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-   -   SpaceX Falcon 9 Live Landing Attempt (https://www.pprune.org/jet-blast/554107-spacex-falcon-9-live-landing-attempt.html)

MG23 22nd Dec 2015 01:07

Third time's the charm!


Will be interesting to see what shape it's in tomorrow. Looked a bit blackened in the video, but otherwise OK.

MG23 22nd Dec 2015 04:03

Looks like it just needs a new coat of paint, and it will be ready to go again :)


glad rag 27th Dec 2015 13:09

Space, the final frontier..
Everything has just changed.
Many cannot see it yet, but it has.
It will be a gradual, but accelerating, process as the vendors of non returning/reusable boosters find themselves slowly but inextricably losing business due to budget pressures..

Mechta 18th Jan 2016 08:57

Sill a few teething problems with Falcon 9. Yesterday's landing was looking good right until the last moment. :{


It will be interesting to read their final report on this landing, if there is one, as although Elon Musk suggests the problem is a lockout collet on one of the legs, there appears to be quite a bow in the rocket body after touchdown, suggesting that momentum (fuel slopping?) is applying a sideways force to the top, and the leg just failed due to the extra load this imposed on it.

Out of interest, does anyone know what proportion of the weight of the recovered stage is due to the need to recover it?

All credit to Elon Musk. Its refreshing to see someone who uses his fortune to push the boundaries of what is possible. He must have inspired a lot of students to opt for engineering and science, rather than easier courses.

Of course this is how it should be done (from 2:08):}:

Mechta 18th Jan 2016 09:34

Elon Musk's quote on this landing: "Well, at least the pieces were bigger this time!"


james ozzie 19th Jan 2016 05:48

The whole idea of hefting the propellant into orbit and then using it for a soft landing seems very compromising from an energy viewpoint. The payload capacity of the rocket must be greatly reduced by tankering the propellant up and back. The traditional ablative shield + parachute seems a much more efficient means.

ORAC 19th Jan 2016 10:25

The whole idea of hefting the propellant into orbit and then using it for a soft landing seems very compromising from an energy viewpoint.
As a fraction of the total fuel load its actually small. First stage fuel load is 418 tons, and landing fuel is around 32 tons, less than the reserve they carry to compensate for the additional burn time in case of a single engine failure out of the cluster of 9.

Empty weight of the first stage is only 18 tons!! Just the weight of the engines and effectively a tin tube with internal bracing - no wonder they crumple so easily.

netstruggler 19th Jan 2016 11:36

As a fraction of the total fuel load its actually small. First stage fuel load is 418 tons, and landing fuel is around 32 tons, less than the reserve they carry to compensate for the additional burn time in case of a single engine failure out of the cluster of 9.
But how much of that 418 tons is only there to lift the 32 tons up into orbit?

Radix 19th Jan 2016 12:15


ORAC 19th Jan 2016 13:29

I thought I covered that above; the 32+ tons is carried to provide a reserve to cover the case of one or more engine failures during ascent and to still achieve orbit. To carry less would turn a mission survival failure into a mission failure.

In the event all or part isn't used, the first stage can still be recovered; turning a necessity into a virtue.

MG23 19th Jan 2016 14:39

Originally Posted by netstruggler (Post 9242370)
But how much of that 418 tons is only there to lift the 32 tons up into orbit?

If I remember correctly, Musk has said that reusing the first stage cuts the payload by about 30%? Which is still a big win if you can safely reuse it even two or three times without major refurbishment.

From what I've read, they did find a problem with one of the engines when they test-fired the first recovered stage. But that's the kind of issue where you need to recover a few stages for analysis to fully debug it.

ORAC 19th Jan 2016 16:25

But most launches don't need it....

"......Just like the v1.0, the Falcon v1.1 launcher provides engine-out capability for a large portion of its first stage flight. All nine engines are ignited on the ground, about three seconds before launch. All must reach operational conditions and liftoff thrust for the launch release command to be issued.......

