-
#20 by su27k on 27 Nov, 2021 02:09
-
Planetary Society has a good article about the funding increase for Planetary Defense: How NASA's Planetary Defense Budget Grew By More Than 4000% in 10 years, work for APL is the direct reason for DART funding as explained in the article, but that happened under the general trend of increasing funding for Planetary Defense, it didn't happen alone.
-
#21 by su27k on 27 Nov, 2021 02:14
-
As to the studies:
https://www.nap.edu/catalog/12842/defending-planet-earth-near-earth-object-surveys-and-hazard-mitigation
https://www.nap.edu/catalog/25476/finding-hazardous-asteroids-using-infrared-and-visible-wavelength-telescopes
The fact that the 2nd study didn't recommend anything like DART is to be expected, since the reason this study is done in the first place is because "NASA’s chief scientist asked the National Academies of Sciences, Engineering, and Medicine to establish a study to address the issue of the relative advantages and disadvantages of infrared and visible observations of near Earth objects (NEOs).", so of course the study is not going to recommend anything like DART because the study is entirely focused on finding asteroids, mitigation is not even part of the study.
The 1st study however did have the following recommendation from Chapter 5 Mitigation:QuoteRecommendation: If Congress chooses to fund mitigation research at an appropriately high level, the first priority for a space mission in the mitigation area is an experimental test of a kinetic impactor along with a characterization, monitoring, and verification system, such as the Don Quijote mission that was previously considered, but not funded, by the European Space Agency. This mission would produce the most significant advances in understanding and provide an ideal chance for international collaboration in a realistic mitigation scenario.
This looks very much like a recommendation for DART. -
#22 by Phil Stooke on 27 Nov, 2021 07:01
-
It's not often that you find a member of Congress doing such thorough homework:
Galvez, A., Carnelli, I., Michel, P., Cheng, A.F., Reed, C., Ulamec, S., Biele, J., Zbrll, P. and Landis, R., 2013, September. AIDA: The asteroid impact and deflection assessment mission. In European Planetary Science Congress (Vol.
.
Cheng, A.F., Michel, P., Reed, C., Galvez, A., Carnelli, I. and Headquarters, P., 2012, September. Dart: Double asteroid redirection test. In European Planetary Science Congress (Vol. 7, pp. 23-28).
Cheng, A., Stickle, A., Atchison, J., Barnouin, O., Rivkin, A., Michel, P., Ulamec, S. and AIDA Team, 2015, October. Asteroid impact and deflection assessment mission: Double asteroid redirection test (dart). In Proceedings of the 4th IAA Planetary Defense Conference, Frascati, Italy.
Michel, P., Kueppers, M., Sierks, H., Carnelli, I., Cheng, A.F., Mellab, K., Granvik, M., Kestilä, A., Kohout, T., Muinonen, K. and Näsilä, A., 2018. European component of the AIDA mission to a binary asteroid: Characterization and interpretation of the impact of the DART mission. Advances in Space Research, 62(, pp.2261-2272.
Cheng, A.F., Rivkin, A.S., Michel, P., Atchison, J., Barnouin, O., Benner, L., Chabot, N.L., Ernst, C., Fahnestock, E.G., Kueppers, M. and Pravec, P., 2018. AIDA DART asteroid deflection test: Planetary defense and science objectives. Planetary and Space Science, 157, pp.104-115.
-
#23 by Star One on 27 Nov, 2021 07:34
-
Thanks for posting that as it certainly gives a rather different prospective than you would get if you just read some of the posts above.As to the studies:
https://www.nap.edu/catalog/12842/defending-planet-earth-near-earth-object-surveys-and-hazard-mitigation
https://www.nap.edu/catalog/25476/finding-hazardous-asteroids-using-infrared-and-visible-wavelength-telescopes
The fact that the 2nd study didn't recommend anything like DART is to be expected, since the reason this study is done in the first place is because "NASA’s chief scientist asked the National Academies of Sciences, Engineering, and Medicine to establish a study to address the issue of the relative advantages and disadvantages of infrared and visible observations of near Earth objects (NEOs).", so of course the study is not going to recommend anything like DART because the study is entirely focused on finding asteroids, mitigation is not even part of the study.
The 1st study however did have the following recommendation from Chapter 5 Mitigation:QuoteRecommendation: If Congress chooses to fund mitigation research at an appropriately high level, the first priority for a space mission in the mitigation area is an experimental test of a kinetic impactor along with a characterization, monitoring, and verification system, such as the Don Quijote mission that was previously considered, but not funded, by the European Space Agency. This mission would produce the most significant advances in understanding and provide an ideal chance for international collaboration in a realistic mitigation scenario.
