Webb Launch Delayed Due To Ground Processing Issues (Update)
Testing Confirms Webb Telescope on Track for Targeted Dec. 22 Launch, Arianespace
“Engineering teams have completed additional testing confirming NASA’s James Webb Space Telescope is ready for flight, and launch preparations are resuming toward Webb’s target launch date of Wednesday, Dec. 22, at 7:20 a.m. EST. Additional testing was conducted this week to ensure the observatory’s health following an incident that occurred when the release of a clamp band caused a vibration throughout the observatory.”
NASA Provides Update on Webb Telescope Launch
“The launch readiness date for the James Webb Space Telescope is moving to no earlier than Dec. 22 to allow for additional testing of the observatory, following a recent incident that occurred during Webb’s launch preparations. The incident occurred during operations at the satellite preparation facility in Kourou, French Guiana, performed under Arianespace overall responsibility. Technicians were preparing to attach Webb to the launch vehicle adapter, which is used to integrate the observatory with the upper stage of the Ariane 5 rocket. A sudden, unplanned release of a clamp band – which secures Webb to the launch vehicle adapter – caused a vibration throughout the observatory.” A NASA-led anomaly review board was immediately convened to investigate and instituted additional testing to determine with certainty the incident did not damage any components. NASA and its mission partners will provide an update when the testing is completed at the end of this week.”
Par for the course of unending delays for Webb. At 70 I don’t know if I will live to see any results from it.
I feel the same way. At 69 I just hope that I live long enough to see Webb successfully launched and to begin operations.
At one time I cared about JWST.
it’ll launch (maybe) before SLS …
great, lucky that an errant piece of of clamp band didn’t contact the multi-B $ payload. This was supposed to be the best launch option available?
and now there is the “what if” the clampband releases too early during flight – or not at all?
It was reported that JWST has been deemed ready to launch Dec 22. So maybe in 7 months or so we’ll start seeing what JWST is really capable of.
I think it was a real mistake not designing the JWST with on-orbit servicing in mind. NASA’s Orion spacecraft, and for that matter, SpaceX’s Starship, could both be adapted to this task if something goes wrong once the telescope is on station. Given the immense cost, and huge importance of this instrument, and the amount of time put in to building it, to not provide some means of insurance against a fault is just crazy. Also, it prevents the ability to upgrade the instruments aboard.
At the time that decision was made, Orion was barely a concept, Starship didn’t exist at all, and SpaceX still hadn’t gotten their first Falcon 1 into orbit. JWST has been in development for a long time. When the decisions that made it impossible to service were made, there were no service options. The Shuttle couldn’t get to the necessary L2 halo orbit and no other vehicles for a servicing mission were even on the horizon. That’s not idea, but things like that are inevitable when the decisions have to be made a couple decades before launch.
So is it worth while to replace the JWST after it’s service life with something similar in capabilities and more contemporary in construction that is serviceable? You could deployed much larger free flyer sunshade array(s).
Or go for the next shiny observatory concept as usual?
There’s no budget for anything like that. Remember it’s not just that JWST took decades to get to flight, during that time it ate the SMD astrophysics budget and blocked many other missions (there’s a great Nature article from _2011_ about it entitled “The Telescope that Ate Astronomy”). Just to get in the pipeline would realistically take 10-20 years, minimum. Plus you’d have to consider the cost of servicing missions as well, which would be flying to a place that to date no manned spacecraft has ever gone.
SpaceX is working with Lawrence Berkeley’s Saul Perlmutter on a Starship based telescope
https://twitter.com/elonmus…
Reminder that there will be something else after JWST’s short 10 years or so of service life. After the Nancy Roman telescope.
So would you choose to replace the JWST with a non cutting edge telescope of similar capabilities before moving on to the next shiny observatory?
The Nature article was 2010 : https://www.nature.com/arti… and when JWST was expected to launch in 2014.
The consensus of the astronomical community (as stated in multiple, Decadal Surveys from the National Academy) is that they do not want a JSWT replacement at the end of its life. Just as they do not want a Hubble replacement at the end of its life. JSWT was designed to answer a set of high-priority scientific questions, and by the end of it’s life, it should have answered those questions. Building a new telescope with similar capabilities could address different but lower priority questions. So astronomers would prefer to move on to a telescope with different capabilities.