The first stage has a primary burn time that varies depending on the mission design. Flights using the full performance of the first stage without propulsive return maneuvers burn the first stage for up to 185 seconds while missions that include a first stage return require the stage to shut down its engines after 155 to 165 seconds of powered flight to leave sufficient propellants for the descent to a landing site.........

The re-usable version of Falcon 9 is known as F9R which itself does not represent a fully different launcher and is more of an add-on to the v1.1 version in the form of the Nitrogen Cold Gas Attitude Control System, the four deployable landing legs and four grid fins used for three-axis control during atmospheric flight, especially during non-propulsive flight phases.....


So for most missions, its just some additional fuel. The aim, of course, is to reduce the number of missions where insufficient fuel would be left to enable a return and hence loss of the first stage. That's where the barge comes in rather than a return to the Cape.

The return to the Cape needs enough fuel to flip over, stop, then reverse speed and head back. With the barge positioned along the route the first stage can follow pretty much a ballistic curve from its separation point only need enough fuel for small course adjustments and the final deceleration to land.

ORAC 23rd Feb 2016 11:18

Sick burn, brah: SpaceX test fires rockets for SES bird launch this week
Get ready for another launch, another attempt for water landing

23 Feb 2016 at 01:56, Iain Thomson

SpaceX reports that it's ready to roll for Wednesday's satellite launch, which will be followed by another attempt to get one of the Falcon 9 rockets to land on a water-borne platform.

Luxembourg-based SES is paying SpaceX to loft a new communications satellite into geostationary orbit along the equator at 108.2 degrees east longitude. The current launch window is available from Wednesday at 1846 ET (2346 UTC) and for about two hours after that point.

The new satellite, dubbed SES-9, will be used to provide data and video services across Asia. The SpaceX rocket will deliver the satellite most of the way, then its electrically powered ion thrusters will take the hardware into the required orbital position over the next few months.

On Monday, SpaceX lit up the rocket that will (hopefully) deliver its hardware cargo. Because the rocket uses liquid rather than solid fuel, the rockets can be switched off and on again without too much trouble. These static burns all look good to go, SpaceX reports.

Full-duration static fire completed. Targeting Wednesday for launch of SES-9 satellite @SES_Satellites pic.twitter.com/lp6nxGvUuH

Once the payload has been delivered, SpaceX will attempt to land the rocket again for testing and possibly reuse it. Because this is a launch to the Clarke orbit (35,786 kilometres (22,236 mi) above Earth), the Falcon isn't going to have much fuel left, so instead of the land-based landing pad the firm used successfully, SpaceX is going to make another attempt at a water landing.

All of SpaceX's attempts at a water landing to date have failed, as it's intrinsically much harder to get a rocket down on a barge that's in moving water compared to a static Earth-based pad. The last attempt, in January, nearly succeeded, but one of the landing legs on the rocket failed to lock down, leading to a biggish bang.

Elon's Musketeers think they have cracked that problem and confidence is high for a world-first water landing. SpaceX will use its East Coast landing barge, named Of Course I Still Love You as an homage to British science fiction author Iain Banks, and has a similar ship, the Just Read the Instructions on the West coast for later launches.

This kind of satellite delivery shows why such barges are needed. Landing on land is a lot easier, but with geosync launches fuel is tight and water landings are the only possibility. They are going to be key to SpaceX reusing its hardware a move that would slash the costs of orbital delivery.

Wednesday's launch currently has a 60 per cent chance of going ahead, thanks to weather conditions, but if all looks good than another Musk bird will fly and hopefully land in one piece this time on Wednesday afternoon.

Mechta 23rd Feb 2016 20:53

In case you are wondering, as I was; the barge is 400miles (650km) down range from the launch pad. That's East of Cape Canaveral in this case.

Falcon 9 clears static fire test before launch this week | Spaceflight Now

ORAC 25th Feb 2016 06:02


Team opting to hold launch for today.

Looking to try again tomorrow; window also opens at 6:46pm ET.

Rocket and spacecraft remain healthy.

WhatsaLizad? 25th Feb 2016 14:54

Should be interesting. Breezy day in Florida after a cold front passage. Surface winds might be a factor for launch. Present gusts up to 30kts in central FL.

