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And can introduce unusual failure cases for these bespoke missions. Mars Observer was lost in flight to Mars three decades ago, probably because of the inapprop

And can introduce unusual failure cases for these bespoke missions. Mars Observer was lost in flight to Mars three decades ago, probably because of the inappropriate reuse of a satellite rocket engine. (1) The space environment out around Jupiter is really quite different from the environment that the JWST is facing around E-S L2 or what the Parker Solar Probe is facing right near the Sun. Even if the component is spec'd to handle the environment, you need to have actual educated humans (read: expensive labor) determine what those conditions will be, and then verify that the part will meet it, and that's where the money goes- to pay all of those humans. If you built even 15 Europa Clippers the cost per-item would come down enormously (because all of those people's work could be re-used), but since the 1970's NASA has not had the budget for multiple probes per missions. So every mission is bespoke, and has to be done again completely from scratch. 1: The engine was normally used for circularizing the orbit of a geosynch comm satellite, so within a few hours of flight. For doing a Mars Insertion burn it needed to sit fueled for months in outer space, which was not appropriately tested, and probably the fuel tank exploded in flight because of that.

quotemstr 2y ago
Yeah. I'm surprised that we don't have a standard deep space probe bus by now in at least serial production, at least for orbiters if not landers, rovers, and such. Each mission has unique requirements, but since payload mass costs are coming down, ISTM it should be possible to create a standard buss that meets most requirements most of the rime, even if it's heavier than a bespoke effort for any one mission.
- accrual 2y ago
  There are somewhat standard busses. Though you're correct, many use custom busses for their specific missions. https://en.wikipedia.org/wiki/Comparison_of_satellite_buses https://en.wikipedia.org/wiki/Comparison_of_satellite_buses For example, the SSL 1300 apparently has hosted 118 satellites so far: https://en.wikipedia.org/wiki/SSL_1300 https://en.wikipedia.org/wiki/SSL_1300 Though maybe the distinction between "satellite" and "spacecraft" bears importance here.
- mandevil 2y ago
  For things in Earth orbit (LEO all the way up to GEO) we do have some fairly worked out buses that can keep commercial missions done on budget within the fairly well developed parameters of commercial up to GEO. Have, honestly, since the 1980's. Multiple companies from multiple countries have demonstrated this, there is a competitive market for commsats and earth observing satellites (the only two markets where business cases really close). If you are doing science from LEO you can probably re-use a lot of components from those markets. For exploration missions and anything in deep space (basically, beyond Lunar Orbit) people have kicked around ideas for common buses, there have been plenty of proposals, but no one seems to have enough value in them to be the third or fourth user of one- everyone has found it better to start from scratch than use someone else's bus design. It is possible if there was a sustained, focused effort at one kind of project, say, something where Mars orbiter launches were guaranteed every 26 months for more than a decade, that the investment in a common bus might pay off. But as long as we are bouncing between Mars, Jupiter, Pluto/KBO's, E-S L2, and inside Mercury's orbit, it just isn't actually reusable. Just as one point, until the past few years everything in the outer planets had to be RTG powered, which requires a totally different design than something solar. It was only with Juno (and now the Europa Clipper) that solar has been demonstrated for outer planets at all, and it is still not exactly a design you'd have off the shelf, nor would the power design you'd want for outer planets solar be at all similar to the design you'd want for inner planets solar. The same is true for comms, for thermal management, for rad-hardening, etc.
dom96 2y ago
> So every mission is bespoke, and has to be done again completely from scratch. Is there room here for making things more reusable? For example, instead of creating one big satellite with tens of instruments, how about they create 10 satellites with one instrument each? or would that still be too bespoke to lower the cost per item?
- philistine 2y ago
  While we now live in an era of abundant rocket launches, it used to cost far more to launch with very few launches per year. The whole strategies of exploration haven’t shifted yet to this new paradigm. Hopefully NASA starts making smaller probes and launching them far more often.
  - mandevil 2y ago
    Europa Clipper is literally the largest thing ever launched to the outer planets (so big that Falcon Heavy can't be reused for this mission, they have to throw it all away in order to get every last jot of performance out of the rocket- so this is not an "abundant rocket launches" situation- this is a fully expendable rocket just like an Atlas V). And the size is not for fun, but because going close to Europa (the entire point of the mission) means going through the second strongest set of EM and radiation belts in our solar system. Even with this size- meaning it can have a lot more shielding than normal- the probe can only survive a few months of the radiation from Jupiter's van Allen belts. The plan is to break that few months of exposure up over about four years of calendar time, by having it do highly elliptical orbits so it stores a lot of data during a close flyby of Europa and then transmits that all back to Earth while it is far outside of Jupiter's radiation storm, then it can head back down and collect more data. And that lengthy transmission time is because it is sending information from so far away- and has so little juice that the effective bandwidth is tiny. It is possible for a swarm of small satellites to fill niches in space exploration. Closely studying Europa isn't really one of them with today's technology.
    - solarwindy 2y ago
      Not quite fully expendable. Commentary during the livestream was that they’ll recover the fairing, for what it’s worth.

