Moon, Mars, or Asteroid? Which is the best goal?

[SpaceForAReason]

There is one other possibility that was ignored. (Typical) We could hone all of our skills by setting up mobile/orbital stations with crews and vehicles that could clean up the mess in orbit. Every technology needed for missions to asteroids, mars, even the moon would be utilized and refined. (I know... dream on; that makes just way too much sense.)

 

[bdewoody]

When spacecraft visit ISS they are not pulled in by gravity, same thing with asteroid, they first station-keep, than dock.

If you can't go to an asteroid, there is nothing you can do on the Moon either. There will be needed more capabilities and technologies for the Moon than an asteroid, not to mention costs.

Program for just one destination is very uninspiring, it's a big Universe.

When they go to the ISS they are still in earth orbit and thereby under the influence of earth's gravity well. To get to the ISS you just have to match orbital altitude.

I didn't say that there is nothing we can do on an asteroid, I said we can't get a manned mission to an asteroid. We can go to the moon and we can do a lot of science and engineering there. Compared to going to an asteroid the moon is a cake walk. It is unbelieveable how little understanding of space flight some of you demonstrate in your claims that going to an asteroid would be easier than the moon.

I still think the President threw in this red herring to divide and conquer the different space factions and that he has no intention of sending men back into space after the ISS is retired.

 

[SteveCNC]

I will agree with you in that the moon is a cake walk by comparison , the biggest problem I see in a asteroid landing is if it is tumbling . We can match speed and vector I'm sure of that to travel along side and slowly come up against but only if it's not tumbling like mad , possibly in 2 axis , that's when it gets tricky and dangerous . As long as it is sufficiently big enough to not be able to tumble to terribly then it should be too hard to land though I still don't see why but it is doable .

 

[vulture4]

The question of whether it is possible to land on an asteroid is moot since both NEAR and Hayabusa have done so. Most asteroids have quite moderate rotation rates. Few asteroids, even small ones, rotate in less than two hours and the average is about 10 hours. Given that for the most part asteroids cannot rotate so fast that chunks will be thrown off the surface, docking should generally be straightforward.

For the full details see:
http://etd.ohiolink.edu/send-pdf.cgi/Co ... 1224698418

 

[bdewoody]

One more time. The previous small unmanned probes that have gone to asteroids or comets have taken years to get there and would take years to get back to earth. A more direct route to any asteroid with a manned vessel would require vast amounts of fuel requiring a bigger craft requiring even more fuel etc, etc. You can't just aim at an asteroid unless you want to do a very quick flyby which would make a mission pointless. Once a manned vessel with all its fuel and supplies onboard approaches an asteroid it must expend a lot of fuel in a braking manuver to match the trajectory of the asteroid without any help from the asteroid's minor gravity well. Then when ready to leave the asteroid the ship would be required to make another large burn to get into an attitude that would bring it back to earth. Do the numbers. We don't have the capability to build such a craft on earth and then launch it. So it would have to be assembled in space after more launches than it took to build the ISS and it would probably be as big as the Jupiter vessel in 2001. There is nothing in planning that could do this before 2050 or later.

 

[EarthlingX]

Numbers, from Plymouth Rock Mission Goals: Earth Security or Job Security? thread :

If you're interested in Plymouth Rock, you may want to take a look at some of the material about this study at the Lockheed Martin website.

If you prefer charts, try the briefing package.
http://www.lockheedmartin.com/data/asse ... ug2010.pdf

If you have a bit more time, here's the full study report.
http://www.lockheedmartin.com/data/asse ... ug2010.pdf

Some of the issues raised in this discussion are addressed in the report.


Josh Hopkins

More details :

David Livingston's interview on The Space Show regarding the Plymouth Rock concept may be of interest. In the discussion we did address some of the justifications for such a mission.

The link to the show is: http://www.thespaceshow.com/detail.asp?q=1418

 

[bdewoody]

OK, I read it and it still reads like a grandstand stunt and not anything that we will get a long term benefit from and the shortest possible mission using 2 Orions is over 6 months. Plus the Orion has no shielding for CMEs and other radiation. A 2 man crew on a minimum 6 month mission to spend at most 5 days near an asteroid. What's the point.

