New Mars Forums

The Winds Still Blow in Thin but Active Martian Atmosphere.

http://www.americaspace.com/?p=33999&cpage=1

It is notable that daytime ground temperatures are above the air temperatures. Eyeballing the ground temperature plot, I estimate the highest ground temperature reached as about 15 C, about 60 F. Depending on the amount of water vapor in the air near the surface this could allow small amounts of water to condense to liquid for short periods.
It would be interesting to find out if the relative humidity would allow water to condense on the surface in the thin Martian atmosphere.

Bob Clark

Which ULA paper are you referring to?

  Bob Clark

Welcome back to the forum.

   Bob Clark

A manned lunar landing flight for less than $100 million in launch cost, assuming the Falcon Heavy really does hit the $1,000 per pound price point:

Budget Moon flights.
http://exoscientist.blogspot.com/2013/0 … ights.html

  Bob Clark

Speculation here that such an impact could make Mars habitable:

Rush to Mars: Comet impact could make Red Planet inhabitable.
Published time: February 28, 2013 16:32
http://rt.com/news/mars-comet-tito-flyby-601/

Bob Clark

I looked at the Userlist and selected the new users option. Some new users did have spam links but most did not. Perhaps an additional protection is that they could be required to include a cogent, relevant post with their application to the forum. Or perhaps they could be required to include a short bio that describes their interest in Mars exploration.

  Bob Clark

Thanks for the interesting links and good luck with the scorps!

   Bob Clark

  Thanks for that. I hadn't heard that Curiosity had the capability to make detections in the ultraviolet. I had wondered if we could improve our mineral discrimination capability if we used all of optical, infrared, and ultraviolet wavelengths. Do you have a reference for papers written on this?
BTW, how do you get scorpions in your apartment? Not something you see just scurrying around, at least not in my neck of the woods.

   Bob Clark

A recent report suggests using the hydrogen tank of an upper stage for the SLS as a space station:

Skylab II: A NASA 'Back to the Future' Concept to Open Up Space Exploration
By Mark Whittington | Yahoo! Contributor Network – Fri, Dec 21, 2012
http://news.yahoo.com/skylab-ii-nasa-ba … 00842.html

Note there had been suggestions before of using the space shuttle external tank(ET) as a space station:

The Space Island Project
http://www.youtube.com/watch?v=sYIo-0qo9FA

STS External Tank Station
www.astronautix.com/craft/stsation.htm

The External Tank Torus.
A Technical Review by David Buth
http://freemars.org/studies/torus/ettoru2.html

Using the External Tank From the Space Shuttle as a Space Station ...
aeromaster.tripod.com/grp.htm

At an empty tank mass of 26.5 metric tons(mT) this would be well within the
capability of the 70 mT SLS of getting this to LEO, as at least an outer hull
of a space station. Note for this purpose we could remove the ET bulkheads so
it would even weigh less than this.
This would have a two and a half times the volume of the ISS.
And at the 130 mT payload capacity of the later SLS version, using Centaur
style in-space stages we could even transport this to the Moon.

   Bob Clark

Experimental Private Rocket Makes Highest Test Hop Yet.
by Miriam Kramer, SPACE.com Staff WriterDate: 26 December 2012 Time:
11:04 AM ET
"In the latest test at SpaceX's proving grounds in MacGregor, Texas,
the Grasshopper rocket flew for 29 seconds and reached a height of
more than 130 feet (40 meters). A video of the Grasshopper test flight
shows the rocket soaring up into the Texas sky, then smoothly
descending to land on four spindly legs."
http://www.space.com/19039-spacex-priva … -test.html

With reduced weight of the Merlin 1D engine while at increased efficiency, the Falcon 9 v1.1 first stage will have SSTO capability. Then ironically Elon is emulating the original purpose of the DC-X program in testing the Grasshopper VTVL stage, without realizing it.

   Bob Clark

NASA administrator Charles Bolden told the NRC committee on human spaceflight that an asteroid mission didn't necessarily have to be a far trip:

Bolden: Don't Have to Travel Far to Asteroid to Meet President's Goal.
Marcia S. Smith
Posted: 19-Dect-2012
http://www.spacepolicyonline.com/news/b … dents-goal

Perhaps he was referring to the Planetary Resources, Inc. proposal to bring a small asteroid to lunar orbit. But another possibility is a mission to near Earth asteroids that can be accomplished in about a month round trip travel time. See the table of NEO's here:

Near-Earth Object Human Space Flight Accessible Targets Study (NHATS).
http://neo.jpl.nasa.gov/cgi-bin/nhats

Select max delta-v <= 12 km/s, visit time => 8 days, unlimited visual magnitude, the H parameter, and unlimited orbital uncertainty, the OCC parameter. Then there are several asteroids at 26, 34, and 42 day travel times, including stay times at or above 8 days. If you subtract off that stay time to make it only a day or so then the round trip travel time will be in the range of a month or so.

This could serve as an intermediate step for BEO missions between the Apollo missions at max. 12 days and a Mars mission at 6 months one-way travel time.

Bob Clark

Reading the "Golden Spike" paper now:

http://goldenspikecompany.com/wp-conten … ockets.pdf

It gives several different architectures and types of missions. But on page 8 it gives the payload capability of the Falcon 9, presumably the new version, as 16,700 kg. However, on the SpaceX site it's given as 13,100 kg:

http://www.spacex.com/falcon9.php#launch_and_placement

Interestingly at the 16 mT number you can do a manned circumlunar mission on a single Falcon 9 + Dragon, even including a LAS, by using a half-size Centaur as the in-space stage. But at the 13 mt number it becomes much more iffy.

Such a mission would be very important to accomplish. Recall the Apollo 8 mission was a manned lunar flyby that served as the prelude to the Apollo 11 mission. It is regarded then as being a part of the very costly Apollo program, requiring the expensive Saturn V launcher.

The skepticism among many about the Golden Spike plan or other commercial lunar plans is that idea it would require large, hugely expensive Saturn V class launchers. However, if the manned flyby could be done by a single launch by what is still just a medium size launcher in the Falcon 9 v1.1 it would show that by going small and following a low cost, commercial approach, that a low cost return to the Moon is feasible.

The Falcon 9 v1.1 will cost in the $60 million range, and we might estimate the half-size Centaur to be in the $15  million range. So the launch cost for such a mission might be in the $75 million range.

As I mentioned  before in regards to using the first test flights of the Falcon Heavy for unmanned BEO test flights, the test flights of the Falcon 9 v1.1 could serve for unmanned test flights for this lunar flyby. Since SpaceX needs to do such tests anyway most of the cost of the Falcon 9 and Dragon capsule would be borne by SpaceX. Then you could have Golden Spike only paying ca. $15 million for the half-size Centaur.

There would be some development cost of course beyond that for this half-size Centaur. For one thing you would have to make the cryogenic propulsion undergo less boiloff for 1 to 2 week missions. ULA has done studies on this so should be doable but still it has to be carried out in practice. An advantage of this would be that this half-size Centaur is about the size you need for the lander. So the lander could be derived from this, and the development cost for the two stages could be reduced.

Bob Clark