Hubble Space Telescope is back online after software glitch
space.com
space.com
I used to do the same when I did software development “I will be done with that in 2 days” then proceeded to build the thing in 2 hours chill 3-4 hours and hand it in earlier than expected. Everyone was happy.
Additionally as another case, Hubble has been continuously losing gyroscopes since it was first launched. Some or all gyros were replaced during most shuttle servicing missions. Seeing the writing on the wall for servicing missions post-Columbia, NASA developed software to operate with fewer gyros at a time, allowing for fewer to be spun up at any time, but importantly, allowing for the telescope to continue to operate after more than 3 of 6 gyros had failed. The key here is that engineers can often coax more performance out of a damaged (or otherwise limited) subsystem given the incentive- this has been the case in my aerospace experience, and seemed mirrored with Hubble too.
I think that's an unnecessarily pessimistic take. Any system can have its life expectancy modeled over a range, e.g. a 99% chance it will survive 1 month but only a 50% chance it will survive to 1 year. When you're just giving one number to the media or other stakeholders, e.g. "expected life span", (or, for that matter, a single estimate to your boss), to be able to give a value with high confidence you will have to pick a number that is in the 99%-ish range, which means there is a good chance your system will survive much longer.
As to your related point, I probably wouldn't use the term "scared." But, yes, there are a lot of incentives to meet/exceed goals and strong disincentives to fail by not meeting a somewhat arbitrary lifetime of a probe. Of course, some probes have clear primary objectives and you want to hit those but you may not want to "promise" you can hit a bunch of less important secondary objectives as well even if you think you probably can.
On the other end of the spectrum, the Mars programs (lately) were incentivized to do the opposite -- cheap, fast, and good, even if some of them fail.
Different circumstances may call for different incentives.
Great examples of this are Spirit and Opportunity. The latter failed at ~61 times its specified design lifetime.
Having been a small part of some space-mission design and larger science collaborations, I can state with confidence that you really don't want your subcomponent to be the one that causes a failure.
https://en.wikipedia.org/wiki/Galileo_project#High_gain_ante...
[0] https://www.forbes.com/sites/startswithabang/2020/11/04/voya...
The cost of renewing operator contracts is much easier than getting funding for a new mission, and the cost of R&D, launch, and new operations.
Apparently the total cost for Hubble is on the order of 10 billion. That's just a fraction of what a tech company like Apple makes every quarter, so I think it was a totally reasonable expense relative to its discoveries.
And luckily we learned building giant, precise mirrors with 1980s technology maybe wasn't the best decision. The James Webb design is totally different and hopefully less prone to such problems.
Firstly, this is about why solar powered Mars missions (specifically InSight) do not have solar panel cleaning devices, but it touches on how missions can be extended and what thinking goes into that.
Robotic missions to Mars are competed like any other; they have to "earn" their chunk of the budget by being effective science missions at effective prices. This causes a very normal tension between "do a lot" and "don't cost a lot".
InSight in particular is part of the Discovery program at NASA, which technically has a cost cap of around $500M. Program managers thus do everything they can to reduce the cost without sacrificing science. You want to avoid taking instruments off, for example.
One really effective way to reduce scope is to shorten missions. This has two big benefits:
1) Every year a mission doesn't operate is a year you don't have to pay salaries for those who operate it
2) Hardware on the spacecraft can be made cheaper if it doesn't have to last
That second point is really critical.
The testing program you have to put stuff through doesn't scale linearly. A mission that lasts twice as long costs more than twice as much to test. It spirals fast.
In InSight's case, they also saved money by reusing a spacecraft bus design from the Phoenix mission, which was also designed for a short mission - just 90 sols in fact.
See the similarity?
So all of these reasons (staying under cost cap, reducing operation cost, reducing testing costs and saving money by reusing spacecraft busses) combined to drive a decision that InSight's prime mission is just 1 Martian Year (about 2 Earth Years), which it completed in November.
So the short answer to "why not add solar panel cleaning devices" is that they don't need them!
By the time the dust takes down the spacecraft, it will have completed its mission. It's an element of disposability, though NASA probably wouldn't characterize it that way.
Now, often the vehicles last longer than their prime mission. Spirit and Opportunity, for example, blew past their prime mission of 90 sols. All of NASA orbiters (ODY, MRO, MAVEN) have gone past their prime mission, too. Last November, InSight also surpassed its prime mission.
When this happens, NASA reevaluates the vehicle's health & cost against further science it can do, and decides to either re-fund or end a mission.
InSight got the funding, and so here we are making the best of that!
NASA isn't scrambling to save a mission hampered by dust they forgot existed. They're doing their best to squeeze out more return on investment for the taxpayer on a spacecraft that has already completed its mission!
0: https://twitter.com/We_Martians/status/1360340875440578560
> By the time the dust takes down the spacecraft, it will have completed its mission. It's an element of disposability, though NASA probably wouldn't characterize it that way.
I don't think that's a very compelling answer. The thing to ask, I guess, is whether they would have added them anyway if they were very cheap and lightweight.
If yes then "it was a waste of resources for the designed mission" hits much closer to the real reason. But if no, it means the real reason is "bureaucratic maneuvering caused a longevity problem on purpose" which is really bad.