 

[EarthlingX]

OK, I read it and it still reads like a grandstand stunt and not anything that we will get a long term benefit from and the shortest possible mission using 2 Orions is over 6 months. Plus the Orion has no shielding for CMEs and other radiation. A 2 man crew on a minimum 6 month mission to spend at most 5 days near an asteroid. What's the point.

Point is, it can be done. I don't like 'how' either, but it can be done. There is not much difference with radiation on the Moon surface, where you also have to cope with the lunar sand, for one.

Spacecraft used for asteroid mission can also sit for quite some time in the Lunar orbit, and do a lot of teleoperating on the surface, without a need to land. It can do many other things too, and many of those missions could be done in a 4 year term, with a sustainable, non-Apollo infrastructure, before winds change again.

 

[rockett]

Point is, it can be done. I don't like 'how' either, but it can be done. There is not much difference with radiation on the Moon surface, where you also have to cope with the lunar sand, for one.

But the moon is only a 3 day trip. We can also design better shielding for the surface, and we can develop ISRU to do it. On an asteroid mission, we have to carry all our shielding with us.

Spacecraft used for asteroid mission can also sit for quite some time in the Lunar orbit, and do a lot of teleoperating on the surface, without a need to land. It can do many other things too, and many of those missions could be done in a 4 year term, with a sustainable, non-Apollo infrastructure, before winds change again.

No arguments about the capabilities of Orion (whether real or on paper), but we can do the same thing with a craft that is built only to operate in space (HEFT explorer vehicle).

Sorry, but the clock has been ticking and two years are already gone almost. More, if you count Congress fiddling. From the look at the two Bills so far, and the House's difficulties in compromising with the Senate Bill, the wind may already be shifting, and some of it is blowing from the Administration's own party.

 

[EarthlingX]

Point is, it can be done. I don't like 'how' either, but it can be done. There is not much difference with radiation on the Moon surface, where you also have to cope with the lunar sand, for one.

But the moon is only a 3 day trip. We can also design better shielding for the surface, and we can develop ISRU to do it. On an asteroid mission, we have to carry all our shielding with us.

Catch is in 'develop'. If they go for NASA HLV there will be no other 'develop', as shown on Cx example. Even USAF is moving towards reusable infrastructure, and they have about five times bigger budget for space than NASA.
There are also more things missing for Lunar base than for asteroid mission, and if you can fly to an asteroid, you can also fly to Venus and Mars, more or less. You can't do that buried under Lunar surface.

Spacecraft used for asteroid mission can also sit for quite some time in the Lunar orbit, and do a lot of teleoperating on the surface, without a need to land. It can do many other things too, and many of those missions could be done in a 4 year term, with a sustainable, non-Apollo infrastructure, before winds change again.

No arguments about the capabilities of Orion (whether real or on paper), but we can do the same thing with a craft that is built only to operate in space (HEFT explorer vehicle).

Sorry, but the clock has been ticking and two years are already gone almost. More, if you count Congress fiddling. From the look at the two Bills so far, and the House's difficulties in compromising with the Senate Bill, the wind may already be shifting, and some of it is blowing from the Administration's own party.

Knowledge, got from the research of technologies, is much harder to kill than any program, and judging on the last 10 years, not for the lack of trying.

As for the moment, this is all paper, or not even that. You can't have Apollo program without Apollo money. and unfortunately, i don't see that in any future, more likely the opposite.

I would really like to see space-only reusable vehicle, assembled in the orbit, lifted with existing launchers, which share costs of their infrastructure operation with other programs, like launching commercial satellites. It can be done now, no need to wait 10 years (25 000 000 000$ + HLV development) for that.

LEO business is NASA's child, it is time to let it go, and help it, not compete with it. NASA should be about pushing boundaries of possible, not a heavy launch operator.

If the result of Administration's original plan would be sustainable infrastructure, orbital assembly, propellant depots, deep space (out of Earth's magnetic shield) vehicle, improved EVA capabilities, closed environment systems, than destination is just something you decide before the weekend (4 year) trip.

 

[rockett]

I would really like to see space-only reusable vehicle, assembled in the orbit, lifted with existing launchers, which share costs of their infrastructure operation with other programs, like launching commercial satellites. It can be done now, no need to wait 10 years (25 000 000 000$ + HLV development) for that.

