How are the Japanese doing that?

On Jun 21, 6:04*pm, Pat Flannery wrote:

It was made into a reliable form of propulsion from what was learned
from DS-1 though, and our Dawn asteroid mission is using it right now:http://dawn.jpl.nasa.gov/

It has improved although it still tends to have some problems (eg:all
the failures on this particular flight). It seems to be a good engine
once its firing and is left alone, but seems to have problems in other
environments. The question though is whether its better than other
forms of Electrical propulsion. Probably mute point that given the
paucity of such flights.

What few people remember (and NASA didn't exactly advertise) is that US
tests of ion space propulsion went _decades_ back before DS-1; behold
SERT 2 and its _nuclear-powered_ ion drive from 1970:http://www.astronautix.com/craft/sert.htm

Argh the good ole days when actual space research was undertaken. Note
though, that this is mercury Ion thrusters as opposed to the newer
ones.

On 6/21/2010 2:53 PM, Brian Thorn wrote:

So did Stardust's. It was Genesis that went splat.

The thing is, if someone had walked into JPL and said:
"Here's what we want the new spacecraft to do:

1. Cruise out to a asteroid under ion power.
2. Autonomously rendezvous with said asteroid without Earth command.
3. Land on said asteroid.
4. Deploy sample collecting robot.
5. Return samples to main spacecraft with the robot collector.
6. Lift off from surface of asteroid and re-engage ion engines.
7. Return to Earth and drop sample to Earth's surface in recoverable
capsule."

....their response would be "And we have how many years and billions of
dollars to do this?".
Between that and the JAXA solar sail spacecraft (we were going to launch
one of those to Halley's comet the last time it went by in 1986, but
never got around to it) take a wild guess who is seizing the high ground
in unmanned space exploration, and doing it on a tight budget to boot?
Then there's the HTV - the Dragon won't dock at the ISS on its first
fully functional test flight.
Guess who's could?
We are worrying about China and India - forget them...this is the crew
that's seizing the high frontier big time.

Pat

On Jun 23, 3:37*am, Pat Flannery wrote:
On 6/21/2010 2:53 PM, Brian Thorn wrote:

So did Stardust's. It was Genesis that went splat.

The thing is, if someone had walked into JPL and said:
"Here's what we want the new spacecraft to do:

1. Cruise out to a asteroid under ion power.
2. Autonomously rendezvous with said asteroid without Earth command.
3. Land on said asteroid.
4. Deploy sample collecting robot.
5. Return samples to main spacecraft with the robot collector.
6. Lift off from surface of asteroid and re-engage ion engines.
7. Return to Earth and drop sample to Earth's surface in recoverable
capsule."

...their response would be "And we have how many years and billions of
dollars to do this?".
Between that and the JAXA solar sail spacecraft (we were going to launch
one of those to Halley's comet the last time it went by in 1986, but
never got around to it) take a wild guess who is seizing the high ground
in unmanned space exploration, and doing it on a tight budget to boot?
Then there's the HTV - the Dragon won't dock at the ISS on its first
fully functional test flight.
Guess who's could?
We are worrying about China and India - forget them...this is the crew
that's seizing the high frontier big time.


As Brian pointed out, NASA already did sample returns, and without
spending billions or many years. Even in the partial failure of the
Genesis recovery, viable samples were still recovered for study, It
also remains to be seen what, if anything, Hayabusa brought back as
the spacecraft suffered through mulitple failures on it's attempts to
land and obtain a sample. Also among the failures was the MINERVA
miniprobe that due to another error was improperly released and failed
to reach the surface of asteroid Itokawa.

Overall the Japanse can be proud of pulling the mission through so
many mulitple failures, and they will gain a huge amount of
engineering data as well as the science that was done in proximity to
Itokawa, but let's not go overboard here and make this out to be
something that it is not, either.
-Mike

On Wed, 23 Jun 2010 02:37:43 -0800, Pat Flannery
wrote:

So did Stardust's. It was Genesis that went splat.

The thing is, if someone had walked into JPL and said:
"Here's what we want the new spacecraft to do:

1. Cruise out to a asteroid under ion power.
2. Autonomously rendezvous with said asteroid without Earth command.
3. Land on said asteroid.

