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Date: 4 Sep 92 09:42:48 GMT
From: ruca@pinkie.saber-si.pt
Subject: Inflatable Space Stations - Why Not ?
Newsgroups: sci.space
In article <BtwzCC.852@news.orst.edu> katzr@ucs.orst.edu (Russell Katz) writes:
This is a bit related to the topic...I think.
I have read in several sf stories about using the shuttle main tanks as
modules for space habitats...just having the shuttle carry the tank with it
into orbit. Some authors stated that it would not take any extra fuel(??)
to do so.
Any of you experts out there have an answer as to why NASA doesn't use the
tanks as at least a temporary habitation?
---
I'm NOT an expert but I've read some of those sf stories and they seemed great (particularly David Brin's "Tank Farm Dynamo").
I've also read NASA is spending some money on a feseability study of putting a small booster under the shuttle ET to give it the extra push into orbit. Then, after parking some ET's in LEO, they could be sold or used by NASA.
Rui
--
*** Infinity is at hand! Rui Sousa
*** If yours is big enough, grab it! ruca@saber-si.pt
All opinions expressed here are strictly my own
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Date: 5 Sep 92 00:42:32 GMT
From: "Thomas H. Kunich" <tomk@netcom.com>
Subject: Is NASA really planning to Terraform Mars?
Newsgroups: sci.space
aweder@iiic.ethz.ch (Andreas Michael Weder) writes:
>two days ago I read an article on the topic of Mars in the german
>magazine 'GEO'; they talked about some of the planned missions to
>our neighbour planet and mentioned that there were still some
>dreamers at NASA that actually intended to transform Mars.
>I'd say, forget about that. Even a manned mission to Mars would cost
>*at least* 500 billion dollars (according to a NASA researcher).
>Terraforming is a nice SF idea and sounds like an easy thing to
>do, but IMHO we don't know enough about the involved systems
>to even think about changing a planet. It's stupid, will cost
>too much (NASA will not be given the money for 'Big Tickets' in the
>next years) and belongs to SF.
If you look back in the postings some you will find that
I made a suggestion for cheaply testing a cheap method
of terraforming. And it doesn't even belong in SF.
If you would like, I could repost it.
------------------------------
Date: 4 Sep 92 16:11:35 GMT
From: smd@fct.unl.pt
Subject: Is NASA really planning to Terraform Mars?
Newsgroups: sci.space
barry@chezmoto.ai.mit.edu (Barry Kort) writes:
> A colleague of mine, who claims to be knowledgeable in such matters
> tells me:
> A fairly large team <at NASA>, is planning the terraforming
> of Mars, which involves destroying the planet as we know it.
> Mars will be rasied 20 degrees C. And with minimal study of
> that planet it becomes clear what chain of events will occur.
> After this chain Mars will be 'polluted' with earth-based
> micro-organisms and rugged plant life.
>
> Can anyone confirm, deny, or refute the above, or otherwise
> elaborate on NASA's plans with respect to Mars?
We all suspected NASA was a bit senile,
now we have the confirmation!
--
Sergio Duarte *** smd@fct.unl.pt *** FCT/UNL *** PORTUGAL
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Date: 5 Sep 92 04:26:23 GMT
From: John Roberts <roberts@CMR.NCSL.NIST.GOV>
Subject: Notes from Rover Expo
Newsgroups: sci.space
On Wednesday, I went to the September 1-2 planetary Rover Expo that was
described in sci.space and sci.space.news. It was extremely interesting.
All of the rovers were on display, and they took turns moving about on a
simulated martian terrain (large rocks and local clay soil mixed with
pigment to give it the vivid orange color of martian soil). There was also
a smooth runway between the simulated terrain and the audience, with a
considerable number of small children allowed to sit along the runway, and the
smaller rovers were moved along the runway so the kids could see them up
close. (Naturally the rovers tracked a lot of the colored soil onto the
runway, and the kids rolled in the dust and quickly spread it to the bleachers
and everywhere else in the tent - few people escaped getting Mars-colored.)
A running commentary was given with each demonstration, often with the same
person talking and controlling the rover.
