Author Topic: SpaceX Crewed Dragon Circumlunar Mission (Read 515475 times)

TrevorMonty · « **Reply #980 on:** 03/11/2017 03:11 pm »

If SpaceX could increase D2 DV to 900-1000m/s they could offer missions to Near Rectilinear Orbit (NRO) 6-8days 2,000 to 75,000km Roughly polar.

Transfer times are 5 days each way giving 21 days total for single orbit round trip. Having a enhanced Cygnus habitation module already in orbit would make for a more comfortable stay and would allow for additional orbits.

http://spirit.as.utexas.edu/~fiso/telecon/Whitley_4-13-16/

vt_hokie · « **Reply #981 on:** 03/11/2017 05:06 pm »

Quote from: MATTBLAK on 03/11/2017 07:29 am

Good grief! I go away from a thread for a few hours - and it goes mad!! Now we're arguing semantics?! It's going to be a manned trip around the freaken Moon, guys! Aren't even some of you going to get behind this?! Or even be a little happy?! Do I know that it's potentially a stunt, compared to a real exploration mission? Yes; probably I do. Do I care? NO!!

In this era of little leadership and budget-strangled mediocrity, this mission should be treated as a step in the right direction. If most (not all, sadly) of us could get behind this flight - this could be our chance to bootstrap something better into being, before too long...

Do I think it's reckless and highly risky? Yes. Am I still excited by the possibility of seeing people leave low Earth orbit for the first time in my lifetime? Absolutely. My only concern would be any possible ramifications of a catastrophic failure for commercial crew.

oiorionsbelt · « **Reply #982 on:** 03/11/2017 06:27 pm »

Quote from: vt_hokie on 03/11/2017 05:06 pm

[

Do I think it's reckless and highly risky? Yes. Am I still excited by the possibility of seeing people leave low Earth orbit for the first time in my lifetime? Absolutely. My only concern would be any possible ramifications of a catastrophic failure for commercial crew.

Are you expressing these same concerns on commercial crew, D2 threads? No.
Catastrophic failure is possible in LEO just as it is in cislunar space.

clongton · « **Reply #983 on:** 03/11/2017 06:32 pm »

Spaceflight is risky. Spaceflight is dangerous. People have died engaging in it. People will die engaging in it.
Get over it. It's the nature of the beast.
Anyone not willing to risk it has the option of staying home.

philw1776 · « **Reply #984 on:** 03/11/2017 06:52 pm »

Quote from: clongton on 03/11/2017 06:32 pm

Spaceflight is risky. Spaceflight is dangerous. People have died engaging in it. People will die engaging in it.
Get over it. It's the nature of the beast.
Anyone not willing to risk it has the option of staying home.

Whew!
Thanks to hear that I won't be strapped down screaming into a Dragon 2.

BobHk · « **Reply #985 on:** 03/11/2017 09:51 pm »

Quote from: clongton on 03/11/2017 06:32 pm

Spaceflight is risky. Spaceflight is dangerous. People have died engaging in it. People will die engaging in it.
Get over it. It's the nature of the beast.
Anyone not willing to risk it has the option of staying home.

Agree. Knowing the risks i'd go this moment. My kids have all been informed if i disappear they're to look for me at a launch pad or in orbit and that I love them but i'd be damned if I passed up the opportunity.

vt_hokie · « **Reply #986 on:** 03/12/2017 01:17 am »

It brings up a broader issue though - what are the ramifications, both positive and negative, of commercial companies using their private systems in ways that have much greater risk tolerance than NASA does while providing taxpayer funded transportation services to NASA? In the long run, it's probably a good thing so long as failures don't threaten to trip up commercial crew right out of the starting gate.

manoweb · « **Reply #987 on:** 03/12/2017 01:20 am »

Quote from: vt_hokie on 03/11/2017 05:06 pm

My only concern would be any possible ramifications of a catastrophic failure for commercial crew.

