Author Topic: Multiple probes on the new LV  (Read 14506 times)

Offline JohnFornaro

  • Not an expert
  • Senior Member
  • *****
  • Posts: 10974
  • Delta-t is an important metric.
  • Planet Eaarth
    • Design / Program Associates
  • Liked: 1257
  • Likes Given: 724
Re: Multiple probes on the new LV
« Reply #40 on: 09/04/2010 09:04 pm »
Why should the probes need to be the same?
They don't need to be exactly the same.  They would be similar, and would use common elements.

The argument is not applicable either way.  Space station elements are not interplanetary spacecraft

ISTM that in principle, the argument is applicable.  In a grocery bag, I can put apples or oranges, or a combination thereof.  Heck, I could have a bag of hammers.  The launch vehicle could, within reason, have multiple similar objects in it.  And certainly a MIRV-able series of probes is not out of the question.
Sometimes I just flat out don't get it.

Online MP99

Re: Multiple probes on the new LV
« Reply #41 on: 09/05/2010 10:48 am »
In a grocery bag, I can put apples or oranges, or a combination thereof.

That seems to imply that the apples & oranges will be going to the same house (planet).

Although they could easily go to different fruit bowls (moons) once they reach the house (planet).

cheers, Martin

Offline Nathan

  • Member
  • Full Member
  • ****
  • Posts: 710
  • Sydney
  • Liked: 16
  • Likes Given: 3
Re: Multiple probes on the new LV
« Reply #42 on: 09/05/2010 11:45 am »
Quote
JPL can only do one large science spacecraft at a time...

And these old dogs can't learn the now trick of doing four quarter sized spacecraft at a time?  Or is it rather that they won't consider the idea in the first place?

The nature of the various objections seems to be an objection of will for the most part.  The alternative will not be discussed.  Therefore it can not be attempted.

Well, there's yer answer Lobo.  It would appear that we'll have to wait til someone at JPL comes up with the idea.  Then, it will have been invented there.

wrong, wrong, wrong

When I said " one large science spacecraft", I am talking about Titan IV/Delta IV heavy class spacecraft, Cassini, MSL, JWST, etc., which is the "quarter sized spacecraft" you are referring to.
Now you want to do four of these at once.  Need more assembly buildings, test facilities, thermal vac chambers, etc
That is what I meant by "overwhelm our facilities "  It has nothing to do with the institutions and the organizations.


Ok. So if we are to have multiple probes on the one LV then a consequence is that we will need new probe manufacturing and testing facilities.
That's fine and is almost implied if one thinks about it.
Given finite cash, if we want to go to Mars then we should go to Mars.

Offline JohnFornaro

  • Not an expert
  • Senior Member
  • *****
  • Posts: 10974
  • Delta-t is an important metric.
  • Planet Eaarth
    • Design / Program Associates
  • Liked: 1257
  • Likes Given: 724
Re: Multiple probes on the new LV
« Reply #43 on: 09/05/2010 02:33 pm »
That seems to imply that the apples & oranges will be going to the same house (planet).

Although they could easily go to different fruit bowls (moons) once they reach the house (planet).

From the OP:

Quote
The larger vehicle, combined with multiple probes on similar platforms, might be able to send, say, four probes to Saturn.  Each sub-mission profile would look more carefully at a subset of the moons, the rings, and the surface weather patterns, say.  The bandwidth would be four times higher, since probes could time their various orbital insertions and data transmission times.  It would open up quite a different way of going about robotic surveying missions.   

Yes, not only would that be an implication, but it would also be explicitly stated.  I thought about the grocery bag analogy for a bit this morning.  The grocery bag is one of those "green" re-usable bags.  Problem is, they cost $1000 a pop, and the apples and oranges ain't cheap either.  The DIRECT people, say, are suggesting that they can get the cost of the bag down to $500, which is great, but still ain't cheap.  Therefore, we should fill the bag with all that expensive fruit each time, and choose carefully where we send that fruit.

Two missions that came to mind immediately to me were first, that polar orbiting comsat constellation around the Moon which I sketched out in another thread.  The one which initially will support the operation of the polar prop plants, and early polar outposts; and which ultimately might grow into a solar power generation scheme for those polar activities.

The second, of course, would be the multiple probes and comsats bound for Mars to determine the exo-biology question beyond a reasonable doubt, so that future policies can be factually based.

As to facilities, I'm not sure where JWST is being made or where Cassini and all were made, but I'll hazard a guess that we don't need a new building at first, just as we don't need a new launch tower for the new LV first.  Whatever huge vacuum facility that JWST was tested in will have to do.  I will object to the type of suggestion that, for example, the crane therein needs a new strap configuration to support and test the new probe, therefore we need a new building. 

I don't know what the timeline for constructing these things is either, but it is clear that probe 1 can sit in a warehouse until probe 4 is finished.  The ideal timeline would be that probes 1 thru "x" can be ready to go in exactly the time needed to build the new LV.
Sometimes I just flat out don't get it.

Offline sbt

  • Veteran
  • Full Member
  • ***
  • Posts: 328
  • Liked: 1
  • Likes Given: 0
Re: Multiple probes on the new LV
« Reply #44 on: 09/05/2010 02:34 pm »
In my opinion the question is the wrong one.

