Could JWST stay at L2 “forever”? The 2019 Stack Overflow Developer Survey Results Are InWhat happens to JWST after it runs out of propellant?How will JWST manage solar pressure effects to maintain attitude and station keep it's unstable orbit?Why should the James Webb Space telescope stay in the unstable L2?Why won't JWST deploy in LEO where it is potentially serviceable?How much of the sky can the JWST see?How will JWST be serviced?Why isn't the JWST mirror bigger?What happens to JWST after it runs out of propellant?JWST observing cherry red Tesla roadsterCould a ball of water stay in orbit?How will JWST maintain its elliptical orbit around L2?How will JWST manage solar pressure effects to maintain attitude and station keep it's unstable orbit?
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Could JWST stay at L2 "forever"?
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Could JWST stay at L2 “forever”?
The 2019 Stack Overflow Developer Survey Results Are InWhat happens to JWST after it runs out of propellant?How will JWST manage solar pressure effects to maintain attitude and station keep it's unstable orbit?Why should the James Webb Space telescope stay in the unstable L2?Why won't JWST deploy in LEO where it is potentially serviceable?How much of the sky can the JWST see?How will JWST be serviced?Why isn't the JWST mirror bigger?What happens to JWST after it runs out of propellant?JWST observing cherry red Tesla roadsterCould a ball of water stay in orbit?How will JWST maintain its elliptical orbit around L2?How will JWST manage solar pressure effects to maintain attitude and station keep it's unstable orbit?
$begingroup$
Using only reaction wheels powered by solar panel and the sunshield as a sail (in continuous active attitude control) to generate thrust from solar photon pressure in the desired direction, could JWST stay in its orbit around L2 "forever" (theoretically at least)?
In this case it couldn't fulfill it's main objective, which is to be a space telescope pointing at distant objects for long exposure time. But this is a hypothetical question asking about its orbital dynamics.
Anyway, could this be a practical way to set JWST on "pause" for say 2 years, without burning fuel/ejecting mass to keep its orbit around L2?
orbital-mechanics lagrangian-points station-keeping james-webb-telescope
asked 11 hours ago
qq jkztdqq jkztd
918315
$endgroup$
add a comment |
$begingroup$
Using only reaction wheels powered by solar panel and the sunshield as a sail (in continuous active attitude control) to generate thrust from solar photon pressure in the desired direction, could JWST stay in its orbit around L2 "forever" (theoretically at least)?
In this case it couldn't fulfill it's main objective, which is to be a space telescope pointing at distant objects for long exposure time. But this is a hypothetical question asking about its orbital dynamics.
Anyway, could this be a practical way to set JWST on "pause" for say 2 years, without burning fuel/ejecting mass to keep its orbit around L2?
orbital-mechanics lagrangian-points station-keeping james-webb-telescope
asked 11 hours ago
qq jkztdqq jkztd
918315
$endgroup$
1
$begingroup$
Here are some different, but related questions whose answers may contain information that is also helpful here: How will JWST manage solar pressure effects to maintain attitude and station keep it's unstable orbit? and also What happens to JWST after it runs out of propellant?.
$endgroup$
– uhoh
11 hours ago
2
$begingroup$
Reaction wheels have to be desaturated occasionally. That takes fuel. Solar radiation pressure is a hindrance on JWST rather than something the vehicle can use to its advantage, more than doubling the stationkeeping costs compared to a vehicle in a similar unstable orbit but without such a huge sunshield.
$endgroup$
– David Hammen
8 hours ago
1
$begingroup$
@DavidHammen If considering an hypothetical very high sail surface/mass ratio probe, meant to solely keep orbit at one Lagrange point, could desaturation of reaction wheel be made by shifting centre of mass (reaction wheel) coplanar to sail, inducing a counter-torque allowing wheel to slow down, thereby using no fuel?
$endgroup$
– qq jkztd
7 hours ago
$begingroup$
Ok I found this about solar sail attitude control and propulsion, which goes into the direction of even getting rid of reaction wheel system, and desaturation related issues.
