ARE JUST THE FIRST SET OF MISSION CANDIDATE STUDIES, selected before the white papers were received. There will be many more that have been motivated by the white papers once the white papers have been assessed.
"Six of the studies are of the type known as “Rapid Mission Architecture” studies. These are high-level studies of overall mission architecture that we expect to take a few weeks. The purpose of these studies is to explore the trade space for a mission candidate, and identify a “point design” for possible subsequent study in much greater depth.
"The six Rapid Mission Architecture studies are:
"In addition to the eight studies listed above, two mission concept studies have been identified that have already been done to a level of maturity such that an independent cost estimate should be possible. Independent cost estimates for each of those will be performed as soon as the company performing the cost estimates is under contract. Those two mission concepts are:
This time, the planetary Decadal Survey has a major focus on defining and costing missions. The approach is to do "Rapid Mission Architecture" studies on a large number of missions to get an idea of the engineering requirements and technical readiness. Then a smaller set of missions judged to be high priority will get full mission studies that are intended to flesh out the details of implementation. Then a small number of missions will receive detailed cost estimates. As I understand the process, to be proposed as a priority mission, a mission has to make it through all three stages, and not all missions that get through the costing stage will make the shorter list of recommended missions. Only a minority of proposed missions will make the cut at each level of assessment and progress to the next stage.
Three organizations -- NASA Goddard, John Hopkin's APL, and NASA's JPL -- will perform the rapid architectures and full mission studies. Then an outside firm will prepare the cost estimates.
The majority of missions that will enter the process will be proposed by the community itself through the hundreds of White Papers and many panel meetings. To kick start the process, however, the panels and steering committee selected several missions prior to the delivery of the White Papers. Early assessment doesn't mean anything in terms of priority. The goal was to even out the work flow for the organizations involved by getting a head start.
Steve Squyres, chair of the process, listed the first wave of missions in a letter to the community. You can read the full letter at http://www.lpi.usra.edu/decadal/vexag/newsletters/100309.pdf. The rest of this blog entry quotes the sections that list the first wave of missions to assessed. As an editorial note, I'll point out how wide ranging the types of missions are. A wide net appears to be being cast to find the intersection of the best science return and the best mission readiness and cost effectiveness.
"Prior to receiving the white papers, each panel met to identify a first set of candidate missions for study. Mission candidate studies were then reviewed and approved by the steering group, and an organization (APL, Goddard, or JPL) was chosen to conduct each study. These studies are just getting underway. IT IS IMPORTANT TO NOTE THAT THESE ARE JUST THE FIRST SET OF MISSION CANDIDATE STUDIES, selected before the white papers were received. There will be many more that have been motivated by the white papers once the white papers have been assessed.
"Six of the studies are of the type known as “Rapid Mission Architecture” studies. These are high-level studies of overall mission architecture that we expect to take a few weeks. The purpose of these studies is to explore the trade space for a mission candidate, and identify a “point design” for possible subsequent study in much greater depth.
"The six Rapid Mission Architecture studies are:
- Mercury lander mission (APL)
- Venus near-surface mobile explorer mission (Goddard)
- Mars 2018 skycrane capabilities study (JPL)
- Uranus system mission (APL)
- Neptune/Triton mission (JPL)
- Enceladus flyby/sample return mission (JPL)
- Mars trace gas orbiter mission (Goddard)
- Titan lake mission (JPL)
"In addition to the eight studies listed above, two mission concept studies have been identified that have already been done to a level of maturity such that an independent cost estimate should be possible. Independent cost estimates for each of those will be performed as soon as the company performing the cost estimates is under contract. Those two mission concepts are:
- Mars trace gas orbiter mission studied to date by JPL
- Comet surface sample return mission studied to date by APL.
Subscribe to:
Posts (Atom)