Launch News SpaceX to send privately crewed Dragon spacecraft around the Moon in 2018

[MaverickSawyer]

This whole thing smells of desperation.

 

[GLS]

The fact that this cislunar flight shouldn't require brand new hardware

I could be wrong here, but they probably use GPS for guidance now, and that doesn't work on the Moon... and they probably also need a more powerful radio.

Like most things SpaceX, it's not necessarily that they can't do it, but that they can't do it in the much advertised timeframe.

 

[jedidia]

Scott Manley made a nice summary for people like me that aren't following the tech development too closely:

 

[K_Jameson]

Just posted also in an Italian space forum:

:hmm: :hmm:

 

[dman]

Refer to SATURN V - 2nd test flight (April 1968) was a partial failure - 2 engines in 2nd
stage shutdown because of problems in fuel line to igniters

Restart of 3rd stage in orbit failed

Yet in December 1968 SATURN V manned Apollo 8 mission to moon

Most of the hardware for FALCON HEAVY has already been flight tested numerous time
(not withstanding that little problem on pad last fall...)

FALCON HEAVY at its basic is FALCON 9 with 2 Falcon 9 first stages strapped to it

Only thing unique is propellant cross feed from the 2 boosters to core stage

 

[GLS]

Refer to SATURN V - 2nd test flight (April 1968) was a partial failure - 2 engines in 2nd
stage shutdown because of problems in fuel line to igniters

Restart of 3rd stage in orbit failed

Yet in December 1968 SATURN V manned Apollo 8 mission to moon

Most of the hardware for FALCON HEAVY has already been flight tested numerous time
(not withstanding that little problem on pad last fall...)

FALCON HEAVY at its basic is FALCON 9 with 2 Falcon 9 first stages strapped to it

Only thing unique is propellant cross feed from the 2 boosters to core stage

Your're forgetting the structure vibrations and loads, control system, aerodinamics, pad acoustics, etc...

You are correct on the history of the Saturn V and Apollo 8 (you forgot the SLA delamination on AS-502 ), but that had a HUGE team behind it, about 1 year to work the issues of those 2 flights and years of manned spacecraft experiance.

 

[ADSWNJ]

@K Jameson

I simply don't get your negativity on this topic. This is a space forum, where we are a bunch of space nerds that get excited by orbital maneuvers, big rockets, and yes, space exploration. If private citizens wish to enter into a commercial agreement with a private space exploration company, knowing full well that they are breaking new ground and there are non-zero risks of death, then who are we to stop them?

I get the feeling that many on this forum are anti-SpaceX because either it's American, or because it's challenging conventional wisdom (e.g. the wisdom that projects should proceed at the speed of SLS, and only 30+ year navy test pilots earn the right to be astronauts, and private companies have no right to go to exotic places like the Moon or Mars, etc. Well, I say: to hell with that. Go SpaceX, go Blue Origin, go Virgin Galactic, go X-Prize competitors, and go all those who are willing to put their capital and hopes on the line to further the boundaries of space for us all.

 

[Thunder Chicken]

You're forgetting the structure vibrations and loads, control system, aerodynamics, pad acoustics, etc...

Yes, but there are tools available today that weren't in the 1960s. Many of these phenomena can be modeled computationally, and those models can already be validated against existing Falcon 9 flight data.

I'm not saying that there won't be any surprises, but it is possible to build something and launch it and have a very good expectation of how it will perform based on current design methods and tools. Whether those tools are being utilized competently, well...that is another matter entirely.

 

[Andy44]

Your're forgetting the structure vibrations and loads, control system, aerodinamics, pad acoustics, etc...

Three and a half decades ago NASA foolishly launched STS on its very first test flight in full stack configuration with two guys riding it, and somehow got away with it.

So it's not impossible, but I still think it's way too risky. At least I trust the Dragon LES more than Columbia's old ejection seats in an emergency.

I think it's basically PR noise. But we'll see.

 

[MaverickSawyer]

I'm with Andy on this one... I think Musk just wants to stay in the headlines right now. I'll believe they're actually doing this once they fly FH.

 

[K_Jameson]

FALCON HEAVY at its basic is FALCON 9 with 2 Falcon 9 first stages strapped to it

If it had been so easy, it would not have accumulated four years of delay. Also, the FH configuration was continuously modified over the time.

Only thing unique is propellant cross feed from the 2 boosters to core stage

FH has no more propellant crossfeed. That feature was cancelled.