The planned next big telescope is the Roman Space Telescope, which should provide a full sky survey at HST-level resolution in the IR. Once that’s done, off on the horizon in around 2040, they want a JWST-sized telescope, but with the ability to observe in the UV and visible as well as a really good coronagraph for studies of extrasolar planets.
It appears the consensus of the Astronomical community for something like a truncated LUVOIR-B as the next shiny observatory. Likely morphed into the LUVOIR-B later, IMO.
However you didn’t answer if a JWST like replacement that is serviceable is worthwhile?
I don’t think the telescope the Decadal Survey will grow back to something the size of LUVOIR. The Survey’s report was very concerned about cost and cost growth, which is why they didn’t recommend LUVOIR. NASA generally follows those recommendations.
But in terms of a serviceable JWST replacement, what do you mean by “worthwhile”? Would it be useful for some types of astronomy? Sure. Not to me, since most of the things I’m interested involve UV astronomy, but it would be useful to some astronomers. Would it be worth the cost? That depends on how much it would cost. Personally, I think it would be several billion, and it probably isn’t worth that much. Would it be a better use of that same amount of money (whatever that is) than some other sort of space telescope? The Decadal Survey panel clearly didn’t think so.
LUVOIR-B is suppose to be a 8 meter diameter segmented telescope. While the Decadal Survey recommend a 6 meter diameter telescope. Which means either starting new or continuing LUVOIR-B is about the same cost, IMO.
Yeah. A JWST replacement depends on how much it cost. A few billions over the extended service life of a telescope that is serviceable seems to be doable budget wise.
The next shiny observatory that seems to be hinted at by the Decadal Survey after the truncated LUVOIR-B is likely to surpass JWST in realistic cost estimate, IMO. As the history of the initial low ball cost estimate and subsequent cost growth of the JWST shows. Which I expected to be repeated with next shiny observatory.
“Impossible” is much too final a word. JW was not particularly well design for Exoplanet Science, but now that’s a major selling point. Also, there were instruments on HST that were “not serviceable”, which in fact were serviced. Same for out-of-gas Geo Birds. So, never say never ?
The Hubble servicing flights were very expensive. It was politically impossible, but it would likely have been more cost effective to build and launch new telescopes. And the Shuttle…three of the satellites it retrieved were designed specifically to be retrieved, the other two were launched together on another Shuttle flight and stranded near their original orbit when their kick stage failed.
Unlike Hubble, JWST doesn’t have an aperture door to protect the mirror from the typical outgas products you’d get from a messy manned s/c. A huge aperture door would have been another expense and potential failure point for the usual suspects to whine & complain about.
AIUI the outgas products of the most likely servicing vehicle is mostly gaseous nitrogen from micro cold gas thrusters.
However that is moot. Since the JWST does not have serviceable components.
About the only thing that can be done is leaving some sort of low impulse station keeping propulsion module to periodically putting the JWST in the proper orbit.
“…NASA’s Orion spacecraft, and for that matter, SpaceX’s Starship, could both be adapted to this task”
Dr Davis comment and my reply to it, were regarding crewed vehicles. Obviously a modified LM Mission Extension Vehicle (MEV) (or similar) would be a different situation.
JWST is life limited because of propellant needed for station keeping and desaturation. Before the observatory’s propellant is completely consumed, a MEV could attach to Webb’s launch adapter ring, and do as its name implies -extend the mission. As I recall, NG added a guidance fiducial
to the adapter ring to aid any future docking of a MEV.
In practice, very few spacecraft have cold gas thrusters. So if you want to use some vehicle for servicing a space telescope, you’d have to modify it and add cold nitrogen thrusters. The hydrazine thrusters on a Dragon 2 or Soyuz would be a problem.
Unlike JWST’s own hydrazine thrusters?
“…cold nitrogen thrusters.”
JWST’s own thrusters use hydrazine. Some are bi-prop and others are mono-prop, depending on which set are used.
I was talking about servicing space telescopes in general. Depending on the wavelength range and the spectral requirements, thruster combustion products can be an issue. It also matters where the thrusters are and what direction they fire in. You can certainly mount thrusters on an observatory in a way which greatly minimizes thruster plume impingement on the mirrors and optics. But that’s different from a servicing spacecraft flying around near it.