This looks very much like a recommendation for DART. -
#24 by Blackstar on 27 Nov, 2021 13:58
-
There's a lot of context left out. The most relevant issue is the 2005 George E. Brown Act, which directed NASA to find 90% of potentially hazardous asteroids 140 meters in diameter or greater by 2020. (Note: it's technically part of a different piece of legislation and not a stand-alone act, but it is generally referred to as the George E. Brown Act.) By 2020--the deadline in the act--NASA had detected about 30% of those asteroids. Even only a few years after the act was signed, it was clear that NASA was not going to accomplish that goal, and by 2020 it was clear that existing asteroid detection systems were never going accomplish that goal even by 2035.
The only way to accomplish the goal is to build an in-space infrared telescope specifically designed for the purpose. The leading proposal for that telescope was the NEOCam spacecraft, first proposed in the 2000s. NEOCam has now been renamed as the NEO Surveyor, but is essentially the same project. The problem was that NEOCam just never got funding. There are a lot of reasons for that, but I won't go into them here. The bottom line was that even a decade after the passage of the act (mid-2010s), NASA was not making any progress at accomplishing that goal. But then along came DART, and if you go digging deep enough in congressional legislation (and draft congressional legislation) you find that DART was lobbied by APL and then added into the NASA budget by a member of Congress. That's where it came from. If you had asked members of the asteroid defense community during the last 16 years what they believed should be their highest priority, it would have been the survey telescope, not an impact mission. If you had gone to SBAG meetings throughout the 2010s, most of the focus would have been on asteroid science missions, not planetary defense, but the people there talked about the requirements for an NEO survey telescope.
As for Casey Dreier's article, he misunderstood a number of key issues (he updated that article after I pointed out some important events that he left out, but there are still some problems with his interpretation of the cause-effect relationships.). He was looking at top-line budget numbers for "Planetary Defense/NEO Observation Funding," but not what was actually in those budgets, and then drew conclusions that the top-line budgets increased primarily because of the human spaceflight program. Simply taking his argument at face value, one could ask why, if the Asteroid Redirect Mission was a major cause of increase in that budget, the budget did not go down after ARM was canceled? Furthermore, the biggest overall increase to the budget was DART procurement, and DART has nothing at all to do with the human spaceflight program. Even further, the most important precursor to the ARM mission was a survey telescope to find asteroids that astronauts could realistically visit, and yet that did not get funded. The human spaceflight and planetary defense subjects weren't linked and increases in the planetary defense budget were not caused by events in the human spaceflight program. In fact, one of the problems with NASA's human mission to an asteroid effort was that they were not talking to the actual asteroid experts. MIT's Richard Binzel made a lot of noise about this at SBAG meetings in the last decade.
In order to understand increases in the planetary defense budget, you have to look at what was actually in the budget. There were a bunch of things that were either increased or added to that budget from elsewhere. For instance, the Antarctic meteorite collection effort was previously book-kept elsewhere in NASA and that was then added to the planetary defense budget, increasing the total. I believe that NASA's portion of Arecibo funding was added to the planetary defense budget. A number of projects for ground-telescope support, upkeep, and observing time were added to the budget (not all of them were related to asteroids--I think NASA funding for the IRTF was in there--but neither was the Antarctica program). There were also infrastructure upgrades that were added into the budget--I was told, dunno if it's totally accurate, that the Minor Planet Center's (they track asteroids) outdated equipment was also upgraded at NASA expense. So those budget increases came from a lot of things added into the planetary defense budget and you'd really have to get down into the weeds to see what all of them were. (There's one other minor issue that I told Dreier about, but it's difficult to find information on. That is that the increase in the budget first occurred in late 2009, not 2011. It happened after the NRC produced the interim report to its 2010 report. The NEO budget increased from about $4.5 million to $6.5 million. But that extra $2 million came out of somebody's existing discretionary reserve account. I cannot remember if it was the NASA administrator's discretionary account or if it was the AA for science discretionary account, but it didn't show in the overall top-line budget because the money came from elsewhere. [Sidenote: people like the NASA administrator and the AAs for various directorates usually have a few million dollars in a discretionary reserve budget that they can allocate however they want. This is actually common to many organizations.])