The main sponsors of the Rover Expo were NASA, the National Air and Space
Museum (which had a sign inside the door of the museum), and the Planetary
Society. Co-sponsors included the Russian Mobile Vehicle Engineering Institute,
the Centre National d'Etudes Spatiales, and the Space Automation and Robotics
Technical Committee of the American Institute of Aeronautics and Astronautics.
>From the literature, here are the rovers that participated, and the
organizations that provided them, with some comments by me:
..............
Babakin Center
NPO Lavochkin, Moscow
Space Research Institute
Russian Academy of Sciences
Mobile Vehicle Engineering Institute
(VNIITransMash)
- Unnamed Marsokhod (Mars Rover)
size: 1.2 x 1.0 x 0.8 meters
mass: 75 kg
speed: 10 cm/s
comments: Rover will be named in an international student contest.
Three pairs of long, tapered wheels with small blades. "Wheel mode"
can handle slopes of 20 degrees, "wheel-crawler mode" 30-35 degrees in
loose soil. Largest individual stones 0.5 m. Service life 100km. Can
be commanded directly from orbiter for use in dangerous conditions,
programmed mode for motion along a specified route, and autonomous mode
for motion in a given direction, with route corrections. Returns
high-resolution color stereo images of surface, also has numerous
scientific instruments. Scheduled for a demo. Tested in the Mojave Desert
with the aid of the Planetary Society.
Also shown was a "hot air balloon" to represent the SNAKE instrument
(dragged along the Martian surface by a balloon) developed by the
Space Dynamics Laboratory (Utah State University), JPL, the French
space agency CNES, and the Planetary Society, and scheduled to be
launched on a CIS Proton booster in 1996.
..............
Carnegie Mellon University
Robotics Institute
Pittsburgh, Pennsylvania
- Ambler
size: 4.5 x 3.0 x 5.5 meters
mass: 3 tons
speed: 0.8 cm/s
comments: The six-legged walker that Marc Ringuette has described. It's
been operational for a year or more - I've seen it on CNN and NASA
Select. It's really enormous, and apparently is quite a job to control -
there was a battery of computer workstations set up to do it. Apparently
the last demo Tuesday was to walk the Ambler out onto the terrain, and
the first demo Wednesday was to walk it back to its resting place.
Able to step over objects 1 meter high, and maintain a level body on
a 30-degree slope. Laser rangefinder on top of body. There are plans
to give the Ambler considerable autonomy. (This should largely make
up for the low speed, for use on Mars.)
- Dante -- the Erebus Explorer
size: 3.0 x 1.9 x 3.5 meters
mass: 400 kg
speed: 2 cm/s
comments: Another (6-legged?) walker, hard to describe. It appears to
be made of beautiful purple anodized aluminum. It's intended to explore
the active volcano Mount Erebus in Antarctica in 1992. Another robot,
Virgil, also called the transporter, is to ascend to the rim of the
crater, where it will lower Dante, also called the rappeller, to observe
the lava lake, measure temperatures, take samples, etc. Not scheduled
for a demo. Cameras return anaglyph stereo display.
..............
IS Robotics
Cambridge, Massachusetts
- Attila II
size: 38 x 25 x 30 cm
mass: 3 kg
speed: 5 cm/s
comments: No other information. Apparently it was not scheduled for a demo.
- Genghis II
size: 38 x 25 x 20 cm
mass: 1.7 kg
speed: 10 cm/s
comments: Was scheduled for a demo. A 6-legged walker.
- T-1
size: 38 x 45 x 25 cm
mass: 6 kg
speed: 30 cm/s
comments: Was scheduled for a demo. Looks like a wheeled vehicle in the
photograph, but hard to tell.
- Treader
size: 45 x 35 x 35 cm
mass: 4 kg
speed: 30 cm/s
comments: Was scheduled for a demo.
..............
Jet Propulsion Laboratory
Robotic Systems & Advanced Computing Technology Section
Pasadena, California
- Rocky III
size: 80 x 80 x 80 cm (JPL literature says 60 cm long by 45 cm wide.)
mass: 8 kg (JPL literature says 15 kg, which seems more likely.)
speed: 10 cm/s
comments: Six-wheeled design with articulated, "rocker-bogie" suspension
to allow it to climb over objects 1.3 times as high as wheel diameter.