$endgroup$
– qq jkztd
4 hours ago
add a comment |
$begingroup$
Using only reaction wheels powered by solar panel and the sunshield as a sail (in continuous active attitude control) to generate thrust from solar photon pressure in the desired direction, could JWST stay in its orbit around L2 "forever" (theoretically at least)?
In this case it couldn't fulfill it's main objective, which is to be a space telescope pointing at distant objects for long exposure time. But this is a hypothetical question asking about its orbital dynamics.
Anyway, could this be a practical way to set JWST on "pause" for say 2 years, without burning fuel/ejecting mass to keep its orbit around L2?
orbital-mechanics lagrangian-points station-keeping james-webb-telescope
asked 11 hours ago
qq jkztdqq jkztd
918315
$endgroup$
Using only reaction wheels powered by solar panel and the sunshield as a sail (in continuous active attitude control) to generate thrust from solar photon pressure in the desired direction, could JWST stay in its orbit around L2 "forever" (theoretically at least)?
In this case it couldn't fulfill it's main objective, which is to be a space telescope pointing at distant objects for long exposure time. But this is a hypothetical question asking about its orbital dynamics.
Anyway, could this be a practical way to set JWST on "pause" for say 2 years, without burning fuel/ejecting mass to keep its orbit around L2?
orbital-mechanics lagrangian-points station-keeping james-webb-telescope
orbital-mechanics lagrangian-points station-keeping james-webb-telescope
asked 11 hours ago
qq jkztdqq jkztd
918315
asked 11 hours ago
qq jkztdqq jkztd
918315
edited 5 hours ago
qq jkztd
asked 11 hours ago
qq jkztdqq jkztd
918315
asked 11 hours ago
qq jkztdqq jkztd
918315
asked 11 hours ago
qq jkztdqq jkztd
918315
918315
1
$begingroup$
Here are some different, but related questions whose answers may contain information that is also helpful here: How will JWST manage solar pressure effects to maintain attitude and station keep it's unstable orbit? and also What happens to JWST after it runs out of propellant?.
$endgroup$
– uhoh
11 hours ago
2
$begingroup$
Reaction wheels have to be desaturated occasionally. That takes fuel. Solar radiation pressure is a hindrance on JWST rather than something the vehicle can use to its advantage, more than doubling the stationkeeping costs compared to a vehicle in a similar unstable orbit but without such a huge sunshield.
$endgroup$
– David Hammen
8 hours ago
1
$begingroup$
@DavidHammen If considering an hypothetical very high sail surface/mass ratio probe, meant to solely keep orbit at one Lagrange point, could desaturation of reaction wheel be made by shifting centre of mass (reaction wheel) coplanar to sail, inducing a counter-torque allowing wheel to slow down, thereby using no fuel?
$endgroup$
– qq jkztd
7 hours ago
$begingroup$
Ok I found this about solar sail attitude control and propulsion, which goes into the direction of even getting rid of reaction wheel system, and desaturation related issues.
$endgroup$
– qq jkztd
4 hours ago
add a comment |
1
$begingroup$
Here are some different, but related questions whose answers may contain information that is also helpful here: How will JWST manage solar pressure effects to maintain attitude and station keep it's unstable orbit? and also What happens to JWST after it runs out of propellant?.
$endgroup$
– uhoh
11 hours ago
2
$begingroup$
Reaction wheels have to be desaturated occasionally. That takes fuel. Solar radiation pressure is a hindrance on JWST rather than something the vehicle can use to its advantage, more than doubling the stationkeeping costs compared to a vehicle in a similar unstable orbit but without such a huge sunshield.
$endgroup$
– David Hammen
8 hours ago
1
$begingroup$
@DavidHammen If considering an hypothetical very high sail surface/mass ratio probe, meant to solely keep orbit at one Lagrange point, could desaturation of reaction wheel be made by shifting centre of mass (reaction wheel) coplanar to sail, inducing a counter-torque allowing wheel to slow down, thereby using no fuel?