If lunar flights become routine, or at least common, who cares about ISS commercial crew honestly

Robotbeat · « **Reply #988 on:** 03/12/2017 01:23 am »

NASA doesn't exactly have a stellar record for safety either. And heck, whether they launch crew on the first or second flight of SLS, that's not terribly risk averse when you get down to it. And I don't think Commercial crew I'll be more dangerous than Soyuz, which NASA uses all the time and which isn't perfectly safe either.

MATTBLAK · « **Reply #989 on:** 03/12/2017 02:52 am »

You're basically correct - Soyuz is only one critical system failure away from disaster, really. Killing Komarov and the Soyuz 11 crew basically ironed out the 'bugs' from the overall system long ago. But there have a been a number of near misses over the years with aborts and malfunctions, and the loss of Progress craft for various reasons.

I shudder when I contemplate main parachute failures, Orbital/Descent module separation mishaps, launcher upper stage failures (explosions)...

It would only take one vehicle loss with one or two American Astronauts included and Congress and the Senate would go ballistic; lots of finger-pointing and political point scoring as they tried to nail down precisely which past Administration to blame for the disaster...

But risk is the business at hand. We've got to get on with it!

deruch · « **Reply #990 on:** 03/12/2017 03:07 am »

Would it be at all feasible to redesign something like the SHERPA to be deployed from the Dragon 2 trunk? SHERPA could then move itself to lunar obit while the Dragon is still doing its fly-by. Easy way to put a bunch of cube sats in LLO?

Comga · « **Reply #991 on:** 03/12/2017 04:38 am »

Quote from: deruch on 03/12/2017 03:07 am

Would it be at all feasible to redesign something like the SHERPA to be deployed from the Dragon 2 trunk? SHERPA could then move itself to lunar obit while the Dragon is still doing its fly-by. Easy way to put a bunch of cube sats in LLO?

No
No
No
Other than that....
There is nothing easy about the small parts of these .... ideas that are not physically impossible
SpaceX is not going to do anything like any of this for a dozen reasons.
Let's start with not putting mass in the trunk and not adding additional propulsion systems and fuel to the flight systems.
The mission is interesting and challenging enough without any additional distractions and requirements.
Can we discuss the mission as announced and not try to tell Musk how to supercharge it?

oldAtlas_Eguy · « **Reply #992 on:** 03/12/2017 04:12 pm »

There is a question as to who would go for the second flight and when?

NASA would possibly fly once on a LFR but not twice. The reason Orion is doing a LFR is test the Orion hardware. NASA wants a destination and craft that can reach the destination and return.

For NASA to use SpaceX some additional hardware would have to be developed. Say a propulsion module that fits in the 14m^3 space of the trunk that can deliver the DeltaV for the LOI and ETI. This propulsion module could also have optional add-ons: RCS clusters, Solar arrays, and landing legs. With the some or all of the options additional uses for the same design propulsion module can be used as a Deep Space tug or a Lunar lander.

NASA could pay SpaceX to create the capability under SAA for support of:
- cargo and crew transport to a L2 station
- emplacement of L2 station elements
- landing on the Lunar surface of crew and cargo

The vehicles and prices would not be cheap but the prices would also at the $3B budget level of SLS/Orion could enable up to 10 flights/yr (3 crew, 4 cargo, 2 Lunar landings, add a habitat element to expand the L2 station or to combining using one Lunar landing trip to place a habitat on the surface.).

This would be a sell-able system to NASA.
SLS/Orion -1 flight 4 crew and a small habitat module.
Price $3B/yr

SpaceX =10 FH flights 4+ crew (total includes crew that visit Lunar surface), 2 crew landed on Lunar surface, habitat landed on Lunar surface, habitat added to L2 station.
Price $3B/yr

For tourist around the Moon in a LFR no new hardware just their money is required. These flights will not be often.