No, they just nudged right up next to it. NEAR Shoemaker did that ten
years ago.

4. Deploy sample collecting robot.
5. Return samples to main spacecraft with the robot collector.

I think the sample collector and the robot were two different things.
The robot didn't work. The collector barely did (maybe getting some
dust, it failed to get a solid sample.)

6. Lift off from surface of asteroid and re-engage ion engines.
7. Return to Earth and drop sample to Earth's surface in recoverable
capsule."

...their response would be "And we have how many years and billions of
dollars to do this?".

I'm still not convinced. I think it would be either a Discovery-class
(it is essentially a combination of three NASA Discovery-class
missions... NEAR and Stardust using Dawn's engine) or a more expensive
New Horizons mission, it wouldn't be a flagship mission.

Between that and the JAXA solar sail spacecraft (we were going to launch
one of those to Halley's comet the last time it went by in 1986, but
never got around to it)

NASA tried to launch a solar sail a couple of years ago. SpaceX dumped
it in the Pacific Ocean. The Planetary Society tried as well, the
Russian rocket launching it was never seen again.

take a wild guess who is seizing the high ground
in unmanned space exploration,

The U.S., by a very wide margin.

and doing it on a tight budget to boot?

Japan is following the U.S.'s lead with the FBC programs, Discovery
and New Frontiers.

Then there's the HTV - the Dragon won't dock at the ISS on its first
fully functional test flight.
Guess who's could?

That's because of SpaceX's very low budget and HTV's very high cost.
SpaceX can't afford to do everything on the first flight, JAXA
couldn't afford not to.

And neither actually docks. They're grabbed by the Station's arm and
berthed.

We are worrying about China and India - forget them...this is the crew
that's seizing the high frontier big time.

One mission that sputters its way to the finish line after seven years
is "seizing the high frontier big time"? Since Hayabusa launched in
2003 the U.S. launched:

MER-A Spirit
MER-B Opportunity
Messenger
Deep Impact
Mars Reconnaissance Orbiter
New Horizons
Mars Phoenix
Dawn
Lunar Reconnaissance Orbiter

Japan has launched its lunar and Venus probes in the same period.

Oh, yes, Japan is really surging ahead. :-/

Brian

On Wed, 23 Jun 2010 13:12:13 -0700 (PDT), Mike DiCenso
wrote:


Overall the Japanse can be proud of pulling the mission through so
many mulitple failures, and they will gain a huge amount of
engineering data as well as the science that was done in proximity to
Itokawa, but let's not go overboard here and make this out to be
something that it is not, either.

Exactly. It was not my intention to belittle the achievements of
Hayabusa.

Brian

On Jun 23, 4:03*pm, Brian Thorn wrote:
On Wed, 23 Jun 2010 02:37:43 -0800, Pat Flannery
wrote:

So did Stardust's. It was Genesis that went splat.

The thing is, if someone had walked into JPL and said:
"Here's what we want the new spacecraft to do:

1. Cruise out to a asteroid under ion power.
2. Autonomously rendezvous with said asteroid without Earth command.
3. Land on said asteroid.

No, they just nudged right up next to it. NEAR Shoemaker did that ten
years ago.

4. Deploy sample collecting robot.
5. Return samples to main spacecraft with the robot collector.

I think the sample collector and the robot were two different things.
The robot didn't work. The collector barely did (maybe getting some
dust, it failed to get a solid sample.)

6. Lift off from surface of asteroid and re-engage ion engines.
7. Return to Earth and drop sample to Earth's surface in recoverable
capsule."

...their response would be "And we have how many years and billions of
dollars to do this?".

I'm still not convinced. I think it would be either a Discovery-class
(it is essentially a combination of three NASA Discovery-class
missions... NEAR and Stardust using Dawn's engine) or a more expensive
New Horizons mission, it wouldn't be a flagship mission.

Between that and the JAXA solar sail spacecraft (we were going to launch
one of those to Halley's comet the last time it went by in 1986, but
never got around to it)

NASA tried to launch a solar sail a couple of years ago. SpaceX dumped
it in the Pacific Ocean. The Planetary Society tried as well, the
Russian rocket launching it was never seen again.

take a wild guess who is seizing the high ground
in unmanned space exploration,

The U.S., by a very wide margin.

and doing it on a tight budget to boot?