$endgroup$
– qq jkztd
7 hours ago
$begingroup$
Ok I found this about solar sail attitude control and propulsion, which goes into the direction of even getting rid of reaction wheel system, and desaturation related issues.
$endgroup$
– qq jkztd
4 hours ago
1
1
$begingroup$
Here are some different, but related questions whose answers may contain information that is also helpful here: How will JWST manage solar pressure effects to maintain attitude and station keep it's unstable orbit? and also What happens to JWST after it runs out of propellant?.
$endgroup$
– uhoh
11 hours ago
$begingroup$
Here are some different, but related questions whose answers may contain information that is also helpful here: How will JWST manage solar pressure effects to maintain attitude and station keep it's unstable orbit? and also What happens to JWST after it runs out of propellant?.
$endgroup$
– uhoh
11 hours ago
2
2
$begingroup$
Reaction wheels have to be desaturated occasionally. That takes fuel. Solar radiation pressure is a hindrance on JWST rather than something the vehicle can use to its advantage, more than doubling the stationkeeping costs compared to a vehicle in a similar unstable orbit but without such a huge sunshield.
$endgroup$
– David Hammen
8 hours ago
$begingroup$
Reaction wheels have to be desaturated occasionally. That takes fuel. Solar radiation pressure is a hindrance on JWST rather than something the vehicle can use to its advantage, more than doubling the stationkeeping costs compared to a vehicle in a similar unstable orbit but without such a huge sunshield.
$endgroup$
– David Hammen
8 hours ago
1
1
$begingroup$
@DavidHammen If considering an hypothetical very high sail surface/mass ratio probe, meant to solely keep orbit at one Lagrange point, could desaturation of reaction wheel be made by shifting centre of mass (reaction wheel) coplanar to sail, inducing a counter-torque allowing wheel to slow down, thereby using no fuel?
$endgroup$
– qq jkztd
7 hours ago
$begingroup$
@DavidHammen If considering an hypothetical very high sail surface/mass ratio probe, meant to solely keep orbit at one Lagrange point, could desaturation of reaction wheel be made by shifting centre of mass (reaction wheel) coplanar to sail, inducing a counter-torque allowing wheel to slow down, thereby using no fuel?
$endgroup$
– qq jkztd
7 hours ago
$begingroup$
Ok I found this about solar sail attitude control and propulsion, which goes into the direction of even getting rid of reaction wheel system, and desaturation related issues.
$endgroup$
– qq jkztd
4 hours ago
$begingroup$
Ok I found this about solar sail attitude control and propulsion, which goes into the direction of even getting rid of reaction wheel system, and desaturation related issues.
$endgroup$
– qq jkztd
4 hours ago
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
According to Wikipedia, the delta-v requirements to stay at L1 or L2 are about 30-100 m/s. That seems quite high, however, more likely is around 5-16 m/s. The sun shield has an area of about 300 m^2. The thrust possible is about 0.00279664 N, assuming purely reflective. Mass of JWST is about 6200 kg. Putting all of that together, the possible acceleration is around 14 m/s per year, not quite enough to station keep. Also, this assumes fully reflective sun shields, and pointed straight at the sun. I'm not sure what the actual direction of thrust that would be required to keep it at L2, but it probably wouldn't be straight on, thus reducing this further.
Bottom line, it might work, but would require some very careful placement of the shield to maintain the proper orientation.
answered 11 hours ago
PearsonArtPhoto♦PearsonArtPhoto
84.5k16243468
$endgroup$
8
$begingroup$
That value of 30 to 100 m/s per year is a bogus number. Perhaps that's for EML1/EML2? This paper claims that "In recent years, typical annual station-keeping costs have been around 1.0 m/sec for ACE and WIND, and much less than that for SOHO." This paper, which addresses JSWT directly, estimates stationkeeping costs for JWST to be 2.43 m/s per year.
$endgroup$
– David Hammen
8 hours ago
6
$begingroup$
Double checking, that "30 - 100 m/s per year" is completely bogus, even for EML1/EML2. Per this paper, the ARTEMIS satellites experienced stationkeeping costs in the range of 5 to 16 m/s per year.
