"Flexible Path" Scenario E for Cx

[simon-th]

I think I have not seen a comprehensive Flexible Path destination list yet. People sometimes seem to forget (or don't know) the extend of the possibilities that Flexible Path offers. There isn't just the Moon and the Mars in the inner solar system. There are countless destinations that a mission program could go to - and most would be forced, be of interest from a scientific and exploration point of view and would provide us with knowledge on how to do space flight that we just don't have right now.

Here is a list - feel free to add to it:

2015-2025+ Basic missions - chemical propulsion - no rad shielding - no artificial gravity required - single (or dual) launch:
1. LEO demonstration missions (30 days - 900 days) (e.g. long-term hab mission demo)
2. lunar swing-by mission (7 days)
3. lunar orbital mission (10 days)
4. EML-1 and EML-2 (maybe even other Earth-Moon Lagrange points) (20 days)
5. SML-1 and SML-2 (30-60 days)

2020 - 2030+ Advanced missions - chemical propulsion - solar radiation event storm shelter partially required - no enhanced GCR shielding required but recommended - no artificial gravity required - dual launch minimum:
6. NEO (meteoroids) missions to small rocks -5 to 20m diameter (100-200 days)
7. Lunar sorties (14 days)
8. Lunar extended stays (30-60 days)
9. Mars flyby (450 days)
10. Mars orbital mission - opposition class - to Deimos/Phobos (500 days)
11. Mars orbital mission with Venus flyby (gravity assist) on flight back (500 days)

2025-2040+ Advanced++ missions - advanced propulsion techniques recommended not required - solar radiation event storm shelter required - enhanced GCR shielding not required but recommended - no artificial gravity required but recommended if feasible - multiple launch scenario or depots required:
12. Mars short-term 20-60 days surface expedition - opposition class mission (500 days)
13. Lunar outpost mission (180 days)
14. Advanced NEO (asteroids) missions to larger NEOs (>50m) (250-500 days)
15. Long-term conjunction Phobos or Deimos mission (900 days) (GCR shielding probably required - AG maybe required)
16. Venus orbital missions with upper atmosphere excursion module (500 days)

2035-2050+ Expert missions - advanced propulsion techniques required - solar radiation event storm shelter required - enhanced GCR shielding required - artificial gravity recommended, maybe even required - multiple launch scenario or depots required:
17. Extended 500 days on Martian surface mission (900 days or less with advanced propulsion)
18. Ceres mission (1000 days or less with advanced propulsion)
19. Other asteroid belt missions (Vesta, Pallas, Hygeia etc.) (1000 days or less with advanced propulsion)
20. Expert NEO (comet) missions - high delta-v required (length depending on availability)
21. Mercury orbital and landing mission - high delta-v required (600 days)

[randomly]

Perhaps it would be good to group these with reference to the enabling technologies.

Telepresence robotics systems
High power Solar energy systems
Sample return probes
In space lab analysis
Artificial Gravity
SPE radiation shielding
Passive GCR shielding
Active GCR shielding
High power nuclear energy systems
ECLSS of increasing duration
Advanced propulsion
Rad hard video games

please fill free to add to the list.

Note that once you have the last 8 items listed your spacecraft can pretty much go anywhere.

[simon-th]

...
Rad hard video games
...

We probably won't go anywhere without that technology development project. I suggest NASA focuses on that first, at least for the first 20 years or so...

[randomly]

Although you can get a rad hard processor that's an architectural variant of the Xbox360, it's one core instead of 3 and it runs 20 times slower.   
Fortunately it's only $200,000 a unit, without controllers.

[Archibald]

Here is a list - feel free to add to it:

2015-2025+ Basic missions - chemical propulsion - no rad shielding - no artificial gravity required - single (or dual) launch:
1. LEO demonstration missions (30 days - 900 days) (e.g. long-term hab mission demo)
2. lunar swing-by mission (7 days)
3. lunar orbital mission (10 days)
4. EML-1 and EML-2 (maybe even other Earth-Moon Lagrange points) (20 days)
5. SML-1 and SML-2 (30-60 days)

2020 - 2030+ Advanced missions - chemical propulsion - solar radiation event storm shelter partially required - no enhanced GCR shielding required but recommended - no artificial gravity required - dual launch minimum:
6. NEO (meteoroids) missions to small rocks -5 to 20m diameter (100-200 days)
7. Lunar sorties (14 days)
8. Lunar extended stays (30-60 days)
9. Mars flyby (450 days)
10. Mars orbital mission - opposition class - to Deimos/Phobos (500 days)
11. Mars orbital mission with Venus flyby (gravity assist) on flight back (500 days)

2025-2040+ Advanced++ missions - advanced propulsion techniques recommended not required - solar radiation event storm shelter required - enhanced GCR shielding not required but recommended - no artificial gravity required but recommended if feasible - multiple launch scenario or depots required:
12. Mars short-term 20-60 days surface expedition - opposition class mission (500 days)
13. Lunar outpost mission (180 days)
14. Advanced NEO (asteroids) missions to larger NEOs (>50m) (250-500 days)
15. Long-term conjunction Phobos or Deimos mission (900 days) (GCR shielding probably required - AG maybe required)
16. Venus orbital missions with upper atmosphere excursion module (500 days)

2035-2050+ Expert missions - advanced propulsion techniques required - solar radiation event storm shelter required - enhanced GCR shielding required - artificial gravity recommended, maybe even required - multiple launch scenario or depots required:
17. Extended 500 days on Martian surface mission (900 days or less with advanced propulsion)
18. Ceres mission (1000 days or less with advanced propulsion)
19. Other asteroid belt missions (Vesta, Pallas, Hygeia etc.) (1000 days or less with advanced propulsion)
20. Expert NEO (comet) missions - high delta-v required (length depending on availability)
21. Mercury orbital and landing mission - high delta-v required (600 days)

Excellent post, excellent program.