Japan is following the U.S.'s lead with the FBC programs, Discovery
and New Frontiers.

Then there's the HTV - the Dragon won't dock at the ISS on its first
fully functional test flight.
Guess who's could?

That's because of SpaceX's very low budget and HTV's very high cost.
SpaceX can't afford to do everything on the first flight, JAXA
couldn't afford not to.

And neither actually docks. They're grabbed by the Station's arm and
berthed.

We are worrying about China and India - forget them...this is the crew
that's seizing the high frontier big time.

One mission that sputters its way to the finish line after seven years
is "seizing the high frontier big time"? Since Hayabusa launched in
2003 the U.S. launched:

MER-A Spirit
MER-B Opportunity
Messenger
Deep Impact
Mars Reconnaissance Orbiter
New Horizons
Mars Phoenix
Dawn
Lunar Reconnaissance Orbiter


Brian, you forgot to add the Lunar Crater Observation and Sensing
Satellite (LCROSS). On a smaller scale, NASA also hitched instruments
on other agencies' spacecraft during that time, such as the ASPERA-3
on ESA's Mars Express, and miniSAR as well as the Moon Mineralogy
Mapper instruments on Chandrayaan-1.
-Mike

On Jun 23, 4:04*pm, Brian Thorn wrote:
On Wed, 23 Jun 2010 13:12:13 -0700 (PDT), Mike DiCenso

wrote:
Overall the Japanse can be proud of pulling the mission through so
many mulitple failures, and they will gain a huge amount of
engineering data as well as the science that was done in proximity to
Itokawa, but let's not go overboard here and make this out to be
something that it is not, either.

Exactly. It was not my intention to belittle the achievements of
Hayabusa.

No, certainly you weren't. You were just tossing cold water on NASA
bashing stroke-fest that was going on there. ;-)
-Mike.

On Jun 21, 3:56*pm, Brian Thorn wrote:
On Sun, 20 Jun 2010 18:17:10 -0700 (PDT), Brad Guth

wrote:
There's no possible comparison, as the Hayabusa was at least ten fold
more complex.

Nonsense. Hayabusa was a combination of NASA's NEAR Shoemaker,
Stardust and Deep Space 1 missions. At most, this would seem to add up
to three times more complex. But of course, it actually isn't because,
for example, launch and return are no more complex for Hayabusa than
they were for Stardust, DS1 had already proven ion propulsion was
viable over long durations, and setting down on the asteroid was no
more complex than it was for NEAR (in fact, probably less, since
Hayabusa was actually designed to do that.)
Your belittlement and discrediting of others is noted.

So is your refusal to address any of the points I made or to simply
admit that you have no idea what you're talking about. I stand by my
assessment that your "no possible comparison" assertion is utter
nonsense.

Brian

Other fellow Semites would naturally have to agree with that.

~ BG

On Sat, 26 Jun 2010 12:12:17 -0800, Pat Flannery
wrote:

However, the spacecraft did come in contact with the asteroid itself,
not once - but twice - to try and recover a sample...and given the low
gravity of the asteroid, that's as close as you could get to landing on it.

Again... that's something NEAR did ten years ago.

Brian

On 6/23/2010 3:03 PM, Brian Thorn wrote:


1. Cruise out to a asteroid under ion power.
2. Autonomously rendezvous with said asteroid without Earth command.
3. Land on said asteroid.

No, they just nudged right up next to it. NEAR Shoemaker did that ten
years ago.

4. Deploy sample collecting robot.
5. Return samples to main spacecraft with the robot collector.

I think the sample collector and the robot were two different things.
The robot didn't work. The collector barely did (maybe getting some
dust, it failed to get a solid sample.)

My bad: I thought the robot was related to the sample collection system,
but it was separate from it.
However, the spacecraft did come in contact with the asteroid itself,
not once - but twice - to try and recover a sample...and given the low
gravity of the asteroid, that's as close as you could get to landing on it.


Pat