$endgroup$
– David Hammen
8 hours ago
1
$begingroup$
I left the links under the question to provide resources for those who'd like to answer. My answer to the 2nd one What happens to JWST after it runs out of propellant? quotes another Wikipedia article that states the delta-v required for station-keeping is only about 2 to 4 m/s per year. It is surprisingly low, but it is achieved by choosing the initial orbit carefully, and executing a carefully determined propulsive correction every 21 days. So I think your answer needs a partial reversal.
$endgroup$
– uhoh
7 hours ago
1
$begingroup$
There's only about 80 m/s available for the entire life of the JWST once it is inserted into orbit. So I think the answer is yes, if it went into non-telescope mode, it could stay at L2 without using propellant, at least for quite a while. The question now is if it could even do momentum unloading through clever maneuvers, so as not to even use propellant for attitude control!
$endgroup$
– uhoh
7 hours ago
1
$begingroup$
Good feedback, have improved. Now we just need to fix Wikipedia...
$endgroup$
– PearsonArtPhoto♦
6 hours ago
|
show 1 more comment
$begingroup$
This paper by Heiligers et al. explores Earth-moon libration point orbits with the addition of solar sail thrusting. While it is of course not directly translateable to Sun-Earth L2 (JWST) the dynamics of libration point orbits in both systems are at least comparable. The study shows that an increase in stability can be acquired for some orbits (lunar L2 halo being one of them).
JWST is however not a typical solar sail spacecraft. These have much higher area/mass ratios and will produce more acceleration, together with a lower mass (I'm assuming also lower inertia) which means they can steer their sails much more effectively.
I would assume that the conclusions from the paper can be applied to the JWST as well, but the impact on the stability will probably be much smaller than in the case of a regular solar sail spacecraft.
answered 10 hours ago
Alexander VandenbergheAlexander Vandenberghe
60129
$endgroup$
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
According to Wikipedia, the delta-v requirements to stay at L1 or L2 are about 30-100 m/s. That seems quite high, however, more likely is around 5-16 m/s. The sun shield has an area of about 300 m^2. The thrust possible is about 0.00279664 N, assuming purely reflective. Mass of JWST is about 6200 kg. Putting all of that together, the possible acceleration is around 14 m/s per year, not quite enough to station keep. Also, this assumes fully reflective sun shields, and pointed straight at the sun. I'm not sure what the actual direction of thrust that would be required to keep it at L2, but it probably wouldn't be straight on, thus reducing this further.
Bottom line, it might work, but would require some very careful placement of the shield to maintain the proper orientation.
answered 11 hours ago
PearsonArtPhoto♦PearsonArtPhoto
84.5k16243468
$endgroup$
8
$begingroup$
That value of 30 to 100 m/s per year is a bogus number. Perhaps that's for EML1/EML2? This paper claims that "In recent years, typical annual station-keeping costs have been around 1.0 m/sec for ACE and WIND, and much less than that for SOHO." This paper, which addresses JSWT directly, estimates stationkeeping costs for JWST to be 2.43 m/s per year.
$endgroup$
– David Hammen
8 hours ago
6
$begingroup$
Double checking, that "30 - 100 m/s per year" is completely bogus, even for EML1/EML2. Per this paper, the ARTEMIS satellites experienced stationkeeping costs in the range of 5 to 16 m/s per year.
$endgroup$
– David Hammen
8 hours ago
1
$begingroup$
I left the links under the question to provide resources for those who'd like to answer. My answer to the 2nd one What happens to JWST after it runs out of propellant? quotes another Wikipedia article that states the delta-v required for station-keeping is only about 2 to 4 m/s per year. It is surprisingly low, but it is achieved by choosing the initial orbit carefully, and executing a carefully determined propulsive correction every 21 days. So I think your answer needs a partial reversal.
$endgroup$
– uhoh
7 hours ago
1
$begingroup$
There's only about 80 m/s available for the entire life of the JWST once it is inserted into orbit. So I think the answer is yes, if it went into non-telescope mode, it could stay at L2 without using propellant, at least for quite a while. The question now is if it could even do momentum unloading through clever maneuvers, so as not to even use propellant for attitude control!
