There [are] some pluses to taking slow route to moon. Plenty of time to find bugs and sort them out before critical landing.
I've warned you before, Chris Bergin, there's a mission thread for this and updates on the above nature should be posted here:https://forum.nasaspaceflight.com/index.php?topic=47217.0Honestly, some people! (Sorry about posting in the wrong place
If SMART-1 could survive it anything else should be OK.
Quote from: Phil Stooke on 02/27/2019 12:57 amIf SMART-1 could survive it anything else should be OK.Presumably SMART-1 went through radiation testing before the mission. That's probably not the case for this mission.I've been seeing some discussion among American space radiation experts who think that the reported computer problem was probably a radiation event, a Single Event Effect:https://radhome.gsfc.nasa.gov/radhome/see.htm
If I understand correctly raw data of this file, Beresheet is going to "upgrade" its orbit this night, raising apogee from 74000 to 120000 km:25/02/2019 9.54 - 74140km26/02/2019 20.49 - 121232kmNext raisings:10/3: 276000 km25/3: 391000 kmSource: http://live.spaceil.com/
yes, it is geocentric orbital state vectors: date x y z vx vy vz
yes, has negative valuesGEOCENTRIC, Earth is the center of coordinates.Beeresht2.png + Moon trajectoryCoordinate systm: Earth Mean Equator and Equinox of Reference Epoch
Quote from: Blackstar on 02/27/2019 02:25 amQuote from: Phil Stooke on 02/27/2019 12:57 amIf SMART-1 could survive it anything else should be OK.Presumably SMART-1 went through radiation testing before the mission. That's probably not the case for this mission.I've been seeing some discussion among American space radiation experts who think that the reported computer problem was probably a radiation event, a Single Event Effect:https://radhome.gsfc.nasa.gov/radhome/see.htmNo spacecraft or instrument I have worked on has been "radiation tested", exposed to protons, gamma rays, electrons, etc., as a whole. Generally components, and occasionally subsystems like circuit boards, are tested like that. I have even sent components and material samples to some of the labs listed in the GSFC link, and another in Colorado Springs, CO. I bet the Israelis have their own facilities for some of this testing.The linked page has a further link to a list of components, whose types have been tested by GSFC and found tolerant to radiation. It is assumed that IAI referred to this and similar lists to choose acceptable parts.
The linked page has a further link to a list of components, whose types have been tested by GSFC and found tolerant to radiation.
No spacecraft or instrument I have worked on has been "radiation tested", exposed to protons, gamma rays, electrons, etc., as a whole. Generally components, and occasionally subsystems like circuit boards,
There are two different steps in this process:1) Components manufacturer tests their components against radiation and provide radiation test reports2) Spacecraft manufacturers purchase radiation hardened components as per mission requirements, BUT they also perform simulation of EACH component behaviour in mission environment and calculate the probability of failure during mission time. If they have enough money...
When is the next burn? I am assuming they can't miss two in a row, no?
Quote from: mcgyver on 02/27/2019 07:35 pmThere are two different steps in this process:1) Components manufacturer tests their components against radiation and provide radiation test reports2) Spacecraft manufacturers purchase radiation hardened components as per mission requirements, BUT they also perform simulation of EACH component behaviour in mission environment and calculate the probability of failure during mission time. If they have enough money...Yeah, all that costs money. On a cost-constrained mission, they just may not be able to do it.I ran a DoE/USAF/NASA-funded study in 2017 on the US infrastructure for testing components. There's a push to use commercial electronic parts in space for lower cost missions like cubesats. One of the more interesting aspects of this work is that automobile electronics perform quite well. When you think about it, they're designed for a broad range of temperatures (arctic to desert), humidity, vibration, and longevity.
I hope my question is not all too stupid: Wouldn't it be possible to encapsulate circuit boards etc. properly to resist radiation? Like put a lead case around it? Or is the radiation just too strong and then the whole probe would become extremely heavy?