Actually, the HEFT report (http://www.nasawatch.com/images/heft2.pdf) says HLV is necessary fo sustainability, and I'm inclined to agree.

(from page 31)
• An HLV is central to any robust human exploration program
• Delaying a decision on HLV configuration and requirements to 2015 limits NASA’s options and hampers planning
• There is no benefit to delaying work on the HLV, no technology needed for capability development

They give very sound reasons for it and the engineering is solid. They also line up an evolvable architecture, that can be fast-tracked.

 

[bdewoody]

I watched Living on the Moon again tonight. This time on the National Geographic Channel. I hope everyone interested in the future of manned space flight can see it at least once. When watching this program the logic for going back to the moon in force seems unassailable. The multitude of science and engineering projects that we can start and maintain while building a moon base and then colony are astounding.

When compared to sending a one time two man mission to an asteroid it seems totally obvious to me where our money should be spent.

 

[EarthlingX]

HEFT report is just an excuse to continue Cx (5seg boosters, RS-86, J2X, Orion), to keep the jobs, and to avoid new investments in infrastructure, which would avoid high costs of launch. There are 10 000 people in the Shuttle program, or dependent on it, at least that's the claim, plus Apollo hardware, built in times when money was not a problem. It was since then. This number should go down to something comparable to aviation industry.

nasawatch.com : Human Exploration Framework Team Presentation Online (with worth reading comments)

I really can't see how a launcher, used exclusively by NASA, can be sustainable. It is more likely an easy target for any budget cuts, if not for else, because it's a big target. EELVs were made to make access to space cheaper, not only for NASA, but also USAF. ITAR denied them access to non-goverment international market, with easy to see results. When was the last time European, or anyone else's satellite was launched on an US carrier ?

There is not only one asteroid, or better NEO, there are plenty, and we are just starting to find them. There will be many more found in the future. It is a basis for in-space resource utilization and long duration flights, where-ever that may be.

Point is, once again, you need much more technology advancements and capabilities for a Moon station than for space-only vehicle, which can be built in orbit, as demonstrated by ISS. There are also much cheaper ways to build it, than it was before (Bigelow - Spacehab).

If you need to go far (an asteroid, Mars orbit - Phobos/Deimos, Venus orbit, ..), lift empty big tank to orbit, plug it to propulsion and habitat module, buy fuel in the orbit on the market, fill it up, and engage. Test runs can be satellite repair, retrieval (junk), satellite refuelling (longer life on orbit), Lagrangian points visit, to see how could interplanetary transport network work, various EVA tricks and so on. Small steps, achievable in the short focus span, but forward, not only promises and show with PP.

If there were international agreement, where partners would bring in missing technology and capabilities (money) needed for the Moon base, it might be different.

China plans to land on the Moon with people by 2025, and they don't have anything heavier than 20t to LEO.

 

[rockett]

EELVs were made to make access to space cheaper, not only for NASA, but also USAF. ITAR denied them access to non-goverment international market, with easy to see results. When was the last time European, or anyone else's satellite was launched on an US carrier ?

That's a policy issue, which, as crippling as it is to American launchers, has to be worked out on the Congressional side, there's no one else who can change it. In spite of that, you are incorrect in that statement, there are a number of foreign launches in the works (and have been in the past). To name a few:
SpaceX launches for: Argentina, Astrium (Europe), Canada, Israel, and Taiwan (possibly Svea for Sweden also)
http://www.spacex.com/launch_manifest.php
ULA launches for: Italy, Argentina
http://spaceflightnow.com/tracking/

There is not only one asteroid, or better NEO, there are plenty, and we are just starting to find them. There will be many more found in the future. It is a basis for in-space resource utilization and long duration flights, where-ever that may be.

Few Asteroids Look Ripe for Astronaut Visit By 2025
http://www.space.com/news/nasa-space-asteroid-mission-near-earth-100831.html

Point is, once again, you need much more technology advancements and capabilities for a Moon station than for space-only vehicle, which can be built in orbit, as demonstrated by ISS. There are also much cheaper ways to build it, than it was before (Bigelow - Spacehab).