-
#25 by LouScheffer on 27 Nov, 2021 14:13
-
I thought the single biggest advance in asteroid detection will be the Vera Rubin (formerly Large Synoptic Survey Telescope), which can do the bulk of the work of discovering unknown asteroids. In its first year of operation, it is expected to double the number of known Earth-crossing asteroids. Is Planetary defense contributing to this project?
NeoWise, or equivalent, will still be needed, since Rubin cannot look too close to the Sun, nor spend the bulk of it's time looking at spots where threatening asteroids are most likely to be found. But it will up the detected fraction by a lot. -
#26 by baldusi on 27 Nov, 2021 19:36
-
From what I remember, ideally NEOSurvey would be flown in a close orbit to Venus so it could look "out". I don't know if SEL1 would be a second best. So it's not only how close but how you look, from what I understand. Looking "outwards" gives you the view with the most brightness. Looking close to the sun you are looking sideways to a hot plate. At least that's what I understood.
-
#27 by GClark on 28 Nov, 2021 08:31
-
...DART was supposed to be done in conjunction with a European mission, but that European mission never got approved...
Ummm...
Hera?
https://www.esa.int/Safety_Security/Hera
-
#28 by Blackstar on 28 Nov, 2021 10:58
-
#29 by GClark on 28 Nov, 2021 12:07
-
I was under the probably mistaken impression that AIM became Hera.
-
#30 by Blackstar on 28 Nov, 2021 15:29
-
I was under the probably mistaken impression that AIM became Hera.
It's different. AIM was more extensive. Whether the current setup produces good data I have no knowledge. -
#31 by Welsh Dragon on 28 Nov, 2021 15:42
-
Why would it had been approved if it wasn't expected to produce good (enough) data?I was under the probably mistaken impression that AIM became Hera.
It's different. AIM was more extensive. Whether the current setup produces good data I have no knowledge. -
#32 by Blackstar on 28 Nov, 2021 16:34
-
Why would it had been approved if it wasn't expected to produce good (enough) data?I was under the probably mistaken impression that AIM became Hera.
It's different. AIM was more extensive. Whether the current setup produces good data I have no knowledge.
People have different definitions of "enough." -
#33 by deadman1204 on 28 Nov, 2021 22:48
-
I thought the single biggest advance in asteroid detection will be the Vera Rubin (formerly Large Synoptic Survey Telescope), which can do the bulk of the work of discovering unknown asteroids. In its first year of operation, it is expected to double the number of known Earth-crossing asteroids. Is Planetary defense contributing to this project?
NeoWise, or equivalent, will still be needed, since Rubin cannot look too close to the Sun, nor spend the bulk of it's time looking at spots where threatening asteroids are most likely to be found. But it will up the detected fraction by a lot.
Won't NeoSurveyor also see things too dark for the LSST survey, since its an IR camera? -
#34 by LouScheffer on 30 Nov, 2021 01:42
-
I think this depends on the asteroid. If it has a high albedo, it's bright in the visible, and LSST sees it more easily. But if it's low albedo (and I think some asteroids are as low a 3%) then there is little reflected light, and LSST has problems. But that absorbed energy has to go somewhere, and such asteroids are bright in the thermal infrared even though dark in the visible. So these are more visible to NEO Surveyor. The combination is better than either alone.I thought the single biggest advance in asteroid detection will be the Vera Rubin (formerly Large Synoptic Survey Telescope), which can do the bulk of the work of discovering unknown asteroids. In its first year of operation, it is expected to double the number of known Earth-crossing asteroids. Is Planetary defense contributing to this project?
NeoWise, or equivalent, will still be needed, since Rubin cannot look too close to the Sun, nor spend the bulk of it's time looking at spots where threatening asteroids are most likely to be found. But it will up the detected fraction by a lot.
Won't NeoSurveyor also see things too dark for the LSST survey, since its an IR camera? -
#35 by Targeteer on 27 Dec, 2021 22:18
-
https://www.nasa.gov/feature/with-its-single-eye-nasa-s-dart-returns-first-images-from-space
Dec 22, 2021
With Its Single “Eye,” NASA’s DART Returns First Images from Space
Just two weeks after launching from Vandenberg Space Force Base in California, NASA’s Double Asteroid Redirection Test (DART) spacecraft has opened its “eye” and returned its first images from space — a major operational milestone for the spacecraft and DART team.
image of about a dozen stars near where the constellations Perseus, Aries and Taurus intersect
On Dec. 7, after opening the circular door to its telescopic imager, NASA’s DART captured this image of about a dozen stars near where the constellations Perseus, Aries and Taurus intersect.