Wheel encoders, bumpers, articulation sensors, magnetic compass, and
attitude sensors. Developed for autonomous sample-acquisition experiment
using computerized navigation system called "behavior control". User
determines location of interest - rover travels to that location
autonomously, scoops up a soil sample, and returns it to the lander,
following an infrared beacon as a homing device. Large obstacles are
avoided. I saw a demo of Rocky III.
- Rocky IV (not present at show)
size: 60 cm long by 45 cm wide
mass: 7.2 kg
speed: ?
comments: Interest in use as Mars Environmental Survey Pathfinder.
Same basic design as Rocky III. Deploys microseismometers, scoops
soil samples, and chips rock surfaces. This is the model that uses
stereo cameras with alternate-field liquid crystal shutter goggles
for the operators. I spoke with the JPL people, and they said they're
using standard NTSC format, 30 frames per second. Onboard spectrometer.
- Go-For (pronounced gopher)
size: 50 x 50 x 50 cm (actual volume is very small)
mass: 3 kg
speed: 30 cm/s
comments: This is the weird little yellow rover that looks sort of like
a dog (named Rover, no doubt) without the head. It has four wheels,
mounted on the ends of front and rear forks. The forks can be pivoted,
which helps greatly with maneuverability. Normally, the forks are
adjusted so that 80% or more of the body weight is on the rear wheels,
which allows the front wheels to climb over obstacles as high as 70%
of the length of the rover. The forks can be stretched out straight
to allow the rover to lie flat, and the body can be tilted forward to
get extreme close-ups of rocks or soil using a front-mounted camera.
It can also drop microseismometers out the back, though it will only
be allowed to do this in the pet exercise area. :-) If a maneuver
is miscalculated and Go-For tumbles over on its back, the forks can be
pivoted to turn it rightside-up again. (Few if any of the other rovers
shown have the capability to right themselves, so they have to have
safety systems to stop motion if they start to become unstable.)
I saw Go-For operated twice, once while Rocky III was still running,
and once while Robby was being demonstrated (they had to be careful
to prevent Robby from running over Go-For). It worked very well,
and successfully recovered from a tumble. Go-For was a great favorite
with the kids, who mauled it mercilessly. It survived that, so I guess
it should do pretty well in the less hostile environment of Mars. :-)
- Robby
size: 4 x 2 x 2.5 meters
mass: 1.8 tons
speed: 1 meter/s
comments: Six 35-inch diameter wheels on a pivoting 3-part body, to allow
it to go over obstacles about 3 feet high. It has four video cameras
on a pivoting bar up top, and a robot arm in front. The camera bar
sweeps up, down, and side to side as Robby maneuvers. It also has
a gyrocompass and attitude and articulation sensors. Robby scans
the terrain with its black-and-white stereo cameras, then plans and
executes a safe path. Autonomous navigation at the rate of 80 meters
per hour has been demonstrated.
During the demo, Robby was kept well away from the kids, so none of
them were run over.
..............
Martin Marietta Corporation
Astronautics Group
Denver, Colorado
- Beam Walker
size: 1.5 x 1.5 x 1.2 meters
mass: 160 kg
speed: 3 cm/s
comments: There are two sets of legs, which can move straight up and down
either individually (I think) or together in sets. The outer set consists
of two legs in front and one in back, mounted to the main frame of the
rover. The inner set is made up of four legs in a square configuration,
mounted to an inner frame. In normal operation, the inner frame goes
down, lifting the three outer legs off the ground. The inner frame
then glides backward relative to the rover body, causing the body
to move forward relative to the ground. The inner frame then moves up,
raising the inner legs off the ground and causing the rover to rest
on the outer legs. In this position the inner frame then glides forward
relative to the rover body, and the cycle repeats. Steering is
accomplished by rotating the inner frame while its legs are holding
up the rover. I saw the demo.
..............
Massachusetts Institute of Technology and Charles Stark Draper Laboratory
Cambridge, Massachusetts
- MITy
size: 53 x 34 x 35 cm
mass: 10 kg
speed: 45 cm/s
comments: Scheduled for a demo.
..............
National Institute of Standards and Technology (hey, that's us!)