To use any asteroid resources, the same can be said as for lunar resources. Your spacecraft is much like Buzz Aldrin's XM: http://buzzaldrin.com/spaceships-worthy-of-the-name/, which has an equivalent in HEFT's SDLV, either of which can do that job.

If you need to go far (an asteroid, Mars orbit - Phobos/Deimos, Venus orbit, ..), lift empty big tank to orbit,

Difficult to accomplish without HLV...

Test runs can be satellite repair, retrieval (junk), satellite refuelling (longer life on orbit), Lagrangian points visit, to see how could interplanetary transport network work, various EVA tricks and so on. Small steps, achievable in the short focus span, but forward, not only promises and show with PP.

Full agreement that we have to build a complete infrastructure if we ever intend to stay, instead of one hit wonders...

If there were international agreement, where partners would bring in missing technology and capabilities (money) needed for the Moon base, it might be different.

Problem there is politics, they don't trust Congress' short attention-span, not to mention the fickleness of the voters (AND FOR GOOD REASON)...

China plans to land on the Moon with people by 2025, and they don't have anything heavier than 20t to LEO.

Considering how far behind the curve they are, it will be interesting to see how that works out. You are also forgetting propaganda value, the Soviets were going to beat us too.

 

[EarthlingX]

EELVs were made to make access to space cheaper, not only for NASA, but also USAF. ITAR denied them access to non-goverment international market, with easy to see results. When was the last time European, or anyone else's satellite was launched on an US carrier ?

That's a policy issue, which, as crippling as it is to American launchers, has to be worked out on the Congressional side, there's no one else who can change it. In spite of that, you are incorrect in that statement, there are a number of foreign launches in the works (and have been in the past). To name a few:
SpaceX launches for: Argentina, Astrium (Europe), Canada, Israel, and Taiwan (possibly Svea for Sweden also)
http://www.spacex.com/launch_manifest.php
ULA launches for: Italy, Argentina
http://spaceflightnow.com/tracking/

SpaceX is ITAR free.

On spaceflightnow launch schedule i found 1 (one) Delta 2 with SAC-D/Aquarius.

There is not only one asteroid, or better NEO, there are plenty, and we are just starting to find them. There will be many more found in the future. It is a basis for in-space resource utilization and long duration flights, where-ever that may be.

Few Asteroids Look Ripe for Astronaut Visit By 2025
http://www.space.com/news/nasa-space-asteroid-mission-near-earth-100831.html

Point is, once again, you need much more technology advancements and capabilities for a Moon station than for space-only vehicle, which can be built in orbit, as demonstrated by ISS. There are also much cheaper ways to build it, than it was before (Bigelow - Spacehab).

To use any asteroid resources, the same can be said as for lunar resources.

Landing on the Moon is not the same as docking (asteroid), or there would be no need for the Altair (Lunar lander).

If you need to go far (an asteroid, Mars orbit - Phobos/Deimos, Venus orbit, ..), lift empty big tank to orbit,

Difficult to accomplish without HLV...

For empty propellant tank to be used with deep space vehicle, just put second stage of any rocket in the orbit, even with a decent amount of propellant left, if you don't have a third stage/payload. Shuttle could bring ET to ISS, if she would have to.

Test runs can be satellite repair, retrieval (junk), satellite refuelling (longer life on orbit), Lagrangian points visit, to see how could interplanetary transport network work, various EVA tricks and so on. Small steps, achievable in the short focus span, but forward, not only promises and show with PP.

Full agreement that we have to build a complete infrastructure if we ever intend to stay, instead of one hit wonders...

If there were international agreement, where partners would bring in missing technology and capabilities (money) needed for the Moon base, it might be different.

Problem there is politics, they don't trust Congress' short attention-span, not to mention the fickleness of the voters (AND FOR GOOD REASON)...

China plans to land on the Moon with people by 2025, and they don't have anything heavier than 20t to LEO.

Considering how far behind the curve they are, it will be interesting to see how that works out. You are also forgetting propaganda value, the Soviets were going to beat us too.

We will see about China, and of course it is propaganda too, as with everybody else. Even if they delay the mission, it's more common than not.
I see most of their launches after they happen, because my Chinese sucks, and they announce them a day before it happens, in Chinese.

