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SpaceX's Big Falcon Topic 2

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17 hours ago, Fall Bass said:

It's probably going to have to piggy-back off of a publicly-funded space infrastructure for those purposes (like if NASA and/or some other countries' space programs puts up a moon base down the line, with all that entails for infrastructure and technology). Either that, or they get the launch costs into space low enough that someone could design, launch, and operate a space capsule for only tens of millions of dollars (at which point you could get space missions funded by business, or by consortia of universities and private donors like with telescopes). 

But what's the business case for any public (govt) investment in the $billions that would be required to develop a moon or orbital platform that could be purposed for space-based / moon-based launches?

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17 hours ago, Erik of Hazelfield said:

Why do they need a third drone ship to land two boosters, if the center core is expended? What would the third drone ship be doing?

One ship ("Just Read The Instructions") stays on the west coast for launches to polar orbit out of Vandenburg Airforce Base in California.

They're probably aiming to rarely expend the centre core.  Best case would be to fly it 9 times and recover it but expend it on the 10th flight (while the side boosters fly a hundred times but refurbish them every 10th flight).  They could schedule their flights so expendable launches is the case for every 10 flights.  Theoretically for those orbits that require a lot of energy to get to, they could send a 4th drone ship way out in the Atlantic for the landing the centre core on, while two other drone ships are a bit closer to shore for the boosters to land on.  But that would be rare they'd need to do that, so with careful scheduling they could avoid having a 4th ship.

Edited by SpaceChampion

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8 hours ago, The Anti-Targ said:

But what's the business case for any public (govt) investment in the $billions that would be required to develop a moon or orbital platform that could be purposed for space-based / moon-based launches?

None. The base would be for scientific and technological research purposes, and paid for by NASA (and possibly other space agencies). The commercial activities would just grow off of the infrastructure already paid for for those purposes. 

Edited by Fall Bass

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14 hours ago, Fall Bass said:

None. The base would be for scientific and technological research purposes, and paid for by NASA (and possibly other space agencies). The commercial activities would just grow off of the infrastructure already paid for for those purposes. 

There still has to be a business case. NASA (and partner agencies) aren't going to build any space infrastructure unless there is a clear case that doing so is necessary (i.e. can't possibly be done on earth or at the ISS) for a sufficient number of research proposals over a sufficiently long time-frame that the investment (cost to the taxpayer in significant proportion) is justified.

Low gravity manufacturing of certain products may eventually have a business case, but only after the public has funded the base infrastructure. It's only going to get done "because we can" if people like Gates, Soros, Musk and a few other mega billionnaires decide to earmark the lions share of the $billions it would take to build the infrastructure, and then donate it to the international community, or at least share it quite openly.

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So one reason they overshot the heliocentric apogee for the Roadster is that during the 6-hour coast phase before firing the 2nd stage engine for the 3rd time to send it on it's final trajectory SpaceX expected some amount of boil off of the oxygen (and freeze of the kerosene), reducing the amount of propellant available for that final burn, but it apparently didn't.

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4 minutes ago, SpaceChampion said:

So one reason they overshot the heliocentric apogee for the Roadster is that during the 6-hour coast phase before firing the 2nd stage engine for the 3rd time to send it on it's final trajectory SpaceX expected some amount of boil off of the oxygen (and freeze of the kerosene), reducing the amount of propellant available for that final burn, but it apparently didn't.

Did they do something that can be repeated to protect the propellant?

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1 hour ago, Ser Scot A Ellison said:

Did they do something that can be repeated to protect the propellant?

It was obviously the playing of David Bowie.   

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1 hour ago, Ser Scot A Ellison said:

Did they do something that can be repeated to protect the propellant?

Without spending a lot on exotic materials, probably not.  Boil off is a problem for all rockets.  However SpaceX cools their propellants much lower than the condensation temperature, in order to squeeze more of it into the same volume, allowing for more lift capacity / larger payloads.  That might have been the beneficial factor.

For BFR they'll actually be putting the oxygen tank within the methane tank (a sphere within a sphere), so it'll be protected for the journey to Mars.  Falcon upper stage dimensions don't really allow for that strategy.

Edited by SpaceChampion

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Falcon 9 launches the Paz satellite for Spain, and two prototype satellites for its own Starlink internet broadband constellation:

They missed catching the fairing with the giant net on the ship "Mr. Steven" by a few hundred meters, but it landed intact and is floating like a boat in the Pacific.  Musk says should be able to have more control with a slightly bigger parachute.

The first stage previously flew last year in August launching the FORMOSAT-5 for Taiwan.  It was an expendable launch of a Block 3, so no landing today.

Starlink satellites (Tintin A & B ) successfully deployed:

 

Edited by SpaceChampion

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24 minutes ago, Erik of Hazelfield said:

How does the fairing re-entry work? Is there a heat shield on just one side or do they spin uncontrollably during descent? And how do you steer them towards the ship?

From SpaceChampion's comments above, it sounds like they deploy a parachute once the faring hits the atmosphere and try to direct a "catcher's mitt" net underneath it to catch it, but they missed this time.  Musk said they might need a bigger parachute to have better control .  Not sure if this means a bigger parachute will slow its descent more so they more time to get the net in position to catch it.  Or they can control the chute enough to guide the faring to closer to a specific location where the net is waiting.