AncientU · « **Reply #993 on:** 03/12/2017 04:50 pm »

Quote

NASA could pay SpaceX to create the capability under SAA for support of:
- cargo and crew transport to a L2 station
- emplacement of L2 station elements
- landing on the Lunar surface of crew and cargo

All of the NASA-related Lunar support tasking discussed above may happen, but that would be supported for revenue, not for enabling technology for the long range plan. (Revenue does enable the long range plan.)

I think the logical* follow-on to this Lunar flight is an initial propellant depot. Just as the Lunar flight (and Red Dragon for that matter) came out of left field for the spaceflight community, a depot demo would be directly on the path to Mars, while offering the Public-Private Partnership (3P) another much-needed facet of capability. As we've discussed thoroughly, on-orbit refueling leverages to a huge degree the capabilities of anything on orbit that can refuel -- making 'smaller' payloads bigger. In Lunar orbit, reusable landers become the obvious choice. Methlox of course.

* Logical, in this usage, is logical relative to SpaceX plans, not what we'd do in Cis-Lunar space.
And wishful thinking.

oldAtlas_Eguy · « **Reply #994 on:** 03/12/2017 05:30 pm »

Quote from: AncientU on 03/12/2017 04:50 pm

Quote
NASA could pay SpaceX to create the capability under SAA for support of:
- cargo and crew transport to a L2 station
- emplacement of L2 station elements
- landing on the Lunar surface of crew and cargo

All of the NASA-related Lunar support tasking discussed above may happen, but that would be supported for revenue, not for enabling technology for the long range plan. (Revenue does enable the long range plan.)

I think the logical* follow-on to this Lunar flight is an initial propellant depot. Just as the Lunar flight (and Red Dragon for that matter) came out of left field for the spaceflight community, a depot demo would be directly on the path to Mars, while offering the Public-Private Partnership (3P) another much-needed facet of capability. As we've discussed thoroughly, on-orbit refueling leverages to a huge degree the capabilities of anything on orbit that can refuel -- making 'smaller' payloads bigger. In Lunar orbit, reusable landers become the obvious choice. Methlox of course.

* Logical, in this usage, is logical relative to SpaceX plans, not what we'd do in Cis-Lunar space.
And wishful thinking.

As we have seen in the past, the current Lunar fly-by being the latest, if you pay for it and it is not difficult to make changes to implement SpaceX is willing to provide.

AncientU · « **Reply #995 on:** 03/12/2017 05:52 pm »

Agree, particularly if it is a piece of the Mars puzzle that has to be put into position.

TomH · « **Reply #996 on:** 03/12/2017 10:36 pm »

WaPo article today:

https://www.washingtonpost.com/national/health-science/trump-with-nasa-has-a-new-rocket-and-spaceship-wheres-he-going-to-go/2017/03/11/4193f1be-002d-11e7-8f41-ea6ed597e4ca_story.html?utm_term=.faa4be9cbfde

Robotbeat · « **Reply #997 on:** 03/12/2017 11:33 pm »

EM-2 will be putting a hab module at DRO. I think Dragon/FH can reach that. It'd allow NASA to rotate crew and have cheap logistics. That'd be a less stunt-y mission. Especially if combined with low-latency lunar telerobotics.

Jim · « **Reply #998 on:** 03/13/2017 12:10 am »

Quote from: Robotbeat on 03/12/2017 11:33 pm

EM-2 will be putting a hab module at DRO.

There is no such payload for EM-2 or other SLS missions.

Robotbeat · « **Reply #999 on:** 03/13/2017 12:53 am »

Quote from: Jim on 03/13/2017 12:10 am

Quote from: Robotbeat on 03/12/2017 11:33 pm
EM-2 will be putting a hab module at DRO.

There is no such payload for EM-2 or other SLS missions.

Are you sure that will stay true?
http://forum.nasaspaceflight.com/index.php?topic=38818.msg1652065#msg1652065