 

[HopDavid]

http://en.wikipedia.org/wiki/Delta-v_budget

Near earth objects are asteroids that are in orbits that are within the orbit of Mars. The delta-v to return from them are usually quite small, sometimes as low as 60m/s, using aerobraking on Earths atmosphere (substantial reentry shields would be required).[10] The orbital phasing can be problematic; once rendezvous has been achieved, low delta-v return windows can be fairly far apart (more than a year, often many years), depending on the body.

I question the part of delta-V usually being quite small. On very rare occasions Trans Earth Insertion can take 60 meters/sec. But these are very exceptional cases and occur infrequently.

The long trip times and infrequent launch windows make asteroids more difficult.

If a ship can use in situ propellent for the trip back, this makes the mission much more doable. Extracting water from hydrated clays may be difficult. It's possible some asteroids have icey interiors. But we haven't found such asteroids yet.

The moon, on the other hand, evidently has massive ice deposits at the poles. Water ice can be made into propellent. It can also be used as radiation shielding, drinking, and oxygen for breathing.

Further, lunar propellent is 2.5 km/sec from EML1 and 3.2 km/sec from LEO. The proximity of lunar propellent to LEO and EML1 would make asteroid missions far more doable.

 

[oldAtlas_Eguy]

Using ISS as the minimum cubic space per person for long duration (1 year or more) gives us 200 cubic meters per person. Four BA-330 will give this space for 6 persons. An Orion has only 15 cubic meters total and a Dragon 10 cubic meters. Using two Orion for a long duration Asteroid mission just doesn’t make sense. 3 persons in two Orions is 10 cubic meters each, most of which will be taken up with supplies and human occupancy support equipment, leaving very little elbow room.

 

[rockett]

I question the part of delta-V usually being quite small. On very rare occasions Trans Earth Insertion can take 60 meters/sec. But these are very exceptional cases and occur infrequently.

What they are omitting (possibly to look good) is all the maneuvering and station keeping propellant. That could be considerable with a particularly uncooperative rock. No way to tell how much of that you would need. Yes, we can estimate tumbling and rotation, it's just that, an estimate, and we've been fooled before. If you're going that far, you better have pleanty of extra fuel.

The long trip times and infrequent launch windows make asteroids more difficult.

Without question, we only have 2 known rocks within the 25 year goal, if I remember correctly.

If a ship can use in situ propellent for the trip back, this makes the mission much more doable. Extracting water from hydrated clays may be difficult. It's possible some asteroids have icey interiors. But we haven't found such asteroids yet.

Only one we've found so far is 24 Themis between Mars and Jupiter as far as I know.
Water Ice Found on the Surface of an Asteroid for the First Time
The asteroid 24 Themis has organic material and a layer of frost, bolstering theories that asteroids could have seeded Earth with both water and the precursors to life
http://www.scientificamerican.com/article.cfm?id=asteroid-24-themis

The moon, on the other hand, evidently has massive ice deposits at the poles. Water ice can be made into propellent. It can also be used as radiation shielding, drinking, and oxygen for breathing.

Further, lunar propellent is 2.5 km/sec from EML1 and 3.2 km/sec from LEO. The proximity of lunar propellent to LEO and EML1 would make asteroid missions far more doable.

Lunar ice is a pretty sure thing at this point, we just need to land some rovers to test ways to harvest it. Even on the surface we would use robots probably, because of around 100K temperatures.

 

[HopDavid]

I question the part of delta-V usually being quite small. On very rare occasions Trans Earth Insertion can take 60 meters/sec. But these are very exceptional cases and occur infrequently.

What they are omitting (possibly to look good) is all the maneuvering and station keeping propellant. That could be considerable with a particularly uncooperative rock. No way to tell how much of that you would need. Yes, we can estimate tumbling and rotation, it's just that, an estimate, and we've been fooled before. If you're going that far, you better have pleanty of extra fuel.

That, and most near earth asteroids have healthy inclinations, eccentricities and semi-major axis more or less than 1 A.U.. All these things make entering/departing the asteroid's neighborhood more expensive in terms of delta V.

If a ship can use in situ propellent for the trip back, this makes the mission much more doable. Extracting water from hydrated clays may be difficult. It's possible some asteroids have icey interiors. But we haven't found such asteroids yet.