I'm not sure what the current plans are, but the last servicing mission installed the Soft Capture Mechanism, and the current understanding is that an uncontrolled re-entry would pose an unacceptable risk to human life. So, it seems like there is still a chance to put it in a musuem.
I think one driver for the enormeous cost of a lot of space missions is the amount of overdesign happening as due to the high costs, failure is not an option. Just designing for 5 years and allowing for the early failure, costs should be so low that a failure is no longer a big issue.
Also, if there is one basic platform, sending different telescopes with quite different sensor packages would be an option.
Considering that a single shuttle launch costet close to 1 billion and the Webb telescope costs many billions, spending 1 billion on a set of 5 telescopes including launch costs sounds like a worthwhile program. Which could be scaled to more telescopes as long there is budget.
Current and future telescopes target 10-30m mirrors, purely for light capture reasons. We’d need to put something that big in space for it to be worthwhile.
There are several aspects we could improve on the current situation: make "better" telescopes or make more telescope. Having only 1, soon 0 space-based telescopes is cutting it very thin. Having 5-10 would increase our research a lot as more things could be observed.
Of course, eventually there will be a need for large space telescopes too, probably those will be enabled by Starship. But first we should use the currently available technology to make sure we don't fall back into the level of the 80ies when Hubble dies. And use modern technology to make this a "cheap" effort vs. the extremely expensive Hubble.
You are correct - the NIR is blocked by the atmosphere. That is why we are launching Webb. Optical, however, is very much now the domain of ground-based astronomy.
Apparently they went the other way and instead of multiple Hubble-equivalent telescopes they build one which has equivalent sharpness of images but a much larger field of view, so can take images 100 times as large as what Hubble can.
https://en.wikipedia.org/wiki/Nancy_Grace_Roman_Space_Telesc...
> Also, if there is one basic platform, sending different telescopes with quite different sensor packages would be an option.
Satellites are usually designed around an integrator's platform, called "bus". https://en.wikipedia.org/wiki/Satellite_bus
https://www.eso.org/public/images/ann13071c/
Huge instruments like these that actually power today’s science is another reason why ground based astronomy is required, and why we can’t just move all observation to space if satellite clusters ruin the night sky.
And yes, I am aware of the challenges of space-going equipment. But if a system is designed for a life time of rather 5 than 30 years, things become a bit easier. Also, if you look at the camera equipment of Perseverance, a lot of it is off-shelve, only slightly enhanced for its intended purpose.
Also your claim about the instruments on Hubble is incorrect.
See: https://www.nasa.gov/content/goddard/hubble-space-telescope-....
Hubble is 30 years old, and there isn't any direct replacement in sight at all. At latest now, with cheap launches and much improved technology, it is more than time to replace it and as it is more or less a direct replacement, use the scale of production. Don't build one telescope for 3 billion, build 10 at like 100-200 million each. If one ore more of them fail, so what?
In many ways, to move forward, we must go bigger with the tech, not wider. What you are essentially suggesting is a survey - we already have instruments and telescopes to do exactly that, with new ones coming online soon (see the LSST). Deep observations like Hubble was meant to do can actually be done better from the ground now (e.g. the VLT, ELT, etc.). As such, focus has shifted to those for optical observations.
The community at large, however, has decided where it would like to spend its budget. That was on Webb for the IR wavebands, to study so-called 'high redshift' objects that Hubble struggles to see, and leave the more detailed imaging to those ground based observatories.
Look, I would love another Hubble. That would be really useful! And that's why WFIRST exists. But an in-place replacement doesn't make sense. The tech on Hubble (not necessarily the mirror, but the _instruments_, the spectrographs, the interferometers) is really old. You can't take an off-the-shelf component, because it needs to be built to withstand space. So you need to create a one-off, 'prototype', space-hardened instrument. It is also not a case of worrying about them 'failing', but you also must worry about them slowly drifting out of a calibrated range. On the ground, you could fix the instrument, or re-calibrate it. That's not possible in space. That's not a 'random' style error, where we can get out of it by upping the number of them - they are systematic, so all 10 of your proposed telescopes would be ruined.
I wonder what it would take to have a Commercial Orbital Servicing type system. Shove a Canadarm onto a X37B and fix the bastard
There's a fair amount of room in those trunk sections for any gear or parts they need to bring up, too. I guess my biggest concern would be whether the hatches are big enough for real EVA suits to get in and out easily, and whether the life support system can support multiple repressurizations without significant modification. They might also need to modify the docking adapters, which are "supposed" to be androgynous but IIRC actually aren't.
* It's being deployed at L2 Lagrange point instead of LEO - so the launch costs are even higher.
* HST had the insurance of knowing that repair was possible - JWST does not (both due to it's location and lack of capability) and so everything drags on even more to try to reduce risk
* JWST is technically more complicated. The thermal management system needed, and entire origami unfolding mechanism alone would make it more complicated and expensive. This doesn't even start looking at the optics.
Originally targeted to launch in 2020, the project has encountered delays, and NASA is currently aiming for January 2025 as the launch date [1]
[0] https://nexis.gsfc.nasa.gov/OSAM-1.html
[1] https://sma.nasa.gov/docs/default-source/sma-disciplines-and... page 4
hubble: recovers after software glitch rustafarians: