On Friday, April 1, 2022 at 10:25:43 PM UTC-6, RichA wrote:
> The HEIGHT of stupidity. 25ft twin solar panels have to "unfold." Compare this to an RTG, especially going to the ASTEROID BELT!! It's not the only one. Psyche is using them too.
>
> https://www.cnn.com/2021/10/20/world/nasa-lucy-mission-solar-array-issue-scn/index.html

Rockets can, and do, blow up on the launch pad. So launching
radioactive material into space presents a safety hazard.

It doesn't help that rockets, for ease of access to the equatorial,
and hence the ecliptic, plane need to be launched from a southerly
location - and, as well, for other safety reasons, a southerly location
close to an Eastern shore. That lets out remote locations in Alaska
as potential sites for a replacement for Cape Canaveral.

The inverse-square law, on the other hand, is something predictable,
and hence manageable.

Yes, solar panels can fail to unfold, but that's only money, not lives.

John Savard

On Saturday, April 2, 2022 at 7:00:59 AM UTC-4, Quadibloc wrote:
> On Friday, April 1, 2022 at 10:25:43 PM UTC-6, RichA wrote:
> > The HEIGHT of stupidity. 25ft twin solar panels have to "unfold." Compare this to an RTG, especially going to the ASTEROID BELT!! It's not the only one. Psyche is using them too.
> >
> > https://www.cnn.com/2021/10/20/world/nasa-lucy-mission-solar-array-issue-scn/index.html
> Rockets can, and do, blow up on the launch pad. So launching
> radioactive material into space presents a safety hazard.
>
> It doesn't help that rockets, for ease of access to the equatorial,
> and hence the ecliptic, plane need to be launched from a southerly
> location - and, as well, for other safety reasons, a southerly location
> close to an Eastern shore. That lets out remote locations in Alaska
> as potential sites for a replacement for Cape Canaveral.
>
> The inverse-square law, on the other hand, is something predictable,
> and hence manageable.
>
> Yes, solar panels can fail to unfold, but that's only money, not lives.

There have been several mishaps involving RTGs, but in the case of any US launch or re-entry incident, no release of radioactivity. This is because the units are DESIGNED to not break apart or melt in the event of a mishap.

On Sun, 3 Apr 2022 04:50:05 -0700 (PDT), W <wsnell01@hotmail.com>
wrote:

>On Saturday, April 2, 2022 at 7:00:59 AM UTC-4, Quadibloc wrote:
>> On Friday, April 1, 2022 at 10:25:43 PM UTC-6, RichA wrote:
>> > The HEIGHT of stupidity. 25ft twin solar panels have to "unfold." Compare this to an RTG, especially going to the ASTEROID BELT!! It's not the only one. Psyche is using them too.
>> >
>> > https://www.cnn.com/2021/10/20/world/nasa-lucy-mission-solar-array-issue-scn/index.html
>> Rockets can, and do, blow up on the launch pad. So launching
>> radioactive material into space presents a safety hazard.
>>
>> It doesn't help that rockets, for ease of access to the equatorial,
>> and hence the ecliptic, plane need to be launched from a southerly
>> location - and, as well, for other safety reasons, a southerly location
>> close to an Eastern shore. That lets out remote locations in Alaska
>> as potential sites for a replacement for Cape Canaveral.
>>
>> The inverse-square law, on the other hand, is something predictable,
>> and hence manageable.
>>
>> Yes, solar panels can fail to unfold, but that's only money, not lives.
>
>There have been several mishaps involving RTGs, but in the case of any US launch or re-entry incident, no release of radioactivity. This is because the units are DESIGNED to not break apart or melt in the event of a mishap.

Which is one of the factors that results in their high cost in
comparison with solar, which then impacts other aspects of missions.

On Sunday, April 3, 2022 at 9:48:42 AM UTC-4, Chris L Peterson wrote:

> Which is one of the factors that results in their high cost in
> comparison with solar, which then impacts other aspects of missions.

That is a statement made without any supporting evidence.