quotemstr 2y ago

Yeah. I'm surprised that we don't have a standard deep space probe bus by now in at least serial production, at least for orbiters if not landers, rovers, and such. Each mission has unique requirements, but since payload mass costs are coming down, ISTM it should be possible to create a standard buss that meets most requirements most of the rime, even if it's heavier than a bespoke effort for any one mission.

accrual 2y ago
There are somewhat standard busses. Though you're correct, many use custom busses for their specific missions. https://en.wikipedia.org/wiki/Comparison_of_satellite_buses https://en.wikipedia.org/wiki/Comparison_of_satellite_buses For example, the SSL 1300 apparently has hosted 118 satellites so far: https://en.wikipedia.org/wiki/SSL_1300 https://en.wikipedia.org/wiki/SSL_1300 Though maybe the distinction between "satellite" and "spacecraft" bears importance here.
mandevil 2y ago
For things in Earth orbit (LEO all the way up to GEO) we do have some fairly worked out buses that can keep commercial missions done on budget within the fairly well developed parameters of commercial up to GEO. Have, honestly, since the 1980's. Multiple companies from multiple countries have demonstrated this, there is a competitive market for commsats and earth observing satellites (the only two markets where business cases really close). If you are doing science from LEO you can probably re-use a lot of components from those markets. For exploration missions and anything in deep space (basically, beyond Lunar Orbit) people have kicked around ideas for common buses, there have been plenty of proposals, but no one seems to have enough value in them to be the third or fourth user of one- everyone has found it better to start from scratch than use someone else's bus design. It is possible if there was a sustained, focused effort at one kind of project, say, something where Mars orbiter launches were guaranteed every 26 months for more than a decade, that the investment in a common bus might pay off. But as long as we are bouncing between Mars, Jupiter, Pluto/KBO's, E-S L2, and inside Mercury's orbit, it just isn't actually reusable. Just as one point, until the past few years everything in the outer planets had to be RTG powered, which requires a totally different design than something solar. It was only with Juno (and now the Europa Clipper) that solar has been demonstrated for outer planets at all, and it is still not exactly a design you'd have off the shelf, nor would the power design you'd want for outer planets solar be at all similar to the design you'd want for inner planets solar. The same is true for comms, for thermal management, for rad-hardening, etc.

dom96 2y ago

> So every mission is bespoke, and has to be done again completely from scratch. Is there room here for making things more reusable? For example, instead of creating one big satellite with tens of instruments, how about they create 10 satellites with one instrument each? or would that still be too bespoke to lower the cost per item?

philistine 2y ago
While we now live in an era of abundant rocket launches, it used to cost far more to launch with very few launches per year. The whole strategies of exploration haven’t shifted yet to this new paradigm. Hopefully NASA starts making smaller probes and launching them far more often.
- mandevil 2y ago
  Europa Clipper is literally the largest thing ever launched to the outer planets (so big that Falcon Heavy can't be reused for this mission, they have to throw it all away in order to get every last jot of performance out of the rocket- so this is not an "abundant rocket launches" situation- this is a fully expendable rocket just like an Atlas V). And the size is not for fun, but because going close to Europa (the entire point of the mission) means going through the second strongest set of EM and radiation belts in our solar system. Even with this size- meaning it can have a lot more shielding than normal- the probe can only survive a few months of the radiation from Jupiter's van Allen belts. The plan is to break that few months of exposure up over about four years of calendar time, by having it do highly elliptical orbits so it stores a lot of data during a close flyby of Europa and then transmits that all back to Earth while it is far outside of Jupiter's radiation storm, then it can head back down and collect more data. And that lengthy transmission time is because it is sending information from so far away- and has so little juice that the effective bandwidth is tiny. It is possible for a swarm of small satellites to fill niches in space exploration. Closely studying Europa isn't really one of them with today's technology.
  - solarwindy 2y ago
    Not quite fully expendable. Commentary during the livestream was that they’ll recover the fairing, for what it’s worth.