Space X to build reusable launch vehicle

williatw · Post by **williatw** » Sun Feb 26, 2012 4:16 pm

kunkmiester wrote:How big of an investment would P&W have said Falcon 9 would be?

Regardless of the economics, one thing a moon base would accomplish is to put advanced propulsion like TRITON beyond the reach of bureaucrats and NIMBYs. The base would be used for a variety of other purposes, so the multi-billion dollar investment for it wouldn't be held by engine development alone. In fact, you'd probably not want to tell anyone you're building an engine until the base is up. Anyone building a moon base would have to deal with a lot of national and international politics. Building flying nuclear reactors wouldn't help with the stupid that exists in those areas.

And the purpose of a TRITON is an ambitious manned interplanetary program. If Musk succeeds in $100/lb or less to orbit he just made such a program far more feasible, if not inevitable. That in itself would make a NTR like TRITON much more likely to happen whether SpaceX does it or someone else does.

Skipjack · Post by **Skipjack** » Sun Feb 26, 2012 5:53 pm

I think that Musk would do better in investing into Helion Energy. John Slough only needs 30 million for a demonstration reactor. That is not a lot of money for Musk. Then he could continue funding Slough to develop his spin off propulsion technology.
With all that, Musk would solve the worlds energy problems and create new enabling technology for space exploration. Double win!

williatw · Post by **williatw** » Sun Feb 26, 2012 11:50 pm

A website I have liked over the years on space topics: http://www.projectrho.com/rocket/

Skipjack · Post by **Skipjack** » Mon Feb 27, 2012 12:21 am

A website I have liked over the years on space topics: http://www.projectrho.com/rocket/

It seems rather outdated to me. Maybe the author can be motivated to update it with a new design (wiki maybe?) and new content including things like DPF- based engines, FRC, ELF and of course the Polywell (whats known of it anyway).

williatw · Post by **williatw** » Mon Feb 27, 2012 1:12 am

Skipjack wrote:
A website I have liked over the years on space topics: http://www.projectrho.com/rocket/
It seems rather outdated to me. Maybe the author can be motivated to update it with a new design (wiki maybe?) and new content including things like DPF- based engines, FRC, ELF and of course the Polywell (whats known of it anyway).

Your a hard man to please skipjack: http://en.wikipedia.org/wiki/Skipjack_class_submarine
considering that your namesake has been out of commission for years. I agree it could stand a format change maybe..some of the info on the site is still good on many types of rocket engines, spacesuits, weaponry etc.

Skipjack · Post by **Skipjack** » Mon Feb 27, 2012 1:28 am

Your a hard man to please skipjack

Yes, I am but in this case I might have appeared more harsh than I intended to.
The site is really great and I used to send people there a lot myself. It just needs to be brought a bit up to date, that is all. There have been a few quite exciting developments in the last few years and I think that they should be up there.

http://en.wikipedia.org/wiki/Skipjack_class_submarine
considering that your namesake has been out of commission for years.

Yes, my name is in honor of the 585, the best submarine class that the US had in service for a very long time, still outperforming all its successors until the 688 thanks to a true "Albacore" shape (which successors replaced with a simpler/cheaper cylindrical shape). In many ways the Skipjack class was outstanding. That is why I chose the name for my nick.

krenshala · Post by **krenshala** » Wed Feb 29, 2012 4:19 pm

Looks like SpaceX has the Dragon/Falcon9 fully built as of a day or two ago. I believe there are still a few tests before they will launch, but one comment I saw on the UniverseToday article was that Elon posted on Twitter that they were looking at launching in late April.

dmshiplo · Post by **dmshiplo** » Wed Feb 29, 2012 5:35 pm

This was posted on SpaceX's Twitter:

http://p.twimg.com/Amr-Go5CEAATWWZ.jpg:large

Looking good! I'm very optimistic about SpaceX's progress.

Skipjack · Post by **Skipjack** » Wed Feb 29, 2012 6:45 pm

Update, Falcon9+Dragon now out on the pad for a wet dress rehearsal:
http://science.ksc.nasa.gov/shuttle/cou ... 4large.jpg

Nydoc · Post by **Nydoc** » Fri Mar 02, 2012 9:12 am

Skipjack wrote:I am assuming that with the new flight profile, they will "aim higher" so that the rocket travels less distance downrange, but reaches a greater hight before staging occurs. That would probably give the second stage a bit more "to work with" and will reduce the problem for the first stage having to break down and travel back all the way. I think it now resembles more closely the flight profile of the Kistler K1.

SpaceX has some literature that states the typical timing of F9 stage1/stage2 separation, but doesn't mention the altitude or how far downrange it is. I think they prefer not to reveal that information. We can assume they reach mach 10 within 176 seconds of liftoff. It would be interesting to know the altitude at which they plan on separating the RLV to calculate the amount of fuel they'd have in reserve and maybe their chances of success.

Prior to separation, Falcon 9 can point the upper stage/payload to any desired attitude and minimize all rotation rates. Attitude errors will be no greater than 1.4 degrees about each axis. Attitude rotation rates will be less than 0.2 degree/sec in pitch and yaw, and 0.25 degree/sec in roll. For spin stabilized missions, prior to separation, Falcon 9 points the upper stage/payload to the desired attitude and provides a spin about the longitudinal axis. The spin axis orientation will be accurate to within 1.75 degrees, assuming a maximum 0.5 inches payload center of gravity offset as mentioned in Section 4.3.

Time After Liftoff (seconds) Event
0.0 Liftoff from Cape Canaveral
7.5 Initial Pitch Kick
55.0 Begin gravity turn
76.0 Max-Q
115.0 Release angle of attack restrictions
155.5 Shutdown 2 engines for acceleration limit
174.2 Main Engine Cut Off
176.2 Stage 1/Stage 2 separation

Skipjack · Post by **Skipjack** » Fri Mar 02, 2012 3:58 pm

Nydoc, the numbers I posted were quoted elsewhere before. I simply requoted them here. Elon Musk stated in a recent interview that staging of the current F9 occurs at Mach 10 and that the reusable F9 will stage at Mach6.
I read elsewhere (and I cant remember where, sorry), that the altitude at staging was a little above 100km and 300km downrange. After separation, the first stage will cruise to an altitude of 300km and 1100km downrange (IIRC). I think that more exact numbers were posted here earlier.

Nydoc · Post by **Nydoc** » Sat Mar 03, 2012 6:07 am

Test of Grasshopper engines:

http://www.kwtx.com/news/headlines/McGr ... ml?ref=053

*Maybe? or perhaps just a test of a normal F9...

Betruger · Post by **Betruger** » Sat Mar 03, 2012 6:55 am

Grasshopper is now nine-engined?

kunkmiester · Post by **kunkmiester** » Sat Mar 03, 2012 4:52 pm

I'd figure grasshopper is a modified Falcon 9 if possible. You could probably at least you a 9 for static tests, if you're not using one for the actual test vehicle.

krenshala · Post by **krenshala** » Mon Mar 05, 2012 10:55 pm

Universe Today mentioned the 9-engine test as being prep-work for the launch after COTS 2/3. IIRC this is for a non-NASA customer.