On Sun, 3 Apr 2022 12:36:02 -0700 (PDT), W <wsnell01@hotmail.com>
wrote:

>On Sunday, April 3, 2022 at 9:48:42 AM UTC-4, Chris L Peterson wrote:
>
>> Which is one of the factors that results in their high cost in
>> comparison with solar, which then impacts other aspects of missions.
>
>That is a statement made without any supporting evidence.

It's true, and you can easily research it yourself.

On Sunday, April 3, 2022 at 3:38:24 PM UTC-4, Chris L Peterson wrote:
> On Sun, 3 Apr 2022 12:36:02 -0700 (PDT), W <wsne...@hotmail.com>
> wrote:
> >On Sunday, April 3, 2022 at 9:48:42 AM UTC-4, Chris L Peterson wrote:
> >
> >> Which is one of the factors that results in their high cost in
> >> comparison with solar, which then impacts other aspects of missions.
> >
> >That is a statement made without any supporting evidence.
> It's true, and you can easily research it yourself.

At best, a half-truth. It has, as some say, "truthiness." The main reason an RTG costs so much is the rarity of the material.

On Sun, 3 Apr 2022 12:50:23 -0700 (PDT), W <wsnell01@hotmail.com>
wrote:

>On Sunday, April 3, 2022 at 3:38:24 PM UTC-4, Chris L Peterson wrote:
>> On Sun, 3 Apr 2022 12:36:02 -0700 (PDT), W <wsne...@hotmail.com>
>> wrote:
>> >On Sunday, April 3, 2022 at 9:48:42 AM UTC-4, Chris L Peterson wrote:
>> >
>> >> Which is one of the factors that results in their high cost in
>> >> comparison with solar, which then impacts other aspects of missions.
>> >
>> >That is a statement made without any supporting evidence.
>> It's true, and you can easily research it yourself.
>
>At best, a half-truth. It has, as some say, "truthiness." The main reason an RTG costs so much is the rarity of the material.

If you look at mission budgets, the extra effort that goes into making
them very robust, and even modifies the entire launch procedure is
very expensive.

On Sunday, April 3, 2022 at 7:48:42 AM UTC-6, Chris L Peterson wrote:

> Which is one of the factors that results in their high cost in
> comparison with solar, which then impacts other aspects of missions.

Cost doesn't have any impact on a mission by itself, unlike weight,
or limitations in power output. The only way cost can have an impact
on other aspects of a mission is if Congress _allows_ it to do so.

Therefore, it is not a fundamental technical obstacle. The problem is not
"an RTG is expensive", the problem is "the political process is assigning
an insufficient priority to space science".

An example of a valid concern about using an RTG is that just as a
solar panel might have difficulty collecting enough sunlight to produce
the desired amount of energy without being inordinately large, an RTG
may, in the vacuum of space, have difficulty dissipating enough heat
to actually produce useful electricity from the heat it produces.

John Savard

On Sun, 3 Apr 2022 18:41:21 -0700 (PDT), Quadibloc <jsavard@ecn.ab.ca>
wrote:

>On Sunday, April 3, 2022 at 7:48:42 AM UTC-6, Chris L Peterson wrote:
>
>> Which is one of the factors that results in their high cost in
>> comparison with solar, which then impacts other aspects of missions.
>
>Cost doesn't have any impact on a mission by itself, unlike weight,
>or limitations in power output. The only way cost can have an impact
>on other aspects of a mission is if Congress _allows_ it to do so.
>
>Therefore, it is not a fundamental technical obstacle. The problem is not
>"an RTG is expensive", the problem is "the political process is assigning
>an insufficient priority to space science".
>
>An example of a valid concern about using an RTG is that just as a
>solar panel might have difficulty collecting enough sunlight to produce
>the desired amount of energy without being inordinately large, an RTG
>may, in the vacuum of space, have difficulty dissipating enough heat
>to actually produce useful electricity from the heat it produces.

Objectively, cost always impacts a mission directly. No mission ever
has an infinite amount of resources. No matter how generous the
funder, there will always be a budget, and if one system is more
expensive, something will have to give elsewhere.