XCOR and the Lynx rocket

[quanthasaquality]

For small engines it ends up being lighter than a turbopump, and for moderate size engines it may be a bit heavier, but is a lot cheaper, and potentially a lot more reliable.

I have heard the turbine engine replaced the piston engine in airplanes and higher performance ships in the early twentieth century due to the turbine's lower weight, simplicity and reliability. A look at wikipedia gives a nice table on power to weight ratio of some engines.  http://en.wikipedia.org/wiki/Power-to-weight_ratio 

It has been fourty years since the start of the STS program, driven in part to reduce cost to reach orbit. Why are piston engines suddenly now light enough to use in rocket engines for reaching orbit? Or, have they been good enough, but no one tried them before xcor?

[docmordrid]

Probably modern high strength / lightweight alloys and other materials combined with people crazy-smart enough to try it.

[Moe Grills]

Probably modern high strength / lightweight alloys and other materials combined with people crazy-smart enough to try it.

Well? I want to fly that thing.
I think 90 percent of the members on this forum would want to do the same, if they had pilot training.
 (wagging my finger with a smile) Sticks and stones may break my bones.

Just to put things in perspective, I heard a professional pilot saying
on Discovery Channel (the gist) he regards any aircraft he flies as a machine that's trying to kill him.
   So are spacecraft any different?

[docmordrid]

Not that I can tell. Same goes for a '67 Pontiac GTO or a spacecraft; you have to treat the situation the same as the first time you ride a strange quarter horse - you assume its first priority is to dump your butt over the nearest fence.

[Jason1701]

For small engines it ends up being lighter than a turbopump, and for moderate size engines it may be a bit heavier, but is a lot cheaper, and potentially a lot more reliable.

I have heard the turbine engine replaced the piston engine in airplanes and higher performance ships in the early twentieth century due to the turbine's lower weight, simplicity and reliability. A look at wikipedia gives a nice table on power to weight ratio of some engines.  http://en.wikipedia.org/wiki/Power-to-weight_ratio 

It has been fourty years since the start of the STS program, driven in part to reduce cost to reach orbit. Why are piston engines suddenly now light enough to use in rocket engines for reaching orbit? Or, have they been good enough, but no one tried them before xcor?

XCOR isn't talking about reaching orbit with a piston pump - just using it in the Lynx, doubling as the first stage of a nanosat launch system (and a low-powered one at that). I gathered from Jon's posts that piston pumps are totally unsuitable for hefty orbital-class engines with immense power output.

[QuantumG]

XCOR isn't talking about reaching orbit with a piston pump - just using it in the Lynx, doubling as the first stage of a nanosat launch system (and a low-powered one at that). I gathered from Jon's posts that piston pumps are totally unsuitable for hefty orbital-class engines with immense power output.

They're making an LH2 pump too. XCOR's ambitions go far beyond orbit.

[RanulfC]

Not that I can tell. Same goes for a '67 Pontiac GTO or a spacecraft; you have to treat the situation the same as the first time you ride a strange quarter horse - you assume its first priority is to dump your butt over the nearest fence.

I like the horses YOU know

My experiance is that they would MUCH rather throw you somewhere near-by and accessable since they would also like to stomp on you for a bit JUST to make sure you got the message... YMMV however

I the end you reduce what risks you can and try and mitigate any "off-nominal" situations with training just to be on the safe side. That doesn't mean things still can't or won't go "south" on you at any given moment. But isn't that part of the 'fun' in the first place?

Randy

[Danderman]

XCOR Aerospace Announces Space Expedition Corporation
(SXC) As General Sales Agent For Space Tourism Flights

http://www.xcor.com/press-releases/2012/12-06-07_XCOR_announces_SXC_as_general_sales_agent.html

June 7th, 2012, Mojave CA, USA and New York City, NY:   With the Tom Sachs space-themed art exhibit, “Space Program: Mars“ as a backdrop, XCOR Aerospace named Space Expedition Corporation (SXC) as the new General Sales Agent (GSA) for the XCOR owned Lynx Suborbital vehicle flying from the Mojave Air and Spaceport. SXC was previously announced as the first wet lease customer for a Lynx production vehicle with planned flights from Curacao.  The GSA places the responsibility with SXC for ticket sales through the extensive network of XCOR Space Tourism Specialists and for astronaut training and relations for XCOR Lynx flights from Mojave. Currently, the combined sales of Lynx fights between XCOR and SXC are over 175 flights, with a published retail price of $95,000.

In making the announcement, Andrew Nelson, Chief Operating Officer of XCOR noted “In SXC, you will not find a better team of commercial space retail marketers and sales professionals in the world. We are very pleased to have them on our team and sharing their knowledge and experience with our Space Tourism Specialists.”

