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#20
by
Orionwillstay
on 13 Sep, 2021 16:49
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The data rate of EnVision is much higher than that of VERITAS while it will study a smaller area of Venus - may I know the reason behind please? Thank you!
As suggested in the previous post, two possibilities:
The greater focus on imagery and repeat coverage for change detection may cause data rates to be higher for EnVision all other things being equal
SAR instruments, as I understand them, inherently produce very large amounts of data off the instrument that must be processed and reduced to provide information, and the secondary products are smaller. We don't know if EnVision and VERITAS will perform equal levels of onboard processing and data compression or not.
Understood. Much thanks vjkane!
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#21
by
Don2
on 14 Sep, 2021 02:19
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VERITAS processes radar data on board the spacecraft, which reduces the data rate from 691 Mbs to 120 kbps (more than 1000 fold).
Envision is going to return raw radar data.
The VERITAS radar is a single mode instrument that does one job very well. The Envision radar has multiple operational modes and appears to be more flexible but there is a cost in performance.
For example, VERITAS produces topography with 5m accuracy at 250m spacing (a 125m option is under study). Envision can produce altimetry data with 20m accuracy at 3km spacing in altimeter mode. In stereo SAR mode it can achieve 25-50m accuracy at 240m spacing. This is an example of duplication of capability which hopefully will be eliminated now that both missions have been selected.
For comparison the Magellan radar in altimeter mode achieved 100m accuracy at 15-20 km spacing. In stereo SAR mode Magellan achieved 50 m accuracy at 400-500 m spacing, but that data only covered 17% of the surface.
(These numbers are from the 2020 Radar Conference paper)
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#22
by
Orionwillstay
on 14 Sep, 2021 14:21
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VERITAS processes radar data on board the spacecraft, which reduces the data rate from 691 Mbs to 120 kbps (more than 1000 fold).
Envision is going to return raw radar data.
The VERITAS radar is a single mode instrument that does one job very well. The Envision radar has multiple operational modes and appears to be more flexible but there is a cost in performance.
For example, VERITAS produces topography with 5m accuracy at 250m spacing (a 125m option is under study). Envision can produce altimetry data with 20m accuracy at 3km spacing in altimeter mode. In stereo SAR mode it can achieve 25-50m accuracy at 240m spacing. This is an example of duplication of capability which hopefully will be eliminated now that both missions have been selected.
For comparison the Magellan radar in altimeter mode achieved 100m accuracy at 15-20 km spacing. In stereo SAR mode Magellan achieved 50 m accuracy at 400-500 m spacing, but that data only covered 17% of the surface.
(These numbers are from the 2020 Radar Conference paper)
Thank you Don2. It's so nice to see how the two missions complementing each other (oh and DAVINCI+!) - it will be great that the respective NASA and ESA teams deepen their cooperation on the missions!
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#23
by
FutureSpaceTourist
on 04 Nov, 2022 15:42
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twitter.com/jeff_foust/status/1588571181229170690
Tom Young, chair of the Psyche independent review board, is delivering the results of the review in an online town hall. Finds issues with the mission management but also broader issues at JPL with staffing and erosion of technical acumen.
https://twitter.com/jeff_foust/status/1588571817299660800Wow: NASA’s Lori Glaze says that the agency will delay the next JPL-led Discovery class mission, VERITAS, by three years to no earlier than 2031 as a result of this review.
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#24
by
vjkane
on 05 Nov, 2022 01:46
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My take: JPL has been too successful in securing new missions. It’s website lists 15 future missions and doesn’t list MSR which is a massive undertaking
From the press release:
https://t.co/8X52R4UfKCTo support JPL’s staffing needs, NASA anticipates delaying the launch of the Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy (VERITAS) mission for at least three years. This choice would allow experienced staff at JPL to complete development of strategic flagship missions further along in their development. A delay of VERITAS, a mission in early formulation, would also free up additional resources to enable the continuation of Psyche and positively affect other planetary funding needs.