$endgroup$
– uhoh
7 hours ago
1
$begingroup$
Good feedback, have improved. Now we just need to fix Wikipedia...
$endgroup$
– PearsonArtPhoto♦
6 hours ago
|
show 1 more comment
$begingroup$
According to Wikipedia, the delta-v requirements to stay at L1 or L2 are about 30-100 m/s. That seems quite high, however, more likely is around 5-16 m/s. The sun shield has an area of about 300 m^2. The thrust possible is about 0.00279664 N, assuming purely reflective. Mass of JWST is about 6200 kg. Putting all of that together, the possible acceleration is around 14 m/s per year, not quite enough to station keep. Also, this assumes fully reflective sun shields, and pointed straight at the sun. I'm not sure what the actual direction of thrust that would be required to keep it at L2, but it probably wouldn't be straight on, thus reducing this further.
Bottom line, it might work, but would require some very careful placement of the shield to maintain the proper orientation.
answered 11 hours ago
PearsonArtPhoto♦PearsonArtPhoto
84.5k16243468
$endgroup$
8
$begingroup$
That value of 30 to 100 m/s per year is a bogus number. Perhaps that's for EML1/EML2? This paper claims that "In recent years, typical annual station-keeping costs have been around 1.0 m/sec for ACE and WIND, and much less than that for SOHO." This paper, which addresses JSWT directly, estimates stationkeeping costs for JWST to be 2.43 m/s per year.
$endgroup$
– David Hammen
8 hours ago
6
$begingroup$
Double checking, that "30 - 100 m/s per year" is completely bogus, even for EML1/EML2. Per this paper, the ARTEMIS satellites experienced stationkeeping costs in the range of 5 to 16 m/s per year.
$endgroup$
– David Hammen
8 hours ago
1
$begingroup$
I left the links under the question to provide resources for those who'd like to answer. My answer to the 2nd one What happens to JWST after it runs out of propellant? quotes another Wikipedia article that states the delta-v required for station-keeping is only about 2 to 4 m/s per year. It is surprisingly low, but it is achieved by choosing the initial orbit carefully, and executing a carefully determined propulsive correction every 21 days. So I think your answer needs a partial reversal.
$endgroup$
– uhoh
7 hours ago
1
$begingroup$
There's only about 80 m/s available for the entire life of the JWST once it is inserted into orbit. So I think the answer is yes, if it went into non-telescope mode, it could stay at L2 without using propellant, at least for quite a while. The question now is if it could even do momentum unloading through clever maneuvers, so as not to even use propellant for attitude control!
$endgroup$
– uhoh
7 hours ago
1
$begingroup$
Good feedback, have improved. Now we just need to fix Wikipedia...
$endgroup$
– PearsonArtPhoto♦
6 hours ago
|
show 1 more comment
$begingroup$
According to Wikipedia, the delta-v requirements to stay at L1 or L2 are about 30-100 m/s. That seems quite high, however, more likely is around 5-16 m/s. The sun shield has an area of about 300 m^2. The thrust possible is about 0.00279664 N, assuming purely reflective. Mass of JWST is about 6200 kg. Putting all of that together, the possible acceleration is around 14 m/s per year, not quite enough to station keep. Also, this assumes fully reflective sun shields, and pointed straight at the sun. I'm not sure what the actual direction of thrust that would be required to keep it at L2, but it probably wouldn't be straight on, thus reducing this further.
Bottom line, it might work, but would require some very careful placement of the shield to maintain the proper orientation.
answered 11 hours ago
PearsonArtPhoto♦PearsonArtPhoto
84.5k16243468
$endgroup$
According to Wikipedia, the delta-v requirements to stay at L1 or L2 are about 30-100 m/s. That seems quite high, however, more likely is around 5-16 m/s. The sun shield has an area of about 300 m^2. The thrust possible is about 0.00279664 N, assuming purely reflective. Mass of JWST is about 6200 kg. Putting all of that together, the possible acceleration is around 14 m/s per year, not quite enough to station keep. Also, this assumes fully reflective sun shields, and pointed straight at the sun. I'm not sure what the actual direction of thrust that would be required to keep it at L2, but it probably wouldn't be straight on, thus reducing this further.