Only one we've found so far is 24 Themis between Mars and Jupiter as far as I know.
Water Ice Found on the Surface of an Asteroid for the First Time
The asteroid 24 Themis has organic material and a layer of frost, bolstering theories that asteroids could have seeded Earth with both water and the precursors to life
http://www.scientificamerican.com/article.cfm?id=asteroid-24-themis

I stand corrected. And I believe it's also a pretty good bet Ceres has sub surface water.

However these take lots of delta V for several reasons. They're further out in the solar system. They have no atmosphere to lend a hand with aerobraking. And there's little Oberth benefit. So far as low hanging fruit go, these guys are higher up the tree than moon, NEOs or Mars.

The moon, on the other hand, evidently has massive ice deposits at the poles. Water ice can be made into propellent. It can also be used as radiation shielding, drinking, and oxygen for breathing.

Further, lunar propellent is 2.5 km/sec from EML1 and 3.2 km/sec from LEO. The proximity of lunar propellent to LEO and EML1 would make asteroid missions far more doable.

Lunar ice is a pretty sure thing at this point, we just need to land some rovers to test ways to harvest it.

Indeed. If I were in Vegas, I'd give exploitable lunar ice better than even odds.

For any given NEO, I'd give 100 to 1 odds against.

Even on the surface we would use robots probably, because of around 100K temperatures.

The moon is the only extra-terrestial body where teleoperated mining equipment is remotely plausible, in my opinion. Light round trip is about 2.7 seconds. A slower reaction time than you'd like granted. But far better than light lag to NEOs or Mars.

I still regard NEOs as low hanging fruit. Back when I thought the moon was hydrogen poor, I regarded NEOs as well as Phobos and Deimos as the best potential sources of the fuel component of rocket propellent that wasn't at the bottom of a deep gravity well. Since Chandrayaan-1's and LRO's discoveries via mini-SAR radar, my opinion has changed. Thick ice sheets at the lunar poles tips the scale towards the moon.

 

[rockett]

Using ISS as the minimum cubic space per person for long duration (1 year or more) gives us 200 cubic meters per person. Four BA-330 will give this space for 6 persons. An Orion has only 15 cubic meters total and a Dragon 10 cubic meters. Using two Orion for a long duration Asteroid mission just doesn’t make sense. 3 persons in two Orions is 10 cubic meters each, most of which will be taken up with supplies and human occupancy support equipment, leaving very little elbow room.

You want to use the ISS? Don't think it could take the strain of that much acceleration...

 

[EarthlingX]

Using ISS as the minimum cubic space per person for long duration (1 year or more) gives us 200 cubic meters per person. Four BA-330 will give this space for 6 persons. An Orion has only 15 cubic meters total and a Dragon 10 cubic meters. Using two Orion for a long duration Asteroid mission just doesn’t make sense. 3 persons in two Orions is 10 cubic meters each, most of which will be taken up with supplies and human occupancy support equipment, leaving very little elbow room.

How about Centaur with bigger tank, Sundancer, and Orion for command and decent module ?

Centaur would have to be refuelled, of course, and using LH doesn't make me happy, due to evaporation problems.

 

[rockett]

How about Centaur with bigger tank, Sundancer, and Orion for command and decent module ?

Centaur would have to be refuelled, of course, and using LH doesn't make me happy, due to evaporation problems.

And how to launch the fuel?

 

[EarthlingX]

How about Centaur with bigger tank, Sundancer, and Orion for command and decent module ?

Centaur would have to be refuelled, of course, and using LH doesn't make me happy, due to evaporation problems.

And how to launch the fuel?

With whatever is cheapest, can bring it there, and not bust the explorer vehicle. Buy it on the market.

 

[scottb50]

I've suggested launching it as water and processing it using Solar power as it is needed. Water is stable and easily storable and could also be used internally by vehicles and Platforms for electrical power environment and sanitation and recycled for repeated uses.

 

[oldAtlas_Eguy]

I've suggested launching it as water and processing it using Solar power as it is needed. Water is stable and easily storable and could also be used internally by vehicles and Platforms for electrical power environment and sanitation and recycled for repeated uses.

a water cycle power storage system has been proposed many times as one of the highest power storage density devices. A byproduct would be Lox an LH that can be used to refuel spacecraft. The water would have to be replaced.