VERITAS is a JPL-led mission designed to search for water and volcanic activity on Venus. It was selected in 2021 as one of two Venus proposals for the agency’s Discovery Program, a line of low-cost, competitive missions led by a single principal investigator. The mission, with planned contributions from the Italian Space Agency, German Aerospace Center, and French Space Agency, was originally expected to launch in December 2027. The mission is now scheduled to launch no earlier than 2031.
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#25
by
vjkane
on 08 Nov, 2022 01:00
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From today's VEXAG meeting:
https://twitter.com/SpcPlcyOnline/status/1589686776142110722Marcia Smith
@SpcPlcyOnline
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7h
An audience member [I think it was Sue Smrekar, VERITAS PI] said as annoyed [not her word] as the VEXAG community is, also thankful it wasn't worse w/VERITAS cancelled outright. But notes Glaze talks about "if" it is restarted, not when, so just one step up from cancellation.
Marcia Smith
@SpcPlcyOnline
·
7h
Glaze did said "if." Answer depends on JPL progress in fixing problems and how Europa Clipper, NISAR and Mars Sample Return are doing. If Clipper and NISAR slip, $ implications "catastrophic" and could affect MSR. But if all is well w/those, restart VERITAS in 2025 time frame.
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#26
by
deadman1204
on 08 Nov, 2022 14:16
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People are missing that its not just money. JPL doesn't have the bandwidth to work on Veritas right now.
It'll be good to have the next discovery or 2, maybe even NF5 ensured to not be JPL. Other places can do missions, and JPL needs time to get their house in order (which will take several years due to the workload).
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#27
by
ccdengr
on 08 Nov, 2022 15:41
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It'll be good to have the next discovery or 2, maybe even NF5 ensured to not be JPL.
Alliances with NASA centers for a particular mission are made long before the proposals go in. Anyone who allied with JPL will be SOL and might just as well not propose. It's not like you can easily switch after the proposal is written. All the NF5 proposers have picked long ago, though maybe there will be a lot of scrambling to go elsewhere. But the non-JPL mission proposals have a huge advantage.
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#28
by
deadman1204
on 08 Nov, 2022 16:41
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It'll be good to have the next discovery or 2, maybe even NF5 ensured to not be JPL.
Alliances with NASA centers for a particular mission are made long before the proposals go in. Anyone who allied with JPL will be SOL and might just as well not propose. It's not like you can easily switch after the proposal is written. All the NF5 proposers have picked long ago, though maybe there will be a lot of scrambling to go elsewhere. But the non-JPL mission proposals have a huge advantage.
I agree that it sucks for the proposals that work with JPL. However, if APL was having issues, would you still advocate for skipping NF5? How does stopping everything for a couple years seem fair to everyone who isn't at JPL? At the end of the day, this is about the science, not any specific group of people. We have to pick a single proposal, so most issues WON'T get a mission anyways. There are and will be valid and good proposals from groups not working through JPL for NF5 and the next discovery mission.
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#29
by
redliox
on 08 Nov, 2022 20:12
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Although technically not related to these missions, yet obviously still going to the same target AND part of the Discovery program, is Davinci+ affected by Psyche's delay? I can only assume less so since Goddard and JPL are separate entities. Was curious if the issue affected further elements of the Discovery program.
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#30
by
vjkane
on 08 Nov, 2022 21:52
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Although technically not related to these missions, yet obviously still going to the same target AND part of the Discovery program, is Davinci+ affected by Psyche's delay? I can only assume less so since Goddard and JPL are separate entities. Was curious if the issue affected further elements of the Discovery program.
The problems at JPL don't apply to DAVINCI. However, NASA is investigating whether the problems uncovered at JPL also apply to Goddard and JH APL. They have different workloads and management structures, but they have the same competition for people with the commercial space sector as JPL.