Bottom line, it might work, but would require some very careful placement of the shield to maintain the proper orientation.
answered 11 hours ago
PearsonArtPhoto♦PearsonArtPhoto
84.5k16243468
edited 3 hours ago
answered 11 hours ago
PearsonArtPhoto♦PearsonArtPhoto
84.5k16243468
answered 11 hours ago
PearsonArtPhoto♦PearsonArtPhoto
84.5k16243468
answered 11 hours ago
PearsonArtPhoto♦PearsonArtPhoto
84.5k16243468
84.5k16243468
8
$begingroup$
That value of 30 to 100 m/s per year is a bogus number. Perhaps that's for EML1/EML2? This paper claims that "In recent years, typical annual station-keeping costs have been around 1.0 m/sec for ACE and WIND, and much less than that for SOHO." This paper, which addresses JSWT directly, estimates stationkeeping costs for JWST to be 2.43 m/s per year.
$endgroup$
– David Hammen
8 hours ago
6
$begingroup$
Double checking, that "30 - 100 m/s per year" is completely bogus, even for EML1/EML2. Per this paper, the ARTEMIS satellites experienced stationkeeping costs in the range of 5 to 16 m/s per year.
$endgroup$
– David Hammen
8 hours ago
1
$begingroup$
I left the links under the question to provide resources for those who'd like to answer. My answer to the 2nd one What happens to JWST after it runs out of propellant? quotes another Wikipedia article that states the delta-v required for station-keeping is only about 2 to 4 m/s per year. It is surprisingly low, but it is achieved by choosing the initial orbit carefully, and executing a carefully determined propulsive correction every 21 days. So I think your answer needs a partial reversal.
$endgroup$
– uhoh
7 hours ago
1
$begingroup$
There's only about 80 m/s available for the entire life of the JWST once it is inserted into orbit. So I think the answer is yes, if it went into non-telescope mode, it could stay at L2 without using propellant, at least for quite a while. The question now is if it could even do momentum unloading through clever maneuvers, so as not to even use propellant for attitude control!
$endgroup$
– uhoh
7 hours ago
1
$begingroup$
Good feedback, have improved. Now we just need to fix Wikipedia...
$endgroup$
– PearsonArtPhoto♦
6 hours ago
|
show 1 more comment
8
$begingroup$
That value of 30 to 100 m/s per year is a bogus number. Perhaps that's for EML1/EML2? This paper claims that "In recent years, typical annual station-keeping costs have been around 1.0 m/sec for ACE and WIND, and much less than that for SOHO." This paper, which addresses JSWT directly, estimates stationkeeping costs for JWST to be 2.43 m/s per year.
$endgroup$
– David Hammen
8 hours ago
6
$begingroup$
Double checking, that "30 - 100 m/s per year" is completely bogus, even for EML1/EML2. Per this paper, the ARTEMIS satellites experienced stationkeeping costs in the range of 5 to 16 m/s per year.
$endgroup$
– David Hammen
8 hours ago
1
$begingroup$
I left the links under the question to provide resources for those who'd like to answer. My answer to the 2nd one What happens to JWST after it runs out of propellant? quotes another Wikipedia article that states the delta-v required for station-keeping is only about 2 to 4 m/s per year. It is surprisingly low, but it is achieved by choosing the initial orbit carefully, and executing a carefully determined propulsive correction every 21 days. So I think your answer needs a partial reversal.
$endgroup$
– uhoh
7 hours ago
1
$begingroup$
There's only about 80 m/s available for the entire life of the JWST once it is inserted into orbit. So I think the answer is yes, if it went into non-telescope mode, it could stay at L2 without using propellant, at least for quite a while. The question now is if it could even do momentum unloading through clever maneuvers, so as not to even use propellant for attitude control!
