Design Lessons from MOST?

On 23 Jul 2006 18:08:26 -0400, Chris Jones wrote:

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Given that you've been posting from spsystems.net for several months
now, isn't it time for a new sig?

....Good point. It's been too long since Henry provided a new .sig for
us to admire. Then again, maybe it's time one of us did Henry a favor
and come up with a new one for him. How about it, Henry? Winner gets a
special commemorative t-shirt award for their efforts?

OM
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"Henry" == Henry Spencer writes:

Henry In article ,
Henry John Stoffel wrote:
Now that it's been a few years, what lessons have we learned from MOST
in terms of designing and operating small satellite busses? And their
instruments? I heard a whole bunch about it early on, but nothing
recently...

Henry Unfortunately, MOST suffers from the same PR problem as a lot
Henry of small spacecraft: there isn't money in the budget for a lot
Henry of paper writing! Maybe if it had failed early, but it
Henry hasn't... Three years into the one-year mission :-), there
Henry have been a few problems but nothing deadly.

That's kinda where I was trying to get at, what kinds of technical
problems have you run into and what would you do differently
(incrementally changed I assume...) the next time around with a
similiar type of mission?

Henry I guess the overall lesson is that you really can do a
Henry substantial science mission, using the Amsat design philosophy,
Henry on a ridiculously small budget... given the right management,
Henry the right lead scientist, and a funding agency that's willing
Henry to try a relatively hands-off approach. (That last is
Henry important; CSA's MOST "program office" was one guy, and he made
Henry no attempt to micro-manage the project. Unfortunately, despite
Henry the success of this approach, it's not clear that CSA would do
Henry that again.)

I attended the AmSat talk at LISA in San Diego last year and I was
impressed by the work that they have done. I'm not into Amateur Radio
though, so I'm not sure what I could provide in terms of help. But
anyway, I found it interesting how much they were able to do,
especially early on in space race. I recall the first AmSat was
launched in the late 50s? Something like 4 years after Sputnik?

Anyway, could the MOST chassis be re-used as is, and just the science
payload swapped out? That seems to me to be the holy grail. Provide
a standard bus with plugs and bolts of sensors. The bus doesn't
change at all, it's the sensors which need to change/adapt to the
bus.

This would make it much easier for bunches of missions to be flown,
with bunches of sensors. You could setup simulators ahead of time,
have decent models of the bus and it's interactions in the
environment, etc.

I can see how a fields craft could have different requirements from a
star sensor (MOST?) type, and different from a sample return mission
type. By making them all fit into a standard envelope, you push the
design costs out to the people who are best able to handle them. Make
the bus robust and flexible in terms of data/power/control, but don't
change it at all.

It's like containers. You can't change from the default sizes without
a major increase in costs. So people design packaging to fit within
the envelope, even if they leave 10% (or more!) of the space empty,
the costs aren't worth it to grab every last percentage.

To me, it seems like using the same bus for Mars missions, for Luna
missions, etc would make life so much simpler. The mission control
part splits nicely into the cruise/orbital parts, and then the science
part is it's own thing. You could then have multiple science teams
sharing a dedicate Systems Bus support team. Cost savings all around!

So, back to MOST. Do you think that a future mission from CSA could
use the basic MOST platform and just go with it?

John

On Mon, 24 Jul 2006 09:55:23 -0400, John Stoffel
wrote:

recall the first AmSat was
launched in the late 50s? Something like 4 years after Sputnik?

....Lessee: 1957 + 4 = 1961 /= "late 50's"



OM
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] OMBlog - http://www.io.com/~o_m/omworld [
] Let's face it: Sometimes you *need* [
] an obnoxious opinion in your day! [
]=====================================[

"OM" == OM writes:

OM ...Lessee: 1957 + 4 = 1961 /= "late 50's"

Yeah yeah... so I got it wrong. What can I say, I wasn't even around
when they all launched. *grin*

Jeff Findley wrote:

(That last is important; CSA's MOST "program office" was one guy, and he
made no attempt to micro-manage the project. Unfortunately, despite the
success of this approach, it's not clear that CSA would do that again.)