Credits: NASA/Johns Hopkins APL
image of the stars in Messier 38, or the Starfish Cluster
On Dec. 10, DART’s DRACO camera captured and returned this image of the stars in Messier 38, or the Starfish Cluster, which lies some 4,200 light years away.
Credits: NASA/Johns Hopkins APL
After the violent vibrations of launch and the extreme temperature shift to minus 80 degrees C in space, scientists and engineers at the mission operations center at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, held their breath in anticipation. Because components of the spacecraft’s telescopic instrument are sensitive to movements as small as 5 millionths of a meter, even a tiny shift of something in the instrument could be very serious.
On Tuesday, Dec. 7, the spacecraft popped open the circular door covering the aperture of its DRACO telescopic camera and, to everyone’s glee, streamed back the first image of its surrounding environment. Taken about 2 million miles (11 light seconds) from Earth — very close, astronomically speaking —the image shows about a dozen stars, crystal-clear and sharp against the black backdrop of space, near where the constellations Perseus, Aries and Taurus intersect.
The DART navigation team at NASA’s Jet Propulsion Laboratory in California used the stars in the image to determine precisely how DRACO was oriented, providing the first measurements of how the camera is pointed relative to the spacecraft. With those measurements in hand, the DART team could accurately move the spacecraft to point DRACO at objects of interest, such as Messier 38 (M38), also known as the Starfish Cluster, that DART captured in another image on Dec. 10. Located in the constellation Auriga, the cluster of stars lies some 4,200 light years from Earth. Intentionally capturing images with many stars like M38 helps the team characterize optical imperfections in the images as well as calibrate how absolutely bright an object is — all important details for accurate measurements when DRACO starts imaging the spacecraft’s destination, the binary asteroid system Didymos.
DRACO (short for Didymos Reconnaissance and Asteroid Camera for Optical navigation) is a high-resolution camera inspired by the imager on NASA’s New Horizons spacecraft that returned the first close-up images of the Pluto system and of a Kuiper Belt object, Arrokoth. As DART’s only instrument, DRACO will capture images of the asteroid Didymos and its moonlet asteroid Dimorphos, as well as support the spacecraft’s autonomous guidance system to direct DART to its final kinetic impact.
DART was developed and is managed by Johns Hopkins APL for NASA’s Planetary Defense Coordination Office. DART is the world's first planetary defense test mission, intentionally executing a kinetic impact into Dimorphos to slightly change its motion in space. While neither asteroid poses a threat to Earth, the DART mission will demonstrate that a spacecraft can autonomously navigate to a kinetic impact on a relatively small target asteroid, and that this is a viable technique to deflect a genuinely dangerous asteroid, if one is ever discovered. DART will reach its target on Sept. 26, 2022.
For more information about the DART mission, visit:
https://www.nasa.gov/dartmission -
#36 by Kaputnik on 29 Dec, 2021 11:50
-
Tenuously on topic question, that I did not find an answer for elsewhere:
Did Deep Impact produce a measurable change in the orbit of comet Tempel-1? From what I've read it may pass too close to Jupiter for any conclusions to be drawn. -
#37 by whitelancer64 on 29 Dec, 2021 23:59
-
Tenuously on topic question, that I did not find an answer for elsewhere:
Did Deep Impact produce a measurable change in the orbit of comet Tempel-1? From what I've read it may pass too close to Jupiter for any conclusions to be drawn.
It produced no measurable change to the orbit of the comet.
DART is hitting a much smaller object, and the change is expected to be easily measurable from Earth. -
#38 by rsdavis9 on 31 Dec, 2021 14:26
-
Tenuously on topic question, that I did not find an answer for elsewhere:
Did Deep Impact produce a measurable change in the orbit of comet Tempel-1? From what I've read it may pass too close to Jupiter for any conclusions to be drawn.
It produced no measurable change to the orbit of the comet.
DART is hitting a much smaller object, and the change is expected to be easily measurable from Earth.
Partially because not only is it a relatively very small asteroid but it is in orbit around another asteroid which allows us to observe the change in period of asteroid orbit around the other asteroid. -
#39 by dsmillman on 25 Jan, 2022 17:01
-
At today's SBAG meeting it was noted that the Dimorphos impact will be at 7:14 PM EST on September 26.
.