Small nitpicking

9. Mars flyby (450 days)

Not very useful. In the sixties, maybe, in our days, no.

I would prefer Zubrin's  Athena

http://pdf.aiaa.org/getfile.cfm?urlX=85%26%5D0%3BU%2BDN%26S7R%20CMU%24CBQ%3A%2B64K8%26%5FOGJ%0A&urla=%25%2ARH%27%21P%2C%20%0A&urlb=%21%2A%20%20%20%0A&urlc=%21%2A0%20%20%0A&urle=%27%2B%22D%22%23PJCU0%20%20%0A

The Athena spaceship use a Mars swingby to go into a heliocentric orbit very similar to Mars.
In other words, the two-man ship closely chase Mars for a year, at an average distance of 1 million kilometers = 3.5 seconds-light, perfect for telerobotics !

After a year, the red planet literally "eject" the ship back to Earth.

Zubrin call that a double flyby, and insists on the fact it is doable with four russian  upper stages; 72 tons of storable propellants, ISP 326 seconds.

I would like too see an uprated Athena. First, the ship would be ferried unmanned to EML-2 by a SEP-tug. This would save a lot of propellants, diminishing IMLEO further.
Secondly, there would be a second ship; this one would go into a halo orbit around Sun-Mars L1.

The two ships would fly side by side, in convoy. Von Braun imagined something similar for its 1969 NTR Mars expedition
http://www.astronautix.com/craft/vonn1969.htm

This allowed two Mars expedition spacecraft to travel in convoy on the mission together, providing Von Braun's preferred mutual support and back-up.

both ship (Athena and Samuel ) would be one milion kilometer away from Mars (one in a heliocentric orbit, the other in a halo orbit.

[mike robel]

My problem with Flexible Path is it appears to ignore the radiation issues.  If we have not solved it, you can't send a crew on a 200 day mission to a NEO, or much anyplace else other than the moon.

And if you do, then just go to Mars.

[simon-th]

My problem with Flexible Path is it appears to ignore the radiation issues.  If we have not solved it, you can't send a crew on a 200 day mission to a NEO, or much anyplace else other than the moon.

Who says 200-day missions can't be carried out without effective GCR shielding?

For 200-day missions you need a storm shelter for solar radiation events. The radiation dose that astronauts would receive on a 200-day mission from GCR is within tolerance (during solar minimum at 10g/cm² minimal shielding it would be about double the annual tolerated dose, at 20g/cm² near the allowable annual tolerated dose and at a combined average shielding of about 25-30g/cm² below the allowed threshold NASA has set - the ISS has between 15g and 30g shielding depending on where you are in the station; during solar maximum even at minimum shielding, GCR exposure is within tolerance for a 200-day mission).

The problem are 500-day and more so 900-day missions. For a 900-day mission you would need some kind of massive passive GCR shielding - or active shielding.

[Robotbeat]

How feasible is biological remediation of radiation damage? Aren't some people (like in Iran and India) naturally resistant to radiation?

[the_roche_lobe]

It would be nice if one of those NEO missions was a technology demonstrator in possible deflection techniques.

P

[Robotbeat]

It would be nice if one of those NEO missions was a technology demonstrator in possible deflection techniques.

P

This is probably the most important thing we can do with the space program in the near term (with the possible exception of modifying Earth's climate from space). We owe it to our children to protect our planet from NEO collisions. This could be sold to the public very convincingly as a strategic imperative, I think. Sometime in roughly the next 100,000 years--could be this month--we will be hit with a civilization-ending collision. It's up to us, as a space-capable species, to stop it. We know it has happened in the past. Perhaps we could even get the greenies on board, since such a collision would devastate ecosystems.*

*NOTE: They would be on-board the idea, NOT on-board the rocket headed to deflect a NEO...

[docmordrid]

How feasible is biological remediation of radiation damage?....

Radiation does its damage by breaking the DNA sequence. 

Some people are more sensitive to radiation illness because of defects in their telomeres; the multiple 'periods' at the end of a chromosome.  Each human telomere has the sequence TTAGGG. Generally speaking more at each end of a chromosome increases stability (to a point), so defects amount to a reduction in the number of 'periods'. 

Causes of telomere shortening can be as simple as aging, inheritance or disease.  Some studies have also shown short telomeres in lower income populations and long ones in higher income populations. Diet?

When a break occurs, due to radiation or otherwise, short telomeres can fuse to a resulting naked end of DNA, causing an inability for that sequence to be repaired normally (which the body can do) and increasing chromosomal instability - a bad thing as it can lead to cell malfunction (cancer etc.) or cell death.

There have been papers about doing telomere repairs using the enzyme Telomerase (adds those 'periods') both as prophylaxis and as treatment for diseases characterized by telomere defects. 

Not practical, or proven, yet.  One problem is that high Telomerase has been implicated in several disease processes, so unless these issues are worked out.....

[mmeijeri]

It would be nice if one of those NEO missions was a technology demonstrator in possible deflection techniques.

ESA was thinking about such a mission (called Don Quijote) a while ago.