PBS's "Nova" and MER

On Fri, 09 Jan 2004 02:02:07 +0000, Greg D. Moore (Strider) wrote:


"Chris Jones" wrote in message

Ooh, could we get a shot of these six-fingered hands?!?

Let me guess, you don't count in binary on your fingers?

Heck you can count in base 4 unless you have arthritis!

Chris Jones wrote:

Ooh, could we get a shot of these six-fingered hands?!?

Count Rugen! You killed my father -- prepare to die!

In article m,
com says...
Finally, i worried not at all about loading software after the hardware went
up. Software is just that, soft. They had the device here, software can be
tested. If the hardware is designed correctly, software follows the form. I
design software for a living, and I know who's boss: reality, not me.

Dijkstra was perhaps the first to realize that we build computers to
execute our programs, not the other way around. Software is soft in the
sense it is easy to change. Yet experience shows that it is *hard* to
make the software correct. It is usually better to get the software
right and let the hardware guys deal with the implications of that
decision.

Defining the hardware and then leaving all the other issues to be fixed
as "a small matter of programing" is a recipe for disaster. There are
many examples of this...
--
Kevin Willoughby lid

Imagine that, a FROG ON-OFF switch, hardly the work
for test pilots. -- Mike Collins

In article , says...
Pat Flannery wrote:
About the time they started talking about sending the finished landing
software to the spacecraft _after_ they launched, a feeling of deja-vu
hit me;

Perhaps because this isn't all that uncommon for planetary spacecraft.
I believe Magellan did the same thing for one.

Essentially the same thing happened with Einstein.

I once worked with a guy who previously had been an
astronomer/programmer. He explained that they wrote some software, then
took a trip to Cape Kennedy to watch the launch of HEAO-B/Einstein and
then returned home to write the real software for that spacecraft.
--
Kevin Willoughby lid

Imagine that, a FROG ON-OFF switch, hardly the work
for test pilots. -- Mike Collins

In article , says...
I will not even comment on the idea to launch the probes before their
landing software was completed; and then uploading it to them in-flight...

There's nothing particularly wrong with that, if you think of software
uploads as routine practice rather than as a dire emergency measure.

Having good-enough software and making it better in-flight is a good
thing. Launching with inadequate software is scary. Assuming that you
can make the software work after the spacecraft is launched is a "high
risk" philosophy. Software has a habit of being behind schedule. After
launch, there is no chance of fixing a hardware error -- you have to
work around every issue in the software. Once the spacecraft is
launched, the landing software becomes quintessentially "hard real
time", I.e., "the right answer at the wrong time is wrong".


And actually, young is good.

Early in my career, I'd agree with that. Only as I gained experience did
I realize that the best team may be a bunch of young guys and just
enough grey-hairs to keep things under control. (The fact that my head
now has many grey hairs is just a coincidence!)

If you've read Tracy Kidder's Soul of a New Machine, you know that the
Eagle computer was built by a bunch of young kids plus a handful of
grey-hair like Tom West. Kidder dealt with the hardware, but as one of
the guys who built the software for Eagle, trust me: it was mostly kids
like me (at least, back then I was a kid) and a few grey-hairs.

Apollo was mostly young kids, but there were a few folks like von Braun
and Gilruth who had been around for a while.


An unfortunately large fraction of the
middle-aged people at JPL, and NASA in general, are viewgraph engineers
whose net contribution to a fast-paced results-oriented project would be
negative.

Without debating that particular point, I'll note that "middle-aged
people" and "viewgraph engineers" are not synonyms.


(If memory serves, the people picking the Mars Pathfinder team
carefully excluded them.)

Yep. Donna Shirley's memoirs ("Managing Martians") made this quite
clear. She was told to exclude any employee that had been working at JPL
for five years but less than twenty years.
--
Kevin Willoughby lid

Imagine that, a FROG ON-OFF switch, hardly the work
for test pilots. -- Mike Collins

In article ov, Bill
Higgins wrote:

I didn't see the show-- but wasn't a Mars rover originally planned to launch
at the 2001 opportunity? The loss of MPL and MCO caused the Mars program to
fall back and regroup. So maybe they did have extra time, in some sense.