The folks at Hawthorne seems to have some expertise with Nitrogen cold gas thrusters with their current booster attitude control system.
Think they can put together something suitable for JWST servicing mission.
“…NASA’s Orion spacecraft, and for that matter, SpaceX’s Starship, could both be adapted to this task”
Dr Davis comment and my reply to it, were regarding crewed vehicles. Obviously a modified LM Mission Extension Vehicle (MEV) (or similar) would be a different situation.
JWST is life limited because of propellant needed for station keeping and desaturation. Before the observatory’s propellant is completely consumed, a MEV could attach to Webb’s launch adapter ring, and do as its name implies -extend the mission. As I recall, NG added a guidance fiducial
to the adapter ring to aid any future docking of a MEV
Dr Davis comment and my reply to it, were regarding crewed vehicles. Obviously a modified LM Mission Extension Vehicle (MEV) (or similar) would be a different situation.
JWST is life limited because of propellant needed for station keeping and desaturation. Before the observatory’s propellant is completely consumed, a MEV could attach to Webb’s launch adapter ring, and do as its name implies -extend the mission. As I recall, NG added a guidance fiducial
to the adapter ring to aid any future docking of a MEV.
JWST does have it’s own thrusters for maintaining attitude. So that shouldn’t matter.
What shouldn’t matter?
Attitude (pointing) is controlled by momentum wheels. The observatory’s hydrazine thrusters are for station keeping and desaturation (aka unloading) of the momentum wheels.
Again, a NG MEV could extend the life of Webb once the onboard propellant is nearing exhaustion. The MEV’s mass would alter the cg of the s/c (“like flying with an elephant on our back”) which may shorten the life of the momentum wheels somewhat.
The thrusters “from a messy manned s/c” contaminating the mirror.
JWST has thrusters and those thrusters could also contaminate the mirror.
If one is of no concern neither should the other.
I said “the typical outgas products” from a messy manned s/c. In a vacuum, organic materials outgas, I leave it as an exercise for you to read up on that.
Compared to a small unmanned s/c that can be carefully designed then subjected to “shake n bake” before launch, a manned vehicle is a comparative pig pin.
Keeping optics clean on ISS is a constant battle, you may (or probably not) recall the bru ha ha from Dragon contamination concerns at ISS. Avoiding outgas products on Webb’s mirror, is an orders of magnitude more difficult problem.
https://uploads.disquscdn.c…
Nice image of Dragon, Did you mean to give a URL to the article itself ?
Wasn’t that about contamination inside the ISS ?
A live URL would cause my message to be blocked.
The contamination issue was over the SAGE III UV instrument, which is an external payload.
The problem turned out to be the paint on the Dragon’s trunk structure. The application formula and process where changed to reduce outgassing
A mistake in a similar sense that neither Vulcan nor Ariane 6 will be reusable (or fully reusable in the case of Vulcan). The space industry has been slow to move away from expendable rockets and satellites. Partly because no one was doing it, so no one had to do it. That is now starting to change.
The Space Shuttle demonstrated both reusability and satellite servicing, but the takeaway for the industry seemed to be that neither idea was cost effective. It took a visionary like Elon Musk who was willing to gamble his own money to prove that if done correctly reusability could be cost effective. But even though the larger traditional companies now realize that this is the future, it will take time for them to completely change course.
In a similar manner the recent success of the MEV project has started to open up the idea of cost effective satellite life extension. Although they had to kludge their approach since existing satellites were not designed for it. And it may take another visionary to prove that satellite servicing can be cost effective in at least some situations, which will then hopefully lead to more satellites being built with servicing in mind, or at least built for easy retrieval for return to Earth by Starship, in the eventuality that Starship proves to be extremely cost effective for that type of mission.
I’m still kinda confused why you can have a clamp band let go and only have a one-week slip. Surely the clamp band has to be replaced? And I’d also think that the clamp-band catcher, which is an integral part of the PAF, could possibly be damaged. Does RUAG just have pre-qualified clamp bands just lying around, ready to go? Same thing for PAFs?