$endgroup$
– uhoh
7 hours ago
1
$begingroup$
Good feedback, have improved. Now we just need to fix Wikipedia...
$endgroup$
– PearsonArtPhoto♦
6 hours ago
8
8
$begingroup$
That value of 30 to 100 m/s per year is a bogus number. Perhaps that's for EML1/EML2? This paper claims that "In recent years, typical annual station-keeping costs have been around 1.0 m/sec for ACE and WIND, and much less than that for SOHO." This paper, which addresses JSWT directly, estimates stationkeeping costs for JWST to be 2.43 m/s per year.
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– David Hammen
8 hours ago
$begingroup$
That value of 30 to 100 m/s per year is a bogus number. Perhaps that's for EML1/EML2? This paper claims that "In recent years, typical annual station-keeping costs have been around 1.0 m/sec for ACE and WIND, and much less than that for SOHO." This paper, which addresses JSWT directly, estimates stationkeeping costs for JWST to be 2.43 m/s per year.
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– David Hammen
8 hours ago
6
6
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Double checking, that "30 - 100 m/s per year" is completely bogus, even for EML1/EML2. Per this paper, the ARTEMIS satellites experienced stationkeeping costs in the range of 5 to 16 m/s per year.
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– David Hammen
8 hours ago
$begingroup$
Double checking, that "30 - 100 m/s per year" is completely bogus, even for EML1/EML2. Per this paper, the ARTEMIS satellites experienced stationkeeping costs in the range of 5 to 16 m/s per year.
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– David Hammen
8 hours ago
1
1
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I left the links under the question to provide resources for those who'd like to answer. My answer to the 2nd one What happens to JWST after it runs out of propellant? quotes another Wikipedia article that states the delta-v required for station-keeping is only about 2 to 4 m/s per year. It is surprisingly low, but it is achieved by choosing the initial orbit carefully, and executing a carefully determined propulsive correction every 21 days. So I think your answer needs a partial reversal.
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– uhoh
7 hours ago
$begingroup$
I left the links under the question to provide resources for those who'd like to answer. My answer to the 2nd one What happens to JWST after it runs out of propellant? quotes another Wikipedia article that states the delta-v required for station-keeping is only about 2 to 4 m/s per year. It is surprisingly low, but it is achieved by choosing the initial orbit carefully, and executing a carefully determined propulsive correction every 21 days. So I think your answer needs a partial reversal.
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– uhoh
7 hours ago
1
1
$begingroup$
There's only about 80 m/s available for the entire life of the JWST once it is inserted into orbit. So I think the answer is yes, if it went into non-telescope mode, it could stay at L2 without using propellant, at least for quite a while. The question now is if it could even do momentum unloading through clever maneuvers, so as not to even use propellant for attitude control!
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– uhoh
7 hours ago
$begingroup$
There's only about 80 m/s available for the entire life of the JWST once it is inserted into orbit. So I think the answer is yes, if it went into non-telescope mode, it could stay at L2 without using propellant, at least for quite a while. The question now is if it could even do momentum unloading through clever maneuvers, so as not to even use propellant for attitude control!
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– uhoh
7 hours ago
1
1
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Good feedback, have improved. Now we just need to fix Wikipedia...
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– PearsonArtPhoto♦
6 hours ago
$begingroup$
Good feedback, have improved. Now we just need to fix Wikipedia...
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– PearsonArtPhoto♦
6 hours ago
|
show 1 more comment
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This paper by Heiligers et al. explores Earth-moon libration point orbits with the addition of solar sail thrusting. While it is of course not directly translateable to Sun-Earth L2 (JWST) the dynamics of libration point orbits in both systems are at least comparable. The study shows that an increase in stability can be acquired for some orbits (lunar L2 halo being one of them).
JWST is however not a typical solar sail spacecraft. These have much higher area/mass ratios and will produce more acceleration, together with a lower mass (I'm assuming also lower inertia) which means they can steer their sails much more effectively.