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I only had speculation before, but Loren Grush at the The Verge today wrote about SpaceX's concept for fairing recovery:

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Normally, companies don’t recover the pieces of the fairing after a launch, but SpaceX CEO Elon Musk has been eager to find a way to save the hardware. “Imagine you had $6 million in cash in a palette flying through the air, and it’s going to smash into the ocean,” Musk said during a press conference in March 2017. “Would you try to recover that? Yes. Yes, you would.”

SpaceX has become famous for landing its rockets after launch so they can fly again. But the way SpaceX plans to recover its fairing is quite different from how it recovers its rockets. The Falcon 9 boosters essentially reignite their engines as they fall back to Earth, helping to control and slow their descent. A typical rocket fairing doesn’t have any onboard engines, however. So SpaceX has equipped its latest nose cone with a guidance system and thrusters, tiny engines that help guide the pieces through the atmosphere when they break away from the rocket.

Then, as the pieces descend, they deploy thin parachute-like structures known as parafoils to slow their fall. Down at the surface, a SpaceX boat named Mr. Steven (a random name, Musk said) attempts to catch one of the fairing pieces with a giant net attached to large claw-like appendages.

SpaceX has been able to land its fairings in the ocean before, but this was the first time the company deployed Mr. Steven to catch one of the pieces. Musk noted that a fairing half missed the boat by a few hundred meters. However, the company should be able to fix the problem by making the parafoils bigger, he said.

Though the pieces may have landed undamaged in the Pacific, it’s unclear if they can be used again. The possibility seems unlikely, as seawater can cause significant damage to spacecraft without proper shielding.

Still, SpaceX will keep trying to save more nose cones in the months ahead. “My guess is next six months we’ve got fairing recovery figured out,” Musk said during a press conference for the Falcon Heavy launch. 

 

Interesting to note that one of the subcontractors for Lockheed Martin's Atlas 5 rocket is going to attempt fairing recovery too, basically deliberately copying SpaceX's method.

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Livestream starting now of SpaceX's launch Hispasat 30W-6 on the company's 50th launch.  Too windy for a landing considering this is the heaviest sat they've even launched so they'll be coming down on fumes and ditching in the sea.

 

Edited by SpaceChampion

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SpaceX president Gwynne Shotwell sat on a panel the other day and had some things to say regarding their rockets and expectations for the future (summary assembled by a redditor):

Quote
  • Will be “significant overlap” between Falcon 9 and Falcon Heavy and BFR, given the effort required to develop Falcon vehicles and getting government certification for them. Source

  • Customers have accepted “flight-proven” first stages much faster than I expected. About half of our launches this year will be on reused first stages. Source

  • Block upgrades are behind us now, we can get cadence up; 9 flight-proven 1st stages launched so far, and 1/2 of this year's flights will use flight-proven stages. Customer acceptance happening faster than we thought. Source

  • BFR will probably be orbital in 2020, but you should start seeing hops in 2019. Source

  • We are going to fly Spaceflight Inc's smallsat group in a dedicated flight this summer. Source

  • SpaceX and ULA agree - Bruno: “Satellites are getting bigger and smaller.” Shotwell: “Disaggregated systems are very helpful to the launch industry.” Source

  • Market is not just demand, it's demand with money. A lot of smallsat guys dont have much money. That's why we ended Falcon 1. But with constellation replacement, small launchers may find a market. Source

  • After demonstrating reusable boosters, it’s now “soul-crushing” to even dispose of payload fairings now. Source

  • SpaceX needs a fully reusable rocket to get humans to other planets. Source

  • Hard to say how declining launch prices will affect emerging market for satellite servicing. Interest was driven in part by high launch prices. Source

 

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Two launches over the next four days:

West coast:  This Friday, Iridium-5 mission to send the next batch of 10 sats into polar orbit.

East coast:  Monday, CRS-14 resupply cargo mission to the ISS.

Both with flight proven boosters.  SpaceX is on track to outpace last year's launch rate by two months for the first 7 missions of 2018.

Later in April, launch of the Transiting Exoplanet Survey Satellite for NASA.

Then the debut of the Block-5 version of Falcon 9, with the Bangabandhu 1 comsat at the end of the month.

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1 hour ago, SpaceChampion said:

Two launches over the next four days:

West coast:  This Friday, Iridium-5 mission to send the next batch of 10 sats into polar orbit.

East coast:  Monday, CRS-14 resupply cargo mission to the ISS.

Both with flight proven boosters.  SpaceX is on track to outpace last year's launch rate by two months for the first 7 missions of 2018.

Later in April, launch of the Transiting Exoplanet Survey Satellite for NASA.

Then the debut of the Block-5 version of Falcon 9, with the Bangabandhu 1 comsat at the end of the month.

When are they going to try another Falcon Heavy?

 

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1 hour ago, Ser Scot A Ellison said:

When are they going to try another Falcon Heavy?

 

Currently scheduled for June 13th.  A launch for the Air Force with over 30 rideshare satellites for military and science purposes.  The primary mission however is as a further certification flight so the Air Force can approve FH for its use on regular contracts.

One of the payloads is for the Planetary Society, finally launching another of their solar sail projects -- LightSail 2.

Edited by SpaceChampion

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