So likely no for DAVINCI, but it is possible there could be similar problems. Goddard also has many projects including one flagship.
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#31
by
Don2
on 11 Nov, 2022 18:08
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I wonder if the money that was allocated for VERITAS could be used to accelerate DAVINCI by a couple of years, assuming Goddard has the capacity? Some of that money will have to go to pay for the Psyche overrun, but there should be quite a bit left over.
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#32
by
deadman1204
on 11 Nov, 2022 18:31
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I wonder if the money that was allocated for VERITAS could be used to accelerate DAVINCI by a couple of years, assuming Goddard has the capacity? Some of that money will have to go to pay for the Psyche overrun, but there should be quite a bit left over.
that money is going to buying down all the risk with all the other jpl programs. Its gonna take a bunch of money to right the ship
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#33
by
vjkane
on 11 Nov, 2022 21:35
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I wonder if the money that was allocated for VERITAS could be used to accelerate DAVINCI by a couple of years, assuming Goddard has the capacity? Some of that money will have to go to pay for the Psyche overrun, but there should be quite a bit left over.
that money is going to buying down all the risk with all the other jpl programs. Its gonna take a bunch of money to right the ship
Lori Glaze has been quoted saying that the money saved by delaying VERITAS isn't enough to cover the costs of the delayed and now longer Psyche mission.
In addition, JPL has a lot of hiring (and perhaps giving raises to existing employees) to fill out its ranks.
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#34
by
Don2
on 12 Nov, 2022 05:35
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#35
by
Star One
on 12 Nov, 2022 09:36
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I assuming that at the base of the funding issue is politics that there hasn’t been enough budget given by the politicians, or is this an allocation issue?
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#36
by
Don2
on 12 Nov, 2022 18:23
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I assuming that at the base of the funding issue is politics that there hasn’t been enough budget given by the politicians, or is this an allocation issue?
The root cause of the funding issues is the failure to manage flagship mission costs, in particular Europa Clipper. That was sold as a mission that was going to cost $2.5 billion or so. Now it is costing $5 billion. If that had been kept on target then they could have flown an additional Discovery mission and a New Frontiers mission.
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#37
by
Star One
on 12 Nov, 2022 18:55
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I assuming that at the base of the funding issue is politics that there hasn’t been enough budget given by the politicians, or is this an allocation issue?
The root cause of the funding issues is the failure to manage flagship mission costs, in particular Europa Clipper. That was sold as a mission that was going to cost $2.5 billion or so. Now it is costing $5 billion. If that had been kept on target then they could have flown an additional Discovery mission and a New Frontiers mission.
Has any recent flagship mission ever come in on its initial budget allocation though.
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#38
by
deadman1204
on 14 Nov, 2022 14:10
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I assuming that at the base of the funding issue is politics that there hasn’t been enough budget given by the politicians, or is this an allocation issue?
The root cause of the funding issues is the failure to manage flagship mission costs, in particular Europa Clipper. That was sold as a mission that was going to cost $2.5 billion or so. Now it is costing $5 billion. If that had been kept on target then they could have flown an additional Discovery mission and a New Frontiers mission.
Has any recent flagship mission ever come in on its initial budget allocation though.
Its more that the missions are deliberately undersold on price. They should have known that the original price tag was lowballing.
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#39
by
Blackstar
on 14 Nov, 2022 15:10
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Its more that the missions are deliberately undersold on price. They should have known that the original price tag was lowballing.
That's part of it. But another part is that the mission that gets flown is not the same as the one that is initially proposed. Often things get added, which drives up the costs. The people who add those things accept that the costs increase. It's not a surprise.
I think it's important to break out of the mindset that the initial cost estimate is somehow holy or good or sacrosanct. It is the start of the discussion, not something that has to be upheld at the expense of other things. Cost increases above the initial estimates do have impacts elsewhere (leading to delaying or canceling other missions), but cost estimates should not be considered in absolute terms, yes/no/good/bad.