As GSA, Space Expedition Corporation will support an existing sales channel of over 100 high end adventure travel focused agents and agencies who have been certified as “Space Tourism Specialists.”  SXC assumes the GSA role from RocketShip Tours (RST) whose founder passed late last year.  “We are very excited about the future of space travel, the naming of our new GSA, and we hope, the introduction of the Lynx into commercial service by the end of next year,” said Nelson.

[Danderman]

Currently, the combined sales of Lynx fights between XCOR and SXC are over 175 flights, with a published retail price of $95,000.

But, there is no market for space tourism, or anything in space except for communications satellites.

[baldusi]

Currently, the combined sales of Lynx fights between XCOR and SXC are over 175 flights, with a published retail price of $95,000.

But, there is no market for space tourism, or anything in space except for communications satellites.

100k and 5M are more than an order of magnitude of difference. So are the physical requirements of training. I would love to be proved wrong, though.

[jongoff]

Looks like XCOR has a high probability of inking an ~$10M economic incentive package with Midland, TX to relocate their R&D operations out to there...

http://www.hobbyspace.com/nucleus/index.php?itemid=39237

Interesting times...

~Jon

[strangequark]

Has anyone been able to find info on what kind of chamber pressures XCOR has hit with its piston pump engines? I've been combing through what's available, but to no avail.

[oldAtlas_Eguy]

If it’s true that TC pressure does not significantly affect ISP on a LH2/LOX engine in vacuum then the only effect of TC pressure is thrust for a given engine weight. A three piston pump would deliver a nearly smooth liquid flow ( a piston pump delivers liquid at a rate equivalent to a half sine wave and three pumps at 120 degrees apart in phase will deliver a near constant liquid flow). Plus a piston pump would have a very wide efficient throttle range.

Assuming the replacement engine for an RL-10 would be roughly the same exit area with approximately the same expansion ratio then the TC pressure would be close to the same or about 500psia.
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19970010379_1997013291.pdf


As to how high XCOR has been able to acheive with their cryo pumps so far, I don't know, but at least we know what their target possibly is.

[strangequark]

If it’s true that TC pressure does not significantly affect ISP on a LH2/LOX engine in vacuum then the only effect of TC pressure is thrust for a given engine weight. A three piston pump would deliver a nearly smooth liquid flow ( a piston pump delivers liquid at a rate equivalent to a half sine wave and three pumps at 120 degrees apart in phase will deliver a near constant liquid flow). Plus a piston pump would have a very wide efficient throttle range.

Assuming the replacement engine for an RL-10 would be roughly the same exit area with approximately the same expansion ratio then the TC pressure would be close to the same or about 500psia.
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19970010379_1997013291.pdf


As to how high XCOR has been able to acheive with their cryo pumps so far, I don't know, but at least we know what their target possibly is.

It doesn't have much effect if you hold expansion ratio constant. However, higher chamber pressure means a smaller, shorter, lighter nozzle for the same expansion ratio (see attachment), or a higher expansion ratio nozzle for the same length. The reason I ask is that I'm interested in piston pump engines for an application that is length constrained, so I was wondering if there's any actual published data on what's been achieved.

[docmordrid]

Looks like XCOR has a high probability of inking an ~$10M economic incentive package with Midland, TX to relocate their R&D operations out to there...

http://www.hobbyspace.com/nucleus/index.php?itemid=39237

Interesting times...

~Jon

.

Likely incentives + low/no taxes relative to Califlakey.

[jongoff]

It's also at a location that you can get easy flights into with Southwest or other providers. Which is better than Mojave, where you have a 90minute drive after the flight into Burbank. I may have to find an excuse to visit them after they're setup.

~Jon

[simonbp]

Nah, they're obviously going there because Midland's Most Famous Resident wants to go for joyrides...

Between SpaceX, Blue Origin, and now Xcor, Texas is really cleaning up in the rocket testing/launch business. California on the other hand seems to quickly lossing their early lead...

[Zond]

The timing is a bit curious for a move to Midland, there's currently an oil boom on and the housing market is very tight. There savings in taxes will be compensated by the fact that they will have to pay their staff a lot more otherwise they will not be able to afford housing or they will lose them to the oil industry. There are plenty of other places were the economy is in a slump and where there are plenty of houses available. Or they could wait until the boom in Midland has turned into a bust.

[krytek]

Any chance housing is somehow part of the deal?

[BrightLight]

I'm not a aeronautical engineer but the canopy on the Lynx just looks wrong to me, I just don't get the feeling that this is going to 100km, what am i missing.