I would assume that the conclusions from the paper can be applied to the JWST as well, but the impact on the stability will probably be much smaller than in the case of a regular solar sail spacecraft.
answered 10 hours ago
Alexander VandenbergheAlexander Vandenberghe
60129
$endgroup$
add a comment |
$begingroup$
This paper by Heiligers et al. explores Earth-moon libration point orbits with the addition of solar sail thrusting. While it is of course not directly translateable to Sun-Earth L2 (JWST) the dynamics of libration point orbits in both systems are at least comparable. The study shows that an increase in stability can be acquired for some orbits (lunar L2 halo being one of them).
JWST is however not a typical solar sail spacecraft. These have much higher area/mass ratios and will produce more acceleration, together with a lower mass (I'm assuming also lower inertia) which means they can steer their sails much more effectively.
I would assume that the conclusions from the paper can be applied to the JWST as well, but the impact on the stability will probably be much smaller than in the case of a regular solar sail spacecraft.
answered 10 hours ago
Alexander VandenbergheAlexander Vandenberghe
60129
$endgroup$
add a comment |
$begingroup$
This paper by Heiligers et al. explores Earth-moon libration point orbits with the addition of solar sail thrusting. While it is of course not directly translateable to Sun-Earth L2 (JWST) the dynamics of libration point orbits in both systems are at least comparable. The study shows that an increase in stability can be acquired for some orbits (lunar L2 halo being one of them).
JWST is however not a typical solar sail spacecraft. These have much higher area/mass ratios and will produce more acceleration, together with a lower mass (I'm assuming also lower inertia) which means they can steer their sails much more effectively.
I would assume that the conclusions from the paper can be applied to the JWST as well, but the impact on the stability will probably be much smaller than in the case of a regular solar sail spacecraft.
answered 10 hours ago
Alexander VandenbergheAlexander Vandenberghe
60129
$endgroup$
This paper by Heiligers et al. explores Earth-moon libration point orbits with the addition of solar sail thrusting. While it is of course not directly translateable to Sun-Earth L2 (JWST) the dynamics of libration point orbits in both systems are at least comparable. The study shows that an increase in stability can be acquired for some orbits (lunar L2 halo being one of them).
JWST is however not a typical solar sail spacecraft. These have much higher area/mass ratios and will produce more acceleration, together with a lower mass (I'm assuming also lower inertia) which means they can steer their sails much more effectively.
I would assume that the conclusions from the paper can be applied to the JWST as well, but the impact on the stability will probably be much smaller than in the case of a regular solar sail spacecraft.
answered 10 hours ago
Alexander VandenbergheAlexander Vandenberghe
60129
answered 10 hours ago
Alexander VandenbergheAlexander Vandenberghe
60129
answered 10 hours ago
Alexander VandenbergheAlexander Vandenberghe
60129
answered 10 hours ago
Alexander VandenbergheAlexander Vandenberghe
60129
60129
add a comment |
add a comment |
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Here are some different, but related questions whose answers may contain information that is also helpful here: How will JWST manage solar pressure effects to maintain attitude and station keep it's unstable orbit? and also What happens to JWST after it runs out of propellant?.
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– uhoh
11 hours ago
2
$begingroup$
Reaction wheels have to be desaturated occasionally. That takes fuel. Solar radiation pressure is a hindrance on JWST rather than something the vehicle can use to its advantage, more than doubling the stationkeeping costs compared to a vehicle in a similar unstable orbit but without such a huge sunshield.
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– David Hammen
8 hours ago
1
$begingroup$
@DavidHammen If considering an hypothetical very high sail surface/mass ratio probe, meant to solely keep orbit at one Lagrange point, could desaturation of reaction wheel be made by shifting centre of mass (reaction wheel) coplanar to sail, inducing a counter-torque allowing wheel to slow down, thereby using no fuel?
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– qq jkztd
7 hours ago
$begingroup$
Ok I found this about solar sail attitude control and propulsion, which goes into the direction of even getting rid of reaction wheel system, and desaturation related issues.
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– qq jkztd
4 hours ago