...Yeah, well, that's how the Cub Scouts of America work. They let the
kids get it right the first time, then the mothers get involved and
totally screw things up.



WTF? I've no idea what you're talking about here. To the extent that
fathers think that mothers "screw up" Cub Scouts is as much their fault for
not being leaders as it is the mothers for being leaders.



If the CSA had gotten it right the first time, they would have pressed
their advantage at Bull Run and marched on Washington.
But then J.E.B. Stuart's meddling mother got involved, and the rest is
history. :-)

Pat

In message
John Stoffel wrote:

Anyway, could the MOST chassis be re-used as is, and just the science
payload swapped out? That seems to me to be the holy grail.

That's the philosophy behind the SSTL satellites. They do have more than
one design of basic bus, but the difference is mostly in size. Small,
very small, incredibly small and "You can get a functional satellite in
that?" size.

Anthony

"Henry Spencer" wrote in message
...
In article ,
But according to NASA, dozens of low-cost satellites with hundreds of
satellite-years working in orbit are all an accident -- "it's an anomaly"
were the words used at a CHIPSat review meeting (confirmed by multiple
witnesses). So Derek is in good -- well, at least distinguished --
company in thinking that the Emperor just *can't* be standing there
naked, and therefore somehow isn't.
Or possibly the Emperor is standing there convinced that the peasants are
all naked...

In article ,
OM wrote:
...Good point. It's been too long since Henry provided a new .sig for
us to admire...

Rest assured, there will be a more interesting signature as soon as the
ISP/domain mess finally gets sorted out...
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spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

On Wed, 26 Jul 2006 15:47:17 +0000, Henry Spencer wrote:

(Ever curious, the zapkitty pokes his nose
in the door...)

Rest assured, there will be a more interesting signature as soon as the
ISP/domain mess finally gets sorted out...

Can you say what happenned? If you say *you*
are being stymied in a net prioblem I must
assume it's something interesting...

--
Chuck Stewart
"Anime-style catgirls: Threat? Menace? Or just studying algebra?"

In article ,
Chuck Stewart wrote:
Rest assured, there will be a more interesting signature as soon as the
ISP/domain mess finally gets sorted out...

Can you say what happenned? If you say *you* are being stymied in a net
problem I must assume it's something interesting...

Nah, not really, just frustrating.

I started out, years and years ago, with a small, technically competent
ISP. By and by, they got absorbed by somebody else, who got absorbed by
somebody else. Which wasn't a big deal -- every now and then the company
name and address on the bills changed, no problem -- except that somewhere
along the way, the details of my original deal got forgotten somehow. So
long as nobody messed with things, it all just kept on working. I did see
signs that I'd sort of been forgotten (except by the billing department,
of course), but I could see that sorting this out would be a hassle, and
doing something about it always seemed to be low priority. Big mistake.

Then the company decided to basically get out of the ISP business. They
passed their customers along to another... but not the infrastructure.
So now the old gear got closed down, and being half-forgotten suddenly
mattered. The new company was fine with setting me up with a simple
ordinary-user account, but the old stuff like an IP address block, DNS
service, etc. was going to take negotiations and money (and if I was going
to have to start from scratch, I wasn't at all sure I wanted to deal with
these particular people). Worse, my old *domain* was still entangled with
the remnants of the old company.

The real problem is simply that it's going to take time and energy for a
lot of phone calls and hassle, plus a certain amount of cash, to get all
this sorted out, and those have been in short supply. What's been needed
is a while with things on an even keel, no great crises needing to be
dealt with, no imminent travel about to put everything on hold, and a
reasonable cash reserve. A week from now (after one last short trip),
these factors should all finally come together.

(In hindsight, quickly getting that ordinary-user account may have been a
mistake. I'd have been more motivated to sort this all out fast if I'd
had no connectivity. Clumsy and awkward connectivity, I could sort of
live with, so arranging a real fix got postponed.)
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spsystems.net is temporarily off the air; | Henry Spencer
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