 

[Pipcard]

If it had been so easy, it would not have accumulated four years of delay. Also, the FH configuration was continuously modified over the time.

The delay was mostly because of the reconfiguring of the base F9.

First flight of Delta IV Medium: November 20, 2002
First flight of Delta IV Heavy: December 21, 2004

 

[K_Jameson]

@K Jameson

I simply don't get your negativity on this topic. [...]

Yeah, I don't like particularly Elon Musk, at least the latter Musk. I think that in the recent times is trying desperately to gather attention with some coup de theatre. That hilarious "mars mission" video was another example.

But despite this, I don't think to be "negative". I only try to be realistic.
I'm skeptical at the same level also on the hypothetical SLS manned debut.

---------- Post added at 08:26 AM ---------- Previous post was at 08:20 AM ----------

The delay was mostly because of the reconfiguring of the base F9.

First flight of Delta IV Medium: November 20, 2002
First flight of Delta IV Heavy: December 21, 2004

FH also had problems. This is demonstrated by the abandon, at least for the moment, of his most publicized feature (the cited crossfeed).
I don't say that new, complex machines must not have problems...
And, you can hate it, but SLS has much more growth potential, speaking of payload. FH currently lacks a proper upper stage for BLEO high energy missions.

 

[Urwumpe]

FH currently lacks a proper upper stage for BLEO high energy missions.

The restartable second stage isn't too bad there. But of course, the mass ratios are rather poorly optimized for this mission. But you can't optimize a rocket for all missions. Even the SLS will have its inefficiencies there.

 

[K_Jameson]

Three and a half decades ago NASA foolishly launched STS on its very first test flight in full stack configuration with two guys riding it, and somehow got away with it.

Other times.
'80 optimism. And, first of all, Columbia wasn't capable of automatic flight, so the manned debut was mandatory.
When possible, NASA has preferred a gradual approach.
Also, Columbia was a step from disaster. Young stated that if it had been aware of the potential damage of the body flap at launch, it would have aborted the ascent, bring Columbia at low altitude, and ejected.

So it's not impossible, but I still think it's way too risky. [...] I think it's basically PR noise. But we'll see.

:thumbup:

 

[Fabri91]

I could be wrong here, but they probably use GPS for guidance now, and that doesn't work on the Moon... and they probably also need a more powerful radio.

Like most things SpaceX, it's not necessarily that they can't do it, but that they can't do it in the much advertised timeframe.

Quoting from here:

Guidance, Navigation and Control

For navigational purposes, Dragon is outfitted with Inertial Measurement Units, GPS Systems, Iridium Recovery Beacons and Star Trackers. Attitude Control and Navigation in orbit is accomplished with the IMU and Star Trackers. Attitude Determination has an accuracy of 0.004 Degrees or smaller. Attitude Control is 0.012 degrees on each axis in Stationkeeping Mode. Dragon provides a fully autonomous Rendezvous and Docking System. For manned missions, a manual docking is also possible by using the override function to control the vehicle by hand.

Dragon appears to have already been fitted with intertial measurement units and star trackers for attitude control, so that should help.

That was the only source on the matter I could find, however.

 

[Urwumpe]

Well, it isn't that easy. GPS is used for correcting position and velocity errors, star trackers do attitude errors.

For a lunar mission, the position and velocity corrections have to be uplinked from the ground. Which means it needs a better communication system.

 

[Fabri91]

Yes, and to be fair to SpaceX that is one of the needed modifications they mentioned in the announcement.

 

[Urwumpe]

Yes, and to be fair to SpaceX that is one of the needed modifications they mentioned in the announcement.

Yes. The key issue for SpaceX shouldn't be GNC, TCS or EPS... it should be the ECLSS and the human payload.

A space station taxi has way simpler demands there.

 

[vchamp]

... That hilarious "mars mission" video...
...I only try to be realistic.

You try very hard to be realistic
For what I love SpaceX is that they try to do what others say is impossible and give a hope for a true space faring humanity, and they are on track to accomplish this and to realize my dream - live in times when humans are walking on another planet.

There is much in their plans that looks crazy and it may be that this will never happen, but they are trying and already made significant progress.

You think that ITS is hilarious? I don't see other ways of creating a self-sustaining settlements on Mars in this century.

I think that people need to dream and do "hilarious" things. Trying to be realistic is a dead end for humanity in my opinion.

So, Go SpaceX, Go Blue Origin! Even if you fail, you already made my life better, by making me dream and love spaceflight again and by giving us hope.