Robotic Systems Division
Bethesda, Maryland (didn't even know about the Bethesda site - I know
there's some robotic work done at the Gaithersburg site - mainly computer
control of advanced industrial robots, but also other projects such as the
Flight Telerobotic Server (?) )
- Spider
size: 3.7 x 3.7 x 3.7 meters
mass: 18 kg (very open framework)
speed: 2.25 meters/s
comments: It turned out that one of the people exhibiting it was an old
friend from high school, who explained how it works. NIST has been
working on a revolutionary type of crane, which consists of a batch of
long poles connected to the ground at three anchor points, plus six
winches and cables, running through pulleys to a triangular central
platform, where the crane equipment is attached. This structure is
useful because of its stability, and because it can lift many times its
own mass. Somebody apparently figured out that you could attach tractor
treads in place of the ground anchor points with sophisticated angle
detection sensors, add a long boom to the top with stereo cameras
on the end, and make the crane into a rover. I was there for the
second demo, but the control computer had blown out. However, there
was a videotape showing it in operation. I still don't understand
exactly how it works.
..............
Sandia National Laboratories
Advanced Vehicle Systems
Albuquerque, New Mexico
- Dixie
size: 1.6 x 1.0 x 1.0 meters
mass: 180 kg
speed: 13.5 meters/s
- Raybot
size: 1.9 x 1.0 x 1.0 meters
mass: 180 kg
speed: 11.25 meters/s
comments: Dixie and Raybot are apparently converted small 3-4 wheel
all-terrain vehicles (including the gasoline engines, though I didn't
see them in operation - presumably a planetary version would have a
different power source). Dixie and Raybot are designed to be used
together, controlled from a single Command Driving Console (CDC).
Raybot is similar to Dixie, but includes an advanced multiprocessor
control architecture and an articulated arm at the rear of the robot.
Dixie is driven out to an overlook position, from which it provides
a wide-field stereo image to be used for analysis and planning.
Dixie is then put into a safe state, with ignition [!] off and the
parking brake set, and the operator switches control from Dixie to
Raybot. Raybot is moved to a specified location within the field of
view of Dixie, and the robot arm and scientific equipment used.
Control may be switched back and forth between the two rovers to
change their positions.
Dixie and Raybot were scheduled to be demonstrated together.
- Ratler
size: 60 x 60 x 46 cm
mass: 15 kg
speed: 10 cm/s
comments: Scheduled to be demonstrated.
..............
General comments:
- Most (but not all) of the rovers described are intended to have some
degree of autonomy in their final application. In the live demos, I
think most of these were more directly controlled than would be the case
in normal use. As one speaker put it, these demos were intended mainly
to show the mechanical capability of the rovers - in many cases, autonomous
control systems are not yet fully functional. There was also the matter of
controlling the rovers in the limited environment of a tent with people
in it - even Robby, which has demonstrated autonomous operation, was
probably pretty closely monitored to keep it from damaging the set or
hitting the spectators.
- According to one speaker, the typical maximum slope most of the rovers can
negotiate in loose soil is around 30 degrees, because of the physics
involved.
- Many of the speakers were optimistic about getting their rovers into
off-earth use within the decade.
- A lot of the information in the comments above is from literature that
was available at the show. Not all the booths had literature, but I
was there late on the second day, so there may have been more at the
beginning. JPL had nice big color photos of all four of their rovers.
- For the most part, the representatives were very informative and helpful.
I was impressed by the heavy involvement of the Planetary Society. (Of
course, this is probably the one technical thing that they do really well.)
I'll have to watch the NASA Select tape I got of their Case for Mars
conference, and decide once again whether I want to sign up. I get
some impression that they're slightly more technical and less political
than in the past. At least, the fact that they're supporting rovers to
Mars before humans is encouraging (since it's something the space program
can afford now).
- I've tried to double check all the information, but there could still be
errors.
- I was only there a few hours of one day, so I only saw a few of the rovers
in operation. However, I got some good 3D video (same format as JPL uses)
of those demos, plus the rest of the rovers on display. When I review the
video, if I come up with any additional information or corrections, I'll
try to post.
Overall, I'd say the Rover Expo was very interesting, and was very well