The proper question should be:

Can the characteristics of the SLS be employed to to do one or both of:

a) Reducing the cost of one or more Planetary Missions

b) Improving the science take of (or even enabling) Planetary Missions.

Note that:

a) I say 'characteristics' - there are volumetric and geometric
differences as well as mass differences in the SLS capability compared
to existing systems

b) I say 'Missions' - meaning that launch and operational costs are
included.


Multiple payloads on a single launch are only one way that this might
be achieved. For example other possible approaches include (and are not
limited to):

i) Would the geometry allow larger antenna, or the mass larger power
sources, to be flown and would this reduce the DSN capacity
required to manage the mission?

ii) Could costs be reduced by designing to less tight mass/volume
constraints (including upping the last stage capability to match any
increase in probe mass)?

iii) Could risk be reduced through probe redundancy, either within a
single, larger, probe or via multiple probes on similar tracks?

iv) Could costs be reduced by employing, for small probes, 'parasite'
launch opportunities on launches for other purposes that do not require
the full launcher capability?

(v) Could the manned mission certification and, perhaps, escape
capability be employed to reduce the, real or perceived, risk of
launching large radioisotope generators or reactors as power sources?

Rick
« Last Edit: 09/05/2010 02:35 pm by sbt »
I am not interested in your political point scoring, Ad Hominem attacks, personal obsessions and vendettas. - No matter how cute and clever you may think your comments are.

Offline clongton

  • Expert
  • Senior Member
  • *****
  • Posts: 12053
  • Connecticut
    • Direct Launcher
  • Liked: 7348
  • Likes Given: 3749
Re: Multiple probes on the new LV
« Reply #45 on: 09/05/2010 02:45 pm »
Perhaps it's a matter of perspective.
For example, was Cassini considered 1 probe or 2?
It was certainly 1 mission.

Consider both Viking missions to Mars.
While popular attention is on the landers, each mission consisted of a lander and an orbiter.
So was Viking 1 probe or 2?
Certainly each was a single mission.

If we look at it from the perspective of a single *large* mission (say 70mT for example), and then give it several distinct sub-missions, like a couple of uniquely different landers and 2 or 3 uniquely different orbiters, all designed to study a single destination from several very different perspectives, perhaps that may actually be a better fit to what this thread is actually driving at.
« Last Edit: 09/05/2010 02:46 pm by clongton »
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 37440
  • Cape Canaveral Spaceport
  • Liked: 21451
  • Likes Given: 428
Re: Multiple probes on the new LV
« Reply #46 on: 09/05/2010 06:29 pm »

I don't know what the timeline for constructing these things is either, but it is clear that probe 1 can sit in a warehouse until probe 4 is finished.  The ideal timeline would be that probes 1 thru "x" can be ready to go in exactly the time needed to build the new LV.

Then from the start of probe 1 to the finish of probe 4 would be around 8 years

Offline JohnFornaro

  • Not an expert
  • Senior Member
  • *****
  • Posts: 10974
  • Delta-t is an important metric.
  • Planet Eaarth
    • Design / Program Associates
  • Liked: 1257
  • Likes Given: 724
Re: Multiple probes on the new LV
« Reply #47 on: 09/06/2010 03:31 pm »
Quote
So was Viking 1 probe or 2?

Well.  There ya go.  We're doin' it already.  so it's not a matter of some scary new qualitative difference, merely a matter of accepting and working to a quantitative difference.

So therefore, if we had "several distinct sub-missions ... all designed to study a single destination from several very different perspectives, perhaps that may actually be a better fit to what this thread is actually driving at", then "each sub-mission profile would look more carefully at a subset of the moons, the rings, and the surface weather patterns", of, say Saturn.  In my mind, a quite acceptable paraphrase of the OP.

If we can tentatively assume an eight year timeline for "x" probes, then the issue of "overwhelming" the manufacturing facilities can be considered in this sequential light, and does not seem to me to be quite such an overwhelming task.  Allowing that the physical size of the facility is sufficient for the moment; realizing that this allowance is a temporary expedient which allows the development of the idea further; allowing that more manufacturing jobs of this sort are a good thing, especially in light of the present layoffs; then a bit of thought can be given to how these probes might be made.

Right now, I believe that the work flow at JPL is:  Start building the probe, and stop building when it is complete.  Store it until ready to launch.  With multiple probes, the work flow ought to be modified.  Using the Mars rovert example: Start building the aeroshells, one at a time.  Put them aside when finished.  Start building the landers and rovers and cruise stages, one at a time.  Put them aside when finished.  Start building the comsats, one at a time.  Put them aside when finished.  Build the central truss.  Build the truss/propulsion thingy.  Build All That Other Shituff.  Put it all together; stick it on top of the J-246; fire it up when ready to go.

In this Mars Exo-biology Rover Scenario, perhaps each rover and comsat are very nearly exactly the same.  The illustration below omits perhaps one or possibly two details, for clarity.
« Last Edit: 09/06/2010 03:33 pm by JohnFornaro »
Sometimes I just flat out don't get it.

Tags:
 

Advertisement NovaTech
Advertisement Northrop Grumman
Advertisement
Advertisement Margaritaville Beach Resort South Padre Island
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
1