I haven't seen much discussion on the landing barge. Any stabilizers to cut the wave affects? Below is the present reading of a NOAA buoy east of Cape Canaveral. It would seem that 5'-7' swells and possible 20kt-25kt surface winds at the barge would push the limits, especially trying to stabilize a tall cylinder with little upper mass.

NOAA Buoy 41047

Location: 27.517N 71.483W
Date: Thu, 25 Feb 2016 14:50:00 UTC
Winds: S (190) at 19.4 kt gusting to 23.3 kt
Significant Wave Height: 5.2 ft
Dominant Wave Period: 11 sec
Average Wave Period: 5.1 sec
Mean Wave Direction: ESE (109)
Atmospheric Pressure: 30.02 in and rising
Air Temperature: 75.4 F
Dew Point: 71.6 F
Water Temperature: 74.7 F

Another site with swell and wind forecasts for the general area:

Central Florida Hurricane Surf Report, Surf Forecast and Live Surf Webcams

I hope it works, goodluck SpaceX team!

ORAC 27th Feb 2016 10:56

SpaceX considering Sunday launch try

SpaceX scrubbed a second Falcon 9 launch attempt from Cape Canaveral Air Force Station on Thursday.

SpaceX is considering a third attempt to launch a commercial communications satellite from Cape Canaveral Air Force Station as soon as Sunday evening.

A forecast posted by the Air Force's 45th Weather Squadron Wing shows near-perfect conditions are expected during a more than 90-minute launch window running from 6:47 p.m. to 8:20 p.m. Sunday. The weather would also be excellent Monday, should an attempt be made then, with a 90 percent chance of acceptable weather.

SpaceX has not yet confirmed its plans, saying only that it is reviewing data and the next available launch date.

The company's first two attempts to launch the SES-9 satellite scrubbed on Wednesday and Thursday. In both cases, SpaceX cited challenges keeping the two-stage rocket's supply of liquid oxygen at cold enough temperatures. Wednesday's countdown was halted about a half-hour before the launch window opened, before the liquid oxygen was loaded onto the 230-foot rocket. Thursday's countdown scrubbed less than two minutes before a planned blastoff.

The Falcon 9 is flying for the second time in what SpaceX calls its "upgraded" or "full thrust" version, which uses liquid oxygen chilled almost to its freezing point to make it more dense, so tanks can hold more. The upgraded rocket generates more thrust, enabling it to lift heavier payloads and creating more opportunities for SpaceX to try to land the first-stage boosters.

The fueling process begins just 30 minutes before the targeted launch time, and SpaceX has said there's only enough time during this window to perform that process once. If the rocket isn't ready to go at the targeted time, the liquid oxygen must be offloaded and the launch delayed to another day.

The nearly 12,000-pound SES-9 satellite, owned by Luxembourg-based satellite operator SES, is the heaviest yet that a Falcon 9 will try to lift to an orbit more than 22,000 miles over the equator, requiring all of the the rocket's performance.

SpaceX plans to try to land the booster on a ship located 400 miles down range. Given the speed the rocket will be traveling and limited fuel to spare, the company has said a successful landing is unlikely.

Tom! 29th Feb 2016 00:02

SpaceX not having any luck this week. First hold due a range safety issue, a boat in the restricted area. Then on the second attempt the computer automatically aborted the launch after ignition due to "less than expected thrust". Apparently the first hold raised the liquid oxygen temperature too high creating a helium bubble in a fuel line causing the thrust shortfall.

ORAC 8th Apr 2016 21:31


SpaceX Just Landed a Rocket on a Drone Ship

"Minutes after a smooth launch of its Dragon spacecraft to the ISS this afternoon, SpaceX hit a long-standing, elusive goal: It landed the Falcon 9 rocket that had launched the spaceship neatly down on an ocean barge like it was nothing at all.........."


Gertrude the Wombat 8th Apr 2016 21:33

Very neat indeed.

So when can I buy a tourist ticket to the ISS for a sensible prices, say ten grand?

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