For them as is interested, as of just-pre MCO/MPL:

2001: "Broadly similar" lander and orbiter. Orbiter was to have three
science instruments, and fly from VAFB (it says "west coast", so I
assume...); the lander was to carry a spare Pathfinder rover, a robotic
arm, and other instruments, "including three that will return data in
support of eventual human exploration". (I assume the orbiter morphed
into Odyssey?)

2003: Start of sample-return mission - a lander with rover, to recover
rock samples and place them in a small ascent vehicle. This was to
launch to orbit. ESA and ASI were to provide an orbiter, which is
presumably what became Mars Express, and may have been going to provide
lander instruments. There may have been a NASA/CNES "micromission"
spacecraft, as well, to deliver "small payloads such as a robotic
airplane or a small telecommunications orbiter"

2005: Ariane V launches a CNES orbiter and NASA lander/rover. The lander
will perform the same mission as before, putting samples in orbit; the
CNES orbiter will retrieve both samples, and "return them to earth in a
vehicle provided by NASA". There may be two further "micromission"
collaborations, and there was a prospect of the CNES craft also carrying
four "netlanders" (small seismo stations?)

2007-9: Essentially rinse and repeat the sample-return missions, it
seems.

[source - the MCO press kit]

--
-Andrew Gray

In article ,
Andrew Gray wrote:
For them as is interested, as of just-pre MCO/MPL:
2001: "Broadly similar" lander and orbiter. Orbiter was to have three
science instruments, and fly from VAFB (it says "west coast", so I
assume...); the lander was to carry a spare Pathfinder rover, a robotic
arm, and other instruments, "including three that will return data in
support of eventual human exploration". (I assume the orbiter morphed
into Odyssey?)

The orbiter *is* Odyssey. There were no significant changes in that part
of the plan. The lander was canceled after the loss of MPL, because of
fears that it might share whatever flaw had killed MPL. (The hardware is
now being recycled into the Phoenix lander.)

2003: Start of sample-return mission - a lander with rover, to recover
rock samples and place them in a small ascent vehicle. This was to
launch to orbit. ESA and ASI were to provide an orbiter, which is
presumably what became Mars Express...

Nope. Whatever ESA was going to provide for that mission was canceled.
Mars Express was ESA's first faster/better/cheaper experiment, a small
Mars mission put together on a (relatively) low budget and a (relatively)
short schedule with (relatively) little bureaucracy.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

In article ,
Scott Hedrick wrote:
(It'd be an interesting detail to see a list of what *is* sitting in the
clean rooms with no definite plan for the future...)

As to *unclean* rooms, I seem to recall reading many years ago (10+) that
the Navy reclaimed a satellite that had been hanging in the Smithsonian for
several years and successfully flew it.

So long as there aren't any serious optics involved, the need for clean
rooms for space hardware is much exaggerated. The practice of doing
everything in clean rooms was a quick fix for some early problems on
spacecraft which did have optics, and when it appeared to work, it quickly
became entrenched superstition.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

In article ,
Kevin Willoughby wrote:
There's nothing particularly wrong with that, if you think of software
uploads as routine practice rather than as a dire emergency measure.

Having good-enough software and making it better in-flight is a good
thing. Launching with inadequate software is scary. Assuming that you
can make the software work after the spacecraft is launched is a "high
risk" philosophy.

There is always a chance of finding a hardware problem after launch, when
it cannot be fixed and you just have to hope it can be worked around. The
flip side, though, is that it gives the software developers more time.
The alternative is to insist that the software must be officially finished
before launch, while privately conceding that it may have to be fixed up
afterward because of the tight schedule; this does not actually strike me
as an improvement on letting the developers do the job right once.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

"Greg D. Moore \(Strider\)" writes:

"Chris Jones" wrote in message
...
(Derek Lyons) writes:

[...]

g It's a *big* job. (Counts on fingers.... ) I can think of a dozen
or more things just on my boat that required accurate alignment.

Ooh, could we get a shot of these six-fingered hands?!?

Let me guess, you don't count in binary on your fingers?

Good guess. I count in my head, type with my fingers.